CT9 vs TD12 vs TD04 - Pros & Cons
- Thread starter Texx
- Start date
Texx
Super Moderator
Thanks for all your input so far lads, it's appreciated. 
So to summarise so far:
Stock CT9: Best option here is to remove the restrictions from the stock cast manifold and boost no more than 1bar. It's the cheapest solution, but won't really provide any major results. When the turbo finally fails your left with the same decision of what to do next, either fit another stock CT9 or upgrade to a hybrid CT9 or TD04 set up, so it's realistically just delaying the inevitable.
Hybrid CT9/TD12: Trying to use the internal wastegate is realistically a wasted effort, so an externally gated manifold is the only real option here. If the turbo fails your almost back to square one and left looking at using another stock CT9 or forking out for a rebuild or replacement turbo. Produces reasonable results, but question marks above their reliability and the cost of buying the turbo, manifold and wastegate being in excess of a TD04 set up suggests they're a false economy.
TD04: Costs slightly less than an externally gated hybrid CT9 set up. Internal wastegate can be used to keep the cost down (although an external gate would be favourable). More of a 'future proof' option as there are a number of different spec turbos that will bolt straight on. Replacement turbos are easily sourced at a reasonable price in the unlikely event of a failure. Not as responsive as a CT9, but more than make up for it once they start to boost.
If my above summary is anywhere near accurate, then I think it's given me the answer I'm looking for. Losing a little response in favour of better reliability is probably a sacrifice worth making.
So to summarise so far:
Stock CT9: Best option here is to remove the restrictions from the stock cast manifold and boost no more than 1bar. It's the cheapest solution, but won't really provide any major results. When the turbo finally fails your left with the same decision of what to do next, either fit another stock CT9 or upgrade to a hybrid CT9 or TD04 set up, so it's realistically just delaying the inevitable.
Hybrid CT9/TD12: Trying to use the internal wastegate is realistically a wasted effort, so an externally gated manifold is the only real option here. If the turbo fails your almost back to square one and left looking at using another stock CT9 or forking out for a rebuild or replacement turbo. Produces reasonable results, but question marks above their reliability and the cost of buying the turbo, manifold and wastegate being in excess of a TD04 set up suggests they're a false economy.
TD04: Costs slightly less than an externally gated hybrid CT9 set up. Internal wastegate can be used to keep the cost down (although an external gate would be favourable). More of a 'future proof' option as there are a number of different spec turbos that will bolt straight on. Replacement turbos are easily sourced at a reasonable price in the unlikely event of a failure. Not as responsive as a CT9, but more than make up for it once they start to boost.
If my above summary is anywhere near accurate, then I think it's given me the answer I'm looking for. Losing a little response in favour of better reliability is probably a sacrifice worth making.
Phil
Super Moderator
you turned the boost up.. on a pre mapped ecu and the she started "bogging down".
and thats it? ^^ case closed? you've turned your car to 1.1bar+ and it doesnt work.
im sorry but that doesnt sound like you had the car setup for the boost at all. its sounds like you had a premapped ecu and a boost controller, which clearly wasnt running bang on as it was "bogging down". not everyone/anyone will have the same ecu as you so they may not have the same problems even with a mines ecu and definitely wont have the same problems if they arre running anything mappable (which texx plans to)
id wager that the majority of folk who have suffered the same problems were doing to same turn it up and hope dance.
im not trying to sound patronising, it was late and i was fed up lol sorry dude. :kiss::kiss::kiss::kiss:
all that being said, nobody is denying that a ct9 will be running more efficiently heat wise at 0.6 bar than it will at 1.2bar.
im just saying that spending the money on a recon/brandnew ct9 hybrid and then running it at 1.2bar is in some cases asking the same exhaust housing to do exactly what your preaching against on a stock ct9.
so to summarise if you cant be arsed with unreliable ct9 hybrids and you cant be arsed with the slight td04 lag then get wepr or zisco to build you a gt25 kit. :haha:
Phil
Last edited:
whiteglanzav
Member +
Texx - get a tdo4 wack it at a bar with a gud map and a wel flowing unrestricted route and itl b mint - you wil not regret it x
finx
Member +
OHH Boy here comes what is going to be a post of epic proportions.
First of all i think this is fantastic thread, it is a question which often comes up but is never asked correctly in such a way that a full comprehensive answer is required which means there is a fair bit of hairsay and mostly info which only one side of the story is given.
I personally having owned built and driven one of every set up your questioning about feel i am able to shead some light on the ins and outs of these set ups.
