tim281

I used to have a 96 cobra with a vortech charger and it had 3.73 gears. The car had tremendous torque with the 3.73s and was really quick to the power band, you could kick the tail out on the car is ease.
I have noticed that my Saleen's 3.55's feels much different and take a lot longer to reach the power band...it is night and day.
I was looking at overall gear ratios and noticed that the Saleen 275/35-20 tires actually make a noticable difference in the gearing as the wheels are much larger than a standard 245-45-17.
It appears that a 3.90 in my Saleen should yeild than same ratio as my old 3.73 in the 96 Cobra. The tire diameter of the Saleen is 27.5 while the cobra was 25.7.

Anyone tired 3.90s? What do you think?

06S281

ORIGINAL: tim281

I used to have a 96 cobra with a vortech charger and it had 3.73 gears. The car had tremendous torque with the 3.73s and was really quick to the power band, you could kick the tail out on the car is ease.
I have noticed that my Saleen's 3.55's feels much different and take a lot longer to reach the power band...it is night and day.
I was looking at overall gear ratios and noticed that the Saleen 275/35-20 tires actually make a noticable difference in the gearing as the wheels are much larger than a standard 245-45-17.
It appears that a 3.90 in my Saleen should yeild than same ratio as my old 3.73 in the 96 Cobra. The tire diameter of the Saleen is 27.5 while the cobra was 25.7.

Anyone tired 3.90s? What do you think?






Hey man Im running the 3.90's in my car and I love them. Totally different from stock 3.55's. First gear goes quick but the power is felt instantly. The car will run about 500rpm higher then the 3.55's did but man I like them. JPC is who did all my work for me and justin said with my set-up that 3.90's is probably best. I would reccommend them, I think 4.10's would be to much and 3.73 in these cars would be notenough change from the stock 3.55's.

elburrito99

06281-- I am likely swapping gears this spring and did some research on 3.90s, which seemed like a good choice for our S197 Saleens with 20" wheels.But I found a lot of complaints about gear whine for 3.90s, so I'm very interested to get your feedback on a couple of things:
1. Do you know who manufactured your 3.90s (apparently Ford Racing sells 3.73s and 4.10s, but not 3.90s)?
2. Do you hear any gear "whine" from the 3.90s?
3. Do you know what speed you redline at in 1st gear? One of my biggest concerns with going to a gear taller than the 3.73s is having too low a top speed in 1st gear. This is already one of my (few) complaints about our Saleens (heck, Vettes can do 60mph in 1st gear!).

Tim281 -- sorry for the thread hijack!

eviligloo

I can answera coupleof the questions even though I don't have an S197. Most of the 3.90 gears that people are running are manufactured by motive. I've heard that they have a little more gear whine than others...but i'm not sure how much.

http://www.americanmuscle.com/motive390.html

I have gear whine from my 3.73 Ford racing gears (apparently the racing gears aren't finished as finely as the stock gears, hence the noise). I've gotten used to the noise and actually kinda like it now. I just wasn't expecting it at first from the FRPP gears.

elburrito99

Thanks, eviligloo.

I'm concerned about gear whine with theMotive 3.90s because there are hundreds of posts on so many forums about the issue. I just did a google search (Motive 3.90 Gears whine) and got almost 400 hits. Most posts claim that the whine comes from the installation, not thegears themselves. But that's almost impossible toprove without having two different shops install the very same 3.90 gears into the very same car. Also, I think I've read that Motive actually makes the 3.73 Ford Racing gears. So who knows.

I'm going by Chicane tomorrow afternoon, so maybe I'll ask Joe what he thinks.

06S281

I check on the box to see the manufacturer of my 3.90's and repost. I do hear a little whine but it doesn't bother me. My exhaust takes care of that. Im not sure what speed I can get to in 1st before redline, I haven't driven it in a little while. I do know that if your racing 1st will go quick and once you hit 2nd it butter. Who really rides around in 1st gear?? As far as them whining by the person who installs them, I think is a crock. JPC installed mine and they are known accross the country. My brother is a mustang motor head with 5 mustangs and he said the whine is normal...I'll get back to you as far as the brand of 3.90's...

cobraT

If you get the correct gear pattern on the installation and bearing preloads are set correct, there should be NO

WHINE. Setting gears takes the proper tools and alot of patience to correct the slightest flaws to get a correct

pattern on the gears. Most often when money is the issue close is good enough.

tim281

How loud is gear whine anyway? It is compareable to exhaust drone?
I really like the ratio of the 3.90, but I don't think I would be happy with any gear whine. Do you hear gear whine only under deceleration when the transmission is running against any unloaded engine or is it a frequency based whine where at certain rpms you get a resonance?


Darn...I really like that 3.90 ratio

06S281

Motive gear performance is the name on the box for my 3.90's. I can hear the gear whine just cruisin. I can notice it if I am listening for it but my exhaust drowns it out. I can deal with it. My first gear speed redline is probably about 40mph.

eviligloo

Just an FYI on my gear whine.....I only get it under deceleration.