My 34's First Dyno

[Abo Bob]

Nope.

I've never seen someone "average" runs and print that out.

Not saying its not possible... But your run is all over the place which is basically a poor tune

I have. Doesn't mean that this is relevant here though. Sorry to have introduced a possble furphy to the thread.

[R31Nismoid]

haha SIF steal my word you cheapskate!

[Abo Bob]

I'm older than you.

[satanic]

You're older than most of us Adam

[G_Force]

Mate; my friend's R34GTT in AUTO with nothing but a Std ECU ran 194rwkw and the curve was A LOT smoother than yours

Glad that my immediate reaction from seeing your graph is shared by a few others.

You have a PFC; your graph should be smooth as all hell!

Hmmm... so should i perhaps bring it back to the tuner and tell him to smooth the curve our & drop the boost a lil... how do they smooth it out just out of curiosity? Also why do u guys think that the boost is dropping off towards the top end, could this be turbo inefficiency?

Bass Junky, i didnt think that the lower 2nd graph could be a reading of torque coz if i converted the figures in LbFt to Nm i'd have a peak torque of 1550Nm. Altho that would be nice if it were only true.....

Thanks for all ur comments/advice btw...

[Bass Junky]

G-Force.

Normally on a dyno graph you are interested in four things.

Power either kW or hP at the wheels

Torque either ft/lbs or nm at the wheels

Boost in either PSI or Bar

AFR only in Air : Fuel

don't worry too much about the numbers of the torque as you have to remember that you are going through a gearbox and rear diff which changes the ratio and stuff of the torque.

It's only a measure, not really an exact number, and at the end of the day, Power is simply a measure of Torque over time.

Bass Out

[G_Force]

G-Force.

Normally on a dyno graph you are interested in four things.

Power either kW or hP at the wheels

Torque either ft/lbs or nm at the wheels

Boost in either PSI or Bar

AFR only in Air : Fuel

don't worry too much about the numbers of the torque as you have to remember that you are going through a gearbox and rear diff which changes the ratio and stuff of the torque.

It's only a measure, not really an exact number, and at the end of the day, Power is simply a measure of Torque over time.

Bass Out

Dont they normally do the dyno run in 4th gear which is close to a 1:1 ratio? Correct me if im wrong, im no dyno expert. Im just interested in wot that 2nd graph was reading thats all.

Back to the more important question. Should i perhaps bring it back to the tuner and tell him to smooth the curve our & drop the boost a lil... how do they smooth it out just out of curiosity? Also why do u guys think that the boost is dropping off towards the top end, could this be turbo inefficiency at 14psi?

Cheers

[Bass Junky]

Remember your diff is about 4.11:1 hence, massively inflated torque.

Drop boost a little. I made 200rwkw on 11 psi and you've seen my graph, it's nice.

the boost is dropping off because your turbo aint got no more to give.

[G_Force]

Remember your diff is about 4.11:1 hence, massively inflated torque.

Drop boost a little. I made 200rwkw on 11 psi and you've seen my graph, it's nice.

the boost is dropping off because your turbo aint got no more to give.

Aha.

Wot mods r u running in urs Bass? Ive been looking thru numerous other dyno graphs on the forum, it does look like mine's rough as hell in comparison.

If i brought the boost back to round 12psi would i still be able to achieve close to the same power figure? I'll give my tuner a ring today and see wot he's got to say. Wot should i say to him to smooth out the power curve? Is it a matter of correcting MAP figures?

[Bass Junky]

When I was making 200 I had FMIC, Dump pipe back exhaust (not turbo back) Power FC, PFC Boost kit, and that's about it.

The roughness of the tune will be a combination of AFR and Timing.

That's basically what a tune is. How much fuel, and how much timing at different load points. Load points are supplied by the MAF sensor.

The AFR is rough as guts and I reckon the ignition timing is going to be all over the place.

Here's what I'd do.

Go into your PFC hand controller and write down the ignition timing and fuel map.

So get an Excel spreadsheet and put 1 thru 20 on the top and 1 thru 20 down the side.

Going in the ingition timing map and write it down number for number.

Same with Fuel.

Then punch those numbers into the spreadsheet and graph it 3D.

the progressions and gaps between numbers should be smooth and clean.

Not big jumps up and then down.

Try it out.

You'll learn a lot about tune maps.

[Bass Junky]

Oh yeah, and the turbo doesn't make any more power at 14 psi than it does at 12 psi as its out of it's efficiency up top.

You'll make a little bit more in the mid range, but you'll overspeed the turbo and it's a recipe for busting it.

[Haines]

Mine did 187Rwkws and it had some small spikes in the AFR's which made the power curve dip but ,other then that it was smooth

I was told to find out why it was spiking by a few ppl but never have