anyone hear actually get this done to their car, and if so..what should I expect out of it, and I mean difference in MPG, accelaration, overall performance, pro's and con's. What else should i worry about before installing it. etc. etc.

 

Only one person on here that I have read has did the 3.7 gear change. He did not say it was a bad thing. But after just getting my 3.5 installed, i can't imagine there being that big a differnce to be noticable myself going from the 3.5 to the 3.7. I myself would recommend the 3.9. But if you want to persue that route just do a search for 3.7 fd it will pop up

 

If you're going to d it, do it all the way and get the 3.9; I have it and love it. You'll nitice much quicker acceleration. My city milage has actually gotten better, since I find myself upshifting sooner and staying in the taller gears longer. Highway milage only suffers slightly. Tere really are no cons to this; just make sure you have a good installer.

 

+1

Was just going to say that. Look at the Central 20, it's the same price as the Nissan 3.7

 

Are these a good change for FI though. I'm already shifting quick. Are any of you guys FI with these FD swaps done.

 

3.9 gears are mainly for NA cars, but it also depends on the type of FI. shorter FD gearing works well with a centrifrugal SC like Vortec, since power builds as RPMs rise and the gears get you into the higher RPMs quicker. Pointless for turbo cars, though; they're already hurting for traction and this will just make it worse. Most turbo guys, if anything, swap out to taller gearing (the 3.3 from an AT).

 

Thats what I was thinking, thanks.

 

yea..see.that's what I'm thinking too. cause i already bought the 3.7 FD, i was gonna get the 3.9, but heard it really kills your MPG. However i do plan on going to VRT someitm ein the next 365 days to get the "race" prep turbo kit install.

 

do the 3.9 so l8r when u get the turbo kit u can trade me for my 3.5...lol. party in like 2 weeks

 

Good luck with VRT. Be sure to post your results.

 

I have used (tried) all types of gear ratios on NA and TT'ed cars to find out what works and is a good idea and what isn't. I have found that 3.9 is great for an NA car (that is going to stay NA) and perfect for the centrifigal SC'ed cars like the Vortech and ATI Pro Charger.
With a turboed, or TT'ed car, it is always best to stick with the 3.5 or go with the 3.3 if you can. Let me know if you need any moore spacifics.

 

thanks guys for your input. What's a reqally good not so expensive place that can do this install?

 

I'd try learning to spell before getting this far ahead of yourself with mods.

If you are going turbo, don't get it.

 

How much do installation cost for installing these things?

 

Pumpkin Swap isn't too bad, regearing your pumpkin might sting a bit. Not definate on pricing.

 

how much worse of MPG do u actually lose with the 3.9?

 

I'm actually getting better milage in town, since I find myself upshifting sooner and staying in the taller gears longer. Don't do much long highway driving, but it's not supposed to drop much (2-3 MPG, maybe); with city driving prevalent, it far offsets any losses on the highway. It really all depends on how you drive, though.

 

ha ha. yes. learn to spell.