So I have recently installed 4.08 gears and it's a totally different car. By far the best upgrade I have done. I've been looking into the gtm*aluminum*driveshaft*to cut rotational weight and reduce*drive trainpower loss. I was wondering if anyone has had experience with this set up? Will I even notice a difference?

 

you won't feel any difference with the aluminum driveshaft on the street. You will have peace of mind that your driveshaft will not be the weak link of your drive train for lots more hp...

 

Dont go for the driveshaft...the OEM one is solid and strong as f*ck.

If you want to lose rotational mass, go with a lightweight flywheel and some forged super light 19's. That will do much more than a driveshaft.

 

With the 408 ring and pinion how many rpms are you running on the interstate in 6th gear 70mph? I see lots of folks doing this mod what are the main advantages?

 

At 70mph I'm sitting at 3k for RPMs. I highly recommend the gear swap. Absolutely the best mod you can do to our cars besides FI. The advantages are more low end tq which equals faster acceleration. You won't be disappointed for sure.

 

what is the stock ratio?

 

Depends on 6 MT or Auto but I believe 3.54 and 3.36 respectively.

 

Stock 6MT final drive is 3.69

 

I know that these are pretty pricey ($600?) and I will assume that the fuel efficiency also decreases?
I would love to get this on my car...Congrats!

 

Hahaha what fuel economy? I feel like I'm driving a 4x4!!!

 

Go with the PST carbon fiber DS. and nope its the other way around (increase).


If you take 20lbs of RM directly off you powertrain, that's quite significant. Everything now work better, holds more, uses less, reacts faster and gains everywhere.


If I took a bone stock G37s 7AT, put in a PST DS and that's all. Then lined it up to a G37s 7AT with a CAI, HFC's, an aftermarket exhaust and a tune. I would pull away in the stock G victorious with much more money in my pocket, leaving the other guy saying wtf just happened??


So as far as a (GO) mod. That is the best bang for your buck and time, but that's my personal experience and thought. Tires and lightweight wheels and lugs are the best all around, even though its much more expensive. you get GO, WOE, handling, feedback etc... But take the time to research that package to meet your needs and requirements. But if you want to run big boat anchors, then that DS is really going to help.

 

This will reduce rotational weight but the small diameter of the drive shaft means a low moment of inertia, which is why you will not notice a difference...

 

Can you give me more details on this mod? Also how much will this cost me?

 

The driveshaft is a little over 1000.00 but I think you'd do better to get gears first. It's cheaper if you're 7at and just do a 6mt vsld swap. Equivalent to a 6mt going 4.08. The 6mt rear diff can be had for 400-500.00 on ebay. I'm currently working on mine and received my final parts today. Should be installed by months end. Maybe I'll do the cf driveshaft by year end.

 

I'd be curious to see more driveshaft reports. We had a reputable Driveshaft company tell us that the car revs too high for the weight/power to support an aluminum driveshaft, they would only offer CF. Most other driveshafts were discontinued for the G37 as well.

I'm a bit more worried to get one now that I'm running a little less than 400 to the crank and rev to 8000 rpm.