Tightning converter

[8secpumpgas]

Do you think a 9.5 converter could be too small for a 632 conventional headed motor, its in a 3500lb camaro? On the motor it seems fine, but on the nitrous my shift light stays on from the 1/8 to 1/4. How much to send it in and tighten up? thanks

[camaroman9]

I would think so chris. It seems to me that the smaller diameter wouldn't put up with the heat very well with the horsepower your car makes and the given weight of the car. I'd like to think it would cause too much heat in the trans/converter. I wouldn't go off my word though. I'd just wait for the expert to answer.

[8secpumpgas]

Robert you can buy me converter, and I'll pay you back over a 10 year period.

[John_Heard]

In some cases it might be cheaper to buy another converter if you can find what you need used. More than likely you're going to need a stator change, etc. and that can be expensive. What converter you have in it now?

[8secpumpgas]

An art carr 9.5. It's been in the car for 6 years

[Marty Chance]

The 9.5"converter is going to be too small to effeciently harness the torque of a 4.750" stroke conventional headed motor on nitrous. They do work well on motor but for the juice you will need a 10" and unfortunitly the 10" will be too tight for the motor. There are some acceptions but the above is most likely. If you want me to go over your specs in greater detail , give me a call when you have time to spend about 20 minutes going over the specifics and i can tell you with exactly what will work best for the way you are going to run the car

[TubbedTruck67]

Give Marty a call Chris he's the man. When he tightened mine up I think it was around 300 bucks and i even got the stator out of his own car if I remember right just so I could get back to racing quicker.

[Bob West]

Your fast enough Chris

[camaroman9]

Bob, that's like saying you're tired of doing big fancy wheelies...

[Craig W.]

Hey Marty, what kind of rpm drop should I be seeing on the gear change with my 'glide? 1.76 first gear. I think I've stepped the nitrous up to the point I'm blowing through the converter some.

How would tightening up the converter to take some of the slip out effect the launch? This a Outlaw 8.5 car.

Thanks.

[Marty Chance]

RPM drop should be between 700 to 1200 depending on the torque curve of the motor.


If you tighten the converter up it will not flash as high on the launch , and this may allow you to get your nitrous on sooner

[Craig W.]

I'm seeing 830-840 rpm drop.

I've haven't had this motor on the dyno. Just been on a chassis dyno a few times. I don't have any recent pulls at the power level I'm running at now.

Its flashing to 5500 right now and I shift at 7000. I have to be pretty conservative with the power very early in the run, so help on the low end would be good.

First thing I'm going to do is look at the high gear clutches.

Thanks for the info. I appreciate it.

[Marty Chance]

If it drops 800+ rpm then you are not driving through it , that does not mean you could not benifit from lowering the stall , it means you may not need to lower the stall.
what cI inch is the motor? bore / stroke ? how much nitrous?

[Craig W.]

18 degree 434 sbc. 4.155 bore, 4.00 stroke. I'm spraying around a 400 shot.

Its been a 5.43@127.9 at 3200 lbs on 26x8.5s with a 1.26 60' with limited rules (single stage plate, no wheelie bars are the main ones). Decent for a stock suspension leaf spring car but not enough to run with the #1 guy. I need to get it in the .30s.

Thanks.

[Marty Chance]

your whole combo is pretty good, you need data aquisition at this point to try to improve as the only thing left to tune is the small things that cant be seen with out a data logger. A basic system with engine rpm, driveshaft and g meter is all you need.