Intercooler Restricting Power Over 250rwkw On R34 Gtt

[allthewaytotheskyline]

ok so some of you may know already but i had a boost issue where my r34 gtt rb25det neo engine with hks 2835 pro s was not making over 250rwkw so we dropped the exhaust and NOPE wasnt that...so we then tested the pressure from turbo to after the inercooler and there was a 8 psi drop the moment it hit 5000revs and 250rwkw was the most it would go to then boost would drop dramatically.

so we had almost 25 psi turbo side and inlet side was 17 psi...my tuner has told me that my just jap "cooling pro" intercooler has restricted the flow and the cooler needs to go for something better.

now my aim 280 or so kw...and eventually on e85 up to 330rwkw.

now what intercooler would i be looking for "NOT LOOKING TO SPEND A MINT ON IT" (im looking for intercooler only as ive got the piping and its front mounted with inlet/outlet on each bottom side) what have you guys used to pull bigger numbers and is this a common issue with the just jap coolers or do i just have shit luck.

*pick a brand name cooler ?

*get one custom made?

*any other suggestions?

in advance thanks heaps sau'rs!

Bass.

Edited July 7, 2009 by allthewaytotheskyline

[zebra]

Are you 100% sure its not leaking anywhere?

If so I'd go a Hdi Core

[allthewaytotheskyline]

well the tuners theory is...boost wouldnt be dropping off so dramatically as there would still be volume for it to flow but there overall power reading would be lower.

hance the reason why he claimed it to be the intercooler.

[skylinecouple]

I have the 3071 with .82 turbine housing by Garrett which is supposed to be very close to the 2835. I also had the JustJap cooler and by luck I came across a brand new Hybrid tube and fin so gave it a try. Got to say I felt the difference straight away. Crisper and more torque everywhere. I didn't dyno it alone as we did the turbo as well but didn't need to dyno to know there was a noticeable difference. I had the JustJap cooler for a few years and couldn't believe the crap that came out of it when it was flushed. Give yours a clean if it's been in a while. I'd still get the Hybrid though.

[PM-R33]

If i was in your position and wanted a good core replacement.

http://cgi.ebay.com.au/PWR-Intercooler-600...%3A1%7C294%3A50

Edited July 7, 2009 by PM-R33

[allthewaytotheskyline]

where did you buy the hybrid one from is it the same as hdi??

[skylinecouple]

Yes, same as HDI. You can see the size difference in the tubes. Very obvious. Even before boost it seemed smoother and crisper. Luis at Drift Garage did his after he drove mine and he said the same thing. Just generally better and obviously more power. I am not the only one though as others have noticed the Chinese cores are only good for 250-260rwkws. not that you couldn't make more power but certainly easier with the HDi or Hybrid. Speak to Luis at Drift Garage and he might be able to get a good deal from them as they are just around the corner.

[skylinecouple]

Oh, and I still have my old cooler here like new. Would suit anyone looking to upgrade.

[R31Nismoid]

Use a GTR core - tried and proven for 380rwkw without a drama.

[allthewaytotheskyline]

Oh, and I still have my old cooler here like new. Would suit anyone looking to upgrade.

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

Edited July 7, 2009 by allthewaytotheskyline

[R31Nismoid]

I am not the only one though as others have noticed the Chinese cores are only good for 250-260rwkws.

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?

[Munkyb0y]

I have the 3071 with .82 turbine housing by Garrett which is supposed to be very close to the 2835. I also had the JustJap cooler and by luck I came across a brand new Hybrid tube and fin so gave it a try. Got to say I felt the difference straight away. Crisper and more torque everywhere. I didn't dyno it alone as we did the turbo as well but didn't need to dyno to know there was a noticeable difference. I had the JustJap cooler for a few years and couldn't believe the crap that came out of it when it was flushed. Give yours a clean if it's been in a while. I'd still get the Hybrid though.

Was the Cooling Pro a tube and fin core?

[mad082]

Was the Cooling Pro a tube and fin core?

and was it the stealth type or the standard type that comes up over the radiator?

[allthewaytotheskyline]

it was tubo and fin, and was the standard type that comes over the radiator.

still tossing up as to which intercooler to choose...hdi want $470 for a core only.

[Munkyb0y]

it was tubo and fin, and was the standard type that comes over the radiator.

still tossing up as to which intercooler to choose...hdi want $470 for a core only.

We were asking skylinecouple which type of Cooling Pro core he replaced with the HDI.

Also, contact performance-wise (Paul) from these forums about the HDi core. He can beat that price by quite a bit.

Edited July 8, 2009 by Munkyb0y

[allthewaytotheskyline]

oh didnt realise.

yeh ive just realised his website does it for a lot cheaper...he gets great prices and is quite reliable.

does he have a shop to pick up from??

is there a contact number for him??

[adzR34]

Bass, its hard to believe a pressure drop that great inflicted by the intercooler design. My thoughts are that it would have to be poorly manuafactured or even leaking to yeild such a drop.

I knew a mate that apparently had a minor crack in one of the intercooler welds which also gave him strife for a while.

Goodluck with it.

[W0rp3D]

Bass, its hard to believe a pressure drop that great inflicted by the intercooler design. My thoughts are that it would have to be poorly manuafactured or even leaking to yeild such a drop.

As a reference i had a split in one of my silicon joiners, was in the middle of bum f**k idaho and couldnt get any 2.25" silicon joiners, had to limp it home as it was, could take it to 7psi with out a problem but as soon as i tried to take it any higher the cut would open up and no more boost would get to the engine.

Maybe try making sure all you joiners are tight as at 25psi the pressure would be escaping from any little gap it could find.

[SS8_Gohan]

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.

EDIT2: We also dropped the exhaust in testing, and got the same result as yourself, didn't make difference to boost

[paulr33]

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

thats a big drop

something obvious is missing i suspect