My GTR on dyno today

[GTR032]

Re dyno'd my GTR yesterday, totally different power curve

Made top power about 6000rpm

166kw's in 4WD & 185kw's in RWD

Graph coming....

check last post

Hey people,

Had my R32 GTR on a Rwd dyno today, it made 176kw's. Not sure about the rpm level, but it made peak power at 101km/h. The only mods so far are a K & N panel filter and a TRUST 80mm cat back exhaust system. Apparently the boost restrictor has been taken off?? bcos it was running a solid 12-13 psi. Is this about right? Anyone roughly know what kinda power increase's a full exhaust system will make.. Any suggestions on next mods.

cheers

Jono

GTR 032

[Duncan]

Can't help with the increase, but 100km is about 5000rpm in 3rd, seems pretty low for a peak figure for me. (unless they ran it in 2nd! about 7000rpm.) Was everything working OK?

[GTR032]

Well yeh as far as I know everything was working ok. The power curve is pretty lineal, so there's no real bumps in it anywhere. Pretty sure it was in 4th, but don't know.

[Merli]

http://www.fortheboyz.com/cars/merli/images/mydyno.jpg

100km/h is about 3500rpm in 4th gear... Are you sure? Post your dyno sheet

[Duncan]

yeah, thats why i was wondering, 4th is the correct gear (closest to 1:1 ratio) for getting correct torque readings, but you might hit 180 speed cut before redline.

[GTR032]

sheet..

[GTR032]

Also, on the first power run I had, the wheels broke traction pretty badly! Took about 6 months worth of rubber off my tyres.

[Duncan]

Yeah, thats third, 150 is 7000ish. Very strange power curve you have there.

No idea why it drops off though, any ideas from the dyno gurus?

[Merli]

I think you're mixing up the torque and power lines Dundan.

Power is the red one, and rises gradually to ~175kw and stays there until redline.

Torque is all over the place. Weirdest torque curve I've ever seen. What's with the dip at the start?!?

In fact the flat power curve is very very weird too...

That's one weird-ass dyno reading right there. Stick with Dyno Dynamics

/me writes down "MDXDYNO... Never use".

[GTR032]

The dyno guys didn't really say too much about it, get what you pay for I guess... Gonna try a little more reputable dyno next time. The power curve on my GSR was very straight forward to read compared to this one, except that it had bags less power..well not that much

Cheers

[Guest RedLineGTR]

run your gtr on a 4wd dyno then you will see how much power you really have

[skyr33]

One weird looking dyno graph!In fact,the power curve looks a lot like the torque curve.I mean, when was last time anyone ever saw power curve dead-flat?Definetly looks like torque.And torque looks very much like the power curve.Except it peaks too early and drops-off too quick to be the power curve.Strange.Could be that the dyno parameters/software were not set-up correctly before the run or something.One weird looking dyno graph.

[GTS-t VSPEC]

Yeah, that is one weird curve, have it redone elsewhere. Some of the WA guys are pushing 320rwhp at the rear wheels with there R32 GTR's, with stock turbo's. That have done full exhaust, and run 1bar.

[Merli]

Here's a higher res copy of the dyno sheet guys:

[Merli]

The more I look at that dynosheet, the more I say:

"What the...."

[GTS-t VSPEC]

For my money I'd expect any decent operator to explain the curve and what there opinion is on the features of the curve. I'd go back and ask for an explanation, because it make's no sense.

[Ronin 09]

that is seriously confused. Sure that wasn't made with a spirograph? ...sorry. But it is a weird graph. Use search, and look for 'dyno' - there are may of the guy's dyno sheets on here and you'll probably be able to find a 32 GTR dyno sheet somewhere to compare it to

[BHDave]

Is that the wheel spinning run? That may explain the apparent power loss. Also that torque figure looks a little unrealistic. 32/33 gtr pull 350-360 Nm at around 4500 rpm stock.

Just remember that power = torque x revs. So as torque drops and revs rise power stays flat.

My guess is wheel spin (and the values are too high). What you've got there is wheels breaking traction at 100kms as the torque ramps up and the correction values on the dyno giving a very high reading.

Cheers

(Professor) BHDave

[Sydneykid]

I'm with Dave, that's the sort of result we get when there is wheelspin. The resistance at the rollers gets to a certain point and then the tyres slip on the rollers. So it always shows the same max power as the wheelspin increases and holds the readings constant. It can be bad enough to affect the power readings, but not bad enough to smoke the joint out.

The torque readings are being affected by being in 3rd gear, that may be the reason why they are higher than usual (in 4th).

I'd suggest another run but in 4th gear and tied down better to the dyno.

Hope that helps

[Guest RedLineGTR]

nearly 850nm torque..??