I'm seriously considering getting the Quaife differential to put in my car when I go to change the clutch. I'm sick of one wheeled burnouts and spinning one wheel off the line. Anyway, in talking with both Cattman and Quaife, they say that the diff alone will drop .2-.3 second from 60-foot times, and .5 second from the quarter. If indeed if the estimate is correct, I would be capable of running 14.1's in the 1/4 mile, provided that I can drive the way I drove when I ran a 14.6. Also I would be adding in other variables, such as the ACT or JWT clutch, the motor mounts to supress off the line wheel hop, and possibility of a lightened flywheel. Is .5 seconds reasonable going from an open differential to the torque biasing differential?

 

It looks like you are thinking about ordering some of the same parts as I did. I expect delivery of engine mounts, JWT Stage II Clutch, & Cattman/Quaife ATB Differential next week. I'm still thinking about that aluminum flywheel from Stillen. I'll probably go for it. I also have a NOS dry-shot 70-HP kit ready to install. One of the local Nissan dealers has agreed to do all the work for me, but I don't have an estimate yet... I'll be glad to post once I've had a chance to do a test-drive or two, or three. Any idea what kind of break-in this stuff requires? Please advise. Thanks.

 

I dunno about the JWT but Centerforce clutches say 500 mile break in. As for the differential, that shouldnt need any break in at all. That aluminum flywheel by stillen is the Muellen Fabricators flywheel. From what I've seen its been going for no less then $500. If somebody can get it alot cheaper let me know. At that price I say screw the performance gain (if any) and just go with lightening the stock flywheel. If i'm gonna order this stuff I better order it soon, being its gonna get COLD out here which means no more motorcycle riding and more car driving.

 

.2-.3 off of 60' times seems far fetched, as does .5 off the 1/4 mile time. I just ran my car today, for the very first time, and ran a 14.872@92.68... my engine is bone stock, nothing is done to it. My 60' time for that run was a 2.209.... so according to Quiaffe i could concievably run 1.9 60' on all season no name street tires with 400 treadwear and B traction rating? It would be awesome if that were the case, but somehow I doubt it.

On the other hand, for cars that have more power than mine and have a really hard time hooking up and spin 1 wheel (who manages to do this, i sure as hell don't) it might be very beneficial.

 

I remember hitting the track after upgrading my clutch and putting a set of BFG Drag Radials on the front. My 60' times went from 2.3XX to 2.1XX. My best 60' time to date is 2.123. I believe my 60' times will fall significantly again, once I install my Quaife ATB, polyurethane engine mounts, and JWT Stage II Clutch. No more bunny-hops... I'll be glad to report after I get the mods on, break them in, and return to the track.

 

I wouldn't believe the .2-.3 off the 60' and .5 in 1/4 mile claim. I never get any "peg leg" launching with my car. A limited slip differential is more for autocross than drag racing. I would believe the .5 claim if they were talking about autocross. Seeing that over 60% of the weight sits over the front tires, most fwd cars don't suffer from one-wheel launches. A RWD musclecar with 40% of the weight over the drive tires need posi-traction far more than we do.

If you have trouble with peg-leg launches, invest in a set of drag radials. If you are serious about autocrossing, then get the LSD. You can't go wrong with a better clutch. I'd skip out on the flywheel due to the high price. Most lightened flywheels go for $250-275, but the Maxima's is a ultra high $500. A lightened flywheel will also make for slightly worse driveability under normal driving due to the lack of rotational weight (ie it will be hard to keep rpms up on starts and shifts).


Dave