Longer Gears

I am going rebuild my GearBox soon, there are several options I have for choosing Gears...
Optimistically I will have around 500awhp soon, My mechanist suggests me to use longer gears (1st, 2nd, 3rd) for better quarter mile times.

Can I expect better time with longer gears? how much longer is enough?
Any hint on that?

Thanks everyone...

 

[Luke]

TRE now has 11% taller 1st gear option which Jon sourced from an EVO3. ( just saw this on their website )

I have DSM 1st gear ( shorter than stock ) in my TRE tranny though.
Supposedly, the DSM 1st gear is stronger than GVR4 1st gear.
On the other hand, the GVR4 1st gear ratio is supposedly better for 1/4 mile time.

I also have the taller 5th gear, but that's just for lowered rpm on freeway.

 

[Yao]

Luke, what is your rpm on 5th gear at 60mph?

 

[cheekychimp]

There are some excel files I can send you if you PM me your email address. I think picking the correct gear ratios for the 1/4 mile is just as technical as your turbo choice and working out your tuning. It surely takes into account everything from your power band to your rev limit and the weight and power of your vehicle.

That said if you go to Magnusmotorsports website and look at their dogmission, they have the ratios set out there together with maximum speeds in each gear.

If I remember correctly the JDM RS GVR4 main gears with the GGSX final drive and rear diff gear came very, very close to the Magnus ratios but I can't remember which secondary gear was used. I think the information is on my computer somewhere. As I said if you are interested send me a PM with your email and I'll see what I can dig out!

Paul

 

Thanks Paul, My email address is: "[email protected]"
I guess I'm going to use E3 first to third gears on GVR4, 1st gear will see 70km (44 miles) at 7000rpm, and 2nd gear will see 120km (75 miles) at 7000rpm...
I am going to rev it up to 8500rpm, Hopefully the time should be better that stock gear ratio.

Thanks again...

 

[cheekychimp]

I'll try and dig out some saved PMs I exchanged with Teet on this subject with all the gear ratios.

That together with the excel programs should allow you to 'bench swap' transmissions to your hearts content, until you find something you think will suit you best.

 

[Luke]

I just checked.. it is about 2650.

Quote:
Luke, what is your rpm on 5th gear at 60mph?

 

I would say a complete evo III gear set is the strongest and best ratio to go with. Just the EVO III 3rd alone has been known to take a couple of tenths out of the 1/4. The taller EVO III 1st is the strongest helical gear on the market. I have a few people running these:

http://videos.streetfire.net/video/4c7b19ce-98f0-43a9-a638-997a01470e0b.htm

and

http://video.google.com/videoplay?docid=8584728468397231877

They can take a lot of power and I have EVO III pre-made clusters and more info on my site.

Jack
www.jackstransmissions.com

 

[Yao]

hi Jack! good to see you here! /ubbthreads/images/graemlins/smile.gif

 

Hello, lol. I had an old account, but it must have been deleted or something because I couldn't log in. Had to log in under a new name.

Jack