different compression ratio's

[iamrab]

hi lads

just been thinking over the past while about the whole td04 or td05 conversion and what compression people are using ,the main reason i ask this,...ive watched a few videos of td04 cars and some of them seem to drop off boost between gears or lag badly ..lag is ok if once u come on boost its always on boost but it does seem that it effects a 4e .

so the question is simple running higher compression is gonna help this out a lot but what compression would you use ?

 

[KrissyB]

so your thinking about going forged dude I take it???

and what sort of boost are you going to be running.

For a good responsive setup I'd personally go for a .8mm TRD Headgasket and some ARP headboltsalong with some Forged pistons and rods maybe a -6cc dish like on the Wossner or even standard comp ones.

With a good Td04 @ say 1.4bar you will have an awesome responsive and very very quick road car with supporting mods.

 

[MeisterR]

compression ratio does have something to do with it, but for the dropping off boost using at TD04 Turbo, I think it is more to do with the CAM and the CAM Timing.
Swing the CAM and changing its specification have a big effect on how a turbo react on an engine.

But thats is the down side of using big old turbo...

Modern Turbo are better in terms of actual lag time and lower boost threshold, but the laws of physic still applies one way or the other.

 

[KrissyB]

compression ratio does have something to do with it, but for the dropping off boost using at TD04 Turbo, I think it is more to do with the CAM and the CAM Timing.
Swing the CAM and changing its specification have a big effect on how a turbo react on an engine.

But thats is the down side of using big old turbo...

Modern Turbo are better in terms of actual lag time and lower boost threshold, but the laws of physic still applies one way or the other.

try not to confuse the poor guy lol

Cam timing isn't so easy to adjust in a GT the Cams are geared together so cant be adjusted Independantly. However there is an Adjustable Cam pulley which does allow fine tuning

After market or 5efhe Cams are an upgrade but expensive if on a budget

 

[MeisterR]

try not to confuse the poor guy lol

Cam timing isn't so easy to adjust in a GT the Cams are geared together so cant be adjusted Independantly. However there is an Adjustable Cam pulley which does allow fine tuning

After market or 5efhe Cams are an upgrade but expensive if on a budget

:haha: In that case, just be sensible with picking the size of your turbo, you'll be alright then.

 

[KrissyB]

:haha: In that case, just be sensible with picking the size of your turbo, you'll be alright then.

not everyone has the delightful pleasure in having a fully built RB26 to play with.

are you coming to the xmas meet fella

 

[Chris@CCM]

dude td04s r not lagy at all next time ive one coming round il let u know so u can get a wee run in one wont drop out for boost thats for sure

 

[KrissyB]

dude td04s r not lagy at all next time ive one coming round il let u know so u can get a wee run in one wont drop out for boost thats for sure

Mine never did and was quite responsive I would love too see a lovely td04 setup with a small HG and some higher compression.

 

[Sigma]

Mine never did and was quite responsive I would love too see a lovely td04 setup with a small HG and some higher compression.

Gimme 6 months and I'll show ya

Just in the process of fitting the 0.6mm TRD Tri-layer steel HG, and going to see how it performs on a CT9 first

 

[Rory]

Bearing in mind, even with the adjustable cam pulley, you will adjust both cams, not just one.

However there is an Adjustable Cam pulley which does allow fine tuning

As for compression its something you have to figure out, and work to with the machining.
From what Krissy has said, would work, but im presuming, ((as he hasnt mentioned anything to do with skimming faces on either the head or block, to be 100% sure they are flat))), that he must be running a stock block height and head height.

Any skimming of the block or head will in turn give you a higher compression.
Just something you had better know.

 

[KrissyB]

Bearing in mind, even with the adjustable cam pulley, you will adjust both cams, not just one.



As for compression its something you have to figure out, and work to with the machining.
From what Krissy has said, would work, but im presuming, ((as he hasnt mentioned anything to do with skimming faces on either the head or block, to be 100% sure they are flat))), that he must be running a stock block height and head height.

Any skimming of the block or head will in turn give you a higher compression.
Just something you had better know.

Both my surfaces were skimmed Rory I didnt want to baffle the fella with information, its always good practice to skim both the head and the block when fitting MLS Gaskets as demonstrated on here when people have missed this and things have then proceeded to fail.

Skimming these surfaces only marginally affects Comp ratio as im sure you are aware when worked out on a calculator.

I also stated earlier that the cams are geared meaning both are adjusted.

Rory if you are stating things like skimming the head block then im presuming he is going for a forged build or rebuild then yp may want to inform the fella about knotching the block and the other useful info he may ned to make his build as successful as someone like yourself

 

[richglanzav]

tis eaaasy to keep a fully built 4e on a td04 in boost, mine was at full chat by 4000rpm. i loved it cus was easy to drive off boost, and easy to drive on boost when time was right

 

[MeisterR]

Have anyone play with ball-bearing turbo such as GT2860R, they might do pretty well if you are not looking for a lot of power.

