Transmission & Rear End Questions :)
#1
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Transmission & Rear End Questions :)
I was originally going to purchase a Richmond 5 speed and use my 3.36 rear end but then it was brought to my attention that the Tremec TKO 5 speed w/ overdrive can be had fairly (relative term) cheaply. So where exactly can I purchase a Tremec TKO transmission from at a good price?
Because the transmission has overdrive I have decided that a new rear end is in order. I don't know which rear end to go with 4.11 or a 4.56 (what do you guys think). Should I get a "normal" Corvette rear end from Tom's (approximately $1000) or should I get the 12 bolt version (approximately $2300)?
I will probably wind up using my T10 & 3.36 once I get the big block in until I can scrape the money together for the TKO & 4.XX rear end.
Because the transmission has overdrive I have decided that a new rear end is in order. I don't know which rear end to go with 4.11 or a 4.56 (what do you guys think). Should I get a "normal" Corvette rear end from Tom's (approximately $1000) or should I get the 12 bolt version (approximately $2300)?
I will probably wind up using my T10 & 3.36 once I get the big block in until I can scrape the money together for the TKO & 4.XX rear end.
#2
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Re: Transmission & Rear End Questions :) (bence13_33)
I've been doing alot of reasearch and for our cars (and I know Gkull will agree) and a 2.80 final drive is best. I arrived close to that with 4.11's and a .70 overdrive gear. A ZF six speed with a .50 overdrive would be near optimum with my 4.88's, but that's on the back burner for now. Try and arrive close to 2.80 with whatever combo you choose.
[Modified by Stingy74, 5:40 PM 2/5/2002]
[Modified by Stingy74, 5:40 PM 2/5/2002]
#3
Le Mans Master
Re: Transmission & Rear End Questions :) (bence13_33)
Forte's is where most people get Tremecs for GM applications.
I really don't think a gear ratio change is necessary for you, but I guess it depends on what you want and how you use your car. A total ratio of around 10.0-10.5 in first gear is generally considered ideal. With the Tremec's 3.27 first gear, and your 3.36 rear gear, you will have a 10.98 first gear ratio. That is plenty steep, and with your new big block, you will have no trouble smoking your tires at will. If you were to go up to a 4.11, you would end up with a 13.4 first gear ratio which is 'tractor-like'.
But like I said, it depends on your own personal preferences and usage - if you're just gonna be stoplight racing up to 30 mph, no one could touch you. But if you do any 60+mph cruising, even with the OD 5th gear your cruise rpm will still be higher than it needs to be. I don't know how much rpm you're planning on getting out of your BBC, but you'd proabably find yourself doing alot of shifting if you go with the 4.11+ gears.
I really don't think a gear ratio change is necessary for you, but I guess it depends on what you want and how you use your car. A total ratio of around 10.0-10.5 in first gear is generally considered ideal. With the Tremec's 3.27 first gear, and your 3.36 rear gear, you will have a 10.98 first gear ratio. That is plenty steep, and with your new big block, you will have no trouble smoking your tires at will. If you were to go up to a 4.11, you would end up with a 13.4 first gear ratio which is 'tractor-like'.
But like I said, it depends on your own personal preferences and usage - if you're just gonna be stoplight racing up to 30 mph, no one could touch you. But if you do any 60+mph cruising, even with the OD 5th gear your cruise rpm will still be higher than it needs to be. I don't know how much rpm you're planning on getting out of your BBC, but you'd proabably find yourself doing alot of shifting if you go with the 4.11+ gears.
#4
Safety Car
Re: Transmission & Rear End Questions :) (bence13_33)
I think the strength of the rear end required is directly related to the tires you're planning to run. If you'll ever put slicks on the car, go with the 12 bolt. There are plenty of guys around here running real strong motors on relatively stock rear ends without any major problems.
I agree with Monty on the ratios. No way would I run a 4.** rear with a 3.27 first gear for normal street use. Maybe if I had an 8000 rpm small block. My personal preference would be the 3.55 or 3.36 you've already got.
Just keep in mind that the Tremec gives you a better first gear as well as overdrive, so the axle that works with a 4 speed usually doesn't work with a 5.
-Joe
I agree with Monty on the ratios. No way would I run a 4.** rear with a 3.27 first gear for normal street use. Maybe if I had an 8000 rpm small block. My personal preference would be the 3.55 or 3.36 you've already got.
