4.11's in a street car. Am I nuts?

[SlimeGold 69 15]

I'm in the prosess of swaping out the 8 inch open 3.00 rear out of my car with the 9 inch from my wife's 65. I got a good deal on a trac-loc carrier and 4.11 gear. I already got them and I will have the rear set up in a couple of weeks. Anybody run that steep of a gear on the street and if so what's it like? I have a T5 5 speed and don't do very much highway driving. It's just a weekend toy. With the cam I have, Edelbrock RPM intake, long tube headers, ported 351 Windsor heads and a 600 Holey DP it likes to rev so I think it will be fun. Am I wrong?

Edited January 11, 2009 by SlimeGold 69

[69RestoRod 10]

It'll be fun that's for sure. Expect mileage to go in the pisser but it'll be a blast to drive. The five speed should help to iron out RPM problems a bit.

[cphsonic 11]

The T5 comes with a lot of different OD ratios but assuming you have a 0.68 in there and a normal tire diameter, a 4.11 will mean you're turning around 2.250 rpm at 60 mph in 5th. Not that bad at all.

[Juice It 10]

I went from a 2:75 to a 3:50 with trac loc in my 69 and if I could do it over I would have went with a 3:25. I just don't like the high reving for regular cruising around. Sure I have a bit more low end now but I spend more time at cruising speed than I do nailing it from a dead stop. If you are just looking for drag race opportunities it would be great, regular cruising speeds will suffer big time.

[PaleRider 12]

reving at 2,250 would be fine. I've got a c4 with 3.44 trac-loc and revs a little over 3000 at 60 which is not too bad. At least I can live with it. With a 5 speed I would definitely do higher than my 3.44s.

[ForceFed70 14]

With a T5 it'll be no problem. You may find 1st gear kinda annoying tho.. you'll end up having to shift 1/2 way through your left hand turns.

[SlimeGold 69 15]

That's kinda what I was thinking overall. 2250 rpm's at 60mph is alot better than I had figured. I was guessing closer to 3000, so that makes me feel better. I bet that 1st will be REALLY short. I'll probably have to shift right after it starts rolling but I can live with that. I can't wait to "test" it out.

[3Must 10]

What size tires are you running in the rear? If you let me know I have a spreadsheet I can enter your tire size, Tranny ratio, and rear end ratio and get engine rpm. I am going to run a T5 (.68 over drive) with 3.70 gear with 255/60 15 rear tires. At 70 mph I will be running 2189rpm.

[SlimeGold 69 15]

What size tires are you running in the rear? If you let me know I have a spreadsheet I can enter your tire size, Tranny ratio, and rear end ratio and get engine rpm. I am going to run a T5 (.68 over drive) with 3.70 gear with 255/60 15 rear tires. At 70 mph I will be running 2189rpm.

 

 

Cool! I have 235/60/15's. I am pretty sure my T5 has the .68 over-drive. It came out of a 89 5.0 Stang.

[3Must 10]

OK, at 60mph, you would be turning 2160 rpm

at 70mph, 2520 rpm

at 75mph, 2700 rpm.

[SlimeGold 69 15]

Sweet.... Thanks a bunch! Overdrive is a wonderful thing.

[1BAD351 21]

I would do it for sure. If you don't do much highway driving then who cares. I run my 393 at 2300 rpm doing around 60 with my setup now. When I get a 5 or 6 speed in her I will be putting in 4.10 or 4.11's. Most of my driving is highway, but my car is a car I like to have fun in, screw gas mileage/engine wear. When I punch it in the lower gears I want it to jump and go sideways, I don't care what it does on the highway.

[SlimeGold 69 15]

Sorry to bring back a old thread but I got a break in the weather and took my car out for a quick spin for the first time with the 4.11's yesterday. All I can say is.. damn! She will burn rubber in 1-3 with ease. My speedo said 75mph in 5th at about 2200 rpms. I guessing that is about 55-60 mph because I need to change the speedo gear. Anybody have a sugestion on the speedo gear I will need (tooth count)?

Edited February 23, 2009 by SlimeGold 69