Gears and MPH
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Originally Posted by tektrans
You may lose mph all things being equal. You're going to 4:30's with a 1.9 60'??
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Don't expect to gain MPH with gears. A lot of people do and they get disappointed. I'm not saying you WON'T gain MPH, but horsepower is what determines MPH, not gearing, for the most part.
Example, I went 119.80mph with 3.42s in a 10bolt.
Added a 12bolt with 4.30's and went only 120.xx mph, but dropped a lot of ET.
Then went from 4.30's to 4.56's and dropped even more ET, but MPH still is only 120 and some change (120.7)
My ET dropped from 12.2's with the 3.42s to a now 11.3's with 4.56's, and a drop of .5 in 60' times.
Example, I went 119.80mph with 3.42s in a 10bolt.
Added a 12bolt with 4.30's and went only 120.xx mph, but dropped a lot of ET.
Then went from 4.30's to 4.56's and dropped even more ET, but MPH still is only 120 and some change (120.7)
My ET dropped from 12.2's with the 3.42s to a now 11.3's with 4.56's, and a drop of .5 in 60' times.
Last edited by RaNsOm; 12-20-2006 at 07:16 AM.
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What are your rpms now when you pass the traps?
A bigger gear won't always mean a higher mph hence the term "ran out of gear". However, if you do have enough rpms to make it and assuming you have traction and everything else the same except a gear swap ,I'd say 123-124. 4.10 to 4.30 is only a 150 rpm difference with a 1:1 tranny ratio. -Mark
A bigger gear won't always mean a higher mph hence the term "ran out of gear". However, if you do have enough rpms to make it and assuming you have traction and everything else the same except a gear swap ,I'd say 123-124. 4.10 to 4.30 is only a 150 rpm difference with a 1:1 tranny ratio. -Mark
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Originally Posted by 98SS2836
Last year I ran 4.11's all year and ran 122. This year im going to run 4.30's. So the question is How much more mph am I going to get?
I would work on making it dead hook like it is before I looked into changing gears. Automatic cars should not turn a tire at launch. I have also found the lower a car is geared the more a little wheel spin hurt my times. I would not expect lower gears to improve my mph.
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I'm doing the gear change be cause the car crosses the traps to low of an rpm like 6100 6200. Plus I think this cam should be run with a 4.30 or above. I was going to change the tire but then I would never hook. We'll see I should be at the track with about 20-30rwhp more and the gears. I don't want to do the suspension yet till I can go any faster then see what the gains will be with the suspension.
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Originally Posted by 98SS2836
I'm doing the gear change be cause the car crosses the traps to low of an rpm like 6100 6200. Plus I think this cam should be run with a 4.30 or above. I was going to change the tire but then I would never hook. We'll see I should be at the track with about 20-30rwhp more and the gears. I don't want to do the suspension yet till I can go any faster then see what the gains will be with the suspension.
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I can only help with what happened on my slow car.
Went from 3.73 to 4.10, trap speed stayed the same, 60' & ET went down a little.
Don't remember exactly. I agree with the traction will be worse with a steeper gear,
until you get a better chassis set up.
Went from 3.73 to 4.10, trap speed stayed the same, 60' & ET went down a little.
Don't remember exactly. I agree with the traction will be worse with a steeper gear,
until you get a better chassis set up.
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Originally Posted by Bitemark46
Where does it make peak power at? It makes peak over 6200? What is redline.... 6500? -Mark
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At this point I'd rather see you spend the money on a good suspension to get it to hook than a lower gear that will cause a greater loss of traction. 4.11 to 4.30 isn't that big of a change anyway.
Bill
Bill