Running a non return flow setup

[IM-32-FK]

Hi all,

as I’m aware, but I might be wrong, the gtrs run a non return ffp setup stock. But on my GTT, I was wondering if there is any way to run non return piping post intercooler without having to cut out some metal around the battery area.(even if I retain the stock intake manifold or go ffp)

Is it possible? I just don’t want to cut metal out of the engine bay because I want the body to be stock as possible, but will if I have to because it is said the return flow piping usually restricts at 300kw.

cheers

[admS15]

It can be done, will require custom made intercooler piping on the cold side. I have seen traditional return flow setups making in excess of 400rwkw. It's not that rf can't make the power, they tend to have a bigger pressure loss across the core making your turbo work harder to make the desired boost which then also increases intake temps. Ultimately it's not as efficient as could be but unless you're chasing every little bit of power and response they are sufficient for most street setups.

[IM-32-FK]

1 hour ago, admS15 said:

It can be done, will require custom made intercooler piping on the cold side. I have seen traditional return flow setups making in excess of 400rwkw. It's not that rf can't make the power, they tend to have a bigger pressure loss across the core making your turbo work harder to make the desired boost which then also increases intake temps. Ultimately it's not as efficient as could be but unless you're chasing every little bit of power and response they are sufficient for most street setups.

Wow, really? I’ve got the setup where the exit port on the intercooler(cold side) has a 180 degree bend to the bottom and the piping goes underneath the intercooler. Are you saying I could 300kw+ with it? I’m looking to get about 310-320kw from my setup so I’d have that extra 20kw if I can.

btw how does the stock headgasket and head studs hold up at 320kw unopened neo? Big job to pull apart the head and change the gasket that’s all.

cheers

[Kinkstaah]

Yes, I've made 420+ through an auto with a stall converter, so close to 500 with a damn manual. I know the losses of the converter because I went back to the same dyno with a manual later and plotted the differences.

My intake air temp on the track at a track day was something like 35C on a 28C day. My engine was not unopened and I was running 24psi on E85.

Others have noted differences by changing the intercooler but reports are thin on the ground when someone only changes the intercooler.

There's many many reasons 300kw is a good number to stop at for sanity reasons (grip, clutch drivability, lag, reliability in general). If you're near there already, then leave the car alone and enjoy driving the damn thing instead of pulling it apart and paying tens of thousands of dollars.

[admS15]

7 minutes ago, IM-32-FK said:

Wow, really? I’ve got the setup where the exit port on the intercooler(cold side) has a 180 degree bend to the bottom and the piping goes underneath the intercooler. Are you saying I could 300kw+ with it? I’m looking to get about 310-320kw from my setup so I’d have that extra 20kw if I can.

btw how does the stock headgasket and head studs hold up at 320kw unopened neo? Big job to pull apart the head and change the gasket that’s all.

cheers

I have the same style cooler and am making 312rwkw with a high flow turbo on e85. Made 260 on 98. Stock head studs and gasket handled that no problem and my car has done many many track days without issue and intake temps similar to what kinkstaah mentioned above. As you read, his car made well over 400 before he bitched out and went LS.

[GTSBoy]

9 minutes ago, IM-32-FK said:

I’ve got the setup where the exit port on the intercooler(cold side) has a 180 degree bend to the bottom and the piping goes underneath the intercooler

Important parts underlined.

• The 180° bends involved in these things are certainly restrictive (compared to having the pipe come straight out). It's not a killer amount of extra restriction, but it is there. Some of them are pretty ugly designes, some a bit better.
• The fact that such return flow coolers cannot be as tall as a straight through, because the return pipe runs under the core (where there could be and is more core in straight throughs) means that the flow area through the core is that much smaller. That also definitely causes the flow limit of the return flows to be lower. That part is actually simple to work out. If you only get 85% of the height, you can presume that its max power capacity would be only 85% also. Core thickness and tube design, plus differences in tank design etc notwithstanding of course.

[IM-32-FK]

6 hours ago, admS15 said:

I have the same style cooler and am making 312rwkw with a high flow turbo on e85. Made 260 on 98. Stock head studs and gasket handled that no problem and my car has done many many track days without issue and intake temps similar to what kinkstaah mentioned above. As you read, his car made well over 400 before he bitched out and went LS.

