Rear gears and trans help
Thread Starter
4th Gear
Joined: Jan 2013
Posts: 4
Likes: 0
From: Philadelphia PA
Rear gears and trans help
Been lingering around the forums for the past year and finally decided to make an account so I can get some help finishing my car. It an '85 automatic and has came a very long way since I got it two years ago. Long story short I was ready to sell it when the motor went on me. Instead of parting it out I decided to drop a carb'd 355sbc in it. Of course I wanted more power and slapped a 144 weiand blower on it too. Decided that I wanted this to be a 1/4 killer, I purchased a 3500 stall and sent the trans out to get rebuilt and a reverse manual valve body. Now I see 2 issues that are holding back my project.
What are the highest gears I can use with my stock carrier and do I need a new shifter? Keep in mind that I am going for a pro street style car. Thanks, Anthony.
Here are some pics for those who are curious.
What are the highest gears I can use with my stock carrier and do I need a new shifter? Keep in mind that I am going for a pro street style car. Thanks, Anthony.
Here are some pics for those who are curious.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Nice ride. No matter how many times I look, I can't see that blower setup fitting under the stock hood. What am I missing? If this is an all out race machine, no matter what gears you put in the Dana, they will blow with sticky tires and the hp of a blower. Gotta go straight axle or you'll risk your car or your life.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Safety Car
Joined: Aug 2009
Posts: 3,752
Likes: 276
From: Melbourne, Victoria, Australia
I have twisted my half shafts with only 8 psi boost... 
Have replaced them with steel ones and the dana 36 still lives with the 3.07 gears, the tires break loose easily that is probably why the D36 is still alive. Torque is the killer...
For sticky drag racing tires the ford 9 inch diff is the only way to go.
Have replaced them with steel ones and the dana 36 still lives with the 3.07 gears, the tires break loose easily that is probably why the D36 is still alive. Torque is the killer...
For sticky drag racing tires the ford 9 inch diff is the only way to go.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Some clarification.
If stock your auto car has a Dana 36 rear ( think 10 bolt / 8" ) .3.73 gears available
Is a bolt in swap to install the much stronger unit Dana 44 unit that came in the man cars ( think 12 bolt / 9" ) . 4.10 gears available
Both styles use identical components outboard of the diff; uni's , half-shafts , stub axles and suspensions items
BUT;
The geometry of the C4 IRS setup is not the best for drag racing , it places big loads on items as the rear squats on acceleration because the half shaft doubles as the top arm of the suspension as opposed to having a separate top and bottom arm with a half shaft that only sees rotational loads as used in the Viper and later Vettes
Many parts can be upgraded but you are only as good as your current weak point leading to the failures I linked above.
http://forums.corvetteforum.com/1564959552-post7.html
Many serious racers have put lots of time and $$$ into keeping the IRS in the car, ultimately going to a solid rear and almost universally stating that they wished they had made the move sooner
http://forums.corvetteforum.com/c4-t...-irs-work.html
http://forums.corvetteforum.com/1572139196-post7.html
If stock your auto car has a Dana 36 rear ( think 10 bolt / 8" ) .3.73 gears available
Is a bolt in swap to install the much stronger unit Dana 44 unit that came in the man cars ( think 12 bolt / 9" ) . 4.10 gears available
Both styles use identical components outboard of the diff; uni's , half-shafts , stub axles and suspensions items
BUT;
The geometry of the C4 IRS setup is not the best for drag racing , it places big loads on items as the rear squats on acceleration because the half shaft doubles as the top arm of the suspension as opposed to having a separate top and bottom arm with a half shaft that only sees rotational loads as used in the Viper and later Vettes
Many parts can be upgraded but you are only as good as your current weak point leading to the failures I linked above.
http://forums.corvetteforum.com/1564959552-post7.html
Many serious racers have put lots of time and $$$ into keeping the IRS in the car, ultimately going to a solid rear and almost universally stating that they wished they had made the move sooner
http://forums.corvetteforum.com/c4-t...-irs-work.html
http://forums.corvetteforum.com/1572139196-post7.html
Last edited by vetteoz; Jan 29, 2013 at 06:47 AM.
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
I have twisted my half shafts with only 8 psi boost...
Have replaced them with steel ones and the dana 36 still lives with the 3.07 gears, the tires break loose easily that is probably why the D36 is still alive. Torque is the killer...
