would that help alot with acceleration going from a 4.10 to the gtu 4.30?

 

Acceleration will be better but youll be losing speed in each gear(shorter final gear = slower top speed in every gear)

Although if you are n/a i doubt you will ever be able to max out 5th gear i think youd have to be going atleast 160+ mph even with the 4.30 final gear, with 4.10 stock it would be more like 165+ mph once youre hitting the redline.

 

You get faster acceleration down low, but once you are in higher gears you lose speed. So its a toss up. My GTUs has em and the acceleration isnt that big of a difference between the 4.10. The only reason I keep them is because its an LSD and i drift. Dont waste money on buying a set for your car. It wont help much unless you do other power adding mods.

 

You don't "loose speed" as such, you just need more revs for the same speed. Theoretical top speed is lower, but this is irrelevant for most people.

 

Yah, thats the best way of explaining it. I dont like 80mph in 5th gear to be 4k rpm.

 

Actually engine speed at 80mph would go from 3250rpm to 3400rpm. It's a only a 5% change, so neither performance or cruising revs will increase that much.

 

I cant speak from first hand experience right now since my speedo cable doesnt work and hasnt since ive had the car, but other GTUs owners have said that 80mph in 5th gear is 4000rpm. Soon as I get my new cable in im going to find out for sure.

 

as a reminder, only the GTUs model (note the small "S") came with the 4.3 rear end. Not any of the GTU models.

 

I rechecked the FSM and the GTUs should have a 0.756:1 5th gear rather than the 0.697:1 I used. That still only gives 3700rpm at 80mph, so mayby they just meant near 4000rpm.

But all that really matters is that if you stick a 4.3:1 diff in you revs will still only go up 5% for a give speed.

 

That's cool I didn't know that. I guess people can learn something everyday. Thanks for the edumacational lesson fur today!

 

for me, 80 is at 3500 rpm (GTUs)

 

Ive got the 4.3 on my 90na and the increse in accel wasnt something huge to brag about... Its better but I wouldnt shell out a bunch of money to get it.

 

Ive read quite often that the GTUs tranny has a different 5th gear but when I actually wanted to know for sure I read this and it says its the same as other S5 NA's.



So unless mazda misprinted it or something, then its just a regular S5 NA tranny.

 

According to the S5 FSM the NA's 5th gear is 0.697:1 unless an LSD is fitted, in which case it's 0.756:1. Since the GTUs has an LSD...

 

Hmmmm........this is interesting and leaves me in a predicament. My GTUs tranny took a **** on me and stopped running so I have an S5 GXL tranny on the engine now. I was going to throw the tranny away but now i might get it rebuilt if this is true.

 

I'll be in AZ next month. I'll take your GTUs tranny off your hands if you were just gonna toss it.

 

Haha, maybe, im going to take it apart and see what exactly went wrong first before deciding what to do with it. Ill PM you though.

 

what wheels and tyres are you running?

use a lower profile tyre and it will be the same as putting a bigger ratio in the diff but much simpler. (not exactly the same for the smart ***** depending on the change it could make more or less difference)

i'm running 205 50 15's instead of the stock 205 55 16"
made quite a difference about 7.7%
and lowered the car by 20mm

 

+1


I have 4.3 gears on my tII and I feel it acelerates faster after 3rd if I compare it to the old 4.10 gears. I did not notice any change on 1st and 2nd gears though. Maybe its just me.

JP

 

Basically, if you want to:

a. Race, get 4.3. For low-horsepower cars I imagine it would actually INCREASE the top speed, but only for NAs or stock turbo cars.

b. see how fast you can get your car to go (assuming you have mucho horsepower), get the automatic rear-end (3.9) (although I don't know if they have the 3.9 for turbo rear ends), or a 4.1 and a low 5-th gear (low meaning a low ratio number, not a "low" gear persay). This is the 180 MPH+ kind of speed I'm talking about, though...

c. want a reasonably quick car with reasonable gas mileage that doesn't DRONE your ears to the point of bleeding after a 4-hour drive, get a 4.1... (slight exaggeration... but 500-1000 rpms makes a BIG difference in terms of noise at 80 MPH).

 

If you swap in the GXL tranny, you'll get slightly better gas mileage!