Before and After Dyno

[XfireZ51]

Dyno results from beginning of tuning to last session.



~+20rwhp/+10rwtq

Changes include:

SW Xpipe
DynoMax Ultraflow w Z06 flappers
Re-ported IH's

I think if I went back again I would lean out fuel just a bit morew some more timing at lower rpms. However, one thing that is disappointing is that it seems from the graph that the dyno operator was lifting at about 6800rpm rather than going thru 7K. Looking at the slope of the curve (blue), it looks like the trajectory may have gone a bit higher. Note how the before ad after lines are increasingly diverging.

[FU]

20 + 10 that's nice work 1

[scottfab]

good AB test with actual data.
Data always beats "feel" for accuracy.

[Tony Davila]

Originally Posted by XfireZ51

Dyno results from beginning of tuning to last session.

I think if I went back again I would lean out fuel just a bit more, some more timing at lower rpms. However, one thing that is disappointing is that it seems from the graph that the dyno operator was lifting at about 6800rpm rather than going thru 7K. Looking at the slope of the curve (blue), it looks like the trajectory may have gone a bit higher. Note how the before ad after lines are increasingly diverging.

Most of the Tachs are off by 1000 RPM up high. My tach is off by 1000 past 7000 and 200 off at idle.

[rhipsher]

Still Dom at 434rwhp I wouldn't be complaining at all. And I take it that's without head work.

[RHanselman]

Very nice! now it's time for some boost!

[-=Jeff=-]

Originally Posted by rhipsher

Still Dom at 434rwhp I wouldn't be complaining at all. And I take it that's without head work.

no, he has a set of GVD Ported heads on it

[XfireZ51]

Originally Posted by Tony Davila

Most of the Tachs are off by 1000 RPM up high. My tach is off by 1000 past 7000 and 200 off at idle.

Tony,

This was the rpm output from the dyno connected to ignition. You can see it with the lifting at about 6800rpm.

rhipsher,
Just to clarify, the motor has Pete's regrind for the intake cams, GVD ported heads and DIY top end porting. A few months ago I listed measurements I made on the GVD porting. In comparison to what Pete and Marc do for porting, I would characterize it as "conservative"(not in the political sense ). Starts out at 36.5mm on deck and then necks down to 34 or so at the bowl.
I think all of the examples we've seen in the last year or so suggests to me that an aggressive head porting (36mm+) is probably the best bang for the HP buck.
It's my opinion that my current heads don't take full advantage of the cams. Having said all that, the 434rwhp feels pretty damn good.
BTW due to time constraints, these hp #'s were done with coolant temps at
193F.

[rhipsher]

Originally Posted by XfireZ51

Tony,

This was the rpm output from the dyno connected to ignition. You can see it with the lifting at about 6800rpm.

rhipsher,
Just to clarify, the motor has Pete's regrind for the intake cams, GVD ported heads and DIY top end porting. A few months ago I listed measurements I made on the GVD porting. In comparison to what Pete and Marc do for porting, I would characterize it as "conservative"(not in the political sense ). Starts out at 36.5mm on deck and then necks down to 34 or so at the bowl.
I think all of the examples we've seen in the last year or so suggests to me that an aggressive head porting (36mm+) is probably the best bang for the HP buck.
It's my opinion that my current heads don't take full advantage of the cams. Having said all that, the 434rwhp feels pretty damn good.
BTW due to time constraints, these hp #'s were done with coolant temps at
193F.

I gotcha! I'll bet the hp does feel pretty good. You outta be running in the high 11's to very low 12's if at all in the 12's.

[XfireZ51]

Originally Posted by rhipsher

I gotcha! I'll bet the hp does feel pretty good. You outta be running in the high 11's to very low 12's if at all in the 12's.

Gotta get the power to the ground. Need DRs altho I will say the Nitto Invos on the car are a sticky street tire.