Second sensible question

Anonymous · Post by **Anonymous** » Tue Sep 18, 07 10:51 pm

thats a light car! our runner weighs 2700 without my dad with an all ally motor, 500hp should put you easily into the 10's as our 493 was making around 620 and ran 9.90's without gas, i think i'd go 4:56 gears and around a 4000 stall 10inch coverter, when we were ordering a new converter we spoke to a lot of different people and ended up going for a PTC 9in which is around 5200 rpm stall with the billet front but we're now putting out arounb 800hp, but if you give any manf your combo they will spec you a verter just for your set up, expect to pay £500+ for a good one tho (ours ended up at £1100!)

Anonymous · Post by **Anonymous** » Tue Sep 18, 07 10:55 pm

no problem, thats just my opinion tho i am prepared for being shot down in flames

Mick · Post by **Mick** » Tue Sep 18, 07 11:42 pm

Pete
What diameter tyre do you run, you want at least a 9" convertor with that cam.

Kev · Post by **Kev** » Tue Sep 18, 07 11:46 pm

Mick · Post by **Mick** » Wed Sep 19, 07 12:08 am

4.88 gears would be better.

Dave-R · Post by **Dave-R** » Wed Sep 19, 07 8:52 am

marc-jerryatric wrote:no problem, thats just my opinion tho i am prepared for being shot down in flames

Why would you be shot down in flames?

You only repeated what some of us were saying anyway!

AllKiller · Post by **AllKiller** » Wed Sep 19, 07 11:44 am

The more power/ torque your car makes the higher your stall will be anyway , regardless of the spec'd stall

Dave-R · Post by **Dave-R** » Wed Sep 19, 07 2:34 pm

Absolutely. Which is when it was said that the cam is a solid I said stick to the 4000rpm convertor because it will stall higher than with the Hydraulic cam.

But I wouldn't want a stall much higher than that to be honest. It depends on what his rpm limit is. I personally wouldn't want to shift and have the next rpm point below the stall speed.

For example. If he is shifting from first at 6500rpm his rpm at second will be 3846rpm. At the start of third rpms will be 4140rpm. If the stall speed is 4500 it will slip for a fraction of a second.

I don't know if it would be a bad thing for performance or not but I don't like the sound of that.

AllKiller · Post by **AllKiller** » Wed Sep 19, 07 2:43 pm

Very true

Mick · Post by **Mick** » Wed Sep 19, 07 9:26 pm

The only true way to pick a convertor, is from a dyno sheet for the engine, it should stall about( i think) around 500 rpm above max torque but dont quote me on that.
Mick

Anonymous · Post by **Anonymous** » Wed Sep 19, 07 11:05 pm

and the best way to kill the motor is also on the dyno Mick, i bet more motors blow on the dyno than on the track, you don't need to dyno a motor to spec the converter, you can spec it from the engine spec,

AllKiller · Post by **AllKiller** » Thu Sep 20, 07 9:35 pm

Why would a motor be more prone to blowing on the dyno than in the car Mark ??

Dave999 · Post by **Dave999** » Fri Sep 21, 07 10:40 am

glad you asked that..

anything to do with no real life air flow through the rad?