What Gears?

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 said:

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.

Click to expand...

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.

LarsD said:

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.

Click to expand...

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.