Intercooler Restricting Power Over 250rwkw On R34 Gtt

[W0rp3D]

hmmm... this is interesting. I'm having the same problem mate, although it could be the size of my rear housing, i guess it could also be my cooler (more things to check out)

here's my boost curve...

don't think we've checked the pressure differential...

plus something is howling like a mo fo, maybe somethings up with the cooler...

EDIT: i'm using the Just Jap Stealth version cooler. So i guess we have the same cores but different piping.

Your core is actually smaller, it isnt as high so there is room for the return piping to run underneath it.

What turbo are you using and how big is your rear housing?

[allthewaytotheskyline]

hmmm... this is interesting. I'm having the same problem mate, although it could be the size of my rear housing, i guess it could also be my cooler (more things to check out)

here's my boost curve...

don't think we've checked the pressure differential...

plus something is howling like a mo fo, maybe somethings up with the cooler...

EDIT: i'm using the Just Jap Stealth version cooler. So i guess we have the same cores but different piping.

yeh thats extremely similar to what is happening to mine...

thanks adz34....i will change this intercooler 1st and go from there...im also changing all my hose clamps (ive checked my hose joints there all good)to the t-bolt clamps.

yeh..it has shown quit a restriction...i guess the only way to fix things is to go over them again.

either way i will let you all know how it turns out.

if any1 has any idea's it would be much appreciated to have your input.

[allthewaytotheskyline]

id be surprised at an 8PSI pressure drop across the core

thats a big drop

something obvious is missing i suspect

any suggestions?

[Dose Pipe Sutututu]

that's happening to me as well!

I've been told that the turbo itself is too small and running out of puff, i.e. it's fallen out of it's efficiency band to produce boost.

At lower boost settings, you will see less of a boost drop.

Guilt-Toy's solution to this "Buy a bigger turbo" lol...

I'm using a HKS 2535 btw.

[Munkyb0y]

how much boost thru the 2535 before it runs out of puff?

[SS8_Gohan]

Bass's 2835pro S shouldn't be dropping so much. Just check out joeyjoe's car.. same turbo and can hold boost fine. The rear housing on those turbo's are big enough to flat line. It's gotta be something else.

My rear housing on the other hand (OP6 in a highflow) is questionable if it can hold that sort of boost flat line. But it's just interesting we're both using Just Jap coolers (well, very similar), pushing the same sort of #'s, and have similar boost outcomes.

I'm going back to the tuner on Monday and i guess will just do a process of elimination. The car is tuned, so we don't need to worry about that. It'll just be testing pressures i guess (like you did Bass), boost leak test perhaps, and maybe even change BOV to a GTR one.

You've got a GTR BOV yeah?

[R31Nismoid]

I know someone who has a 6PSI drop across the core.

8psi is highly possible.

[skylinecouple]

when you say old cooler which one do you mean the hdi or the one you had previously.

also have you got luis' from drift garage's number???

so will these hdi cores take up to 330rwkw??

still flipping that this china just jap cooler hit a brick wall...grrrr

Sorry, have the old one, the JustJap one. This proved reliable enough as it is the model with the larger end tanks. Have to lose your driving lights though as is a little wide. Or you could trim them like I did.

Luis mobile no. is 0404081116. You can find him in Ingleburn. He is a top bloke and excellent fabricator. The core I have is Hybrid. They would be good for a considerable amount of power.

To be honest, I would look at exhaust size or dump, muffler, tune, boost controller or catalytic converter. May still be your cooler but check other things.

[skylinecouple]

Sadly that's wrong.

There are decent cores, and there are crap cores. Not all the China stuff is bad. Its the SUPER CHEAP stuff you need to be wary of, all stuff that is cheap - is not good, never is.

A certain workshop i know of uses China made cores for 400rwkw XR6t's - they are nowhere near the size of the 'jap spec' coolers yet they perform better - go figure huh?

Absolutely. I buy parts like I buy my clothes, look at the stitching and quality of material and NOT the brand.

And I just noticed he dropped the exhaust so that's not it. I would count the tubes and look inside to see how close the tubes are. If it's a bar and plate there is usually a 1cm gap between tubes, this is going to cause a little turbulence inside the cooler and a lack of tubes obviously will also restrict flow. Down side is you won't know what your looking at till you see a few different coolers.

A tube and fin will have the tubes closer together and should be able to fit more tubes in the same size cooler. JustJap normally do bar and plate.

[Dose Pipe Sutututu]

how much boost thru the 2535 before it runs out of puff?

running 18PSI, around 5k+ RPM, the boost drops like flies dropping out of the sky to like 15.5

[skylinecouple]

That's normal. The 2535 is really a small compressor in the grand scheme of things. The 3076 or HKS 3037 is where you start to see boost holding all the way to redline. My 3071 drops in the top end also as the comp gets a little asthmatic.

