dyno numbers

[DrifterProdigy85]

12.5-12.8 is pretty damn lean for a boosted car. I always ran my SR @ 11.4-11.6. NA cars are usually tuned for 12.8-13.0.

[Bwana]

It's a stock ecu map, not a "tune" so I'm not surprised a bit.

[al_v]

Can anyone explain the bump in tq from 4500-5000 rpm?

This is produced by the VCT system.

12.5-12.8 at 10psi... looks fine to me.

low 11s is the correct AFR in all turbo engines....with 12.5-12.8 ,you will blow your engine....

[Shocker]

low 11s is the correct AFR in all turbo engines....with 12.5-12.8 ,you will blow your engine....

not nessasarly.... What you are saying is dependent upon timing and also the octane of fuel being ran. Your tuner should know best, idealy its as much timing as a lean as possible w/o any signs of knock for maximum power.... That is if your trying to pump out all the power possible from a setup.

Conservative timing along with slightly rich a/fs is the safe route.

now for matafields graph something is wrong. My a/fs were 12 flats with basicaly the same setup at the same boost pressure. Seems like his FPR might not be set properly.... Scary spike after 6.5k to 14 to 1 o.O....... Surprised the stock ECU didnt start pulling timing.

[Racinjitter]

There is a lot of pics of my car out there. I took it for its inagural long trip run today to the other side of the state with another rb powered car (280Z) and we had a blast.

[Bwana]

low 11s is the correct AFR in all turbo engines....with 12.5-12.8 ,you will blow your engine....

Better tell Nissan, cause that system they made is going to kill that engine they made...



While low 11's may be the ideal afr for performance, (I agree, I tune even mildly upgraded engines to run in that range) it is not an ideal balance for a production vehicle. At 10 psi, 216whp and 12.5 afr it'll run a long, long time. He is running a basically stock setup, which would explain the basically stock numbers.

Side story: I ran a ka24e-t one time up into the 15's (afr) on the track (Miller Motorsports Park, Salt Lake City) for 8 laps until it blew a radiator hose and had to stop(this was intentional, I was trying to kill it ). On tearing down the engine I found 0 sign of detonation (no management, only a 8:1 FMU and 3 deg initial retard) and the stock head gasket was in excellent shape. That engine had 250k on it...

Good times...

[HPF Chrisk]

While low 11's may be the ideal afr for performance, (I agree, I tune even mildly upgraded engines to run in that range) it is not an ideal balance for a production vehicle. At 10 psi, 216whp and 12.5 afr it'll run a long, long time. He is running a basically stock setup, which would explain the basically stock numbers.

i ran 216whp at only 5.5 psi not 10. if i put down 216 at 10psi then i would no something is for sure wrong, but i thnk the motor is just fine.

[eh?]

Better tell Nissan, cause that system they made is going to kill that engine they made...



While low 11's may be the ideal afr for performance, (I agree, I tune even mildly upgraded engines to run in that range) it is not an ideal balance for a production vehicle. At 10 psi, 216whp and 12.5 afr it'll run a long, long time. He is running a basically stock setup, which would explain the basically stock numbers.

Good times...

What are you looking at?matafied has 275whp with only 10psi and a FMIC. That is 20-25 rwhp higher than a stock RB25 would dyno at with 10psi. He's running leaner- almost 13:1- than a stock RB25 normally does and his power does reflect that. egt's are important with RB25 weak ring lands and AFR's don't directly correlate with egt's. Cast piston and Forged pistons are not the same- if you think you can run the same AFR's and egt's with both go ahead, i wouldn't.

[Bwana]

Arghh... Sorry guys, was mixing info from two different dyno sheets there...

Mah bad.

Really tired + a couple beers = fail.

[DrifterProdigy85]

Hmm, my RB25 seems to run a solid 11.0 AFR. Fuel pressure is stock 43.5psi. I still have to check for boost leaks though, doesnt seem like theres any.

[matafied]

yea you cant trust the afr reading, it took a good 5 pulls before it started even reading, so yea those are not correct! i think o and before that pull i did run it as close to stock as possible 7psi only exceptinon is the ghetto front mount, and im not even gonna tell you what the piping is

[DrifterProdigy85]

Cool, faulty wideband explains the lean readout. Im gonna try to guess the piping is PVC? I ran PVC for a little while on my SR before 18psi became too much and started cracking pipes. Its always funny to have someone tell you how well the car runs and then you tell them you have PVC IC piping. There like WTF!?!

[silent dave]

there has to be a boost leak or something else wrong with your car because i did 244 whp on a dynojet off just the waste gate w/ the stock sidemount. 2 years later i did 256 whp w/ stock sidemount @ 10 psi on a mustang w/ fouled plugs. fix your boost leaks and redyno. GL

[wawazat8402]

[IMG][/IMG]

stock with just frontmount and mbc 10psi

If this was a 3rd gear pull, the numbers wont directly compare to most other dyno numbers. 4th gear is 1:1 and is where the car should be dyno'd until traction becomes an issue.

[DrifterProdigy85]

Numbers are numbers. The engine still makes the same power from one dyno to another and from 3rd to 4th gear.

[wawazat8402]

Not really. As you change the gearing, the engines leverage on the drivetrain is different. The engine makes the same power but the gearing affects what the dyno actually thinks its making. Same effect as throwing a 4.36 FD in a car and it looking like it makes more power. The engine still makes the same power, but a 4th gear pull will read like it makes more power. Ive actually never seen nor heard of a reputable shop doing dyno pulls in anything lower than 4th.

[matafied]

[IMG][/IMG]

this was the next run OMG 2 rwhp j/k guy

[wawazat8402]

Haha, I wasnt trying to be argumentative at all. I just think that the parameters should be as similar as possible when comparing 2 dyno sheets. There are some things that people see as insignificant that can affect the pull.