What Gears?

[sneaky98gt]

For a bone stock, automatic 04 Mach 1?

My granddad wants to put a set of gears in his Mach 1, and I was wondering what teh Stangnet suggests.

To be clear, the car is completely stock other than a catback and a programmer that it will be getting at the same time as the gears. It is on 275/40-17 Nitto NT555s on the stock 8 inch wheels. It will never see the track, and is primarily driven as a weekend warrior by my grandparents. It will most likely never have any significant power mods.

I was originally thinking 4.10s, as that's what I've always heard with the Mach 1s and their lack of low end torque. However, I've been worrying a little bit that it will be too much gear for the street tires and will leave 1st gear completely useless, which is exactly what he doesn't want to do with the car. So I've also thought about going with 3.90s to keep from that happening.

What says Stangnet?

 

[007]

Did you REALLY just start a "which gears" thread!!?


Anyway. This is EASY. 4 speed automatic GTs need 4.10s, NOT 3.73s. Machs rev better than GTs, so 4.10s are an absolute no brainer. Many would recommend 4.30s (thats what I would get).

4.10s and a tuner make a SHOCKING difference to an auto.

 

[LarsD]

I like the 4.10's in my Cobra a lot. 1st is fairly useless on the street. Course I am running on very worn 18" KDW's.

 

[sneaky98gt]

Did you REALLY just start a "which gears" thread!!?


Anyway. This is EASY. 4 speed automatic GTs need 4.10s, NOT 3.73s. Machs rev better than GTs, so 4.10s are an absolute no brainer. Many would recommend 4.30s (thats what I would get).

4.10s and a tuner make a SHOCKING difference to an auto.

Yea, I know. I feel like such a noob starting one of these threads...

Under normal circumstances, or if it was my car, or if it was for going to the track, or if it had some DRs sitting out back, 4.10s would be the minimum I'd even consider, probably 4.30s. I KNOW what the biggest performance gain is considering you can put the power to the ground.

BUT, since traction on the street with street tires is the biggest concern, I'm a little more lost. I don't have any first hand experience with geared autos and what to expect traction-wise on the street, so that's why I asked. And before someone asks, I DID do a search.

I suspect it would be an entirely different animal with gears and a programmer. First, you'd eliminate the problem those cars have with the lack of low end torque (which is VERY evident, especially in an auto). Second, you can increase the line pressure a bit to get it so shift a little firmer. For whatever reason, it actually shifts softer than his auto 01 GT does. And third, you can raise up the shift point a little bit (it's around 5800 rpm stock) so that it doesn't fall out of its power band for a second or so when it shifts into 2nd gear.

I like the 4.10's in my Cobra a lot. 1st is fairly useless on the street. Course I am running on very worn 18" KDW's.

Yea, that's what I'm most worried about. If it can't put the power to the ground in 1st gear, the car has just become more useless than it was before, as well as less safe when you're talking a 75 year old man/woman driving.

 

[Maxpowers]

Did you REALLY just start a "which gears" thread!!?

Agreed

With my 4.10s, I still have to use first gear from a stop. There's no reason not to go with them. I've still gotten as good as 24 mpg on the highway.

Be careful with the shift points. You may need to set it a little lower than red line so it doesn't hit the limiter in 1st. The rpms will be climbing very fast.

 

[LarsD]

Yea, that's what I'm most worried about. If it can't put the power to the ground in 1st gear, the car has just become more useless than it was before, as well as less safe when you're talking a 75 year old man/woman driving.

Well, I'll be more specific. I can make 1st gear useless. If I take it easy, it drives just fine.

 

[txredgt]

Doesn't Auto Mach's come with 3.55's stock? It wouldn't be much different if he were to go with 3.73's and with that I say 4.10's or nothing.

 

[Deleted member 38176]

auto + 4V = more gear the better!

4.10's would be the absolute lowest. Some 4.30's and improved shift calibrations from a tuner would turn that thing into a damn animal!

 

[1fun281]

4.30 and dont look back!

 

[Crzyhrse]

For just a nice weather car, 4.10's will be more than he'll ever need. 4.30's would be overkill.