bbundy

Curios what rear end ratio you’re using with the Quaife gear set for autocross. I assume it’s the wide. By my calculations and experiences I think I would want a 4.875 definitely not more than a 4.44. Stock 5 speed with a 3.909 was too tall in second I got significantly faster with a 6 speed 3.636 second gear combo plus turning up the revs to get barely enough top speed. But throttle response and torque is instantly available at all the places on an autocross course that you want it that way. Reaching 73 mph bouncing off the rev limiter for a short bit versus 68 doesn’t mean **** for lap time if you’re loosing any acceleration and throttle response off the 30mph corner to get it.

Quaife wide 2nd through 5th looks very close to 3rd through 6th on the stock 6 speed and 1st is a little taller than mid-way between 1st and second on the stock 6 speed. This is Excellent track gearing! Totally useless on the track if you select the proper rear end gear it for autocross in my opinion.

Maybe I just need two rear ends and add rear carrier swap that to my growing list of swap parts to run both disciplines with the same car. Add another couple grand to the cost of using a Quaife.

codingparadox

iTrader: (2)

Wide set, 4.3 rear end. 8000 rpms = 75 in 2nd.

bbundy

That's almost Identical 2nd gear to a stock 5 speed with a 3.909. my car bogged a lot out of slow autocross corners with that gear which in turn prompted a lot of initial over application of throttle pedal followed shortly thereafter by too much wheel spin and the feeling you were going to lose control and crash when the power comes on. With my current gearing it never bogs in second if the car is rolling at all. Power response to pedal movement stays fairly instant and linear.

I'm thinking maybe another 5mph worth of gear at the top of second than what I have might be good 10 is definitely too much for my power delivery to stay in the sweet spot.

TNTUBA

iTrader: (1)

What that guy said. But I only spin my motor 7700

TNTUBA

iTrader: (1)

There is no such thing as a racing part that wont eventually break. I have seen Jerico transmissions shatter gears at 1/2 of the power for which they are rated.

Leafy

iTrader: (1)

Bob you're talking two guys with twin screws that make over 200ftlbs starting at idle.

hankclaussen

iTrader: (5)

Sure but I don't think the Quaife is taking 500ft/lbs very well, this other one is designed for it. Not that I'm going to make that.

bbundy

I make 200 ft-lbs at 3100 rpm but Over 300 by 4200 rpm till about 7200 where it slowly tapers down. Car is substantially faster if it stays above 4000 rpm off slow corners and much easier to drive staying away from transitioning through the rapid torque rise part of the curve.

bbundy

Codingparadox versus my dyno plot, same dyno same tuner. David is using E85, Im using pump gas. And that dyno pull for me is at my 20 psi boost cut. I run 18-19PSI for autocross so take out 10 to 15 off the numbers on my plot. ~14PSI for NASA TT2 to get right around 330 hp. I make a boatload more torque ~50 ft-lbs but to keep the car in the controllable flat torque curve part of the plot slow corners need to be taken at 4000 rpm or better.

codingparadox

iTrader: (2)

The point of the above statement was simply that we have linear/controllable torque from as low as needed, so we can make our gearing as wide as we want.

bbundy

With my power curve I have become a gearing snob. I'd hate to spend a shitload of money and have my car be slower.

Leafy

iTrader: (1)

They have different gearing requirements than us. We want a 7.74 total gear reduction, they want 7.04ish. Thats the difference between having a 8500rpm redline and a 7500 rpm redline with matching powerbands for both.

TNTUBA

iTrader: (1)

Que the pointless Supercharger vs Turbo pissing contest.

Leafy

iTrader: (1)

My redline's higher than your redline.

kaisersoze

iTrader: (8)

Emilio, any updates on the 6 speed gearset?

emilio700

iTrader: (3)

I would not keep it a secret. We're building a 350whp track car that could certainly use such a trans so my interest is very specific now.

kaisersoze

iTrader: (8)

Great, just wanted to know if you were still moving forward with the gearset so I can continue to wait, instead of saving up for the PAR gearset or the Richmond 6 speed.
Thanks for taking this on

bbundy

Keep me posted. I could certainly put such a gearset to the test.

92mazdaspeed

I am also eagerly awaiting a 949 custom gearsets. Thank you Emilio in advance for your hard work getting one put together.��

codingparadox

iTrader: (2)

I'm about to also have a low miles 5-speed box with Quaife gearset installed and proven to hold power for sale in around a month, for people who need a solution sooner. ;-)