ring and pinion gear set....
12-06-2010, 10:29 PM
#1
3rd Gear Member
Thread Starter
Join Date: Nov 2008
Location: cyprus
Posts: 518
ring and pinion gear set....
currently doing 4500 rpm at 65mph, im running a stock rear axle. If I change the gear ratios to 3.25:1, what do you guys think my rpms would be at 65 mph?
next question, im changing my c4 to c6. Was gonna change to t5 but really like auto, would this change the rpms as c6 newer tranny?
and last, im also upgrading to 351 with stroker kit maybe to 408, not sure yet, would the above gears in rear axle make that much difference on acceleration and if so, would it be noticable even when upgrading to bigger engine?
next question, im changing my c4 to c6. Was gonna change to t5 but really like auto, would this change the rpms as c6 newer tranny?
and last, im also upgrading to 351 with stroker kit maybe to 408, not sure yet, would the above gears in rear axle make that much difference on acceleration and if so, would it be noticable even when upgrading to bigger engine?
12-06-2010, 10:34 PM
#2
Moderator
Join Date: Dec 2005
Location: Hills of California
Posts: 5,208
4500 at 65? What are you running a 5.11 rear end? Or really tiny rear tire height like something 16" tall (25" is stock)
none of this adds up whats going on?
Do you know your current rear end ratio?
none of this adds up whats going on?
Do you know your current rear end ratio?
12-07-2010, 06:49 AM
#5
6th Gear Member
Join Date: Oct 2006
Location: Cork, Ireland
Posts: 6,417
very same here. i'm running 4100 in 3rd on 3.5:1 at 65mph!
either you're missing a gear, your speedo is off or you have an utterly mad rear axle or tyres from a go kart
check on what you have first:
a) check speedo against novigation system. 5mph out is no problem, rather expected.
b) what rear tyre size do you have? example: 225/60R15
c) do you have a timing gun that shows rpm or any other rpm gauge so you cna verify your readings. maybe someone stuck a 6cylinder rpm gauge in there???
d) what is your current rear axle ratio. we can never assume it's stock. and even if we were sure it's stock we need door data plate to check what it was in your car.
Measure the rear axle ratio:
- car in neutral, back lifted. if you turn a tyre as if you were driving forward, what does the other tyre do? go forward as well (locked rear), or turn the opposite direction going backwards (open rear)?
if locked rear. count how many turns you need to do on wheel so that the driveshaft turns exactly once. that's your rear axle ratio
if open rear, same as above, but double the value at end (for example it takes 1.75 turns on wheel to turn the shaft once while holding the other wheel): 3.5:1 ratio
Then check if you're missing. switch through all gears in auto. you should have three gears
Kalli
either you're missing a gear, your speedo is off or you have an utterly mad rear axle or tyres from a go kart
check on what you have first:
a) check speedo against novigation system. 5mph out is no problem, rather expected.
b) what rear tyre size do you have? example: 225/60R15
c) do you have a timing gun that shows rpm or any other rpm gauge so you cna verify your readings. maybe someone stuck a 6cylinder rpm gauge in there???
d) what is your current rear axle ratio. we can never assume it's stock. and even if we were sure it's stock we need door data plate to check what it was in your car.
Measure the rear axle ratio:
- car in neutral, back lifted. if you turn a tyre as if you were driving forward, what does the other tyre do? go forward as well (locked rear), or turn the opposite direction going backwards (open rear)?
if locked rear. count how many turns you need to do on wheel so that the driveshaft turns exactly once. that's your rear axle ratio
if open rear, same as above, but double the value at end (for example it takes 1.75 turns on wheel to turn the shaft once while holding the other wheel): 3.5:1 ratio
Then check if you're missing. switch through all gears in auto. you should have three gears
Kalli
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