[rudypoochris]

Originally Posted by jb's335

Lol...all boosted cars?

So what if you fall out of boost in between shifts with the 3.08? A larger turbo than stock twins will shift the powerband up on the rev range. I agree with Terry.

This doesn't make any sense. Changing the rear end doesn't change where you land in boost. That ratio is locked by each gear in the transmission. The rear end just multiplies the entire gear set. If you shift out of 5th at 6,000 and land at 5,000 into 6th that will happen every time regardless of rear end. Changing the rear end out will help you to select what ratio you will start or end at in mph. For this car I don't see a point in going for a shorter rear end personally since it isn't going to get you more load for the motor to spool turbos and it may hurt your 60-130 time because a shorter rear gear will mean another shift on the top end. How much it actually matters on 6 gear transmissions though is up for debate. It comes down to intended use.

[NetEagle]

196 speedometer indicated or GPS speed?

[ApolloTheGod]

Originally Posted by NetEagle

196 speedometer indicated or GPS speed?

VBox confirmed actually. I could physically not go any faster at all. The car was starting to lift and I had no more pull. Damn aerodynamics!

[dirty330]

Are there anymore people out there that went from 3.08 to 3.46 manual transmission? I've been on every forum out there from supra to mustang trying to nail down a better guideline for turbo car final drive gearing. The main consensus being: one guy will say turbo cars need load to spool, throw what you think about gearing an NA car out the window. Then another guy will post about how that's not proven and a higher geared car will be 10X faster light to light. Anyone out there recently do any gearing changes?

[Stucks]

http://www.youtube.com/watch?v=RrRIcMAuczg

Dat oil temp increase doe.

[Indo Rider]

Im glad I stayed with the 3.08. The gears already go by fast enough and since I plan to go upgraded twins or single some day I have no doubt it was the right choice.

[jbarzelatto]

sorry to revive the thread, but i feel like we didnt reach a conclusion.

I have a 135i 6 speed mt, and have upgraded to the vargas single turbo. i want to know if going to the larger ratio wil give me a faster pull, when for example doing a 2nd gear run on the highway.

we all know that MPG will change, and that revs will run higher.

from what i understood terry said, bascially its a GOOD idea to change to a larger ratio if you upgrade the turbo.

any inputs? lets reach a concensus lol

[frmtl2_335i]

Can you fit a small pumpkin (at) with 3.46 gears in a mt car? Does the pumpkin size affect mounting points?
Basically I'm trying to ask if the at diff would bolt up to a mt car with no mods.

[johmei]

Originally Posted by jbarzelatto

sorry to revive the thread, but i feel like we didnt reach a conclusion.

I have a 135i 6 speed mt, and have upgraded to the vargas single turbo. i want to know if going to the larger ratio wil give me a faster pull, when for example doing a 2nd gear run on the highway.

we all know that MPG will change, and that revs will run higher.

from what i understood terry said, bascially its a GOOD idea to change to a larger ratio if you upgrade the turbo.

any inputs? lets reach a concensus lol

Generally going higher in end gear ratio will be a loss in trap speeds and 1/4 times as most US drivers seems to be bothered about. For a one gear pull you will effectively have 12% more torque to the ground which is probably not a good thing as you reach traction limits already stock in 2nd. With a ST car I imagine you will struggle to put the power to the ground even in 3rd if going with the higher gearing. Also you will be shifting quite a bit more. It all depends on what you use your car for. As long as you are not introducing another shift (because of shorter gears) in a specific situation you should benefit. Go smaller tires to test and see how you like it, it is exactly the same!

For myself, driving a FBO stock turbo MT car at the track (road course), a 3.46 MFactory LSD is getting fitted. I made a couple of graphs and compared the speeds at optimal power to videos from trackdays to see if it would make sense. 3.46 seems like the right choice but I will not know until mid summer. =)

Sorry for km/h but thats how I live my life! =)
(the switch will give a theoretical top speed under 300km/h which sucks)

[lcvette]

Bringing up an old thread again, does anyone know where I can find a 3.46 ring and pinion set for a 2007 MT bolt on diff? We switch to the large pumpkin in my dad's 135i AT6 car but aren't digging the 3.08 for drag strip launches. Looking to go back to a 3.46 but keep the lsd and large pumpkin in the car.

Thanks!

Chris

[GR1P]

Originally Posted by lcvette

Bringing up an old thread again, does anyone know where I can find a 3.46 ring and pinion set for a 2007 MT bolt on diff? We switch to the large pumpkin in my dad's 135i AT6 car but aren't digging the 3.08 for drag strip launches. Looking to go back to a 3.46 but keep the lsd and large pumpkin in the car.

Thanks!

Chris

Contact Mfactory

[lcvette]

OK, will do!