[mad082]

you would think that if there was a restriction due to the cooler being crappy you would think the restriction should be there all the time and it should just slowly increase. it shouldn't just flick on like a light.

may also be worth checking the core for any cracks, etc. to do that the best way is to cap the ends and have a tyre valve in 1 end and use a pump to presurise it and stick it in the bath or a drum of water.

as for boost dropping off at higher rpm, i have changed boost controllers and found differences. i had a turbotech controller (the cheap one with the really big thread about it) and then i put a turbosmart dual stage on and at 14psi it was dropping about 3psi at high rpm. but the other one back on and i would drop about 1psi at high rpm (which was more the stock turbo running out of puff).

[allthewaytotheskyline]

Bass's 2835pro S shouldn't be dropping so much. Just check out joeyjoe's car.. same turbo and can hold boost fine. The rear housing on those turbo's are big enough to flat line. It's gotta be something else.

My rear housing on the other hand (OP6 in a highflow) is questionable if it can hold that sort of boost flat line. But it's just interesting we're both using Just Jap coolers (well, very similar), pushing the same sort of #'s, and have similar boost outcomes.

I'm going back to the tuner on Monday and i guess will just do a process of elimination. The car is tuned, so we don't need to worry about that. It'll just be testing pressures i guess (like you did Bass), boost leak test perhaps, and maybe even change BOV to a GTR one.

You've got a GTR BOV yeah?

yeh ive the gtr bov, have tried blocking it off also (jsut incase it was leaking) but to avail nothing different occured. your right about the 2835 being able to go further...ive dropped the exhaust and it made no difference at all and btw im running a 100cpsi metallic 3" cat and a hks dump, fujitusbo 3 inch down pipe and trust ti 3.5inch exhaust so im sure it isnt there...the thing with a leak would be that boost would keep being made but...it wont be making power.

Now with the pressure drop from one side of the intercooler 25psi to a 17psi drop on the other side...i dont see how it could be the turbo (especially after its been proven time and time again that the 2835 is capable of it.

i will be replacing all my clamps to t bolt clamps and looking to buy a plazmaman intercooler which hopefully fixes the issue.

i appreciate all the help from all of you.

as soon as the issue is found and it is sorted i will let every1 know.

and mad082 ive got a hks evc 4 and i dont think its the boost controller due to the fact that there is 25 psi pre intercooler and only 17psi at throttle body.

is that right???

btw...this turbo comes on like a light switch...18psi boost at 3600rpm and 250rwkw by 5000rpm...the tuner was impressed.

Edited July 9, 2009 by allthewaytotheskyline

[hypergear]

8psi is too much drop. When I was testing mine I only had 2psi drop at 26psi. and its just a cheap China cooler. Might want to check for leaks. Hoo and HKS2530's turbine housing is too small, Its not going to be able to hold high boost. Thats why its only rated at 380HP.

[GUN_METAL_GTR32]

id just get a trust cooler

ive made the same mistake as u have and got a china cooler and now i want to upgrade the turbo and gor for 340kw at the rear wheels and im gonna have to change my cooler as well.

such a waste of cash

[R31Nismoid]

8psi is too much drop. When I was testing mine I only had 2psi drop at 26psi. and its just a cheap China cooler. Might want to check for leaks. Hoo and HKS2530's turbine housing is too small, Its not going to be able to hold high boost. Thats why its only rated at 380HP.

HKS 2530's regularly hold 20psi on a RB20 without an issue, i know friends RB25's that hold 18psi without issue.

In twin setup (on GTR's) plenty of people have run over 24psi on them.

Go figure i guess, real world examples and proof - gotta love it

[sick_skidz]

should just save up a bit more for trust 1 i got 1 and stuff all pressure drop cost bit more but the old saying goes here to "mesure twice cut 1ce" i wont need to change intercoolers for my build target now

[kwickr33]

HKS 2530's regularly hold 20psi on a RB20 without an issue, i know friends RB25's that hold 18psi without issue.

In twin setup (on GTR's) plenty of people have run over 24psi on them.

Go figure i guess, real world examples and proof - gotta love it

Learn the definition of "high boost."

should just save up a bit more for trust 1 i got 1 and stuff all pressure drop cost bit more but the old saying goes here to "mesure twice cut 1ce" i wont need to change intercoolers for my build target now

Try HKS coolers. Been told those cores flows lots better as the inner division is in " > " sort of shape instead of " | "

Edited July 10, 2009 by kwickr33

[allthewaytotheskyline]

8psi is too much drop. When I was testing mine I only had 2psi drop at 26psi. and its just a cheap China cooler. Might want to check for leaks. Hoo and HKS2530's turbine housing is too small, Its not going to be able to hold high boost. Thats why its only rated at 380HP.

checked for leaks today..plumbed(with pump) it up and pumped up to 25 psi and it held steady...no leaks...that i could hear or see, bumped it up too 30 psi...and the piece i plumbed it with popped out.

so im guessing leaking wasnt an issue.

any other idea's before i splurge on a intercooler??

regards, Bass

[R31Nismoid]

Learn the definition of "high boost."

30psi then - ive known people that have run 2530's to that also