Bigger Intercooler And Piping

[conan7772]

Currently have standard gtr intercooler 50mm or so , with 2.5 inch piping on both sides.

Turbo has 4 inch inlet , plenum is 3 inch.

Exhaust is 3 inch right through off stock manifold.

337rwkw now.

If I went 80mm intercooler and 3 inch piping, what would I expect.

cheers

[Adriano]

Standard gtr intervooler is 65mm with 3.25 inch (80mm) piping, not sure what you are running?

[R31Nismoid]

^ agreed. 65/80mm.

So that said - IMO nothing really. Making 365rwkw here, factory GTR core, factory piping which is certainly not 2.5".

A 3.5" exhaust would offer more benefit either way.

[Harey]

Nice power figure! Is there anywhere I can see your mods? Last time I thought you were around the 300rwkw.

[XRATED]

A rough guide for cooler plumbing is-

Hot side- keep the pipe diameter the same size as the turbo outlet..

Cold side- keep the pipe work a close size to the tb...

Your stock gtr cooler shouldn't hold you back for your power level, to make it a little more efficient- close the gaps up between it and the front bar and above the grill.

If your going to do anything, swap out the post cooler to tb pipe with a 3" pipe. There will be very little gain, unless you have some crazy bends in there though...

For the same money as a custom 3" cooler pipe (say $35 per bend + fab = $200 odd) buy a better set of brake pads/fluid/lines or a 3.5" muffler to see a better performance gain.

J.

[conan7772]

Nice power figure! Is there anywhere I can see your mods? Last time I thought you were around the 300rwkw.

I'm in rb25/30 dyno results.

Mods are listed.

[DVS JEZ]

Ahh so u have a gtr cooler on ur gtst? With custom 2.5inch piping?

[R31Nismoid]

Are you on E85 now?

More boost?

Did you fix the boost dropping issue from your previous runs? (dyno thread)

310rwkw @ 15psi from a 3076 is a bit unrealistic so it's looking like you've changed fuel to me (just goin off the dyno sheet)

[Harey]

Found it:

RB25/30 Series 1 R33

Tomei Poncams

550 top feed injectors

Plasmaman plenum 72mm throttle body

Forged internals

Haltech Sport 2000 ECU

Single 044

GT3076R low mount

I suppose the only real way to confirm if larger piping would be beneficial is to measure the pressure drop and temperature increase along the different sections of the piping. I agree with the previous post that the hot pipe will be fine, if there are gains it will be the cold pipe going to your 72mm throttle body.

I have been looking at 'infrared thermometer guns', wow they look cool. Chuck the car on a dyno and sit there pointing at different parts of the pipework measuring the temp!

Another idea I am looking at as well is to ceramic coat the cold pipe, but that will depend on the temp results you get. I was reading about an R32 GTS-T that their during the cold pipe air increased temps by 26 degrees!!

[R31Nismoid]

Are you on E85 now?

More boost?

Did you fix the boost dropping issue from your previous runs? (dyno thread)

310rwkw @ 15psi from a 3076 is a bit unrealistic so it's looking like you've changed fuel to me (just goin off the dyno sheet)

Also more thoughts.

Tested pressure turbo outlet & @ plenum to find out if there is a pressure drop?

And/or temp diffences? (you might have a sensor. not sure)

[conan7772]

Also more thoughts.

Tested pressure turbo outlet & @ plenum to find out if there is a pressure drop?

And/or temp diffences? (you might have a sensor. not sure)

No, still on 98Ron pump fuel.

Don't think I'll ever go E85, I like the current setup too much.

Injectors are 570 top feed on custom rail, not 550.

Drives economically and idles like a kitten.

3.5 exhaust is tempting, but probably pointless with stock manifold, plus Db exhaust levels will increase.

There is a temp probe on the cold side.

Intercooler is fully custom made,was on it when I bought the car.

One reason why I'm looking at new ones is I'm assuming my existing one is full of oil again, after massive surge through PCV last track day. Oil was dripping out my BOV for 6 weeks, so I reckon is was drawn back into the cooler.

Already had it pulled out and flushed before, may as well replace it.

PCV now blocked.

Not really after more power gains, just curious if low down response and spool will improve.

Might try and jam a 100mm one in.

[conan7772]

Yeah , boost drop was the actuator, large can fixed that.

Flat lines 21 now, but injectors are maxed

Edited April 6, 2011 by conan7772

[Harey]

3.5 exhaust is tempting, but probably pointless with stock manifold, plus Db exhaust levels will increase.

I disagree with this, I think a 3.5 exhaust will assist you greatly. Even just the cat and catback system.

Here is info from another car:

stock 25NEO

standard exhaust manifold

3076 .82 rear .6 front cover

E85

1000cc injectors

running 27psi

Power FC

Blits Return flow cooler

3" dump pipe, 3.5" cat and 3.5" hks catback exhaust

350rwkw

Plus, even on my lowly 270rwkw setup a dyno test without my 3" fujitsubo catback exhaust revealed 10rwkw gain through mid range and up top. So surely a 3" catback is limiting your power.

[R31Nismoid]

^ Ye but think, ~5psi for only 20rwkw more (or there abouts). Things are certainly on the limits of flow @ these points.

Be interesting to see the heat/Intake temps as well on such high levels

Still agree though, 3.5" exhaust could add benefit. Simple way to test that anyhow, just drop it from before the CAT - do a run and have a looksee

Not really after more power gains, just curious if low down response and spool will improve.

Might try and jam a 100mm one in.

I'd be surprised if going from a 60mm to 100mm I/C, larger piping and so on - That you'll see increased response. It's more than likely going to hurt it making everything bigger. It's just more volume/area that needs to be filled at the end of the day.

[Harey]

^ Ye but think, ~5psi for only 20rwkw more (or there abouts). Things are certainly on the limits of flow @ these points.

Be interesting to see the heat/Intake temps as well on such high levels

Remember Conan is running a built RB25/30, the other guy is running a stock RB25 Neo.

Still agree though, 3.5" exhaust could add benefit. Simple way to test that anyhow, just drop it from before the CAT - do a run and have a looksee

I Agree

I'd be surprised if going from a 60mm to 100mm I/C, larger piping and so on - That you'll see increased response. It's more than likely going to hurt it making everything bigger. It's just more volume/area that needs to be filled at the end of the day.

I Agree

[R31Nismoid]

Remember Conan is running a built RB25/30, the other guy is running a stock RB25 Neo.

And hence i didn't say 7-8psi

As seen from Al's own 3076 results, the turbo simply noses over around the 320-340rwkw marker anyway as they just can't flow anymore and are absolutely on the limit.

conan isn't after more power anyway - it's a response question. Exhaust could aid in that area, i dont think the rest however will. (unless its tested and shown to have issues)