XKR Super G... Going for Mach 1
That dyno looks good and the tune looks well dialed in already but the motor isn't being pushed (as noted, not at redline). It looks like a healthy 4L motor with nice cool air being generated by the turbos, which at 11 psi, is not even at peak efficiency yet. And at 7500 rpm that's easily 550 whp or 600 whp DJ. It's as good as any other setup you'll see at 11 psi, given that that pressure ratio is suboptimal for many turbos.

I am very impressed with the spool though.
Congrats Mike, Sharif.

EDIT: str8dum, where is your overlay between Jayz 20G tune and this one?
Last edited by rcdash; Oct 18, 2009 at 06:42 AM.
Yeah....He had no intension of posting until he had it fully tuned.....he was just doing this to get me off his back
Dont forget that redline is 7500 or 7600 rpms......I am thinking with a proper tune and him running it to redline we will get much more at 11 psi....Sharifs numbers were correct from what I see so far by going with the C8/Gt35r.......Do you think the heads are helping anything at this low level boost?? I was using the 18G comparison also....and what PSI it would take for an 18g to reach 530whp coming out of FP...
Dont forget that redline is 7500 or 7600 rpms......I am thinking with a proper tune and him running it to redline we will get much more at 11 psi....Sharifs numbers were correct from what I see so far by going with the C8/Gt35r.......Do you think the heads are helping anything at this low level boost?? I was using the 18G comparison also....and what PSI it would take for an 18g to reach 530whp coming out of FP...
Yes. I beleive those heads were designed for an N/A motor, so you should be seeing benefit from them in the upper rpm range, regardless of the boost level. You may lose a little bit of mid rpm torque, but if Cosworth did their homework, the gains up top should more than offset any losses in the middle.
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Short and sweet, sounds good to me!

That dyno looks good and the tune looks well dialed in already but the motor isn't being pushed (as noted, not at redline). It looks like a healthy 4L motor with nice cool air being generated by the turbos, which at 11 psi, is not even at peak efficiency yet. And at 7500 rpm that's easily 550 whp or 600 whp DJ. It's as good as any other setup you'll see at 11 psi, given that that pressure ratio is suboptimal for many turbos.
I am very impressed with the spool though.
(unfortunately!)
Congrats Mike, Sharif.
EDIT: str8dum, where is your overlay between Jayz 20G tune and this one?
That dyno looks good and the tune looks well dialed in already but the motor isn't being pushed (as noted, not at redline). It looks like a healthy 4L motor with nice cool air being generated by the turbos, which at 11 psi, is not even at peak efficiency yet. And at 7500 rpm that's easily 550 whp or 600 whp DJ. It's as good as any other setup you'll see at 11 psi, given that that pressure ratio is suboptimal for many turbos.

I am very impressed with the spool though.
Congrats Mike, Sharif.

EDIT: str8dum, where is your overlay between Jayz 20G tune and this one?
The tune is far from being finished....This was a get XKR off my back run


Yes. I beleive those heads were designed for an N/A motor, so you should be seeing benefit from them in the upper rpm range, regardless of the boost level. You may lose a little bit of mid rpm torque, but if Cosworth did their homework, the gains up top should more than offset any losses in the middle.
Last edited by XKR; Oct 18, 2009 at 09:24 AM.
So here is Mike's rough in tune vs Jay's 20g at 15psi. You can tell Mike's tune is really rough as there are like 3 flat spots in the trq where it could be alot more linear.

This is XKR's same dyno vs Cass's APS kit with 3071's on pump. Cant remember the psi, btu I think like 17-19 though.

1 more thing to note. The purple intersection is the where XKR's turbos are fully spooled so as he increases the boost, area under that wont change much. Its pretty beefy compared to the smaller turbos.
Everyone says smaller turbos are faster down low. Well, I think most people just repeat what they hear....

This is XKR's same dyno vs Cass's APS kit with 3071's on pump. Cant remember the psi, btu I think like 17-19 though.

1 more thing to note. The purple intersection is the where XKR's turbos are fully spooled so as he increases the boost, area under that wont change much. Its pretty beefy compared to the smaller turbos.
Everyone says smaller turbos are faster down low. Well, I think most people just repeat what they hear....
Last edited by str8dum1; Oct 18, 2009 at 12:57 PM.
Nice comparison. Keep in mind Mikes' motor is 4.0L vs 3.5L for the others. Nonetheless, I'm still amazed by Mike's low end torque.
My new 4.0L motor is very similar to Mikes, even the same cams. I have the GT3071/0.64 A/R turbos. We'll compare them once mine is up and running.
My new 4.0L motor is very similar to Mikes, even the same cams. I have the GT3071/0.64 A/R turbos. We'll compare them once mine is up and running.
Last edited by ttg35fort; Oct 18, 2009 at 01:44 PM.
3 Different kits. 3 Different turbos. Different displacement engines. 3 Different builds, i.e. combination of parts. Not apples. For any situation such as this, imagine the most extreme ends of the spectrum, and watch the behavior patterns of the parts. If your conclusion was correct, why would we need ANY small turbos...
For large turbos, XKR's spool is sick. Keep in mind, my tune is far from complete, although I don't expect the area under 4K to change much. Mike's car is in a whole other league now, but I should be able to give Raj all he can handle
Hey, what's with the pick on Raj posts?
Besides I've got all winter to figure something out...
Last edited by rcdash; Oct 19, 2009 at 05:25 PM.
that graph is still 1000 rpms or more from redline, so we dont know what its goin to look like at redline
we havent seen a straight 3.5 vs 4.0l comparison either. we just know based on the 1st curve, he'll walk a 3.5 with much smaller turbos from a dig.
doesnt anyone have like a JWT 530bb dyno. that would a nice curve comparison bc thats the smallest turbos people have and they should be fully spooled on a 3.5L way low, and have more area under teh curve.
we havent seen a straight 3.5 vs 4.0l comparison either. we just know based on the 1st curve, he'll walk a 3.5 with much smaller turbos from a dig.
doesnt anyone have like a JWT 530bb dyno. that would a nice curve comparison bc thats the smallest turbos people have and they should be fully spooled on a 3.5L way low, and have more area under teh curve.
The smaller turbos spool by around 3500 at low boost, right? 500 rpms is no big deal to me, especially considering I can't remember ever driving my car at 3500rpms :P
Last edited by Motormouth; Oct 19, 2009 at 06:42 PM.





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