clockworks

For those with MANUAL transmissions with 4.10's in your rear...what are your observed top speeds of each gear? When I mean top speed, I mean speed at like 5500, not necessarily your redline.

I have to make a make a decision by 6pm tomorrow: 3.90's or 4.10's. :bang:

Thanks for the info, guys.

The Boss Hog

at 5500 rpm with stock tires and 4.10 gears:

1st = 31 mph
2nd = 52 mph
3rd = 79 mph
4th = 105 mph
5th = 154 mph


change to 3.90 and you get:
1st = 33 mph
2nd = 55 mph
3rd = 83 mph
4th = 110 mph
5th = 162 mph

The Boss Hog

mikem

Go with the 4.10s.you wont be disapointed.I can do 80 mph at 2800 in fifth.

eighty6gt

Get four thirties.

www.f-body.org/gears

mcomb

What kind of mileage do you get doing 80 on the freeway with 4.10s?

Clem

I rarely find enough open space to run 80 around here, but I get about 22-23 mpg @ 70 on the mildly hilly stuff around here. I was getting 2-3 mpg more with the stock 3.55's. I once averaged over 27 mpg coming back from Skyline Drive to DC while running 70-80 when I was stock. Not gonna happen with the 4.10's, but the fun factor around town is huge!

outdoorstom

Great info Boss....thanks! I'm just waiting for the call from my mechanic to tell me when he's free to install mine.. That's the trouble with a good mechanic....everybody wants to use him.

clockworks

Did you get those number from a calculator? Did it account for drag and load and stuff? I used the calculator on corral.net and it gave me some seemingly bogus numbers. Also, I seem to remember someone saying that with the 4.10's their first gear blew by before they were going 15 mph. I could be completely wrong and just making that up in my head though.

Thanks.

The Boss Hog

I have an Excel spreadsheet with some macros that calculate the data. The numbers are theoretical numbers and are not effected by "Drag, load and stuff". Actual numbers would be effected by many things. Examples:
1.) I doubt our cars (stock) have enough power to overcome the drag necessary to reach 5500 rpm in 5th, but are quite capable of hitting redline in 4th.
2.) Low or high air pressure in the tires can also effect the actual numbers because it would change the rolling circumference the tires.


The Boss Hog

PS I have 4.10's and I can assure you I can do more than 15 mph in 1st

pittperson

Do the 4.10s. They are definitely worth it. I just made a(nother) trip to Pittsburgh last night and averaged ~22mpg at ~73mph.

max2000jp

I was toying with the idea of a gear. For the guys with gears, how do you hook up? My car rips the tires loose in first and spins then on the 1-2 shift. I am on stock 3.55's too. I know upgrading the tires will help, but in the short future I plan on adding more power. I can only imagine how much wheelspin a 4.10+ geared car would have.

clockworks

Hehe, I'm still a newb at this stuff...still learning the lingo...:P

<!--QuoteBegin-The Boss Hog@September 30, 2005, 9:57 AM
PS I have 4.10's and I can assure you I can do more than 15 mph in 1st [/quote]
Welp, I'm sold. You and everyone else sold me...FRPP 4.10's it is...

Thanks for the input, everyone.

300HPGT

1.) I doubt our cars (stock) have enough power to overcome the drag necessary to reach 5500 rpm in 5th, but are quite capable of hitting redline in 4th.


Well I do know that my car can hit 6200 RPM's in 4th gear. and then I backed off because I dont feel like going to Jail plus I proved my point to the little SRT4 that was behind me. I have stock 3.55's. That is about 140 mph with a 26.8" tall tire that i have. The little dodge did give me a thumbs up tho. The horse owned the Ram. So I think with 4.10's 5500 RPM's is reachable with our cars in 5th gear.

The Boss Hog

Everyone has an opinion on this and they are all valid. I'll give you mine. If you add power at the high end (centrifical S/C or cam & heads), go with the 4.10's. If you add power at the low end or across the board (roots or whipple S/C), stay with the 3.55's.

The Boss Hog . . . . JMO

max2000jp

I am concerned though that a Supercharger with 4.10s would anihilate the tires on the street. I just want to make sure that the car will hook. If it doesn't hook, then why add the extra power?

300HPGT

I want 4.10's I just cant afford it. I think 4.10's + Kennybell S/C = Holy crap I think I need new underpants.

Scothew

I think you will need new tires.

porsche

GET 456S IF YOUR NOT GOING TO STUPID CHARGE

TehSLeeper

HAHAHAHA!!! Beat me to it.

With N/A applications 4.10's and higher ratios are better and will increase 1/4 mile times.

With Supercharged/Turbocharged applications lower ratios like the 3.73's are better because with the higher ratios you'll get less traction with all of that low end torque.

hawgman

I am probably wrong, but I thought you had to have a 9" to put in 3.90s. I didn't think they would work in a 8.8" rear end.