I know there are other people on this forum that also have allot of experience and info regarding these sets ups and some opinions will differ from my own but i hope i cover the gist of it all. There are many angles from which one can choose to perceive what aspects of each set up are beneficiary for different particular types of driving and i dont think i will be able to cover them all in one post so for now ill stock to an angle which will answer texx' question and most people likely to use this info.
if there are any questions at the end please feel free to ask and i will endeavor to answer them all as i get time
SET UP ONE
Stock CT9 Turbo
Unlike common conception these turbos are underrated and can perform very well. This is mainly due to the fact that not many people support the turbo to the same extent as they do larger turbos so maximum output is often down on what is achievable. In saying that i understand why it is that people choose to go to larger turbos and more extensively modify those set ups as maximum power output potential is higher. For the purpose of this thread i will stick to whats needed to gain the most from each set up and what characteristics you can expect from each.
The most common set up of this turbo type in high performance applications seems to include the following
stock 4efte engine
stock ct9 turbo
ported stock exhaust manifold, or an off the shelf stock replacement manifold.
aftermarket inter cooler and piping to suit, anywhere from 2inch to 2.5inch and small to large core sizes
HKS or other aftermarket adjustable internal actuators
2-2.5inch exhaust system
decat or aftermarket catilatic converter downpipe
good direct fed cold air intake
These set ups seem to make anywhere between 150-180BHP and 275-350NM torque (this is another reason why there are so many theorys as to why ct9s are good or bad depending on who you talk to, as BHP isnt a very defined or accurate form of power output calculation. wheel HP/KW and torque is quite a bit more reliable for many reasons which i wont go into in this topic)
spool time as most know on these turbos is about as fast as you will ever get with a turbocharged gasoline fueled engine, and can pick up anywhere from 1800-2750rpm depending on the users set up. my own 5e powerd ct9b set up makes boost at 13-1400rpm due to the amount of development which i have invested in the setup.
Spool time, this is one of the key points of this topic.
On this turbo its not as essential that you have such free flowing airways due to the characteristics of the turbo and its suitability to the engine size. However the less restriction on the air being forced through the pipes/head/engine the more power and response you are going to gain.
Every setup of this type shouldn't have a problem picking up almost instantaneous boost in any gear given wheel speed is corresponding. Fifth gear sudden acceleration on the motorway should also see boost straight away. but at those kinds of loads dont expect it to pull like 747 on take off.
This set up is extreemly suited to daily driving, around town, or twisty country roads as it is highly responsive and provides loads of down low and mid range torque.
As most will know this is also the downfall of the stock ct9 turbo. it lacks the top end grunt/ HP and mainly torque due to its insignificant size and ability to produce enough compressed air at high engine rpm when the most air is being consumed.
There are a few ways around this, and top end power can be improved greatly using a few modifications in the right areas which aren't usually touched on with this turbo.
Firstly and formost boost control is a huge issue with these turbos. The stock internal wastegate actuators are rubbish to be frank. The diaphram and spring are weak and are only able to allow a maximum airflow output of 9psi to be created with the high/low boost solenoid deactivated.
They are also designed to slowly bleed power on as load increases rather than give instant power as soon as the turbo reaches a significant enough rpm to produce compressed air (boost).
easy fix is to replace it with a Hks or similar aftermarket item with a harder spring and larger diaphram area which will open the wastegate faster and earlier meaning a more broad and higher power output.
But this crates issues with boost spiking and creep because of the minute hole the unwanted pressurized gasses have to try and escape through (internal wastegate hole).
This is where an external wategate comes in.
If a reputable brand is used it will eliminate boost creep and spike and thus produce much better boost pressure influx to the engine. meaning better responce and better boost control overall which means more useable power.
Second on the list of things to do to increase top end power with the ct9 whist maintaining a good down low spool up is a good aftermarket intake manifold which is always neglected on ct9 set ups. most people deem it not necessary but it is if you want to extract maximum top end power and use the turbo to its full potential.
The best and coincidentally cheepest option for this task is the Stock ACIS intake from a 5EFHE engine.
if set up correctly it will dramatically reduce the top end torque and HP drop off.
The long thin intake runners are open at low rpm which support down low torque quick spool up time and overall response. Whilst the larger short intake runners open suddenly (if configured correctly) at a preset desired rpm higher in the rev range allowing more direct and larger volumes of airflow to the engine when it is most needed without sacrificing any of the desired down low and mid range characteristics of the ct9 turbo.
Third thing to do on your quest to gain the best results possibly from the ct9 is an aftermarket stand alone computer (not a piggyback as they are extreemly limited and most of the time provide no ignition timing tuneability and a lesser ability to tune the fuel map over a full stand allone computer).