That’s good to know. I need to get the dump pipe v banded, the stock ex mani external wastegated, need new piping fab done post compressed housing so I’ll just see if he can also do me a non return setup. A guy sent me pics of how u can do non return flow without cutting anything. But I would need to cut the exit port on the blitz intercooler so it’s straight rather than coming down 180 degree. Why didn’t blitz just make it straight and put 180degree silicon hose instead?

anyway stupid question but do the internals of the intercooler make it a return flow or is it just the exit port? Like if I cut the port and make it straight then will the intercooler be a non return intercooler and act accordingly?

cheers

Edited June 2, 2021 by IM-32-FK

[admS15]

That is a nice way of doing it. If you're going to go that way, don't try to modify the rf core, just sell it on and replace it with a traditional full size core with custom piping. The blitz rf cores are not full height or thickness. Get a 600x300x76 to suit your budget, aeroflow is ok on the cheap end, if you have the $ and want to do it properly, plazmaman is nice.

[IM-32-FK]

15 minutes ago, admS15 said:

That is a nice way of doing it. If you're going to go that way, don't try to modify the rf core, just sell it on and replace it with a traditional full size core with custom piping. The blitz rf cores are not full height or thickness. Get a 600x300x76 to suit your budget, aeroflow is ok on the cheap end, if you have the $ and want to do it properly, plazmaman is nice.

The blitz rf is 620 x 266 x 76mm.  I was thinking maybe 600x300x100 but that might lag and that’s the last thing I want. Otherwise I’ll just go the size you mentioned. What do you think is best?

[admS15]

100mm would be nice, bigger is better but don't think you'll get it in there without cutting up stuff. You'll need to do some research and see what others have done to fit one in.

[GTSBoy]

There's no such thing as lag from a slightly bigger cooler core. The internal volume is approximately 3/5 of f**k all.

[Kinkstaah]

The one I was using is the Blitz. There's sometimes a difference between academic gains and actual real world gains you can feel.

Do a dyno before and after and see, but a larger core IS better and having less bends IS better, but what you have will suit what you need well enough too. It's up to you to determine if your $ is worth ... however much gain this truly is for however you truly use the car, and how truly stock you want it to look and so on

[IM-32-FK]

On 03/06/2021 at 9:11 AM, Kinkstaah said:

The one I was using is the Blitz. There's sometimes a difference between academic gains and actual real world gains you can feel.

Do a dyno before and after and see, but a larger core IS better and having less bends IS better, but what you have will suit what you need well enough too. It's up to you to determine if your $ is worth ... however much gain this truly is for however you truly use the car, and how truly stock you want it to look and so on

Thanks a lot for that. If anything you can get plazmaman 600 300 76 intercoolers for really cheap like $500, but then I’d need to spend another $500 at least to get pipe work post intercooler.

I think I now have everything and am ready to put it all in.

I don’t plan on running a catch can to turbo intake, so I’ll run the two breathers on rocker cover to a catch can that vents to atmosphere. And I also bought a pcv blanking bung, so I don’t get oil into the plenum. Is it safe to run it like this? It won’t cook the engine?

also I got a z32 afm but I heard the r35 gtr afm cards are ‘better’.  I’m pretty sure with my setup I’m going to be pushing maybe 18-22psi on a 3076r. Obviously r35 afm is better but will the z32 suffice? 

[Kinkstaah]

[old man hat on]

You're potentially adding complication here for little benefit.
Consider the piping in the bay and the convoluted path it needs to get back to the throttle.
Consider the issues/cost going FFP and visual legalities too, you'll need to do one or the other but plenty of people do route piping to the stock throttle body location.

It's really sensible to let the PCV continue doing what it was designed to do. There's two elements of it (by "fixing" it), venting excess crankcase pressure, and controlling oil from going back into the intake. Keep in mind you will be adding something to manage (i.e emptying the can) but it won't draw nearly as much oil if it's not connected to some kind of suction point.

PCV and oil control are really track mods - What do you really plan on doing with the car, are you modifying systems that even need improvement? Have you identified where the stock PCV is holding you back, and how, and how it needs to be changed to suit your use? The simplest way is to put a can 'between' the PCV system hoses so it intercepts the intake, then proceed to worry if the amount of caught oil is normal

Spoiler: It's been going into your motor the entire time with minimal issues 😛

Same story with the AFM. I've never heard anything other than "It kinda works most of the time" with AFM's post Z32 (the card style, and R35 style upgrades)

Most people go a MAP based ECU at that the point that a Z32 is truly no longer usable.

[Dose Pipe Sutututu]

22 hours ago, IM-32-FK said:

If anything you can get plazmaman 600 300 76 intercoolers for really cheap like $500

I doubt that's their Pro series core, most likely their bar & plate stuff which is pretty much China cores.

If you're on a budget, I would install a R35 card MAF post intercooler. This would increase driveability as well eliminate any issues with reversion, lack of return BOV, etc.

Sure the Z32 works, makes the power you need, etc. but does it drive really well? I would say no.