As the title states I'm looking for opinions on what gear ratio I should go with for the differential? I just placed an order yesterday for a puddymod stage 2 with a 3:90 gear but now I'm contemplating If I really should go with the 3:63. The car has the following upgrades- stock bottom end never opened, ferrea beehive springs and titanium retainers, id2000's, walboro 485 (wires correctly with the sos return kit), afi T4 twinscroll kit, and a Borg s366 with the billet wheel upgrade. Currently running boost by gear on flashpro 1st and 2nd= 12 psi, 3rd= 16 psi, 4th= 22psi, and 5th/6th= 28-30psi. Goals for the car are some 1/4 mile here and there but I would really like to do some 1/2 mile and mile events. I posted a video of me racing my buddies ford gt in the street encounters section and most comments were "with better gearing you could take him" so another goal I have is to be able to pull on him until I run out of gear. I spoke to Ben (puddymod) and he thinks ill be just fine with a 3:90 since i already have bigger drag radials on it now. It's got hoosier 275/40r17's currently. What's everyone's thoughts? Here's the video I was talking about. Enjoy and thanks for the input!

https://youtu.be/uQx88E4si48

 

This motor needs to rev. The lower you go with the differential, the harder its going to be to stay in the powerband. 3.6 rear might make the car too lazy on the street. Try out the 3.90 and see how you like it first before you go that low.

 

Yeah with your rear tire id tend to agree on the 3.90. Your turbo is pretty laggy compared to your buddys car so you are losing some time there, If you can remove the boost by gear at least from 3rd up and modulate the car a bit more with your right foot if traction is still an issue, that would probably help quite a bit. The re gearing should help address some of the traction issues.

 

Thanks for the input I think I'll definitely stick with the 3:90 and see what she does and if she doesn't work how I want its not that big of a deal to change!

 

Thanks for the help.. It was your post in the street encounters section that got me contemplating the 3:63 gear ratio lol. You're exactly right on why the boost in 3rd is set so low, it would blow the tires off even with the drag radials. Hopefully the 3:90 gear will help out with that a bit sorry I didn't reply to you in the street encounters thread I totally thought I did :\

 

Its all good, I didn’t know you were running a 275/40. So 3.90 would probably be the best overall option. Especially if you decide to go with a taller DR tire at some point to help with traction.

 

http://www.turnzero.com/technical_re...ear_calculator

 

stage 4 is only a little extra. pictured is my old one (left) and new on (right) with larger capacity finned reservoir.

 

I have a 4.9 ratio, its fun

 

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