The advantages of a full stand alone ecu are huge and i wont be able to list them all here but the main gains to be made with a ct9 turbo are that a good tuner will be able to retune the ignition map to incrase timing throughout the rpm range giving a total power increase over the whole scope as well as increase and tweak the tune down low to promote quicker spool times and most importantly add extra timing up top to counter the drop off in airflow which we all by now know means a dramatic hault in Hp and Torque.
Other things that can be done on this set up to boast extra top end power and spool up are head work, cams (if they are specificly ground to suit the ct9 turbos characteristics otherwise they can be more harm full than good) higher compression, larger capacity engine (5e) and last of all if all else fails theres always a nice wet shot of NOS to keep things going if you want to get extreem.
one of the biggest mistakes i see happen all the time with the ct9 based set ups is that heeps of people seem to think you need a forged engine to make power on a ct9 which is not tru. if you are blowing engines to bits on a ct9 then your doing something wrong somewhere.
The biggest down factor of the forged engine builds is that they almost all end up having a lower than stock static compression ratio, which means a reduction in natural internal combustion pressures and tempratures which are conicidentaly the two of the sole aspects that make a turbo work. When your staring with a small engine to begin with and an even smaller turbo and then you go and reduce the ability of the engine to help maximise the turbos output then you pushing shit up hill basically and thats why i see so many people having to push stupid amounts of boost pressure from ct9 turbos to try and acheive good power results.
The beauty of all of these modifications is that after doing them all and then later deciding that you still havnt had or got enough 75 percent of it all will be directly reusable on a larger turbo set up with just a retune and some slight modifications.
as a rule of thumb these are the pressures at which ct9s are maxed out of their efficiency and whist they may make 1-2HP per psi over these ratinging im giving all you are achieving is forcing hot compressed air through your engine creating extreem stress on the internal components and this is the reason why so many innocent engines fail.
ct12 (found on 2et,3et, and all 1/2jz-gte engines (supras etc)
max efficiency @ 12psi
ct9a (found on 4efte engines)
max efficiency @ 12-13psi depending on a set up
ct9B (found on 4efte engines)
max efficiency @ 12-14psi
Hybrids.
while there are so many vairents i am yet to see one that (even though it may be claimed) to actually produce significant amounts of extra power over 14-15psi. they all suffer from the same max efficiency range as the stock turbos maby slightly better but stuff all.
biggist gain is with the larger compressor wheels they will most deffinatly produce more power throughout the rev range with little if no extra lagg and have a much more stable top end torque output
These ratings are from my own years of experience tuning building and developing ct9 spec set ups.
pros and cons of each of the ct series turbos that i determine are as such:
ct12
whist it has a wider inlet throat to the turbine (hot side) the maximum outer diameter where it meets the exhaust manifold is slightly smaller than that of its ct9 counterparts. it also has a larger stock internal wastegate port (redundant if you go external wastegate) and a slightly larger exhaust turbine wheel
its downfall is in its overall construction. these were the first turbos ever independently produced by a car manufacturer and as such while having some good technology and quite advanced for the time had the same pitfalls as other turbos of their time.
Ceramic shafts were used which meant the turbos rotating mass was ligher they were not as strong and susceptible to breaking when over spooled which meant that was the end of the turbo.
they also have a slightly smaller compressor wheel that that of the ct9 series turbos
The other issue which plauges all ct series turbos is the seals are not great. overspool is the main killer.
ct9a
smaller exhaust housing than that of ct12 and slightly smaller exhaust wheel than some ct12 models but steel shaft which means they stand upto overspool better and no broken shafts, but still suffer from leaky seals if asked to much of.
they have a larger intake and larger compressor wheel than that of the ct12
ct9B
same deal as ct9A but have one extra fin on the exhaust wheel and a slightly larger exhaust wheel diameter which helps produce a few extra Hp at the top end. this is the pick of the bunch and will produce the greatest results of all the stock ct9/12 turbos
if anyone has pics that would suit this part of the guide?post please pm me and i will put them in when i have time as i will put some of my own comparisons up as time permits.
This is about where we head into hybrid territory for those that having acheived all the above and are still not happy with the total output of their set up.
SETUP TWO
Hybrid ct9
Im not going to go into which ones are good and which ones are bad as there are so many out there its not funny and i would be here for another year trying to point out the good and bad about each one.
Basically as i have said a bit further up in the efficiency ratings part of my guide, the hybrids all have an uprated compressor wheel of some kind. this means that you will effectively have a greater amount of air going into the engine throughout the engines rev range so a greater power and torque output is yielded.
