Ordering New Transmission, but What Gears ? - Page 3

Rich Biebel · 03-31-2014, 02:44 PM

40+ years ago on 7" slicks I learned that the steeper first gear Muncie transmission would only run fast when the traction was very, very good.

Even in a small block hydraulic cam rpm limited 3200lb car.

A 2.5 trans with a 4.88 rear gear and a steel flywheel dug holes in the starting line sometimes......

Basically we needed an aluminum flywheel at the minimum to adjust to the track conditions. Going from a 2.5 to a 2.20 first was a huge change and we threw that at the car in desperation at one race. A bog was faster than a spin........by a lot...We were racing on asphalt then and hot summer was way less traction than cooler conditions by a mile....Smoking the tires on the launch was normal....but only a little....

The fastest car in our class ran less gear in the trans and upped the TQ as much as possible with long collectors and other tricks....

Back in the traction limited days of 7" slicks...

Basically I think you have to pick something that is not as aggressive as you might like or think it could use. A happy medium so to speak.....

I don't miss those days one bit.....LOL

Adger Smith · 03-31-2014, 04:16 PM

Rich,
I think we walkd in the same shoes. I cut my teeth racing with a 69 Z-28 as a stocker. I raced it while I was in college. We carried 2.52 and 2.70 gear set trannys with us,as well as a 14 lb alum flywheel and a 34 lb Flywheel
I also had an alum hat with a Schiefer alum plate I had a lot of trouble with the heat shield. Back in the day it was fun, but today it would be hard work.

Rich Biebel · 03-31-2014, 08:14 PM

Yes we did Adger....

My race partner and I became friends with a man that had a '69 Z/28. It was nearly new but was a racecar running F/S at the time. He had fully prepped the car and it had a race engine I drove it a couple times.

I was convinced he should get that 2.20 first gear trans out and I installed a 2.5 first like we ran in our car.

I was used to the hydraulic cammed engine we ran....350/295

His 302 was nothing like the 350 and would spin the tach to the moon if it spun the tires which it did. Leaving at 6500-6800 and with not much traction at our local track.....well forget about it......LOL

I also learned that the 2.5 box would not shift anywhere near as good behind the 302 at the much higher rpm...

Broke some trans parts pretty quickly with it but man that car was great fun to get behind the wheel of....

Black with white panels on the hood and trunk....black and white houndstooth interior and the cold air hood with all the stuff to go with it....except he threw some of it away thinking it was no good for racing....

The car went 12.1's in F/S in 1969 or 1970

Aubrey N Bruneau · 03-31-2014, 08:52 PM

I'm getting closer to settling on this. Thanks for ALL the "combinations".
Yes, it's more inclined to be a "torque engine", but it still does pull nice up at the big end.

ss wannabee · 03-31-2014, 11:07 PM

Aubrey...did you ever try launching it at 5000 rpm?

Aubrey N Bruneau · 04-01-2014, 12:04 AM

I did in Medicine Hat... but traction wasn't dependable. When it did hook, it bogged.
I don't go there any more.

Hoping for Mission in early June, but we're going on a big trip in May, for our daughter's wedding. That may stifle that particular race.

Geerhead55 · 04-01-2014, 01:18 AM

I hope you can pull it off, Aubrey. It would be great to see you and the car again at Mission. Its one of my "must do" trips every year at one of my favorite tracks. Take care.
Danny Durham

Dwight Southerland · 04-01-2014, 11:00 AM

Aubrey, I would not be afraid of the 3.19 first gear. The super light clutch-flywheel assembly will allow you to accelerate the car without wheelspin. I would go with a 2.00 second and 1.40 third with the 3.19. The faster you can accelerate the car in the first half of the track, the lower the ET. Race setups have you in high gear at the eighth mark and it's just the ride from that point on regardless.

Pvt Parts · 04-01-2014, 08:32 PM

Quote:

Originally Posted by Dwight Southerland

Aubrey, I would not be afraid of the 3.19 first gear. The super light clutch-flywheel assembly will allow you to accelerate the car without wheelspin. I would go with a 2.00 second and 1.40 third with the 3.19. The faster you can accelerate the car in the first half of the track, the lower the ET. Race setups have you in high gear at the eighth mark and it's just the ride from that point on regardless.

Yep...

Todd Hoven · 04-01-2014, 08:57 PM

Quote:
Originally Posted by Dwight Southerland View Post
Aubrey, I would not be afraid of the 3.19 first gear. The super light clutch-flywheel assembly will allow you to accelerate the car without wheelspin. I would go with a 2.00 second and 1.40 third with the 3.19. The faster you can accelerate the car in the first half of the track, the lower the ET. Race setups have you in high gear at the eighth mark and it's just the ride from that point on regardless.

Yep...
__________________

X2.

