Aftermarket Highlift cams - Help!

wildchild

wildchild

Member +
Hi guys.
i have a GT running a fully forged 5EFHE engine. standard ignition, GT28R bb turbo on WEPR godzilla manifold. It made only 203HP at 1bar boost on octane 95.
Here in SriLanka i guess that it's actually equivalent to octane 90.

Thereafter i fitted the 265/265 8.7mm lift speedvision cams and took in for mapping. This time it made only 233HP at 1.4 bar boost. I think the car is capable of much more power. Browners glanza on UKSO made 380bhp at 1.5bar boost (on either a VF35 or TD06)

The problem wit my car is that it is very laggy after fitting the cams. Takes alot of power to spool up and less low end power. my opponent is already ahead of me when i shift to 3rd. lost a few races after fixing the cams. Is it advisable to keep the cams or take them off? . Are they good for my turbo setup? was previously running 5EFHE cams . Im in a dilemma whether to swap the cams back or not. I sometimes wonder whether my car is not mapped properly or else the cams are too aggressive and needs to be taken off.
My car was much quicker and more responsive when i had the 5EFHE cams in.
Can anyone shed some light on this pls?
Thanks a bunch :)
 
A

AdamB

Member +
I don't think your setup needs cams, the stock cams will do just fine. The cams certainly won't be helping your cause though with lag as I think they are the wrong spec. I would only use them cams if your pushing the turbo to its max and out of its efficiency.

Whats the rest of your engine spec? I would have thought you would of made more power than that. Is there any reason why your only running 1 bar?
 
weeJohn

weeJohn

Lifer
I agree with what Adam says, but with the problems with Speedvision cams in the past, I think I would check the cams are opening the valves at the right time in the crank cycle.

More power does not always mean more speed, I lost 25 bhp when I changed my set but gained 0.3 seconds up the quarter mile.
 
S

Skalabala

Member +
You need to fit a vernier cam gear and have the cams dialed in :)
Is that HP figures at the wheels? What ecu are you using and what is your max timing?
 
wildchild

wildchild

Member +
im running the following setup-

Fully Forged 5EFHTE
Wossner 74.5mm Forged Piston's
Scat Forged Conrod's (with ARP Bolts)
ACL bearings (main, rod & thrust)
Athena 1.2mm Metal Headgasket
ARP head bolts
Adjustable cam gear
Garret GT28r Ballbearing turbo
WEPR godzilla series manifold
WEPR Decat downpipe
WEPR stainless steel 3" straight thru exhaust pipe
WEPR cold air intake
720cc injectors
TRD ignition leads
NGK Iridium heat range 7 plugs
Adjustable FPR
255lph genuine walbro pump
HKS bov
38mm tial ext wastegate
Front Mount Intercooler
Oil Catch Tank
Manual boost controller
Haltech sprint 500 ecu

when i first mapped the car i was running the standard FHE cams and a 3bar map sensor. my tuner said that boost was leaking through the bov so he could only get 1bar at the moment. i wasnt there when it was mapped. it made 203hp on 850cc injectors. made 13.9secs on the quartermile.
(previously it made 201HP on TD04 turbo at 1 bar boost on 440cc injectors and emanage ecu)


Then i changed the injectors to 720cc as the 850cc ones began to get stuck and wouldnt open at times.
Changed the bov to a very stiff tial replica. (Changed my tuner too)
This time the 3bar map sensor got damaged so had to attach the boost pipe to the ecu. so was limited to 1.4bar only.
Fitted the speedvision cams and mapped it and it made 233hp at 1.4bar
Made 13.5 secs at the quartermile.
All the above HP figures are WHP.

but with the extra boost i didnt see any power gains in the car. it was much laggier and needed very high revs to get power. it takes ages for turbo to spool up.
Sometimes i wonder if intake pressure is being released earlier thru the exhaust valve when it remains open longer.
There arent many tech heads here in SL and the only few are too busy to get hold of and cannot advice me properly. Tuners charge $400.00 for mapping and the dyno session for 1 hour is $200.00 so i cant be testing all the time too :-(

depending on your views i'l take a decision whether to remove the cams or keep it. i personally want to remove the cams but reading other posts about cams and the high end power i want to keep it. but its of no use if my turbo is bigger and i cannot get any good quarter mile numbers.
 
A

AdamB

Member +
Personally I would remove the cams, they really aren't needed for that kind of setup, I think you'll need to be pushing at least 1.8 bar on that turbo before considering upgrading the cams.

The problem with buying these cams, or any cams for that matter which don't come from an actual cam manufacturer is you never get the full specs. The duration and lift is only half the story with spec'ing the correct camshafts. This makes it very hard to dial the cams in correctly.

Just something else, whats your compression ratio? The size of your boost pipes? Are you still using the stock intake manifold?
 
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wildchild

wildchild

Member +
Is it so?.... guess the cams hav to come out then..
yes these cams dont have a brand and my tuner says they are more aggressive than stated.
Never measured the compression ratio and i doubt if my tuners did..