Also because of the extra air going into the engine at the higher end of the rpm scale most hybrids will be able to produce enough extra air to counter the typical ct9 high rpm power drop and while it wont produce significantly more power at the high end it will plateau and level off instead of dropping off like with stock ct9s with limited supporting mods.
Highly supported Hybrids may and can produce more power at the top end instead of flattening off and will keep gaining but at a slow steady rate, but dont expect huge power in this area.
As I have also stated above hybrids are still susceptible to a low efficency scale and i am yet to see one (even if spec sheets have claimed it) to produce big power incresesed per psi over 15psi. you are effectively still just adding unnecessary extra stress on your engine for little overall gain.
The biggest reason for this is while you might still be producing more power at a lowerd output per psi you are not creating any extra torque because at those pressures the intake charge starts to increase in temprature no matter how good your intercooler/aftercooler or water-air cooler is.
Hp is is a derivative of torque and without it is useless and nothing more than a number.
The other downfall of the Hybrid (and this is also directly related the their lack of high pressure efficiency) is that most (and i have seen very few that are contrary to this) have stock or close to stock exhaust housings and turbine wheels.
Without going to much in depth as to the inner working of a turbo, the exhaust wheel drives the turbo's shaft which in turn rotates the compressor wheel which compresses the volumes of air which are forced into the engine.
Now picture this scenario
Your mouth and lungs are an engine sucking in air and blowing air out at the rate at which it is needed.
When you are doing sport or other recreational activity's your body needs to get as much air into the blood stream as quickly as possible for it to perform.
now relate this to your engine and turbo chargers exhaust housing with the following:
while you are at a walking pace you dont require as much air to perform the required task same as while at idle or cruze your engine doesnt rquire as much air to perform the necessary task.
at jogging pace you require slightly more air to keep up with your bodys demands to keep moving
as so does your engine while you change down a gear to go up hill or rev the engine out to take off from an intersection
ar running pace your body needs as much air as is can possibly get to keep up with the highly demanding load
and your engine in the same situation requires as much air going in and out as fast as it can to keep up with a sudden burst of accleration and high rpm such as racing situation.
now while your running try an breath in with your nose and out your mouth via a straw. there is suddenly a huge restriction and because not all the air can get out at the increased rate of flow there is a reduction and drop off in how fast you can operate.
this is directly related to your turbo. while it is possible to create loads of pressure and send it to the engine the exhaust housing is a restriction in the airflows exit so only the amount of air that can fill the space in the exhaust housing cn exit at any one time choking the maximum output of all that extra pressure going in rendering it useless.
This is where the last of out turbo set ups comes in. the Tdo4L
SETUP THREE
Tdo4L Turbo
The scope for overall performance and power output of these turbo is always going to be much greater than the other two we have been discussing, due to its increased size. this is where it can be its own worst enimy as well when it comes to a set up requiring all out response and down low/ mid range power.
The best and in mu opinion only TD04 series turbos worth looking at are the Subaru vairents.
while the Mitsubishi ones also have the scope for increased performance they lack the same level of reliability and maximum power output as its Subaru counterparts even thou both are designed and built BY IHI industry's.
spool times.
now this is assuming that the turbo is equiped to a good all round set up composing of all the same minor aspects of the ct9 set up.
an average set up will see full boost at around 4000rpm
A good free flowing set up with short and appropriately sized ic piping and appropriately sized exhaust with other supporting mods can see full boost of upto 14psi @ 3500rpm. higher boost pressure will have a comparatively later full boost rpm
I personally think that the TD04 is a great compromise between quick spool up and outright power if it is set up correctly.
more on this later as its late and i have just spent most of the evening typing this. that should give you some ideas for now
also i have not proof read this at all yet so if i have contradicted myself or made spelling and or grammar errors which are a high probability 'beer' with me and ill fix them when i have time.
cheers
Ryan
First of all i think this is fantastic thread, it is a question which often comes up but is never asked correctly in such a way that a full comprehensive answer is required which means there is a fair bit of hairsay and mostly info which only one side of the story is given.
I personally having owned built and driven one of every set up your questioning about feel i am able to shead some light on the ins and outs of these set ups.
I know there are other people on this forum that also have allot of experience and info regarding these sets ups and some opinions will differ from my own but i hope i cover the gist of it all. There are many angles from which one can choose to perceive what aspects of each set up are beneficiary for different particular types of driving and i dont think i will be able to cover them all in one post so for now ill stock to an angle which will answer texx' question and most people likely to use this info.
if there are any questions at the end please feel free to ask and i will endeavor to answer them all as i get time
SET UP ONE
Stock CT9 Turbo
Unlike common conception these turbos are underrated and can perform very well. This is mainly due to the fact that not many people support the turbo to the same extent as they do larger turbos so maximum output is often down on what is achievable. In saying that i understand why it is that people choose to go to larger turbos and more extensively modify those set ups as maximum power output potential is higher. For the purpose of this thread i will stick to whats needed to gain the most from each set up and what characteristics you can expect from each.