Just keep in mind that the Tremec gives you a better first gear as well as overdrive, so the axle that works with a 4 speed usually doesn't work with a 5.
-Joe
#5
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Re: Transmission & Rear End Questions :) (Flareside)
Joe:
I am not quite sure what you mean by this, could you please help me understand :blueangel:
I am not quite sure what you mean by this, could you please help me understand :blueangel:
Just keep in mind that the Tremec gives you a better first gear as well as overdrive, so the axle that works with a 4 speed usually doesn't work with a 5.
#6
Drifting
Re: Transmission & Rear End Questions :) (bence13_33)
Shane,
I took the conservative approach to gear ratio (in the trans) and the rearend ratio (3.08's). With a 2.77 First gear and 3.08's, I will be running a 8.53 to one final drive ratio which seems low but with a BB, I should be able to spin the tires from a stop. I will wait and see how the motor runs instead of just running out and buying a 3.36 unit. With the 3.36's, I would be running a 9.31 to one final drive ratio in first. That seems high enough.
With your 3.27's and a 3.36 rear, that 10.99 to one is TOO high in my opinion. With a 3.08 unit, it would be at 10.07 to one. You want to have some usefullness out of first gear (otherwise you will find yourself starting off in 2nd gear with the Tremec 5). With all that BB torque, you will spin tires all the time in 1st and not even mean it with the 3.36's and EVEN the 3.08's.
I think that Stingy74 has the right idea with his steep gears and 700 trans since he is running a small block but it wouldn't be a good idea with a BB.
I would start thinking abou 3.08's when you do your overdrive trans, IMO.
Email me at robert@scme and I will send you a MS Excel file I created.It help me see different transmission gear ratios with different rearend ratios when deciding on Richmond six speed gear ratios. You can modify it to include Tremec 5 sp gear ratios. Let me know if you (or others) want it.
Hope this helps!!
Bob :cheers:
I took the conservative approach to gear ratio (in the trans) and the rearend ratio (3.08's). With a 2.77 First gear and 3.08's, I will be running a 8.53 to one final drive ratio which seems low but with a BB, I should be able to spin the tires from a stop. I will wait and see how the motor runs instead of just running out and buying a 3.36 unit. With the 3.36's, I would be running a 9.31 to one final drive ratio in first. That seems high enough.
With your 3.27's and a 3.36 rear, that 10.99 to one is TOO high in my opinion. With a 3.08 unit, it would be at 10.07 to one. You want to have some usefullness out of first gear (otherwise you will find yourself starting off in 2nd gear with the Tremec 5). With all that BB torque, you will spin tires all the time in 1st and not even mean it with the 3.36's and EVEN the 3.08's.
I think that Stingy74 has the right idea with his steep gears and 700 trans since he is running a small block but it wouldn't be a good idea with a BB.
I would start thinking abou 3.08's when you do your overdrive trans, IMO.
Email me at robert@scme and I will send you a MS Excel file I created.It help me see different transmission gear ratios with different rearend ratios when deciding on Richmond six speed gear ratios. You can modify it to include Tremec 5 sp gear ratios. Let me know if you (or others) want it.
Hope this helps!!
Bob :cheers:
#8
Safety Car
Re: Transmission & Rear End Questions :) (bence13_33)
Bence: My motor makes pretty close to the same HP (approx 580) as your is going to. I am running forged stub axels, a heavy duty rear end cover, smart struts, 360 lb mono leaf, brute force u joints, and do not run slicks. I have had no problems, and I drive the car hard. A friend of mine has a stout 427 with nothing more than stock 67 big block parts and forged stub axels. He drag races on slicks and has had no problems. You are going to find a lot of different opinions on this subject. I would venture to guess your car does not have as strong a rear end as the older ones, I do not know for sure, but the stock hp ratings at the time were pitiful. When you call Tom's ask to talk to Zeus, he is much more patient with questions than Tom is.
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Re: Transmission & Rear End Questions :) (69 N.O.X. RATT)
When you start comparing the Richmond and the Tremec, spend a little time with a Qtr Jr program or something.
Since the Tremec has to get from 3.27 to 1.00 in four gears, and the Richmond only goes from 3.27 to 1.23 or whatever combo you choose, it usually comes out better acceleration wise.
Every combo I tried was better with the Richmond with less rear gear than the Tremec. The 4th gear underdrive works great on the Richmond.