Turbo Intake = 2.25"
Turbo outlet to intercooler = 2"
Intercooler outlet to intake mani = 2.5"

Yes stock intake (4EFTE intake)
 
E

elison

Member +
Buddy i advice you to take them off. With the setup you have you should be able to push close to 300ish. I have the same specs but engine is a 4e and a electronic boost controller.

With that turbo kit would produce huge power above 1.5 to 1.6 bar. And as adam said sometimes its difficult to dial in those cams due to lag of information provided.
 
weeJohn

weeJohn

Lifer
Get your tuner to check what the cams are opening and closing the valves at, there are some specs on here and other sites, compare them and see what he thinks. I take it the valve clearances were checked and the valves are all closing properly?

The problem with trying to dial cams in with a vernier pulley on these engines is the fact the 2 cams are meshed together inside the head. Its not like other twin cam set ups that have 2 pulleys to adjust, 1 for each cam, so its very hard to adjust both desirably. Its down to whether the cam gear sprocket pins have been drilled in the right place on the cams.

I think you should have a little more power and a faster time with that set up, but it would depend on the map also. Have you ever considered buying race fuel just for dragging and having another map also?
 
A

AdamB

Member +
The problem with that though John is that he would have to get the information from Sam as to what the specs are for valve opening and closing times, I imagine they would be different from stock, at least they should be.

Agree it is a problem with the meshed cams :(
 
wildchild

wildchild

Member +
we didnt take off the head to fit the cams. Still using the stock springs too. Valves clearance is upto the marks. checked it after installing and also before mapping.

I take it that the head has to be removed to check at which angle the valves open and close? or is it possible to make it out by removing the rocker cover and inspecting the cam lobes & valve angle while turning the cam by hand?

didnt use race fuel as its abit hard to comeby here. aviation fuel is not easily obtainable and only a few top end racers hav access to them and they get the required quantity for their purposes in advance. must order next time. is it alright to run purely aviation fuel or good to mix? av fuel is octane 100 or so..

Btw how can i run two maps? i mean do i have to change ecu's or can i have two maps in one ecu? what will be the difference in both Maps? wont they be tuned to the max performance of the existing motor? (kinda confused)
 
weeJohn

weeJohn

Lifer
Here is an article on how to check the cam timing

http://www.musclemustangfastfords.com/tech/mmfp_1105_how_to_check_cam_timing/

Here are the stock 4E and 5E cam duration specs as a reference (I would consider the high lift point of each cam as a basic reference), spot the math error if you can lol.

Engine20comparison.gif


With the size of the injectors you are running, its possible you could run a fuel/methanol mix for drag racing, methanol is cheaper than fuel!
 
HYBRID

HYBRID

Super Moderator <a href="http://www.toyotagtturbo.
well after reading this post im pretty sure there are a few problems with ur setup...

1.) having cams and a stock intake is pointless... as ur biggest bottleneck is now present in the oem tb and plenum...
2.) on a gt28 to start getting a decent amount of power without lag between gear changes u need to at least run 1.8bar.. and thats a bare minimum... as otherwise ur out of its efficiency range..
3.) stock springs with cams? right... thats a BIG no no.. with those cams u want ur car to rev to at least 8500rpms... DO NOT try that on stock springs as ull 100% have valve bounce around 8000rpms... suggest u get them changed ASAP..

those 3 things will help ur setup alot... also improving the quality of fuel you run will allow for a more aggressive timing map helping the turbo spool and more power to be made :)

hope that helps
kon
 
S

Skalabala

Member +
Stock springs :eek: haha
There is no point in using nobrand cams if you do not dial them in.
You put a dial gauge on the shim bucket. And check when the valve opens when you turn the crank.
For a start just check at what angle the crank is when the 1st intake valve wants to open.

If you have a capable machinist and are happy with results after dialling in the cams then you can make the second cam vernier also :)

If the cams work like they should then you might get an 30hp max power increase over the stock cams.

And will be good for future mods as Hybrid said, intake etc.

Have you played with the vernier cam gear at all?
Retard one tooth and do power run. And advance one tooth and do power run.

With the management you are using you should have around 100hp more that you have now.
 
wildchild

wildchild

Member +
thanks for the help guys. yes cams were measured with a feeler gauge if thats what u mean by dialing the cams.
The cam gear wasnt adjusted. its at the 0 mark.
hmmm a custom intake is one of the hardest bits to find. quite expensive i reckon. if im to change valve springs then i will have to take out the head which means i need a new steel head gasket.. $_$
i guess i'l remove the cams and put the FHE cams in.
My tuners arent so cooperative too and i hav to keep experimenting with the car at their hands :/
Same tuner took one of my other cars to map and came with a bent rod, damaged piston and a broken block. says one rod bolt had broken off. dunno who or what to believe! thats running stock internals and a TD04 turbo.
Thanks for the support ppl. cheers!
repped :)
 
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