The most common set up of this turbo type in high performance applications seems to include the following
stock 4efte engine
stock ct9 turbo
ported stock exhaust manifold, or an off the shelf stock replacement manifold.
aftermarket inter cooler and piping to suit, anywhere from 2inch to 2.5inch and small to large core sizes
HKS or other aftermarket adjustable internal actuators
2-2.5inch exhaust system
decat or aftermarket catilatic converter downpipe
good direct fed cold air intake
These set ups seem to make anywhere between 150-180BHP and 275-350NM torque (this is another reason why there are so many theorys as to why ct9s are good or bad depending on who you talk to, as BHP isnt a very defined or accurate form of power output calculation. wheel HP/KW and torque is quite a bit more reliable for many reasons which i wont go into in this topic)
spool time as most know on these turbos is about as fast as you will ever get with a turbocharged gasoline fueled engine, and can pick up anywhere from 1800-2750rpm depending on the users set up. my own 5e powerd ct9b set up makes boost at 13-1400rpm due to the amount of development which i have invested in the setup.
Spool time, this is one of the key points of this topic.
On this turbo its not as essential that you have such free flowing airways due to the characteristics of the turbo and its suitability to the engine size. However the less restriction on the air being forced through the pipes/head/engine the more power and response you are going to gain.
Every setup of this type shouldn't have a problem picking up almost instantaneous boost in any gear given wheel speed is corresponding. Fifth gear sudden acceleration on the motorway should also see boost straight away. but at those kinds of loads dont expect it to pull like 747 on take off.
This set up is extreemly suited to daily driving, around town, or twisty country roads as it is highly responsive and provides loads of down low and mid range torque.
As most will know this is also the downfall of the stock ct9 turbo. it lacks the top end grunt/ HP and mainly torque due to its insignificant size and ability to produce enough compressed air at high engine rpm when the most air is being consumed.
There are a few ways around this, and top end power can be improved greatly using a few modifications in the right areas which aren't usually touched on with this turbo.
Firstly and formost boost control is a huge issue with these turbos. The stock internal wastegate actuators are rubbish to be frank. The diaphram and spring are weak and are only able to allow a maximum airflow output of 9psi to be created with the high/low boost solenoid deactivated.
They are also designed to slowly bleed power on as load increases rather than give instant power as soon as the turbo reaches a significant enough rpm to produce compressed air (boost).
easy fix is to replace it with a Hks or similar aftermarket item with a harder spring and larger diaphram area which will open the wastegate faster and earlier meaning a more broad and higher power output.
But this crates issues with boost spiking and creep because of the minute hole the unwanted pressurized gasses have to try and escape through (internal wastegate hole).
This is where an external wategate comes in.
If a reputable brand is used it will eliminate boost creep and spike and thus produce much better boost pressure influx to the engine. meaning better responce and better boost control overall which means more useable power.
Second on the list of things to do to increase top end power with the ct9 whist maintaining a good down low spool up is a good aftermarket intake manifold which is always neglected on ct9 set ups. most people deem it not necessary but it is if you want to extract maximum top end power and use the turbo to its full potential.
The best and coincidentally cheepest option for this task is the Stock ACIS intake from a 5EFHE engine.
if set up correctly it will dramatically reduce the top end torque and HP drop off.
The long thin intake runners are open at low rpm which support down low torque quick spool up time and overall response. Whilst the larger short intake runners open suddenly (if configured correctly) at a preset desired rpm higher in the rev range allowing more direct and larger volumes of airflow to the engine when it is most needed without sacrificing any of the desired down low and mid range characteristics of the ct9 turbo.
Third thing to do on your quest to gain the best results possibly from the ct9 is an aftermarket stand alone computer (not a piggyback as they are extreemly limited and most of the time provide no ignition timing tuneability and a lesser ability to tune the fuel map over a full stand allone computer).
The advantages of a full stand alone ecu are huge and i wont be able to list them all here but the main gains to be made with a ct9 turbo are that a good tuner will be able to retune the ignition map to incrase timing throughout the rpm range giving a total power increase over the whole scope as well as increase and tweak the tune down low to promote quicker spool times and most importantly add extra timing up top to counter the drop off in airflow which we all by now know means a dramatic hault in Hp and Torque.
