I have a 91 camaro with a 350. got some shi t done but it still has the stock gear. So my buddy just gave me a 4.10 how my question is once this gear is installed about how much time can i expect to shave off my 1/4 mile.

 

A rear gear swap isn't like a bolt on horsepower gain, but I believe the TQ might change. The idea behind swapping gears is to either get rid of the economy set that included in most cars or put you in the powerband for your TQ and HP range. That way you can wrap out the motor just before or reaching the line. Also it allows for quicker launches off the line, unless it's spinning like crazy.

If this is on a TPI that still only sees the 4.5k to 5k peak power. I wouldn't switch to 4.10s especially with the low internal 1st gear on the 700-r4. I imagine those will be way to big for that intake setup. Most members on here either get 3.42s or 3.73s due to the TPI's not liking to rev sky high.

Don't know about you, but my TPI falls on it face a little after 5k rpms.

 

well this car is pretty much just my toy so im not worried at all about gas milage and i donno my car is pretty strong to its redline ive never brought it over that. So as long as i wont be past the redline in the 1/4 im happy with it. I have the 700r4 trans so at least i have overdrive so i was told that ill be fine. Is this true?

 

yep, 7004r's have overdrive, but as said, with lower first gear 4.10 might not help you too much.. or even at all.

 

I think you might even run slower because your going to be out of the TPI power band.

 

Course thinking again if you went with a really large tire like a 27" or larger slick that would/could counter the gear making it a little more mild.

All I know was by the time 6k RPMs rolled around I was down about 80 HP off my peak.

If you think you can use OD on the dragstrip you can try, but you'll have some problems with it. The OEM trans unless it has the B4C package will not shift into OD at full throttle so you'll have to lift off the gas for it to shift. Along with that it'll want to downshift out of OD at 3/4 throttle or so.

 

Does your "stuff" include a different intake, heads, or cam?

 

yea i got a cam in there intake is ported a little along with mildy ported heads. i realized that my car still pulls pretty hard after 5000 rpm i havent found out exactly when i start to loose power cause i havent wound it out that long but its still pulling at 5500

 

I'd check out the https://www.thirdgen.org/newdesign/t...ulations.shtml

You can mess around with the gear ratios and tire sizes.

If I used it correctly in 3rd gear with the 4.10s you'll run ~103 MPH @ 5500 RPMs (26" tire). ~113 @ 6000 RPMs

If you go to a 27" tire (like a slick) you'll gain another 4 MPH or so at that same RPM. The below figures are with a 27" tire (13.5" radius).

In OD you'll be ~126 MPH @ 4500 RPMs.

So if you think you'll beable to run faster than a 103 or 113 MPH in the 1/4 I wouldn't get 4.10s, because you'll have lift off the throttle to shift into OD and you won't beable to go more than 70% or so into the throttle again.

3.42s would max you out around ~129 MPH @ 5500 RPMs.

While 3.73s would max you out around ~118 MPH @ 5500 RPMs. (Note the above speeds where considering a 13.5" radius (such as a 27" drag slick). Course those are just guessimates since slicks do have a growth height when they start turning fast, but it's still a valid point to consider.

 

[B]

Seat of the pants can be very misleading. I agree with Fireturd350, and go with the 3.42, or 3.73. Preferably the 3.42!