can poorly rebuilt manual transmission slow car?
10-06-2011, 10:45 PM
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can poorly rebuilt manual transmission slow car? I had my tranny rebuilt by six speed inc. several years ago. Since that time I've managed to produce a dyno queen that has been slow on the top end. I've changed my rear gears over 4 times. So I'm guessing its not the rear end. I've changed my lca, torque arm and clutch. and shocks. Here's the deal, even at 410 hp, stock c5's would start to walk me down at the end of the quarter. My traps were about 111. It never made sense. From a 50 roll on a highway stock zo6's pulled hard. It seems i have to overwhelm the car with nitrous and hp just to get it to move some. It's a M6 TA. Just wondering can there be some internal components to the tranny that would allow a strong dyno but weak street performance?
10-07-2011, 08:41 AM
#3
Since you dyno in 4th gear, the input and output are mechanically locked together. If the countershaft was shimmed way too tight it might cost you some HP, but I would imagine the heat/load would cause the bearings to fail you by now if that were the case.. Are you running out in 4th, or needing to got into 5th at the top end? What clutch are you running and could it be slipping? (dyno rollers are easier to turn then pushing a car on the street..)
10-07-2011, 08:50 AM
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It's only going to effect the shifting quality of the unit. If it shifts good and nothing has broke inside the unit, its not costing you enough to even talk about it if any at all.
10-07-2011, 12:16 PM
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The shifts are notchy, The clutch doesn't slip. It should cause a rise in RPMS, That's not the issue. I've had the car dynoed at 4 different places. When the car is making greater than 400 hp, it still is sluggish at high speeds. more sluggish than stock vettes. I've changed the rear gears four times. I now have 3.90s with plenty of room to go on the end of the track. It's not just the driver because, even if the car is in gear on the highway and I punch it along side a car with 60 less horses it can't keep up. Ive changed the tires shocks, etc. Don't know what else to do.
