My ring and pinion has decided to give up on me and now I'm debating going to a different ratio. It is a tube chassis car with sniper x headed 632 1.80 glide, 33x15x15 slicks. It had a 4.56 gear and am debating going to a 4.86 since it is 1/8 mile only and crosses the stripe at 7100 shifting 74-7500. My question is will that be too much starting line ratio? Traction is never an issue at this point, runs low 5.0's @138-139 with 1.09's-1.10's 60'.

Put a 5.13 with a 1.64 low. The converter will slip 5-6% crossing 7400. Instead of 10% as it is now. It'll rock n roll when you put it in high gear, et better.

Or a 5.00 x 1.64, starting line ratio will remain identical to it is now.

How often do you make it to the final round?

Not nearly enough.

quote:

Originally posted by inferno camaro:
Not nearly enough.

If you get the right gear in it, that will change I was in 13 S/Pro finals in 21 races, I ran a 3.89 gear, that gear wins a lot. I'd go with it

Kidding of course. I'd do a 5.13 or a 5.00 with a 1.64 low. Just doing a 4.86 won't move your program forward. Do a 1.64 low w/ 5.00 or 5.13 , you'll be shifting lower rpm just to get in high gear sooner. Cross 7400 rpm wfo, or less ripping it.

1.80 x 4.86 = 8.74

1.64 x 5.00 = 8.20

1.80 x 4.56 = 8.20

1.64 x 5.13 = 8.41

This message has been edited. Last edited by: Mike Rietow,

You could do a 1.58 low as well to improve the SLR for S/Pro bracket racing, it'll still et better with the convert closer to 1:1 with the engine.

1.58 x 5.00 7.90

1.58 x 5.13 8.10

If you just put a 4.86 gear it'll just challenge the tire more, with the SLR approaching the T400 SLR you already abandoned when you went PG. Converter might improve 1.5 2% efficiency.

If it's a 1/8 mile specific S/Pro bracket car, it's the perfect one for taking this approach. If it were me I'd want the back half super strong, with the front half mediocre.

Been weighing my options on getting through this season and getting it up and running quickly. I have a race this weekend so throwing a r&p in it for now and next time the trans is out will look hard at planetary swap.
Thanks for the input.

quote:

Originally posted by inferno camaro:
Been weighing my options on getting through this season and getting it up and running quickly. I have a race this weekend so throwing a r&p in it for now and next time the trans is out will look hard at planetary swap.
Thanks for the input.

Yeah, I wouldn't go that way with the SLR. You've already been there, I'd go the other way.

To be competitive S/Pro, you want a mediocre front and super strong back half for not only the tire, but affect (visual).

I agree but I've also learned a lot since that time. What I thought was tire spin was actually lack of wheel speed on some runs. The car was borderline dead hooking or not. I now have ds sensor so can tell more what is going on.
Thanks again and I completely agree with your suggestion, time just doesn't allow right now.

quote:

Originally posted by inferno camaro:
I agree but I've also learned a lot since that time. What I thought was tire spin was actually lack of wheel speed on some runs. The car was borderline dead hooking or not. I now have ds sensor so can tell more what is going on.
Thanks again and I completely agree with your suggestion, time just doesn't allow right now.

What you wanna learn in terms of SLR and wheel speed is, it's easier to ad wheel speed through adjustments with enough SLR, than it is to subtract wheel speed through adjustment, too much SLR. No sensor can help, you want a mediocre front half with an exceptional back half S/Pro bracket racing, which is the equivalent of a inefficient converter early in the run and efficient converter late. 1/8 mile or 1/4 mile don't matter.

This is the quickest path to doing it 1/8 mile. 1000-1200 rpm drops at the shift with a loose converter at the stripe going 5.0's 1/8 mile ain't the easiest most efficient path to getting paid.

I'm actually struggling to get more wheel speed at this point. Can't seem to keep the speed up through .5 seconds.

quote:

Originally posted by inferno camaro:
I'm actually struggling to get more wheel speed at this point. Can't seem to keep the speed up through .5 seconds.

Can you post an image of the graph?

Not sure how to put it on here.

quote:

Originally posted by inferno camaro:
Not sure how to put it on here.

https://drr.infopop.cc/eve/foru...912/m/4367032496/p/1

Instructions scroll down

More gear doesn’t always translate to faster car.
I went from 4.10 to 4.56 same day and ran less than .01 difference and that was in 1/4 mile.

quote:

Originally posted by green1:
More gear doesn’t always translate to faster car.
I went from 4.10 to 4.56 same day and ran less than .01 difference and that was in 1/4 mile.

I believe it, have had several people tell me to go 4.30 gear but seems like that would just make it work the converter harder. Maybe that's not a bad thing just seems like additional heat for no reason but I'm just guessing.

I'm curious of the results. I'm on the fence about a gear change myself, might go the opposite direction I was thinking

quote:

Originally posted by green1:
More gear doesn’t always translate to faster car.
I went from 4.10 to 4.56 same day and ran less than .01 difference and that was in 1/4 mile.

The rate of work (power) is dependent on torque and rpm

hp = torque x rpm / 5252

Well I've found a 4.86 I'm going to use the rest of the season. I'll decide this winter what to put in it.

quote:

Originally posted by Mike Rietow:

quote:

Originally posted by inferno camaro:
I'm actually struggling to get more wheel speed at this point. Can't seem to keep the speed up through .5 seconds.

Can you post an image of the graph?

I just made it a video and put it on you tube.

https://youtu.be/Wu3vYLolj58