Throttle Stopping
 

This will be my first venture into S/R racing and was kinda looking for pointers on the T/Stop settings. My car will be approx 1.75 sec under the index. I am looking at going on the stop at .2 or .3 and shifting at .6 and then being on the stop for 1.75 or the approx differance in et on a wide open run to a T/Stop run. Think I may be close or way off ?

Re: Throttle Stopping
 

Search the forum for "stop" and you'll see several helpful threads, this being one of them.

http://classracer.com/classforum/sho...highlight=Stop

Lots of variables (like stop RPM) but get close to find your ratio and go from there. Someone running about the same ET can give you a start point but "your results may vary". Biondo's site also has some good tech tips on running a stop.

Re: Throttle Stopping
 

Thanks,will do.

Re: Throttle Stopping
 

Look us up in Virginia and Jr will help you get in the right direction. Call me if you need to..
We will be there Thursday nite (early)

Re: Throttle Stopping
 

My car will run 8.50 flat out and I am on the stop at .3, shift at .5 and am on the stop about 2.20 with air about 2500-3000ft and 4200 rpm while on the stop. Last year at Virginia in October I was on the stop about 2.5 seconds, hopes this helps.

Re: Throttle Stopping
 

cdh124 is close if your "cruise " rpm's are about 4200. you'll be at 2.50 or so...good luck.

Re: Throttle Stopping
 

I will go to idle at .2 or .3 and shift @ .6 and thought that with a car that can run at least 1.75 under index that I would start by taking that amount (1.75) and stay on the stop that amount of time for starters. By running a Terminator I will go to idle quickly. I could be all wet here:confused:

Re: Throttle Stopping
 

You're assuming a 1 to 1 ratio and that's incorrect...remember you're still covering ground while on the stop. And your RPM on the stop needs to be up in the ~4200 range. Think the others are right with 2.50 being close. Danny and his son can get you close too...better do the test and tune, you'll need 2-3 laps to even get close to your ratio.

Re: Throttle Stopping
 

Thanks for helping.

Re: Throttle Stopping
 

One of Biondo's excellent primers on stops, more on their site. They are great to deal with and one of ClassRacer's sponsors BTW.

http://www.biondoracing.com/manuals/...20Stops/TS.pdf

Re: Throttle Stopping
 

Going to idle w/fi changes a lot from carbs...try to find a racer with the same set-up,you could wind up 1-1 or close

Re: Throttle Stopping
 

You can install an electric leanout......turn it on when you go on the stop.

Experiment with pills to see what runs clean at somewhere around 4000 and once you have that done you can run your injection just like a carb.

Thats what I did and it worked well for me . I used a .050 pill in my leanout if I recall right.

Most people go to an idle with injection and if that works for you fine.....

I killed a second to go 8.90....and had close to 2 seconds stop time usually and used the leanout all the time.

One race the car was not responding to t-stop changes right.....I went down to 4 cars anyway..

I discovered the coil for the electric leanout had burned out and the leanout was not opening and that was why my t-stop time inputs were not following as they should have..

I have a Terminator on my dragster now.....never installed the leanout yet...mostly bracket race with it...

Re: Throttle Stopping
 

I have a electric lean-out on it with a .40 in it. Just like to throw something in the ole pit and see how we all look at it. More than likely will test and throw 1.75 in for a starter and then a change to get the multiplier and give them a whirl.