Dyno safe for my rear end?
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Joined: Jul 2004
Posts: 98
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From: Maple Grove Minnesota
Dyno safe for my rear end?
I had a gameplan to get my 91 vette dyno tuned and then based on the dyno reconsider my gear selection (currently 3.73) while I upgrade from the Dana 36 to the Dana 44 rear end. Then I started wondering, is it possible to blow the Dana 36 during the dyno pull? I can't say that I've ever heard of anyone blowing the rear end during a dyno pull, but it's still developing the max torque and horsepower, so why wouldn't it give, because there's no "shock" like there is on a launch?
I think (read: hope) I'm putting down somewhere in the 600 hp range to the rear wheels (this is not the same car in my profile BTW) with a 383 stroker, lingenfelter headers, Borla exhaust, ATI Procharger, F.A.S.T engine management, MSD ignition, ported polished, bowls blended and lots more goodies.
Is it a significant risk, or am I just being paranoid? Does it make more sense to select the gear ratio without the dyno and upgrade to the Dana 44 before the dyno pull?
I think (read: hope) I'm putting down somewhere in the 600 hp range to the rear wheels (this is not the same car in my profile BTW) with a 383 stroker, lingenfelter headers, Borla exhaust, ATI Procharger, F.A.S.T engine management, MSD ignition, ported polished, bowls blended and lots more goodies.
Is it a significant risk, or am I just being paranoid? Does it make more sense to select the gear ratio without the dyno and upgrade to the Dana 44 before the dyno pull?
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
My car has had more dyno runs than I care to count...mostly due to tuning. I can say that unless you already have something seriously wrong with your read end that the dyno is not going to hurt anything. They always start the car soft, like a light street launch, then hold the RPMs around 2500 or so then nail the throttle...but because your drivetrain is already spinning there is very little shock to it. Go for it an have fun! Hopefully uou'll meet your HP goals, but that's a pretty high one! 
Drifting
Joined: Aug 2001
Posts: 1,500
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From: Holliston MA
Cruise-In VII Veteran
The pulls will be done in 1:1 transmission ratio. Either 3rd gear with an automatic or 4th with a stick. You don't have the force multiplication of 1st gear to deal with nor the shock loads. Don't worry about it.
Le Mans Master
Joined: Apr 2000
Posts: 5,713
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From: Manassas VA
Originally Posted by SloRvette
The pulls will be done in 1:1 transmission ratio. Either 3rd gear with an automatic or 4th with a stick. You don't have the force multiplication of 1st gear to deal with nor the shock loads. Don't worry about it.
Even with a 600 hp motor, the torque on the dana 36 is not going to be as much, assuming the dyno operator stays in 3rd gear, as a full throttle launch in first gear with a stock motor.