Other things that can be done on this set up to boast extra top end power and spool up are head work, cams (if they are specificly ground to suit the ct9 turbos characteristics otherwise they can be more harm full than good) higher compression, larger capacity engine (5e) and last of all if all else fails theres always a nice wet shot of NOS to keep things going if you want to get extreem.
one of the biggest mistakes i see happen all the time with the ct9 based set ups is that heeps of people seem to think you need a forged engine to make power on a ct9 which is not tru. if you are blowing engines to bits on a ct9 then your doing something wrong somewhere.
The biggest down factor of the forged engine builds is that they almost all end up having a lower than stock static compression ratio, which means a reduction in natural internal combustion pressures and tempratures which are conicidentaly the two of the sole aspects that make a turbo work. When your staring with a small engine to begin with and an even smaller turbo and then you go and reduce the ability of the engine to help maximise the turbos output then you pushing shit up hill basically and thats why i see so many people having to push stupid amounts of boost pressure from ct9 turbos to try and acheive good power results.
The beauty of all of these modifications is that after doing them all and then later deciding that you still havnt had or got enough 75 percent of it all will be directly reusable on a larger turbo set up with just a retune and some slight modifications.
as a rule of thumb these are the pressures at which ct9s are maxed out of their efficiency and whist they may make 1-2HP per psi over these ratinging im giving all you are achieving is forcing hot compressed air through your engine creating extreem stress on the internal components and this is the reason why so many innocent engines fail.
ct12 (found on 2et,3et, and all 1/2jz-gte engines (supras etc)
max efficiency @ 12psi
ct9a (found on 4efte engines)
max efficiency @ 12-13psi depending on a set up
ct9B (found on 4efte engines)
max efficiency @ 12-14psi
Hybrids.
while there are so many vairents i am yet to see one that (even though it may be claimed) to actually produce significant amounts of extra power over 14-15psi. they all suffer from the same max efficiency range as the stock turbos maby slightly better but stuff all.
biggist gain is with the larger compressor wheels they will most deffinatly produce more power throughout the rev range with little if no extra lagg and have a much more stable top end torque output
These ratings are from my own years of experience tuning building and developing ct9 spec set ups.
pros and cons of each of the ct series turbos that i determine are as such:
ct12
whist it has a wider inlet throat to the turbine (hot side) the maximum outer diameter where it meets the exhaust manifold is slightly smaller than that of its ct9 counterparts. it also has a larger stock internal wastegate port (redundant if you go external wastegate) and a slightly larger exhaust turbine wheel
its downfall is in its overall construction. these were the first turbos ever independently produced by a car manufacturer and as such while having some good technology and quite advanced for the time had the same pitfalls as other turbos of their time.
Ceramic shafts were used which meant the turbos rotating mass was ligher they were not as strong and susceptible to breaking when over spooled which meant that was the end of the turbo.
they also have a slightly smaller compressor wheel that that of the ct9 series turbos
The other issue which plauges all ct series turbos is the seals are not great. overspool is the main killer.
ct9a
smaller exhaust housing than that of ct12 and slightly smaller exhaust wheel than some ct12 models but steel shaft which means they stand upto overspool better and no broken shafts, but still suffer from leaky seals if asked to much of.
they have a larger intake and larger compressor wheel than that of the ct12
ct9B
same deal as ct9A but have one extra fin on the exhaust wheel and a slightly larger exhaust wheel diameter which helps produce a few extra Hp at the top end. this is the pick of the bunch and will produce the greatest results of all the stock ct9/12 turbos
if anyone has pics that would suit this part of the guide?post please pm me and i will put them in when i have time as i will put some of my own comparisons up as time permits.
This is about where we head into hybrid territory for those that having acheived all the above and are still not happy with the total output of their set up.
SETUP TWO
Hybrid ct9
Im not going to go into which ones are good and which ones are bad as there are so many out there its not funny and i would be here for another year trying to point out the good and bad about each one.
Basically as i have said a bit further up in the efficiency ratings part of my guide, the hybrids all have an uprated compressor wheel of some kind. this means that you will effectively have a greater amount of air going into the engine throughout the engines rev range so a greater power and torque output is yielded.
Also because of the extra air going into the engine at the higher end of the rpm scale most hybrids will be able to produce enough extra air to counter the typical ct9 high rpm power drop and while it wont produce significantly more power at the high end it will plateau and level off instead of dropping off like with stock ct9s with limited supporting mods.
Highly supported Hybrids may and can produce more power at the top end instead of flattening off and will keep gaining but at a slow steady rate, but dont expect huge power in this area.
As I have also stated above hybrids are still susceptible to a low efficency scale and i am yet to see one (even if spec sheets have claimed it) to produce big power incresesed per psi over 15psi. you are effectively still just adding unnecessary extra stress on your engine for little overall gain.
