Long distance race . . .

In September I'm doing the road race at the Silver State Classic. The speed I can go at is about 120 and I have a 331 engine with a 9" (soon) with 4.10 gears. The tranny is a T5. I have G-force gears except in the 5th gear. I was told that it's probably not good to race in 5th gear even though I will be mostly going at same speed with not a whole lot of turns. Do you guys think I should stay with 4th gear or upgrade the 5th gear and race in 5th?

 

What the rpm going to be in 4th, or 5th, with 4.10 gears @120 mph?

 

4th gear it would be 6238
5th gear would be 4679 (0.75 5th gear)

 

right now mo you will be spinning 6300 rpm in 4th at 120mph. we will swap gears to some 2.73s for that event. that will put you at 4200 at 120mph. it might be worth it for us to put the 5th gear set that will have the lowest amount of rpm drop from 4th.

 

Do you think your motor will hold together at 6200 rpm, for an extended period of time? I hope you don't have stock connecting rod bolts.

 

I was posting while you were posting this, that sounds safer..

 

connecting rod is from probe, it's aftermarket, whether it's stronger than aftermarket, I don't know but I hope so.

 

the one I have now I think is 0.68 5th gear if I'm not mistaken. And the 5th we have is 0.75. They make 0.90 as well from G-force.

 

Man I have always wanted to do that, will you have a co-pilot? So what are the rules, you have to run as close to your 120mph speed as possible for the 90 miles without going over? I am sure you will but keep us posted on the thrill factor and how you do.

 

I haven't found a navigator but should be ok without one. It's 90 miles and for my class it's a certain speed I need to average.

 

You better install a good oil cooler and consider a pump and gear oil cooler (for the diff) as well. 90 miles at a buck twenty will put some abusive heat into the components. As for the OD. You wont be useing it much on a road course with 20 or 30 other cars trying to lap you...Good luck!!! Sounds like a blast!!!

 

See the way they have it set up, it's one car going down the track every 10 minutes or something. So you really racing their time but not them. Is 5th just weaker or does it create too much heat?

 

i would go with the .90 ratio. but using 5th consumes power. having the trans in 4th is the most efficient. the trans it self is not consuming power. its not heating up because none of the power is going through any of the gears. 5th will generate the most heat of any of the gear ratios. as for the rear end i trust the oil we use to stand up to heat. 2.73s wont be generating allot of heat when compared to what 4.10s would.

 

I'm shure the Mav will try to fly at 120. Gotta think about keeping the air out from under the front end. Also gotta have a good cage, just in case.

 

cage is in, hopefully with the new suspension and getting the car lower I should be able to be safer on that road.

I just got an email back from G-force. They say it's ok to run the car in 5th gear as long as temp stays under 240, she suggested getting a tranny temp gauge and if it hits 240 shift to 4th. I probably will install the 2.79 gears like Bry said and then drive it in 5th for a while and see what temps I get.