Dyno Results - Stage 2a + GT28R

[wilko33]

BBBIIIGGG smiles!!! 338 bhp @ 7k and 304 lbft @ 5k (1.32 Bar Peak)

GT28R with HKS adj act set to 18psi peak
HDev mani
3 inch exhaust front to back (with decat)
Nismo 555s
Walbro 255lph
Apex FMIC Type 1
Apexi Induction
HDev Stage 2a Map






I havent got the booost graph yet (forgot it ) but as expected it spooled really quick and was up above 1 bar boost by 3k if I remember correctly. The blip in the AFR was put down to the plugs needing re-gapping, a quick run after they were gapped and that curve seemed to level itself out.

Can anyone help me out with an explanation to the blip at 6k??

[Hugh Janus]

that some big power from the 28r you have there

[Teggers]

Looks good! Gives me plans for 555's and a chip for mine. I have the rest Dammit! I'm supposed to be saving money!

[wilko33]

Its well well worth it, the torque difference between stage 1a and 2a is brilliant. Never had my old car dyno'd so dont know what that was making but this is back to worrying me.... a bit!!!

[DJBB]

Are you still running the standard afm?

[wilko33]

Are you still running the standard afm?

Yeh, all as directed by HDevs spec other than a 28R instead of the the standard turbo

[M.D.]

Isnt the gt28r the same as a t28 but with a bearing core?

[joey200sx]

Think the second run isn't correct.
Seems like s fair jump compared to first run.
8 whp makes extra 38hp?

[wilko33]

Not going to disagree plainly on the basis I have had exactly the same thought. But i dont know how whp is corrected to ehp so I cant comment, the first run was stopped at just over 6k, second one went all the way over 7k if that makes a difference.

Thre 6k hole remains.... any direction from anyone for a cause?

[joey200sx]

The only reason I say it as I have had my car on the rollers more than most.
The blip could be to do with the std afm only being good for 300bhp as u just went over it.

[wilko33]

I have spent the last few hours on here trying to find threads on maxing the standard afm and what people say about it. On opinion over 300-310 the afr reading should go dangerous. Mine went up to 11.7 i guess at max power. i know there are some people who say 350 is possible but Im not chasing numbers. i want a safe engine. (my last one blew up... its been costly!)

[HermaN]

Always take flywheel figures with a pinch of salt on a chassis dyno. If you want to know true flywheel HP, stick it on an engine dyno. A chassis dyno is only accurate for power at the wheels.

For example on your first run the drivetrain loss was 11.7% and on your second run it was 19.3%, however if you use a drivetrain loss of around 16% your flywheel HP would be 325 on your 2nd run. Like I said, take it all with a pinch of salt. Any ideas why they cut the run short the first time?

Fueling could be leaned out lower down for better response, and torque seems to peak then tail off opposed to holding. Good results, but always room for improvement.

Oh, and the stock MAF is only good for 290-ish BHP.

[wilko33]

the 1st run was enough for me as far as numbers were concerned. but if the engine hp is a correction of the flywheel 325 run would be more realistic?

the first run cut when the power started to drop, I had meantioned my concerns with hitting the rev limiter on an SR, this was later overcome by peer pressure on another run when it made 333 bhp after the plugs were gapped iirc.

If i needed to lean out fuel would this be a fuel pressure reg or boost control solution?.

[wilko33]

Fueling could be leaned out lower down for better response, and torque seems to peak then tail off opposed to holding.

im running no boost control other then an HKS adj actuator. so power tailing off was expected. although having seen the boost read out i dont think thiscould be improved.

[HermaN]

If i needed to lean out fuel would this be a fuel pressure reg or boost control solution?.

It would be a mapping solution. However I can't comment on boost without seeing a graph.

[silvia_200sx]

Quite optimistic for t28r, 555s and stock afm.

[wilko33]

So, say the blip is the afm maxing out, does that mean everything above 6k should be unsafe? If it is an optomistic figure would an engine continue to make good power after the afm maxes out? I can see the torque completely drops off as expected while the bhp continues to rise?

[clive]

its not gonna last. thats for sure

my stock AFM was read 4.9V @ 298bhp @ flywheel lol

but, I would be taking your figures with a massive pinch of salt.

oh and tubby will shit itself soon. keep it @ 1.1-1.2bar and be happy... if you want more consider a Z32 AFM and a custom map.

edit, fueling does look well, even the blip to 12:1 is still safe.

[wilko33]

So the wheel horsepower are correct but the corrected horsepower should be taken as optomistic? As I said before I'm no dyno expert and I wasn't number chasing, just a healthy engine is the good news.

1.3 bar is as per HDevs recommendation, why is this too high?

[Shirunai]

LOL my engine mapper whould laugh his ass out, he thinks 10% loss on similarpower is more realistic, always go for BHP why care how much you have in the car,
you english guys make me laugh the car I bought in uk made 267whp and the corrected flywheelpower was 360hp@fly

I have now mapped my car on a dynpack and made 323whp instead of 267whp.....always go for whp

you have like 300flywheel estimated but that doesnt matter, just say your whp