Another turbo I always thought it will be interesting to use is the standard R34 GTR Turbo. It use a Ceramic compressor wheel, so you only want to push about 1.2bar MAX on them.

But on a RB26 running twin turbo (so 1.3 litre runs 1 turbo), it was able to achieve close to 500bhp and got 1 bar of boost in 5th gear at 1500 rpm.
Therefore, this turbo might be a mid 200bhp turbo with exceptional spool up characteristic if it was fitted to the 4E engine.

It will require a custom manifold (the expensive parts), but can be interesting.

 

[azerty]

Have anyone play with ball-bearing turbo such as GT2860R, they might do pretty well if you are not looking for a lot of power.

not looking for a lot of power ??? it is quite a big turbo for a tiny 1.3 litre.
I don't think you'll see 1 bar boost before 4500 rpm
what would you mean when you say "lot of power" ???

I would love too see a lovely td04 setup with a small HG and some higher compression.

few guys do with great results

 

[ramses974]

tercel or paseo are the same cars...

i have experimented a lot of things and configuration...

i have been with high compression and no problem with 1.1bar all day on a tdO4 with high compression piston...but the problem is not the pistons but the rods ..rods are weaker than the 5EFHE rods and especialy when it is on high compression...
i am now with an another set up cause i saw and heard a rod lightly different...
i am with Wosner low compression pistons with standard Hg toyota oem with scat rods...
i have no lag not so what i have heard...
i have the 5EFHE cam too that help me and a ported and polished head ...

 

[ramses974]

hi lads

just been thinking over the past while about the whole td04 or td05 conversion and what compression people are using ,the main reason i ask this,...ive watched a few videos of td04 cars and some of them seem to drop off boost between gears or lag badly ..lag is ok if once u come on boost its always on boost but it does seem that it effects a 4e .

so the question is simple running higher compression is gonna help this out a lot but what compression would you use ?

high compression is very good but the key is tuning...and sometimes you have to maintain at high rev an AFR of 10 and be atentive to the octane,knock ...the key is the timing and fuel...AFR at 10 is not the best option but it helps to cool down the temp in the high set up..i have verified this in my egt gauge...
without this ,you can destroy your head gasket and go to a slightly overheating...

 

[Rory]

If he is asking regarding compression ratio's, then skimming the head and block is a walk in the park for the lad to understand.

Yes, marginally, but still affects them all the same

With any headgasket its pratice to skim the head at least, but with a metal H/G both surfaces have to be extremly flat, or it wont seal.
But not all forged rods require notching of the block, and im not going to take the thread off course, and inform him how to build a full forged motor.
Mearly stating facts, regarding the comp ratio and the surrounding areas of the engine thats comes into question.

Both my surfaces were skimmed Rory I didnt want to baffle the fella with information, its always good practice to skim both the head and the block when fitting MLS Gaskets as demonstrated on here when people have missed this and things have then proceeded to fail.

Skimming these surfaces only marginally affects Comp ratio as im sure you are aware when worked out on a calculator.

I also stated earlier that the cams are geared meaning both are adjusted.

Rory if you are stating things like skimming the head block then im presuming he is going for a forged build or rebuild then yp may want to inform the fella about knotching the block and the other useful info he may ned to make his build as successful as someone like yourself

 

[Phil]

hi lads

just been thinking over the past while about the whole td04 or td05 conversion and what compression people are using ,the main reason i ask this,...ive watched a few videos of td04 cars and some of them seem to drop off boost between gears or lag badly ..lag is ok if once u come on boost its always on boost but it does seem that it effects a 4e .

so the question is simple running higher compression is gonna help this out a lot but what compression would you use ?

td04 wont/shouldnt drop off boost between gears even with stock compression. they arent a laggy turbo, ecu is more important, get something that you can have mapped with a nice afr coming on boost and adjustable timing. Emanage ultimate id recommend, or apexi pfc espec if chris is going to start mapping them.

phil

 

[KrissyB]

td04 wont/shouldnt drop off boost between gears even with stock compression. they arent a laggy turbo, ecu is more important, get something that you can have mapped with a nice afr coming on boost and adjustable timing. Emanage ultimate id recommend, or apexi pfc espec if chris is going to start mapping them.

phil

x2 on that Phil or he could go 5e and get ct9 spool up


GAZ_EP85 his old 5e TD04 started making boost @ around 1800rpm it was awesome

 

[Phil]

on a budget = 4e td04. but thats completely off topic.

this thread is about compression or the need for higher comp to save on lag, and the thread starters interest was in getting a td04 that wont drop off boost between gears, the simple answer is it wont and if it does somethings wrong.

Phil