03-31-2014, 02:44 PM	#21
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,275 Likes: 25 Liked 510 Times in 200 Posts	Re: Ordering New Transmission, but What Gears ? 40+ years ago on 7" slicks I learned that the steeper first gear Muncie transmission would only run fast when the traction was very, very good. Even in a small block hydraulic cam rpm limited 3200lb car. A 2.5 trans with a 4.88 rear gear and a steel flywheel dug holes in the starting line sometimes...... Basically we needed an aluminum flywheel at the minimum to adjust to the track conditions. Going from a 2.5 to a 2.20 first was a huge change and we threw that at the car in desperation at one race. A bog was faster than a spin........by a lot...We were racing on asphalt then and hot summer was way less traction than cooler conditions by a mile....Smoking the tires on the launch was normal....but only a little.... The fastest car in our class ran less gear in the trans and upped the TQ as much as possible with long collectors and other tricks.... Back in the traction limited days of 7" slicks... Basically I think you have to pick something that is not as aggressive as you might like or think it could use. A happy medium so to speak..... I don't miss those days one bit.....LOL __________________ Rich Biebel S/C 1479 Last edited by Rich Biebel; 03-31-2014 at 02:55 PM.

03-31-2014, 04:16 PM	#22
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,349 Likes: 435 Liked 677 Times in 261 Posts	Re: Ordering New Transmission, but What Gears ? Rich, I think we walkd in the same shoes. I cut my teeth racing with a 69 Z-28 as a stocker. I raced it while I was in college. We carried 2.52 and 2.70 gear set trannys with us,as well as a 14 lb alum flywheel and a 34 lb Flywheel I also had an alum hat with a Schiefer alum plate I had a lot of trouble with the heat shield. Back in the day it was fun, but today it would be hard work. __________________ Adger Smith (Former SS)

03-31-2014, 08:14 PM	#23
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,275 Likes: 25 Liked 510 Times in 200 Posts	Re: Ordering New Transmission, but What Gears ? Yes we did Adger.... My race partner and I became friends with a man that had a '69 Z/28. It was nearly new but was a racecar running F/S at the time. He had fully prepped the car and it had a race engine I drove it a couple times. I was convinced he should get that 2.20 first gear trans out and I installed a 2.5 first like we ran in our car. I was used to the hydraulic cammed engine we ran....350/295 His 302 was nothing like the 350 and would spin the tach to the moon if it spun the tires which it did. Leaving at 6500-6800 and with not much traction at our local track.....well forget about it......LOL I also learned that the 2.5 box would not shift anywhere near as good behind the 302 at the much higher rpm... Broke some trans parts pretty quickly with it but man that car was great fun to get behind the wheel of.... Black with white panels on the hood and trunk....black and white houndstooth interior and the cold air hood with all the stuff to go with it....except he threw some of it away thinking it was no good for racing.... The car went 12.1's in F/S in 1969 or 1970 __________________ Rich Biebel S/C 1479

03-31-2014, 08:52 PM	#24
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: Ordering New Transmission, but What Gears ? I'm getting closer to settling on this. Thanks for ALL the "combinations". Yes, it's more inclined to be a "torque engine", but it still does pull nice up at the big end. __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

03-31-2014, 11:07 PM	#25
ss wannabee Senior Member Join Date: Jun 2005 Posts: 663 Likes: 0 Liked 5 Times in 5 Posts	Re: Ordering New Transmission, but What Gears ? Aubrey...did you ever try launching it at 5000 rpm?

04-01-2014, 12:04 AM	#26
Aubrey N Bruneau Member Join Date: Sep 2003 Location: South Eastern Alberta, Canada Posts: 311 Likes: 6 Liked 7 Times in 3 Posts	Re: Ordering New Transmission, but What Gears ? I did in Medicine Hat... but traction wasn't dependable. When it did hook, it bogged. I don't go there any more. Hoping for Mission in early June, but we're going on a big trip in May, for our daughter's wedding. That may stifle that particular race. __________________ Aubrey N Bruneau 6409 C/S 62 BelAir sport coupe, 409 HP 409

04-01-2014, 01:18 AM	#27
Geerhead55 VIP Member Join Date: Sep 2002 Location: Tacoma, Washington Posts: 1,632 Likes: 0 Liked 5 Times in 5 Posts	Re: Ordering New Transmission, but What Gears ? I hope you can pull it off, Aubrey. It would be great to see you and the car again at Mission. Its one of my "must do" trips every year at one of my favorite tracks. Take care. Danny Durham

04-01-2014, 11:00 AM	#28
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,980 Likes: 53 Liked 724 Times in 177 Posts	Re: Ordering New Transmission, but What Gears ? Aubrey, I would not be afraid of the 3.19 first gear. The super light clutch-flywheel assembly will allow you to accelerate the car without wheelspin. I would go with a 2.00 second and 1.40 third with the 3.19. The faster you can accelerate the car in the first half of the track, the lower the ET. Race setups have you in high gear at the eighth mark and it's just the ride from that point on regardless.

04-01-2014, 08:57 PM	#30
Todd Hoven VIP Member Join Date: Jul 2007 Posts: 1,329 Likes: 883 Liked 720 Times in 151 Posts	Re: Ordering New Transmission, but What Gears ? Quote: Originally Posted by Dwight Southerland View Post Aubrey, I would not be afraid of the 3.19 first gear. The super light clutch-flywheel assembly will allow you to accelerate the car without wheelspin. I would go with a 2.00 second and 1.40 third with the 3.19. The faster you can accelerate the car in the first half of the track, the lower the ET. Race setups have you in high gear at the eighth mark and it's just the ride from that point on regardless. Yep... __________________ X2. __________________ Todd Hoven 1035 Stock