Haveing Problems Making Power When Runnin Big Boost

[rob82]

Valve float - does the power just nose over? How does the engine sound at this point. Have you got a dyno graph?

[timsr33]

Scott from insight motorsports is very switched on. Check out his website. He is very helpful. May have some suggestions

ive herd scott is good i might talk to him later in the week thanks for the help

[Adriano]

Valve float +1, unless the higher load point is running heaps less timing

[timsr33]

Valve float - does the power just nose over? How does the engine sound at this point. Have you got a dyno graph?

it basiccally just goes flat doesnt te engine still sounds fine im just confused that a t04z is making less power then twin t517z it seems the more power i try to make the less it is making

[Adriano]

32deg ignition timing at 5000rpm, are you sure?

[timsr33]

Valve float +1, unless the higher load point is running heaps less timing

whats valve float and the timing is only 3 degree less then 15

[rob82]

32deg ignition timing at 5000rpm, are you sure?

Its probably got no boost at 5000rpm hence the ignition numbers. What does the boost do - its sometimes easier to hear valve float external to the dyno room. Also when valve float occurs your boost can go all over the place. Does more boost make more power through the mid range but then just flattens off upto where it should be making more power?

[rob82]

Also whats your timing control like at high rpm? The only three ECU's I would ever use when using a std CAS is a PFC, std ECU or Motec every other ECU I've seen issues with signal filtering - haven't seen the new Vipec.

[timsr33]

Its probably got no boost at 5000rpm hence the ignition numbers. What does the boost do - its sometimes easier to hear valve float external to the dyno room. Also when valve float occurs your boost can go all over the place. Does more boost make more power through the mid range but then just flattens off upto where it should be making more power?

only making 5 psi at 5000 boost climb sharp then sits flat till 9000 more 7 pound made 7 kws difference and even the base number of 353 at 15 was to low according to my tuner

[timsr33]

Also whats your timing control like at high rpm? The only three ECU's I would ever use when using a std CAS is a PFC, std ECU or Motec every other ECU I've seen issues with signal filtering - haven't seen the new Vipec.

pretty good i think mark hasnt complained about filtering only about having to use a haltech in general

[timsr33]

I know that...

Well from where the "de-cat" pipe is, same spot, matters not... So i take it as a NO you have not tried the 10mins quick test to totally discount exhaust

i miss understood you ill give it a go tomorow it got to be worth a try thanks

[tridentt150v]

Does it hold boost? when you wind on past 15 psi do you still get a flat line or is it all over the place? Whats your spring rate in your WG?

[timsr33]

Does it hold boost? when you wind on past 15 psi do you still get a flat line or is it all over the place? Whats your spring rate in your WG?

its got a 17psi spring in it and it sits dead flat no spiking or flat spots at all

[rodger1]

how'd you go did you sort it out?

[T04GTR]

well i thought mine was bad....

i have 25pound in a loaded gear by 4300rpm.

mine is IDENTICAL to yours except you have valve springs. my t04z is .84 split (ta45 footprint) 3.5" straight exhaust no cat.

i have an ebay manifold. with 1.1/4" runners.

mine on 1.6 bar makes 376awkw (505hp) on 1.4bar it made 355kw on 1.8 it made 377kw

i think mine is valve float...

[timsr33]

how'd you go did you sort it out?

i might of fixed it had a valve clearance issue witch is now resolved but wont no till it gets back on the rollers it seams to make more power now and is coming on earlier so fingers crossed

[timsr33]

well i thought mine was bad....

i have 25pound in a loaded gear by 4300rpm.

mine is IDENTICAL to yours except you have valve springs. my t04z is .84 split (ta45 footprint) 3.5" straight exhaust no cat.

i have an ebay manifold. with 1.1/4" runners.

mine on 1.6 bar makes 376awkw (505hp) on 1.4bar it made 355kw on 1.8 it made 377kw

i think mine is valve float...

ive been looking at yours we both seam to be in the same boat if you end up fixing it let us no im concidering trying standard cams to see if makes better or worse

[mazman]

I thought i would join in and give you my experience as well.

I however have a supra 2jzgte with a gt42.

Long story short, i have very low power numbers for the size of turbo and boost im running, ive tried a lot of things, people were saying also valve float, small cams etc.. after replacing them, i am still having the same issue's.

My boost comes on hard at 5500rpm@26psi and thats where it makes its max HP, then just flat lines all the way to redline.

All the info is in the links here, i have posted my issue's on a fair few forums, so if you can be bothered, have a read what ive done, im pretty sure we may have a similar issue, also running a haltech e11 and having a hard time finding someone to tune it...

http://www.performanceforums.com/forums/sh....php?t=67205139

http://www.supraforums.com.au/forum/showthread.php?t=37070

http://www.supraforums.com/forum/showthread.php?t=529982

Not sure if you'll be able to go on all of them, may need to sign up? and some are a very long read, but plenty of suggestions, just everything ive tried so far hasnt worked, very frustrating!

[rodger1]

I thought i would join in and give you my experience as well.

I however have a supra 2jzgte with a gt42.

Long story short, i have very low power numbers for the size of turbo and boost im running, ive tried a lot of things, people were saying also valve float, small cams etc.. after replacing them, i am still having the same issue's.

My boost comes on hard at 5500rpm@26psi and thats where it makes its max HP, then just flat lines all the way to redline.

All the info is in the links here, i have posted my issue's on a fair few forums, so if you can be bothered, have a read what ive done, im pretty sure we may have a similar issue, also running a haltech e11 and having a hard time finding someone to tune it...

http://www.performanceforums.com/forums/sh....php?t=67205139

http://www.supraforums.com.au/forum/showthread.php?t=37070

http://www.supraforums.com/forum/showthread.php?t=529982

Not sure if you'll be able to go on all of them, may need to sign up? and some are a very long read, but plenty of suggestions, just everything ive tried so far hasnt worked, very frustrating!

It really sounds like you need a new tuner, just one idea on your car is with the cat converter if it has no core in there it can cause a vortex and cause back pressure and power loss. I don't think this is your problem though I think that your problem is more likely to be a tuning or sensor problem I dont know much about 2j's except the make a lot of power but could it be a problem with your vvti not advancing the cams as it's meant to? let me know what you think

[T04GTR]

MAZMAN i relied to your post on supra forums... small world!! it would drive me insane!

timsr33 i had standard cams.. well bog stock motor 1.4 bar same everthing made 315awkw. lag was almost identical,put the cams in a mild head and went to 376awkw on 1.6 bar.

ive been told its the small cams and weak valve springs... but there are the odd freak ones on here making 400+ kw on same boost. either im missing something or they arnt telling us something..

but you have valve springs. wich make me worry about mine. but yours has crazy lag! what was the "clearance issues" you discoverd?

ps.. my girly has a rb25 and a gt35 with .68 ar rear. she made 345rwkw on 1.5 bar. little 252 poncams and type a springs on a 6 boost. now when i built the motor it made 260kw on 1.2 bar i opened up the small radius on exhaust ports only! went straight to 301kw..

so i think our cyl heads are the place to look at.