The gears are too big, you'll cruise in 4th on the freeway. Check the FM gearing calculator.

 

These are my ratio's (fc t2 tranny)

3.483
2.015
1.391
1
0.762

Don't you think I need something wider for 340whp?
Currently I am running a 4.1 fgr

 

That's be me.

Built '97 block, '99 head w/ 1-mm oversized valves and essentially a BEGI S5(+) setup.

Saw an avg of 20mpg while "playing", 25 when obeying most traffic laws and conventions and never measured on a long enough trip to get highway numbers.

These figures may change soon. Corky and I are in the midst of the next round of "upgrades"...

- L

 

How is the performance? Does it feel slower than the 4.1 or it eats distances like crazy? How much power do you have?

 

Details details!!!!! Please?

 

I'll cut you some slack because your people know how to make yogurt.

http://www.flyinmiata.com/tech/gearing.php

 

True about the yogurt. We make great feta cheese also.

About the site.. been there done that, doesn't help much. I need feedback from someone who actually drives this thing.

 

I start building boost at about 1600 and see full pressure from 3k to redline. No, it doesn't feel slower.

The car generates about 200/200 at 7psi and 250/240 at 12psi. Runs like a scalded cat.

- Adjustable timing gears to drop a few degrees from the intake cam, and add a couple from the exhaust.
- COPs courtesy Savington.
- 255 Walbro.
- Corky's new cast intake manifold.
- Thermostat'd oil cooler.
- Under tray/ducting.
- Some minor maintenance bits; ie: adjusting valves, belts, etc.
- Retune at the dyno.

As soon as we have some numbers, they'll be posted. However, the aim is to significantly increase power at the same boost levels, with the aim of breaking the 150mph barrier *with the top down* on street tires (non-R comp) at the Texas Mile this October.

(Then I'll put a hardtop on it and see what 160+ looks like...)

- L

 

If you want to retain a 5 speed, and you think the 4.10 is too short, you could do a 5 speed/3.9 rear and have a decent set up. My 6 speed/3.63 isnt in due to procrastination/lack of time.

 

I and others have said it before. the 3.63 and 6-speed combo is fantastic. The ratios in 1-5 are not exactly the same as a 4.30 with a 5 speed, but it is close enough such that it behaves like a normal 5-speed with an additional 'overdrive' gear.

Now that being said, when I did the 3.63 6-speed swap in my turbo car (versus 4.30 5-speed) I did not see a big jump in mileage like I had hoped. I do mostly highway driving at 70-80 mph, with some stop-and go. I checked/logged mileage every time I filled up. I also checked the odometer to be sure it was accurate.

I was also tuning for lean cruise. But, I was conservative with my fuel tuning, adding fuel (richness) at anything above 100 kPa, which is easy to exceed on the highway with just light passing, which I do a lot of. My fuel curve sloped upward quickly at anything above 80-100 kPa. So I did not spend a lot of time in the lean cruise mode.

YMMV, literally.

DVCN is tuning for lean cruise with E85 and is getting good initial results. His commute is very, very similar to mine. IIRC he covers this in his recent E85 thread.

Even though it was my intent going in, I was so happy with the improved highway drive-ability that I did not care so much about getting the big mileage return-on-investment (ROI) on the taller gear set.

 

What kind of prices are you guys paying to get these installed? I bought a set of 3.63's and need to get 'em in.

C

 

$400. I will sell my whole thing for $1200

 

i need a torsen with 3.63s already installed. I'm lazy