Want to run 9.90
 

First post..........
I would like to run SG in some Div 7 races but mostly run Super Pro @ 9.90 in local bracket races on the West Coast.


I'm new to all the delay box, throttle stop stuff plus I'm running a 3 speed transmission. I've installed a Pro Cube delay with 1 timer and I have a 2 stage ACD throttle stop, SLE and down track ET controller capable. Also a PPP Air shifter.


I being told I can't shift on RPM (using my separate 2shift RPM switch) when on the stop. If one timer is capable of 4 stages on time, could the stop and shifter be wired into the box using the same timer so I'm not shifting while on the stop? Is this even possible?


I apologize in advance for my complete lack of knowledge or correct use of terminology.


Jeff

Re: Want to run 9.90
 

I don't think I fully grasp the question about the stop and shifter using the same timer, but you can absolutely just shift on RPM if you want to. I shift my SST and SC cars on RPM.

If someone told you that you can't, it is possible that they were saying "you can't shift by RPM while on the stop" because being "on the stop" implies that the throttle stop is activated, and your RPM generally stays flat while that is the case.

Re: Want to run 9.90
 

Yes, I was told I couldn't shift by RPM though the box because the Stop was on. But I could shift on time through the box.


I don't know enough to know how to word my question yet. Let me ask another question if I may?


I have a delay box with one timer. My throttle stop starting line function would be hooked to pro-stage terminal on box and ET limiter side hooked to the "only" remaining timer function on the box. I have an air shifter that needs activated to shift my C-4 transmission. How do I accomplish activating the shifter in conjunction with delay and throttle stop?


Do I need a box with more timers ?

Re: Want to run 9.90
 

Explain what you'd like the shifts to look like.

Do you want the car to shift while it is coasting on the throttle stop, then shift a second time downtrack at wide open throttle?

Do you want to launch hard, then go on the throttle stop, back wide open while still in first gear and shift twice down the track at wide open throttle?

Does your ignition system have the ability to control the shifts, or must the delay box control it?

Re: Want to run 9.90
 

Launch hard then go on the stop, then shift down track.


Ignition can not control shifts, just delay box or separate shift controller

Re: Want to run 9.90
 

If you want both of your shifts to happen by RPM, you can absolutely do that. No issue.

Re: Want to run 9.90
 

Thank you Lenny for the help.


I just purchased the Pro Cube with 3 timers and ZForce from K&R so I'll let the box shift it on time.


Jeff

Re: Want to run 9.90
 

Seems less than ideal, if I'm understanding it correctly. If you want the shifts to happen down track at wide open throttle, the time setting for your desired RPM will change every time you change your throttle stop time. You'd be better off using RPM as the shift trigger.

Re: Want to run 9.90
 

As I mentioned in my first post, it's painfully obvious that I have no clue what I'm doing. That really is the main reason I joined this forum, to read and ask questions.


I guess I need to shift into 2nd on the stop then coming off the stop say 7000 rpm = time? shift into 3rd for the remainder of the run. Thought time was more consistent than RPM?


I thank you Lenny for taking the time to help this racer whom thought he'd have a go at electronics racing.

Re: Want to run 9.90
 

What about getting it to shift to high gear when your on the stop? Wouldn't that be the most consistent? Thinking you would need a little down track speed but your really fooling the car to think it has a PG trans.

Re: Want to run 9.90
 

How fast does the car run wide open? That will influence the options you have. As Hacksaw mentioned, you can go all the way to High gear while on the stop, but you probably want to be a full second quicker than the index (say a 8.90 or quicker car when trying to run 9.90) to pull that off. I get the feeling that your car isn't that quick.

I've never run a 3-speed, but here's what I think I would do in your situation. I'd launch the car hard, then put it on the throttle stop. Have your shifter hooked to a timer which would put the car in 2nd gear shortly after the throttle stop turns on. When the car goes wide open again, I'd either have some way to put the car in 3rd based on RPM or just shift it by hand at the desired RPM.

Re: Want to run 9.90
 

That could work. 1, 2 shift........On stop, come off in high gear. What kind of shock to the converter would that be if any?

Re: Want to run 9.90
 

To be honest I have no clue what it runs...........I run at altitude 4000ft. This is an all new combo 445ci SBF, C4 trans, 486 gears. 2260# with me in it.


Just fired the motor first time last Sunday while everyone was watching super bowl.

Re: Want to run 9.90
 

I've never run a 3-speed, but here's what I think I would do in your situation. I'd launch the car hard, then put it on the throttle stop. Have your shifter hooked to a timer which would put the car in 2nd gear shortly after the throttle stop turns on. When the car goes wide open again, I'd either have some way to put the car in 3rd based on RPM or just shift it by hand at the desired RPM.[/QUOTE]



I run a 3 speed TH400 in 9.90 and this is how I have my shifts set.

Re: Want to run 9.90
 

Have you done the math regarding rear gear and tire size? As far as finish line RPM goes?

Re: Want to run 9.90
 

Yes, I have and finish line rpm would be about 7600.

Re: Want to run 9.90
 

I think as long as you have some decent rpm and wheel speed on the stop the converter can handle it and recover quickly. Lots of PG racers do this now. Check with a doughnut maker and get there advice.

Re: Want to run 9.90
 

I would call Chris Continental but they are out of business.

Re: Want to run 9.90
 

Ok, so I made some passes and the car without any tuning or real testing is running 9.55 @ 140.21 @6200ft DA.


1-2 shift @ 1.8 secs and 2-3 shift @ 3.9 secs obviously short shifting some.
A-1 converters just built me a killer converter.

Super Gas adjusted index is 10.30 at my track.


I need to figure when and how long to put it on the stop now.

Re: Want to run 9.90
 

Turn stop on about .2 then shift into 2nd about .5 and come off stop in 2nd and shift into third off RPMs