Throttle Stop w/ 1 blade TB / roll RPM Q

[Lenny5160]

Originally Posted by Tom Goldman

With a small tire like that , shift on the stop . less likely to spin and you will get more MPH

Not saying that I disagree that he should shift on the stop, but I don't agree that it will result in more MPH.

I'm NA, but in both my S/ST and SC car I come off the stop in Low and shift downtrack on RPM. I lose little to no MPH doing this, and especially in SC I will out-MPH cars that have 200+ more horsepower than I do. It takes a lot of power and time to get the car moving in High gear.

Again, if I had a supercharged small tire car I'd be shifting on the stop, but it will cost you some MPH.

[Marc]

Originally Posted by Lenny5160

Not saying that I disagree that he should shift on the stop, but I don't agree that it will result in more MPH.

I'm NA, but in both my S/ST and SC car I come off the stop in Low and shift downtrack on RPM. I lose little to no MPH doing this, and especially in SC I will out-MPH cars that have 200+ more horsepower than I do. It takes a lot of power and time to get the car moving in High gear.

Again, if I had a supercharged small tire car I'd be shifting on the stop, but it will cost you some MPH.

I think they way Tom recommends the OPs car will be traveling slower while on the stop therefore shortening stop time and increasing the length of track to gain MPH. Personally I saw a noticeable increase in trap speed and decrease in stop time just by shortening the shift point from .65 to .40.

[Lenny5160]

Originally Posted by Marc

I think they way Tom recommends the OPs car will be traveling slower while on the stop therefore shortening stop time and increasing the length of track to gain MPH. Personally I saw a noticeable increase in trap speed and decrease in stop time just by shortening the shift point from .65 to .40.

Agree that the earlier on the track you go WOT will result in higher MPH, all other things being equal.

Disagree that with stop RPM and stop ON time being equal, a car coming off the stop in High gear will have more MPH than the same car coming off the stop in Low, even with the Low gear setup having a longer stop duration and going WOT further down the track.

[DailyDriverSst]

Originally Posted by C5 Pete

Question about the single blade TB.

Are you talking about a cable operated TB with a throttle stop, or using a plate under a DBW TB?

I’m trying to figure out a solution to this same problem as the OP. I’m currently using a DBW TB, but I can make the switch to cable, if it’s the only way to make it work.

Thanks for any guidance.

Cable operated TB. FAST/Accufab 4150 (4x44mm) comes with morse ball and F&B 2x58mm can be optioned for a morse ball. Single blade I am still working on, but i'm told that if you can get through to Accufab or Holley tech support, that it's possible to have a morse ball linkage made for their 90-105mm TB's. Worse case, there are 10" cable-wrap to 10-24 morse stud adapters made. But I hate cable-wrap TB's because you can't use a toe hook if it hangs open- it will just push the cable off the guide rather than push the blade closed.

A blade stop will not work with EFI for same reason it won't work with Enderle/Rons injection. You can restrict the airflow all you want, but the barrel valve or ECU TPS will still see WOT and be dumping fuel in.

Just for my 2¢ , I agree (especially in my case of being on the heavy side for factory interior; essentially super stock trim) that coming on the stop in high gear will control wheel speed but lose MPH and possible consistency from the motor lugging from basically a 20-30 MPH roll in high gear. On the other hand, coming off the stop in low gear may yield a traction limited situation depending on how the boost curve comes in.

I'd like to think that even at 9" wide, a 30" tire with a powerglide and 3.89 gear would be pretty damn hard to spin coming off the stop in low gear. But again, depends on the boost curve.

[C5 Pete]

Thanks for the reply. Like you, I’m looking at how to adapt a rod to the single blade TB. I could use a 4150 and an elbow, but I’d prefer not.

And as for forcing the blade closed if it hangs open, I have an interior battery cutoff that will kill everything mounted to my shifter.

[DailyDriverSst]

Originally Posted by C5 Pete

Thanks for the reply. Like you, I’m looking at how to adapt a rod to the single blade TB. I could use a 4150 and an elbow, but I’d prefer not.

And as for forcing the blade closed if it hangs open, I have an interior battery cutoff that will kill everything mounted to my shifter.

I would like to see somebody do an A/B test on a known good intake manifold, pulling through a 4150 with nothing on it, then with a hat/elbow on it, then with a 4150 elbow and single blade TB.

These are the adapters i've found.

https://www.kartek.com/parts/push-pu...-body-cam.html

http://www.pacificcustoms.com/cabletb.html

[C5 Pete]

So, with these adapters, the cable mounts just like a standard cable on throttle body, but the threaded end screws onto the end of the ts shaft?

I was considering welding a rod onto the blade cam of the throttle body to attach the rod, but maybe this cable adapter would work better.

[DailyDriverSst]

Originally Posted by C5 Pete

So, with these adapters, the cable mounts just like a standard cable on throttle body, but the threaded end screws onto the end of the ts shaft?

I was considering welding a rod onto the blade cam of the throttle body to attach the rod, but maybe this cable adapter would work better.

From my understanding, it has 10" of cable that wraps on the cam like the OEM throttle cable, then has an adapter to screw onto a morse cable or throttle rod.

[C5 Pete]

Well, I ordered the 10" cable from Kartek.

I have a TS coming from Biondo, and a cable TB to replace my DBW TB.

I will figure out a way to mount this onto the Holley Hi Ram I have on my 427 LSX.

I'll report back once I get everything.

[B1Ken]

For what it's worth, I used a Ron's Terminator on the stop for ONE RUN. I got gassed out by the Methanol, so I put the carburetor with gasoline back on. I ran the Terminator on the stop with a solenoid bleed actuated by the throttle timer, through a 90 pill at 3500 rpm. Worked fine