Oh No...Another Gear Thread

QU!CK

New Member
Apr 27, 2004
146
0
0
Charlotte, NC
Well the mod bug bit pretty quick considering that I've had my car for about a week now...lol


I'm thinking of getting a shifter (Tri-Ax or MGW) but I've only heard good things about both and price for each is about the same so no real worries there.


I'm also considering gears (uh oh, 4.10 vs 3.73) and don't know if I should go with FRPP or Motive. I'm still relatively new to Stangs so bear with me...I did a seach and came back just as confused as before I started. :(


What all is needed for a gear swap and who (if anyone) sells a complete kit. IE, I don't wnat to have to get gears from here, pinion from there..blah blah blah. Does anyone sell everything needed for a complete swap?


And for the FRPP vs Motive debate...I searched and found that Motive seems to be a "hit or miss" as far as gear whine goes. I don't want to save $40 just to shell out big bucks getting my rear end fixed so I think I'll just go with FRPP unless someone else makes a better kit. (content and quality).


Okay, back to 4.10 vs 3.73....I drive ~80mi everyday (70% highway) and make a 4hr drive once or twice every month (95% highway). The car will continue to be my daily driver and will seldom see the track, although I do like to romp on it every now and then if someone wants to play:banana:. I've driven a 98 cobra with 4.10s and loved it but since I have a GT I've heard some say 3.73s are better.


Sorry for such a long post, just trying to make sure that I provide as much info as possible....

Maybe I should just say screw the gears and shifter and just buy a Bassani cat-back :jester:


-J
 
  • Sponsors (?)


well motives arent that bad of gears at all. I tried to decide between 3.73 and 4.10 and just got myself even more confused so I did what was different. I ordered motives 4.30's and there basic install kit. Which will be installed next weekend and i cant wait. But yeah FRPP gears have a great rep but there is more good from motive gears than bad. I travel 55 miles or so a day mainly highway but the speed limit is only 60 so I drive 65 and with 4.30's there is nothing wrong with the RPMs i would be turning. But in your case i would suggest 4.10's anything under that would be a waste unless your goign to supercharger it or something. Sorry i couldnt be more of a help.
 
Nothing wrong in choosing Motive gears over FRPP gears. One gear set is not any easier or any harder to install than the other and Motive gears do not whine more than FRPP gears. Any reputable shop that has performed a gear swap on these 8.8 rear ends will tell you the only difference between the gear sets are in the tolerances (the adjustments) when they are being installed.

-Cale
 
281Ponies said:
Nothing wrong in choosing Motive gears over FRPP gears. One gear set is not any easier or any harder to install than the other and Motive gears do not whine more than FRPP gears. Any reputable shop that has performed a gear swap on these 8.8 rear ends will tell you the only difference between the gear sets are in the tolerances (the adjustments) when they are being installed.

-Cale
Nope, that is incorrect. FRPP gears are easier to install.
 
QUICK to give you some idea of approximate rpms at highway speed.

TR3650 in 5th gear at 80mph
3.73s - 2618rpms
3.90s - 2738rpms
4.10s - 2878rpms

4R70W in 4th at 80mph
3.73s - 2736rpms
3.90s - 2860rpms
4.10s - 3007rpms

I run 275/40/17s in the rear so rpms will be slightly different than running 245/45/17s but it’s very minimal. You can find out more about mph/rpms here http://www.wcfords.com/stuff/calcs/EGTcalc/egtcalc.php

-Cale
 
I have 4.10's in my 99 manual GT, my gas mileage is **** and after flooring it in first I have to shift after about 1.5seconds, the gears are so damn short.

I couldn't imagine 4.56's , it would be damn ridiculous.

If I could re-do it, I'd buy 3.73's just so a kenne bell would be a bit more tame. As it is now though I'll probably go centri because of my 4.10's
 
That's new to me as well, maybe the dial-in for the calibration is different for the FRPP?
But I agree, the differential is holding a ring and pinion, I don't see how another companies ring and pinion is easier to install than the next ones.
 
FRPP gears do not need to be shimmed as much and go in much easier. Do a search like I did and read the same info I did to come to this conclusion...

I have never installed gears, I am just going by the extensive research I did on the subject a few weeks back...
 
Actual finish and patterns will setup different between an aftermarket gear (Motive, Superior, Yukon, Precision, etc) versus a FRPP (OEM) gear. I can usually get a better pattern with an OEM gear for pinion depth than an aftermarket.

Also, a lot of times an aftermarket gear may have a higher possibility of a little whine. FRPP gears are relatively inexpensive compared to a lot of other OEM's but aftermarket can give you more selection in ratios.

As far as ratio, I'm not stepping in that one. I'm going to try both 3.73's and 4.10's just to play around :D
 
Ring and pinion of any brand require shimming to get the correct backlash. The only extra time it takes is reading the instructions that are included with a new gear set. It doesn't take any more time or cost any more money (labor) to get Motive gears to be within lets just say .008" and .012" of backlash to have a correct load pattern which eliminates gear whine. It’s simply the differences in tolerance from one brand of gears to another.
The toughest part is finding someone to do the install that doesn’t install every brand of gears as if they were FRPP gears.

-Cale
 
MustangThief said:
I have 4.10's in my 99 manual GT, my gas mileage is **** and after flooring it in first I have to shift after about 1.5seconds, the gears are so damn short.

I couldn't imagine 4.56's , it would be damn ridiculous.


4.56s really arent that much in a GT, I got them in a rear end swap deal and planned on replacing them. After driving around with them for almost 3 weeks now I love it. First gear is short but the rest of the gears are perfect. The only time 4.56s are too much is on the highway, as 2500 rpms at 65 is a little ridiculous. As far as gas mileage goes I'm still staying right around where I was before. Before anyone flames, its cause now I can cruise around in a 20 mph zone in 5th gear where I couldnt do it before.
 
This is my first post as well, and I'm glad QU!CK brought this up. I did a search on gears as well and still kinda had questions afterwards.

I went to Prewitt Racing up in Austin, TX, and bought a Tri-ax shifter after seeing all the recommendations on this board and the after talking to the guy at Prewitt.

While I was there I asked him what his thoughts were on gears. He said either you do 3.90's or up, or you're just wasting your time. He asked if I did a lot of highway driving, which I don't, and he said go 4.10 since Ford doesn't make 3.90's. My next mod will prolly be gears, I'm sure.
 
artificial HP said:
4.56s really arent that much in a GT, I got them in a rear end swap deal and planned on replacing them. After driving around with them for almost 3 weeks now I love it. First gear is short but the rest of the gears are perfect. The only time 4.56s are too much is on the highway, as 2500 rpms at 65 is a little ridiculous. As far as gas mileage goes I'm still staying right around where I was before. Before anyone flames, its cause now I can cruise around in a 20 mph zone in 5th gear where I couldnt do it before.
just out of curiosity what are your rpms in 5th @~100.( :flag: )