You definitely don't want 4.11s inthe back with the Richmond. I am using 3.36's with a Nash that has 3.27/2.13/1.57/1.23/1.00. It has a 4.13 final drive ratio in 4th. With the 427 in my car it was crossing the finish line at just a hair over 6500 rpm in 4th gear at 123 mph with 10x26 slicks. Just about perfect.
With a Tremec you will have to use 4.11's to get the finish line rpm you want, but the rpm drops going through the gears will be much more pronounced which will hurt acceleration. And as everyone said, a 4.11 with a 3.27 first gear will be worthless. I've ridden in a big block Nova with that combo and it's not good at all!
Just more food for thought.
Jim
Since the Tremec has to get from 3.27 to 1.00 in four gears, and the Richmond only goes from 3.27 to 1.23 or whatever combo you choose, it usually comes out better acceleration wise.
Every combo I tried was better with the Richmond with less rear gear than the Tremec. The 4th gear underdrive works great on the Richmond.
You definitely don't want 4.11s inthe back with the Richmond. I am using 3.36's with a Nash that has 3.27/2.13/1.57/1.23/1.00. It has a 4.13 final drive ratio in 4th. With the 427 in my car it was crossing the finish line at just a hair over 6500 rpm in 4th gear at 123 mph with 10x26 slicks. Just about perfect.
With a Tremec you will have to use 4.11's to get the finish line rpm you want, but the rpm drops going through the gears will be much more pronounced which will hurt acceleration. And as everyone said, a 4.11 with a 3.27 first gear will be worthless. I've ridden in a big block Nova with that combo and it's not good at all!
Just more food for thought.
Jim
#10
Safety Car
Re: Transmission & Rear End Questions :) (427Hotrod)
When you start comparing the Richmond and the Tremec, spend a little time with a Qtr Jr program or something.
Since the Tremec has to get from 3.27 to 1.00 in four gears, and the Richmond only goes from 3.27 to 1.23 or whatever combo you choose, it usually comes out better acceleration wise.
Every combo I tried was better with the Richmond with less rear gear than the Tremec. The 4th gear underdrive works great on the Richmond.
You definitely don't want 4.11s inthe back with the Richmond. I am using 3.36's with a Nash that has 3.27/2.13/1.57/1.23/1.00. It has a 4.13 final drive ratio in 4th. With the 427 in my car it was crossing the finish line at just a hair over 6500 rpm in 4th gear at 123 mph with 10x26 slicks. Just about perfect.
With a Tremec you will have to use 4.11's to get the finish line rpm you want, but the rpm drops going through the gears will be much more pronounced which will hurt acceleration. And as everyone said, a 4.11 with a 3.27 first gear will be worthless. I've ridden in a big block Nova with that combo and it's not good at all!
Just more food for thought.
Jim
Since the Tremec has to get from 3.27 to 1.00 in four gears, and the Richmond only goes from 3.27 to 1.23 or whatever combo you choose, it usually comes out better acceleration wise.
Every combo I tried was better with the Richmond with less rear gear than the Tremec. The 4th gear underdrive works great on the Richmond.
You definitely don't want 4.11s inthe back with the Richmond. I am using 3.36's with a Nash that has 3.27/2.13/1.57/1.23/1.00. It has a 4.13 final drive ratio in 4th. With the 427 in my car it was crossing the finish line at just a hair over 6500 rpm in 4th gear at 123 mph with 10x26 slicks. Just about perfect.
With a Tremec you will have to use 4.11's to get the finish line rpm you want, but the rpm drops going through the gears will be much more pronounced which will hurt acceleration. And as everyone said, a 4.11 with a 3.27 first gear will be worthless. I've ridden in a big block Nova with that combo and it's not good at all!
Just more food for thought.
Jim
Joe:
I am not quite sure what you mean by this, could you please help me understand :blueangel:
Just keep in mind that the Tremec gives you a better first gear as well as overdrive, so the axle that works with a 4 speed usually doesn't work with a 5.
I am not quite sure what you mean by this, could you please help me understand :blueangel:
Just keep in mind that the Tremec gives you a better first gear as well as overdrive, so the axle that works with a 4 speed usually doesn't work with a 5.
What Monty told you above is very important. Try to stay around 10-11 final drive (first gear, 3.27 multiplied by your rear axle ratio) in first gear and still maintain a good highway rpm.