Latest Tune, Thoughts On Cooler Setup?

[CEF33Y]

Hey guys,

So after almost 2 years, I went back for a touch up tune (same tuner, same dyno) as I'd changed a few things. Got a result I wasn't expecting.

So initial tune:

Stock RB20,

OP6 hypergear highflow

3 inch turbo back with catco cat

china 500X300X75 cooler, with return flow piping (turned 180 degrees with a 75mm radius off drivers side of cooler)

Stock coil packs

Stock actuator, preloaded 5mm.

Z32

Sard 800cc

Nistune.

GTR/z32 fuel pump with feed from battery

Profec b boost controller

Made 240rwkw, full boost (20psi) at 4900, tapering off to 17-18 at 7000rpm.

So things I changed/added

Punched cat.

Apexi front mount kit, 2.5 inch piping, core looks is smaller, bar and plate I believe?

New cooler

v's old

Splitfire coil packs (standard ones started breaking down)

New fuel pump, walbro 255 (old one got noisy)

14.7psi actuator.

Now I had changed the actuator and cat to try and hold boost better up top, which it has done, but response and overall power is down.

Topped out at 230rwkw, and coming on boost around 500rpm later. holding 21ish psi to the redline (graph is in car, I'll try and post it tomorrow). It is holding boost right to the limiter now.

It feels a bit lazier onto boost, but feels better revving right out, (doesn't nose over like before)

With better boost control (and higher boost!) and better spark, less restrictive exhaust, less restrictive cooler piping/cooler (maybe?? haha) I was aiming for a increase, or at least match what I made before.

*I understand the dyno is just a tool, and not back to back testing one thing at a time can be inconclusive, let alone 2 tunes almost 2 years apart, but seat of pants dyno backs up dyno sheet, less response, less power.

Compression test came up between 149-153 across all 6, tuner said mechanically car is good.

Thoughts?

Is my cooler too small? restrictive? Wouldn't have thought it would be a restriction up too 250rwkw

[Hadouken]

Different tyres/wheels?

[KiwiRS4T]

Why did you put a smaller cooler on?

Most of your changes would not lead to better performance - coil packs simply restoring the status quo, if you had enough fuel before a better supply will not help,

Major improvement would be holding boost up but this is countered by smaller FMIC so result is not surprising.

[Dose Pipe Sutututu]

Probably IAT have increased, resulting in less power being made.

[CEF33Y]

Yeah I've changed wheels, now run a 235 40 18 from a 235 45 17.

I didn't choose the cooler because it was smaller, but did not expect it to affect it as much.

In the hyper gear thread everyone is anti return flow cooler, thought I'd see some gains, even with a slightly smaller ( but "better quality")cooler.

And tbh it was a kinda impulse buy, as it's a cefiro specific kit, which is rare as, had all the brackets and such.

oh well if I can be stuffed I'll put the old core back on, go for a touch up tune. Or start researching decent coolers. The pwr one in the hypergear looks good, but dang, bit pricey

[Cowboy1600]

With the wheel change it's likely you've kinda gone nowhere.

[KiwiRS4T]

Tyre and wheel sizes make no difference to your power output. Unless you have money to burn just stick your old FMIC on.

If you want a significant power increase save up for a better turbo. At that point you may or may not need a better fmic.

All return flows are not created equal. Some are a lot better than others. Yours might be fine.

[thompo70]

Your worried about a 4% drop in power.

There are way too many variables at play to make up that number.

Your seat of pants feeling is most probably due to you being well used to the car.

Also the dyno may be ever so slightly different to before.

Your compression may be a tad lower than before.

My personal opinion is just make do with what you have. Drive it and have fun.

At least you have an RB20 still running sweet. How many threads have littered this forum with people f**king their engines in many different ways.

My 2c take it or leave it.

Cheers.

[jet_r31]

Your return flow setup you had is nothing like what people are talking about in the hypergear thread

cheers

darren

[CEF33Y]

Yeah, fair calls.

Prob more me putting a number in my head before hand

And just measured coolers, old is 450x300x75, new is 500x230x65, with 25% less 'rows'

Thanks for the replies!

[Trex]

Your return flow setup you had is nothing like what people are talking about in the hypergear thread

cheers

darren

it is though. stao and a few others mentioned the 180deg bend would be a restriction.

I personally have never used any type of return flow. Plenty of people have made big power on them though. So i don't know.

[GTofuS-T]

I'm with Darren, the return flow ones mentioned in the Hypergear thread has the return built into the end tank and is tight, the radius on the one picture isn't so bad, so while it has return flow piping, it's not a return flow cooler (if that makes sense?).

So in saying that to get rid of the "return flow" aspect you could have just replaced the piping, hard to say if the new piping will marry up nicely to the old cooler but it might not be far off?

[jet_r31]

it is though. stao and a few others mentioned the 180deg bend would be a restriction.

I personally have never used any type of return flow. Plenty of people have made big power on them though. So i don't know.

Its nothing like that stupid bend in the end tank in a "conventional" return flow cooler, your tripping..lol

they can mention whatever they want.....but without testing it means nothing.

cheers

darren

Edited February 2, 2016 by jet_r31

[GTSBoy]

I'm with all of the monkeys above. That 180° bend might be a restriction compared to a couple of larger radius 90° bends......but it is all good compared to the return flows that actually would be problem. I also concur with the assessment that the old cooler was probably less restrictive.