Bracket Talk
TD: Engine/Drive Shaft RPM Ratio in Lights?

This topic can be found at:
https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/1737093186

July 17, 2018, 02:55 PM
David Gerard
TD: Engine/Drive Shaft RPM Ratio in Lights?
Our Racepak computer automatically gives us a Engine/Drive Shaft RPM Ratio reading all the way down the track.

We know our current converted is way too tight for the Nitrous HP we were using and have just added another 200 HP to the new fogger system.

I was wondering that other successful TD cars have for a E/DS ratio in the lights.

I am only asking for TD responses please.

Thanks...
July 17, 2018, 09:07 PM
TOP38
TD really has nothing to do with your question. Top end slip is related to load along with the converter makeup. Without more info I'd say 6 to 8 percent is in a good range.
July 17, 2018, 09:29 PM
Bucky
I think there is a top dragster section if that's all you want for responses. Not being wise, just pointing it out.


Foxtrot Juliet Bravo
July 18, 2018, 05:27 AM
BJs Wild Ride
I'm not sure if I'm allowed to answer since I retired from T/D, but if it's slipping, you're doing it wrong.
July 18, 2018, 07:20 AM
jenavet
I think 5 to 7 percent is really good but as bj said my converter guy is trying to get it closer to 0 at the stripe.
I find the closer I get to 0 my trap rpm drops but I et better
July 18, 2018, 08:40 AM
Greg Kelley
It depends on converter design. What I'll call the "new" design can easily go into overdrive - yup DS RPM higher than engine.

I have only seen these converters in power adder or 800+ CI NA motors.

For "regular" converters 3-6% is typical.

Having said all that, IMO it's not a lot of ET in low slip numbers.




GK - www.MotorSportsInnovations.com
609-265-2110 GKelley@MotorSportsInnovations.com


July 18, 2018, 09:04 AM
Old SG
My son's car at 215 mph is 7500 rpm and drive shaft rpm 7500. 3.89 gear, big bubbas, 747 CI on nos. Coan convertor. We have 3 different stators each a little different. One will go to overdrive at the big end. Coan does fab some awesome convertors.


Denny Johnson
I'd rather win than drive.
SG 559
TD 5595 2015 Mile High Champ
TD 559 2016 Mile High Champ
.991
4.112 @ 174
6.372 @ 216 DA 8875