Jump to content
SAU Community

Recommended Posts

i just had my car tuned today and i was a little disappointed with its power figure

it has:

Unopened RB26

Power FC

RB20 AFM x2

Garrett 2860-5 x2

100mm front mount

adj cam sprockets (both)

bosch 044

sard 700cc inj

nismo fpr

CES dump pipes + 3' exhaust

Greddy Profec b spec 2

and it made 375rwhp at 16psi (about 280rwkw)

the tuner said the profec control unit shat itself, hence the single boost level, even tho it is brand new? WTF?

shouldn't these turbos put me around 325-375rwkw (433-500rwhp)???

i'm suspecting that the weakest link is the Afm's, but they should be able to handle more power than that

because i suspect that higher boost alone won't get me to my target power.

can someone offer some opinions on the matter?

other wise the only

Link to comment
https://www.sau.com.au/forums/topic/286087-rb26-2860-5-power-figure/
Share on other sites

he mentioned that this power figure was exactly what he was expecting.

was tuned at brisbane tuning and turbo, and he said after the first hundred GTR's he's tuned, it took the guess work out of the cam gears.

the exhaust is quiet, so that could be an insight.

reading thru the RB26 guide, there are a few cars around this power level with the same turbo's, boost, etc, but this level just doesn't sit well with me

cheers!

anyone else have any ideas?

so much was changed on the car at once

it could be anything

check the basics

ask the mechanic

ask another mechanic

check the dyno chart

check basic engine health and setup - base timing, basic sensors, base compression, base boost check etc

Just curious why you're using that Nismo FPR with the sard 700s, the injectors should be able to support 400kw no problem?

As for power loss, very strange, maybe the timing belt just jumped a tooth.. and what position was/is the CAS set to (the CAS thing shouldnt be an issue if the tuner was familiar with skylines)?

Seem's normal for the boost, slap it on another dyno and you might jump up on the figures. Also, what sort of tune has he done. If it's a stock 26 which is 15 years old that might have to be considered. What the other dudes mentioned might provide some better insight. If it drives well and feels better you should be sweet.

Edited by monga

could be a very tired motor?

i got 214 rwkw out of my RB26 with -5's and running 14psi on stock (ECU, Fuel pump and injectors) with only a full exhaust and pods.

then i had the motor rebuild and now am getting 250rwkw @ 13psi with the same bolt on's, just have had forged pistons put in, full race bearings, R33 crank, head has been recond, block bored, honed and hot washed.

so really it just came down to the fact that the car needed a little bit of a freshen up after 20 years

Brezza

Hey dude, I've got a 1993 R32 that i get tuned at John's, been going to him for a bit now and i think he's always been a straight up guy. He has done a lot of RB's, including his own 240Z conversion putting out 530rwhp with some custom turbos that i've also got on mine. I run a very similar setup to you (plus rebuild) but same afm's and pfc, so if you wanted to swap the afm's over to see if that makes a difference let me know. Can also pressure check you're inlet system for leaks (i found a few after upping the boost). i'm in Brissy (coorparoo) 0403 486 876 if you're interested

Andrew

Seems about right for 16psi through stock cams to me. stick some 260 degree cams and 18-20psi through, and add 100 to that number.

Seems about right, i had HKS 2530s and couldnt get any higher boost then 1.2bar (18psi)

Needed cams, bought tomei 260/260 and made a lot more power and no more boosting problems.. However, im not using RB20 afms, using z32s.

Cheers,

Gordon

You can add 100rwkw on stock cams as well and to make 380rwkw no drama's. Not required.

U'd need at least 22psi and a very aggressive tune to get that on stock cams IMO. Much better to have cams matched to the turbos rather than tryin to push the envelope of one and not the other.

well i'm going to powercruise next weekend, so i'll check it out on their dyno (but is usually really hot there)

i'm looking at a open exhaust for the event and i'll try to turn up the boost a little. hopefully that should give me an idea.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • It would be well worth deciding where you want to go and what you care about. Reliability of everything in a 34 drops MASSIVELY above the 300kw mark. Keeping everything going great at beyond that value will cost ten times the $. Clutches become shit, gearboxes (and engines/bottom ends) become consumable, traction becomes crap. The good news is looking legalish/actually being legal is slighly under the 300kw mark. I would make the assumption you want to ditch the stock plenum too and want to go a front facing unit of some description due to the cross flow. Do the bends on a return flow hurt? Not really. A couple of bends do make a difference but not nearly as much in a forced induction situation. Add 1psi of boost to overcome it. Nobody has ever gone and done a track session monitoring IAT then done a different session on a different intercooler and monitored IAT to see the difference here. All of the benefits here are likely in the "My engine is a forged consumable that I drive once a year because it needs a rebuild every year which takes 9 months of the year to complete" territory. It would be well worth deciding where you want to go and what you care about with this car.
    • By "reverse flow", do you mean "return flow"? Being the IC having a return pipe back behind the bumper reo, or similar? If so... I am currently making ~250 rwkW on a Neo at ~17-18 psi. With a return flow. There's nothing to indicate that it is costing me a lot of power at this level, and I would be surprised if I could not push it harder. True, I have not measured pressure drop across it or IAT changes, but the car does not seem upset about it in any way. I won't be bothering to look into it unless it starts giving trouble or doesn't respond to boost increases when I next put it on the dyno. FWIW, it was tuned with the boost controller off, so achieving ~15-16 psi on the wastegate spring alone, and it is noticeably quicker with the boost controller on and yielding a couple of extra pounds. Hence why I think it is doing OK. So, no, I would not arbitrarily say that return flows are restrictive. Yes, they are certainly restrictive if you're aiming for higher power levels. But I also think that the happy place for a street car is <300 rwkW anyway, so I'm not going to be aiming for power levels that would require me to change the inlet pipework. My car looks very stock, even though everything is different. The turbo and inlet pipes all look stock and run in the stock locations, The airbox looks stock (apart from the inlet being opened up). The turbo looks stock, because it's in the stock location, is the stock housings and can't really be seen anyway. It makes enough power to be good to drive, but won't raise eyebrows if I ever f**k up enough for the cops to lift the bonnet.
    • There is a guy who said he can weld me piping without having to cut chassis, maybe I do that ? Or do I just go reverse flow but isn’t reverse flow very limited once again? 
    • I haven’t yet cut the chassis, maybe I switch to a reverse flow. I’ve got the Intercooler mounted as I already had it but not cut yet. Might have to speak to an engineer 
    • Yes that’s another issue, I always have a front mount, plus will be turbo plus intake will big hasstle. I’ve been told if it looks stock they’re fine with it by a couple others who have done it ahahaha.    I know @Kinkstaah said the stock gtt airbox is limiting but I might just have to do that to avoid a defect so it atleast looks legit. Or an enclosed pod so it’s hidden away and feed air from the snorkel and below Intercooler holes like kinstaah mentioned. Hmm what to do 
×
×
  • Create New...