The biggest reason for this is while you might still be producing more power at a lowerd output per psi you are not creating any extra torque because at those pressures the intake charge starts to increase in temprature no matter how good your intercooler/aftercooler or water-air cooler is.
Hp is is a derivative of torque and without it is useless and nothing more than a number.
The other downfall of the Hybrid (and this is also directly related the their lack of high pressure efficiency) is that most (and i have seen very few that are contrary to this) have stock or close to stock exhaust housings and turbine wheels.
Without going to much in depth as to the inner working of a turbo, the exhaust wheel drives the turbo's shaft which in turn rotates the compressor wheel which compresses the volumes of air which are forced into the engine.
Now picture this scenario
Your mouth and lungs are an engine sucking in air and blowing air out at the rate at which it is needed.
When you are doing sport or other recreational activity's your body needs to get as much air into the blood stream as quickly as possible for it to perform.
now relate this to your engine and turbo chargers exhaust housing with the following:
while you are at a walking pace you dont require as much air to perform the required task same as while at idle or cruze your engine doesnt rquire as much air to perform the necessary task.
at jogging pace you require slightly more air to keep up with your bodys demands to keep moving
as so does your engine while you change down a gear to go up hill or rev the engine out to take off from an intersection
ar running pace your body needs as much air as is can possibly get to keep up with the highly demanding load
and your engine in the same situation requires as much air going in and out as fast as it can to keep up with a sudden burst of accleration and high rpm such as racing situation.
now while your running try an breath in with your nose and out your mouth via a straw. there is suddenly a huge restriction and because not all the air can get out at the increased rate of flow there is a reduction and drop off in how fast you can operate.
this is directly related to your turbo. while it is possible to create loads of pressure and send it to the engine the exhaust housing is a restriction in the airflows exit so only the amount of air that can fill the space in the exhaust housing cn exit at any one time choking the maximum output of all that extra pressure going in rendering it useless.
This is where the last of out turbo set ups comes in. the Tdo4L
SETUP THREE
Tdo4L Turbo
The scope for overall performance and power output of these turbo is always going to be much greater than the other two we have been discussing, due to its increased size. this is where it can be its own worst enimy as well when it comes to a set up requiring all out response and down low/ mid range power.
The best and in mu opinion only TD04 series turbos worth looking at are the Subaru vairents.
while the Mitsubishi ones also have the scope for increased performance they lack the same level of reliability and maximum power output as its Subaru counterparts even thou both are designed and built BY IHI industry's.
spool times.
now this is assuming that the turbo is equiped to a good all round set up composing of all the same minor aspects of the ct9 set up.
an average set up will see full boost at around 4000rpm
A good free flowing set up with short and appropriately sized ic piping and appropriately sized exhaust with other supporting mods can see full boost of upto 14psi @ 3500rpm. higher boost pressure will have a comparatively later full boost rpm
I personally think that the TD04 is a great compromise between quick spool up and outright power if it is set up correctly.
more on this later as its late and i have just spent most of the evening typing this. that should give you some ideas for now
also i have not proof read this at all yet so if i have contradicted myself or made spelling and or grammar errors which are a high probability 'beer' with me and ill fix them when i have time.
cheers
Ryan
Last edited:
finx
Member +
glad to be of help to other members
yea my best ET to date is 13.22 using stock ct9b stock internals and a stock ecu. its winter here now so work in progress to make it faster for next season while retaining the stock ct9b, but thats a story for another day. ill have to do a members garage at some point and keep it updated with progress.
I have run out of time to finnish that post for now but theres a whole heep of more info i want to add as time allows
cheers
Ryan
yea my best ET to date is 13.22 using stock ct9b stock internals and a stock ecu. its winter here now so work in progress to make it faster for next season while retaining the stock ct9b, but thats a story for another day. ill have to do a members garage at some point and keep it updated with progress.
I have run out of time to finnish that post for now but theres a whole heep of more info i want to add as time allows
cheers
Ryan
Iain@CRD
Lifer
It wont mate, TD04 is a bigger turbo and there both at the same PSI so the TD04 would be quicker.
Ted
Member +
great thread, good info for those who have reached the ct9 limit. its horses for courses, a ct9 at a bar setup is a great thing- such fun on back roads. if anone needs more i would say go straight to td04- hybrid doesnt give the best of both worlds- it gives the worst of both worlds.
bucketep91
Member +
i dissagree i loved my hybrid, gave me penty of power where and when i needed it, a big improvement over the stock ct9.
