Track Times: My Best Ever - ZR-1 Net Registry Forums

Locobob · 11-30-2008

My math shows 129mph at 7500rpms with 3.45's and 25.7in tires - I'd say thats just about perfect for the quarter mile assuming your powerband looks a lot like mine. If you're gonna try gears I'd go with at least 4.10's otherwise you'll end the quarter part way through 4th and the extra gearing may not compensate for the time it takes for the extra shift. Your results are making me seriously think about doing a cam swap - stop it already

Jagdpanzer · 11-30-2008

Pete,
Can you tell us some more about the new cams you're now running?

Pete · 11-30-2008

Quote:

Originally Posted by Locobob

My math shows 129mph at 7500rpms with 3.45's and 25.7in tires - I'd say thats just about perfect for the quarter mile assuming your powerband looks a lot like mine. If you're gonna try gears I'd go with at least 4.10's otherwise you'll end the quarter part way through 4th and the extra gearing may not compensate for the time it takes for the extra shift. Your results are making me seriously think about doing a cam swap - stop it already

I was running 26.2" tall tire.
Bob,yes your right 4.10 is perfect for 1/4.

My peak comes in just shy of 6800 474rwhp, 5200 400rwtq

The cams are worth 20 RWHP.

Cam specs
.236 .425 In
.220 .425 Ex
Some cam sound at idle,drives like a stocker,throttle response furgataboutit.

Pete

jonszr1 · 12-01-2008

pete, talked with my suspension guy he seems to think that you can use 4.10 gear if you go to a 27in tall tire if you stay with the tire you have now your wheel speed ie tq multiplication will blow the tires off ruining your 60fts . i shared your dyno results with him . he also thinks that you might find that shifting at 7200 would help. the reason he thought3.92 would work is the fact that you are using the 315-335x35x 17 tire. he was worring about your wheel speed off the line . just food for thought

11-30-2008	#1
Locobob Join Date: Jan 2004 Location: Portland, OR Posts: 1,047	Re: Track Times: My Best Ever My math shows 129mph at 7500rpms with 3.45's and 25.7in tires - I'd say thats just about perfect for the quarter mile assuming your powerband looks a lot like mine. If you're gonna try gears I'd go with at least 4.10's otherwise you'll end the quarter part way through 4th and the extra gearing may not compensate for the time it takes for the extra shift. Your results are making me seriously think about doing a cam swap - stop it already __________________ Robert ZR-1 Net Registry Oregon State Director 91 ZR-1 #431 Black/Black LPE 368 Last edited by Locobob; 11-30-2008 at 01:41 PM.

11-30-2008	#2
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,651	Re: Track Times: My Best Ever Pete, Can you tell us some more about the new cams you're now running?

12-01-2008	#4
jonszr1 Join Date: Sep 2006 Location: lone pine and mammoth lakes Posts: 1,406	Re: Track Times: My Best Ever pete, talked with my suspension guy he seems to think that you can use 4.10 gear if you go to a 27in tall tire if you stay with the tire you have now your wheel speed ie tq multiplication will blow the tires off ruining your 60fts . i shared your dyno results with him . he also thinks that you might find that shifting at 7200 would help. the reason he thought3.92 would work is the fact that you are using the 315-335x35x 17 tire. he was worring about your wheel speed off the line . just food for thought