Lets talk gearing.

[Insaneba]

Very nice, I'm actually talking to a friend of mine at the moment. I have 4.10's, he has 3.90's, both in the box new. We are talking a trade, he wants a 4.10 for a mark viii project. I like the look of the 30's on my car, not sure I want to go much taller. I should have a decision made by the end of the weekend. I'll keep you posed on it. Hey 07Boss, what kind of times are you getting on your set up?

 

[07 Boss]

Very nice, I'm actually talking to a friend of mine at the moment. I have 4.10's, he has 3.90's, both in the box new. We are talking a trade, he wants a 4.10 for a mark viii project. I like the look of the 30's on my car, not sure I want to go much taller. I should have a decision made by the end of the weekend. I'll keep you posed on it. Hey 07Boss, what kind of times are you getting on your set up?

Mid 11's with 1.7xx 60's. Mph is anywhere from 116 to 118. DA here is usually about 3000'-4000'.

 

[Insaneba]

Nice! Thats rolling for a little 281!

 

[46addict]

Mid 11's with 1.7xx 60's. Mph is anywhere from 116 to 118. DA here is usually about 3000'-4000'.

So that translates to 500+whp at sea level with <1000' DA?

 

[ponys197]

I kept the 3.55's in with my Whipple 2.3L HO Kit and pulled 11.32 / 11.43 on 1.58's / 1.60's 60ft at 118.20 / 117.89mph.

 

[07 Boss]

So that translates to 500+whp at sea level with <1000' DA?

485 rwhp. I think last time I converted my time to sea level it was like 11.4 at 120 mph or something close to that. But I think the calculator I used was for NA motors. a Supercharged motor will be less of a difference. I think my last run last year was 11.7 at 117 mph with a density altitude of 3300 ft. She has gone 11.6 a couple of times when I get a good launch.

 

[RED09GT]

I had 4.10's but then had to put the 3.55's back in after my spider gears died a sudden death and chipped one of the pinion teeth on the 4.10's. I liked my car better with the 4.10's even though turbo cars are "supposed" to like numerically lower gears. My trap speeds were 3-4 mph higher with the 4.10's and with more seat time, I have no doubt I would have ran better times with the 4.10's.

I run a 28" drag radial so with the 3.55's, I am just over 5000 rpm crossing the traps rather than at 5800 or so with the 4.10's. I made some boost controller and suspension changes that got me down the track faster but did not gain me any trap speed.

As for wheel spin on street tires, I found that I had more control over it with the 4.10's as the car didn't load as suddenly as it did with the 3.55's. I don't street race so I don't care if I was giving up a bit of performance on the street because as soon as the load is high enough, the tires are breaking loose in 1st or 2nd with either gear set.

 

[Insaneba]

Lots of great information in this thread, which was exactly what I was looking for. Not the best 1/4 gear for lower boost, but a great all around gear. I actually have a set of FMS 4.10's on the shelf, and my buddy has 3.90's, and will trade in a heartbeat. So I'm covered either way. My thought will go into which tire I will run out back, and I will make my gear call from that I guess. Thanks for all the input guys, keep it coming as well. Hopefully this helps others when they use that search button.