Texx
Super Moderator
Brilliant post Ryan, I had a funny feeling you would have some interesting input to give, particularly with regards to the stock CT9.
The point you mentioned regarding the stock intake manifold has put an angle on things I've previously failed to consider. Although I've never had any real experience with Toyota's ACIS system, having owned an early MR2 3S-GTE and a few 4A-GE powered Corolla's that use the T-VIS system (albeit not quite the same idea as the ACIS's long and short runners) and also a DC2 Integra Si which had a 2 stage variable length intake manifold, I can appreciate the benefits the 5E ACIS intake could provide where a stock CT9 set up would typically struggle to supply the demand of high engine speeds. Using the ACIS system with a standalone ECU not only provides the means to control the intake switch over point, but also enables the ability to adjust ignition timing to compensate for the change in intake length, which may result in a slightly higher peak in power and possibly torque? The beauty of the ACIS intake manifold is that although it would provide better flow characteristics for higher engine RPM's, it can switch from using it's short runners to using it's long runners at lower engine RPM's and in doing so would avoid losing the low down torque delivery associated with the stock CT9 set up.
Any idea of the difference in the long and short runner lengths and internal diameters of the 5E ACIS intake manifold compared with those of the stock 4E-FTE manifold? Are the long runners of the ACIS manifold a similar length to the stock 4E manifold, or are they slightly shorter or longer?
The point you mentioned regarding the stock intake manifold has put an angle on things I've previously failed to consider. Although I've never had any real experience with Toyota's ACIS system, having owned an early MR2 3S-GTE and a few 4A-GE powered Corolla's that use the T-VIS system (albeit not quite the same idea as the ACIS's long and short runners) and also a DC2 Integra Si which had a 2 stage variable length intake manifold, I can appreciate the benefits the 5E ACIS intake could provide where a stock CT9 set up would typically struggle to supply the demand of high engine speeds. Using the ACIS system with a standalone ECU not only provides the means to control the intake switch over point, but also enables the ability to adjust ignition timing to compensate for the change in intake length, which may result in a slightly higher peak in power and possibly torque? The beauty of the ACIS intake manifold is that although it would provide better flow characteristics for higher engine RPM's, it can switch from using it's short runners to using it's long runners at lower engine RPM's and in doing so would avoid losing the low down torque delivery associated with the stock CT9 set up.
Any idea of the difference in the long and short runner lengths and internal diameters of the 5E ACIS intake manifold compared with those of the stock 4E-FTE manifold? Are the long runners of the ACIS manifold a similar length to the stock 4E manifold, or are they slightly shorter or longer?
durmz
Member +
This may have been covered but, would u say a ct9 at a bar or a td04 at a bar will put more stress on a 4efte? The td04 may result in cooler intake temps, but the more torque from it will make more stress on the engine. I ask because my engine is reeeaally old these days and while looked after, I was allways a bit scared to go td04 for reliability issues, as I don't really want to go forged
Just to give you my input, when i had my starlet i opted for WEPR power up kit, WEPR FMIC with clocked turbo so shorter turbo > fmic pipe, and TT spec hybrid CT9, ,made a massive difference, had it RR'd @ 167bhp @ 0.6bar i think was definately running under stock boost anyway.
My only regret was never getting it mapped to 1.2 bar before i sold it.
My only regret was never getting it mapped to 1.2 bar before i sold it.
Texx
Super Moderator
I would see combustion temperature as one of the most significant affects on engine reliability. The intake air temperature from a TD04 at 1bar compared to a CT9 at 1bar would be lower, how much lower I couldn't say without measuring both set ups, but a higher intake temperature will result in an increase in combustion temperature. An increase in combustion temperature will result in an increase in exhaust gas temperature, an increase in exhaust gas temperature will most likely increase the operating temperature of the turbo and so have some affect on the initial intake air temperature. It would become a vicious circle that would require additional cooling of the intake charge and engine operating temperature before the conditions in the combustion chamber increased to a destructive level.
IMO from a reliability point of view at 1bar boost pressure a TD04 would probably be 'safer' than a CT9, however it would really depend whether the temperature of the intake charge from a CT9 at 1bar is deemed to be excessive.
durmz
Member +
thats really interesting man, from a logical point of view i automatically assumed my engine would have problems taking on a td04
thanks for that
Aidan@EP-styling
Trader
What set-up had you running prior to the Hybrid? I honestly can't believe you would notice and "big improvement" over a stock ct9 if both turbos where running the same set-up.
And how long have you got it? Alot of CT9 hybrids last about 6-12 months as said somewhere in this thread. Would you still love it if you have to spend approx 500pounds plus labour everytime to replace it?