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Discussion Starter #1
Hey guys, I've got a 1964 mini cooper that's been undergoing a serious transformation to MR layout with a K20A in the back. Now that it's finally running, I've discovered a problem, the gearing is way too short for the small wheels! They're 13x7s and the light weight, high power, and small diameter make 1st gear almost unusable and I can't get past 60 (in 6th O_O) without making my ears bleed out. What options do I have for changing the ratios back to stock feel? Do I just need a new final drive? I've seen a few different ratios of final drive around, but which would work best for 13" wheels? Please make the droning stop and let me put my power down! Thanks for the help

EDIT: Good call, my bad it's the JDM K20A Type-R engine, Y2M3 code tranny I believe, those ratios anyway
 

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which tranny?

early type s' have the lowest FD but I still that would have the same problem....maybe need something custom or fid a way to get bigger wheels in there
 

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13" wheels? What is tire size? Are bigger tires an option for your setup?

Also, there was someone on clubrsx selling *MUCH* longer final drives for people with boosted setups. The 02-04 k20a2 is a 4.389FD which is one of the longest of all the k-trannies (I bought it for this reason). I recall the one made for the boosted folks was a 3.? .

Actually I lied, its a 4.052 : http://www.clubrsx.com/cr/CLU-4FD-p-TFD.html

However thats nearly an 8% reduction across the board.

While you are in there, switch to the tsx 6th gear which is about a 12% reduction.

Put those 2 together and you get about a 20% reduction in 6th gear.

You could also play with your tune w/kpro to help 1st gear a bit. Play with variables like throttle tip-in and gear based ign retard/advance to try to make 1st a little more tame.

http://www.k20a.org/forum/showthread.php?t=6395
 

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First the size of your wheels aren't your problem what is the outer diameter of the tires you plan on using?

So the first link is new final drive, the second link shows the difference in the changes you have made. Just changing this will give you 10mph per gear at crusing speeds and larger increases when your right foot sticks.

http://www.clubrsx.com/cr/CLU-4FD-p-TFD.html

Use this link to get the right gear ratios for your trans

http://www.k20a.org/forum/showthread.php?t=6395

Enter your gears now then using the other FD calculate your speeds

http://www.zealautowerks.com/transcalc.php
 

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Discussion Starter #6
Hey thanks a lot, I'm actually going to look into new tires in January because with about 1500 lbs of car I'm having a bit of a traction problem no matter what gear-> :dance:
I'll have to get on those calcs after I figure out if I can get anything else under those wheel arches, not to mention rubbing. They're pretty cut out but 13 is already huge compared to stock 10's.
 
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