Well I am in the middle of a custom Turbo kit install.. I needed to know some advice from you guys out there.. I am thinking of buying a new Final drive gear.
I am currently runing on 19inch rims and I know that because of the size of my rims it effects the stock ratio of the final gear.. I think the stock is 4:10 but because of my rims it is lower.. So I need to know what Final gear to get? I am not sure about Ricks 4:77 gears.. it mite be a little to high.. I dont want to red line in two seconds.. I was looking into the Kia final gears.. anyway if anyone has any info for me that would be great.. thanks...

 

I personally wanted to lower my final drive, with the turbo your prolly gonna be rippin through the gears.

 

I don't have a turbo but from what I have read on here about turbo and gears....it's a no no....



peace

 

hmmm... Yea i guess you are right.. I just dont want to have a lag on my RPMs.. I saw a video of a dyno run.. It was a love fab turbo kit putting donw 500whp.. they had a close up shot of the RPM and it looked like it took a long time to Red line.. So I thought, maybe if I change my final gear I would make my RPMs quicker.. Still not sure what to do

 

What gear was the run done in?

We had another thread about this a week or two ago and basically what you have to keep in mind is that with a turbo setup, shorter gears can be detrimental to your performance. Shorter gears are used for NA cars and centrifugal SC cars to bring them up in RPMs ASAP so they are in their powerband. With a turbo you spool up much sooner and are in your powerband sooner. With shorter gears you won't be able to make proper use of that because you will be forced to shift really fast since you'll run out of rpms in each gear much sooner. With a lower FD you will actually be able to harness more "power per gear" since you can stay in the gear longer and make proper use of the broader powerband of the turbo setup.

Besides all of that, since a turbo gives power much lower in the rpm range, you'll even have more traction problems with a shorter gear. A longer gear can help you hook up better since it doesn't have the same torque multiplier effect as a shorter gear...

 

500whp is not going to be hard to make you move up rev's (you might have seen them tuning it...which means they keep the revs at the same level to work out fueling).... when you get higher ratio's of gears you are multiplying the torque to the ground... This makes you accelerate faster.... when you are making so much power with a turbo you will reach the limits of adhesion on your tires... much faster with higher ratio gears.... which in most cases means you will accelerate slower... as well as sliding and using up your tires faster...

the question you must ask yourself is what is your end goal of power. If you want lots of power, the stock ratios are fine... even lower might be better... if you want 300 whp, you might want to look into a bit higher!

good luck!

 

I see what you are saying... Right now I am doning a full engine build with turbo.. Looking for 550whp... But I see what you are saying about keeping the power on the ground.. I just was worried about my final gear being so low.. lower than stock because of my Rims.. and I wanted to get a higher final gear to fix the problem