Maximum HP
Race Director
Joined: Dec 2000
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From: El Paso Texas
Le Mans Master
Joined: Oct 2008
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From: Houston Texas
OP what are you building? If you search there are many discussion about this. From what I have read it varies really on the condition of your drive train and how sticky your tires are. I'm only speaking about what I have read and not from personal experience so if i'm wrong please correct me.
Le Mans Master
Joined: Oct 2004
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From: South-central Missouri
Max torque is the question - not horsepower per se. Torque to fail (GM) specs for the various components like spindles, U-joint, differentials, etc might lead to more specific data.
From observation, it seems the ZF trans is near bullet proof - even with some big 427-441 inch motor kind of torque. On the other end of the spectrum is the spindles on the C4. A "few" serious C4 drag racers carry an extra spindle with them when they go to the strip to race. You hear about a spindle breaking on stock or mildly modded C4s. U-joints and differentials failing comes up as "hp" increases to 600 and beyond.
That said, you run up a stock motor to 5000 rpm and side-step the clutch (especially on slicks), and "anything goes"!!
P.
From observation, it seems the ZF trans is near bullet proof - even with some big 427-441 inch motor kind of torque. On the other end of the spectrum is the spindles on the C4. A "few" serious C4 drag racers carry an extra spindle with them when they go to the strip to race. You hear about a spindle breaking on stock or mildly modded C4s. U-joints and differentials failing comes up as "hp" increases to 600 and beyond.
That said, you run up a stock motor to 5000 rpm and side-step the clutch (especially on slicks), and "anything goes"!!
P.
Thread Starter
Heel & Toe
Joined: Aug 2012
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From: Grottoes VA
The drivetrain will determine the cost of the engine. I don't want to build a 500hp engine, then start snapping the transmission and rearend...I have the ZF 6speed. What is the weak link in the drivetrain?
Le Mans Master
Joined: Oct 2008
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From: Houston Texas
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Race Director
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From: moraga ca
It really depends on what the car will be used for and how it will be driven. With stock street tires, a stock drivetrain will probably last with 600rwhp. Spinning tires don't break things. If you are going to run sticky tires at the drags with a manual, then you will have problems.
Race Director
Joined: Dec 2000
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From: El Paso Texas
So determine the power level that will keep you happy and upgrade everything. Because really, if you build it any LESS than that, how long will you like it, and what will it THEN cost you to get it where you want? Do it the way you want the first time out.
Race Director
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From: Overland Park Kansas
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You've also got some specific scenarios to help temper the response to your scenario. (Good thing people will provide answers -- hoping to hit the right one BEFORE you provide the correct specifics)
BTW...I'm thinking U-joints are the weakest link (in the Dana44/ZF combo), but I'm not at the track like other guys. Or, the clutch/FW -- if you're still running an OEM DMF. People have run DMFs over 500hp, but not many for a long time.
Le Mans Master
Joined: Oct 2004
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From: South-central Missouri
Al (holding the half shaft with the spindle sheared off) is installing a 33 spline spindle to go with his 441 LT5 - hopefully in time for the Crown Point Corvette Challenge on September 9th.
P.
Race Director
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From: Overland Park Kansas
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As I said, the stock spindles seem to be the most common failure item (on ZR-1s, anyway).
Al (holding the half shaft with the spindle sheared off) is installing a 33 spline spindle to go with his 441 LT5 - hopefully in time for the Crown Point Corvette Challenge on September 9th.
Al (holding the half shaft with the spindle sheared off) is installing a 33 spline spindle to go with his 441 LT5 - hopefully in time for the Crown Point Corvette Challenge on September 9th.
Le Mans Master
Joined: Oct 2004
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From: South-central Missouri
)Al was running on some big drag radials (I wanna say BFG 335s at least), and the track was in perfect condition (read: sticky!). All our big inch LT5 guys bring either a spindle or a trailer with them to the track, when its "GO TIME"!
P.
Last edited by Paul Workman; Aug 13, 2012 at 05:52 AM.