For sticky drag racing tires the ford 9 inch diff is the only way to go.
Have replaced them with steel ones and the dana 36 still lives with the 3.07 gears, the tires break loose easily that is probably why the D36 is still alive. Torque is the killer...
For sticky drag racing tires the ford 9 inch diff is the only way to go.
Thread Starter
4th Gear
Joined: Jan 2013
Posts: 4
Likes: 0
From: Philadelphia PA
Thanks for all the helpful response. To start off, the blower does not fit underneath the hood, I still need to cut that out.
Anyway, I tried explaining all these IRS issues to my dad but hes convinced that we can throw a set of 3.73s in there and be fine. I really wish there was a way to do a straight axle set up that wouldnt cost me an arm and a leg. What set up does 383vett have? Thats what Im going for, fat tires in the rear and the front tires off the ground!
Anyway, I tried explaining all these IRS issues to my dad but hes convinced that we can throw a set of 3.73s in there and be fine. I really wish there was a way to do a straight axle set up that wouldnt cost me an arm and a leg. What set up does 383vett have? Thats what Im going for, fat tires in the rear and the front tires off the ground!
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
http://forums.corvetteforum.com/1571010479-post19.html
longevity is directly related to how hard you can launch
If your engine is a good as you think it is take a trailer with you on your 1st outing with the stock D36
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Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Thanks for all the helpful response. To start off, the blower does not fit underneath the hood, I still need to cut that out.
Anyway, I tried explaining all these IRS issues to my dad but hes convinced that we can throw a set of 3.73s in there and be fine. I really wish there was a way to do a straight axle set up that wouldnt cost me an arm and a leg. What set up does 383vett have? Thats what Im going for, fat tires in the rear and the front tires off the ground!
Anyway, I tried explaining all these IRS issues to my dad but hes convinced that we can throw a set of 3.73s in there and be fine. I really wish there was a way to do a straight axle set up that wouldnt cost me an arm and a leg. What set up does 383vett have? Thats what Im going for, fat tires in the rear and the front tires off the ground!
Thread Starter
4th Gear
Joined: Jan 2013
Posts: 4
Likes: 0
From: Philadelphia PA
Well at this point im hoping the 3500 stall will help me out a little. If it blows it blows. Would it be worth throwing gears in the diff I have now to buy me some time? Honestly I need to to last at least 3 runs because I need this thing running low times for a big money race as soon as its finished.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Because D36 gears are expensive ,better to put the $$ towards the stronger D44
A lower gear set will generate more torque so you will be putting more load on the outboard parts
http://www.viperclub.org/howto/faqs/...-gear-swap.php
http://www.carcraft.com/techarticles...s/viewall.html
Run street tires and let it spin all the way through 1st
Racer
Joined: Dec 2012
Posts: 301
Likes: 2
From: NY
Nice ride. No matter how many times I look, I can't see that blower setup fitting under the stock hood. What am I missing? If this is an all out race machine, no matter what gears you put in the Dana, they will blow with sticky tires and the hp of a blower. Gotta go straight axle or you'll risk your car or your life.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Get your wallet out
http://www.rodandracecraft.com/products_corvettec4.htm
http://forums.corvetteforum.com/drag...-axle-kit.html
Several have done their own installs
This member's one uses a torque arm
http://www.bowtye8.tzo.com/bowtie8/C...5/9Inch_TN.htm
This is a more conventional setup
http://www.rodandracecraft.com/products_corvettec4.htm
http://forums.corvetteforum.com/drag...-axle-kit.html
Several have done their own installs
This member's one uses a torque arm
http://www.bowtye8.tzo.com/bowtie8/C...5/9Inch_TN.htm
This is a more conventional setup
Last edited by vetteoz; Jan 30, 2013 at 07:43 AM.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
http://forums.corvetteforum.com/1564066339-post13.html
Race Director
Joined: Apr 2003
Posts: 17,700
Likes: 1,667
From: moraga ca
Le Mans Master
Joined: Dec 2003
Posts: 5,768
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From: Van Steel Corvettes
St. Jude Donor '12-'13
Yeah, but I've never heard anyone swapping from an IRS to a solid rear axle to help handling...I've certainly heard going from a solid rear to an IRS to help handling though. You can't beat negative camber and toe-in in the rear to help corner entry and exit.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
