Throttle stopping injection

Hustler1098 · 03-18-2009, 01:06 PM

Wondering if anyone out there has had any luck throttle stopping injection... setup is two toilets on a 572, in its current setup should run roughly 7.50

I've talked with James Monroe and he the advice he gave me was to bring the rpm down to about 2800 on the stop and go out a little further than most do in order to burn the fuel that may puddle up on the starting line

Any other advice anybody might have or does that pretty much sum it up? Also, does anyone have any approximations as to what kind of time I will have to run in the timers...

Thanks...

GaryGoFast · 03-18-2009, 03:07 PM

1st, I would do what James says, he's got some experience but I know more than one who have their stops go to idle and I think its to control the fuel pump rpm. This usually gives you a 1:1 ratio. Hope this helps.

Dave Steltz · 03-18-2009, 03:15 PM

We have some guys doing it here in D1....kill it down as low as possible...(I kill mine to 2000 with a terminator)..that way the pump wont overload you on fuel, and then let it rip..might want to get a electronic bypass to bleed some off...

I also kill mine at .2, so not really going out too far...

At that low rpm, you will be about 1:1 in your ratio, so if you're looking at 8.90 do the math...

Tom Goldman · 03-18-2009, 04:10 PM

With a barrel valve that has a part throttle bypass, you can run it clean at any rpm . ....you can get one from Kinsler.......If you don't want to change the barrel valve,then use the electric bypass, tied in with the timer......without a bypass,you need to get as low as possible on the stop rpm,while going out farther than a carbureted car before going on the stop. .....Tom

Hustler1098 · 03-19-2009, 10:09 AM

Quote:

Originally Posted by GaryGoFast

1st, I would do what James says, he's got some experience but I know more than one who have their stops go to idle and I think its to control the fuel pump rpm. This usually gives you a 1:1 ratio. Hope this helps.

Gary, what he said was to go to "idlespeed" which would be about 2800 downtrack. Honestly, I don't know what idlespeed means in this context.

To the others, when I say further out I don't really mean way out.. I guess a lot of carbs only go out .1 or .2 whereas James said to go out .8 or so we're still talking about going on the stop at about 30 or 40 feet I guess...

When you say 1:1, I guess that means a tenth on the stop for every tenth you want to kill? So to go from 750 to 890 I would be on the stop 1.4 seconds? Sorry if I'm way off base, like I said I've never .90 raced before in my life and have no idea where to start...

Thanks for the replies...

Dave Steltz · 03-19-2009, 10:44 AM

Quote:

Originally Posted by Hustler1098

When you say 1:1, I guess that means a tenth on the stop for every tenth you want to kill? So to go from 750 to 890 I would be on the stop 1.4 seconds? Sorry if I'm way off base, like I said I've never .90 raced before in my life and have no idea where to start...

Thanks for the replies...

Last year my car went 8.70's...I ran .95 in the stop to go 9.90's...so I'm a little less than 1:1...but I'm killing it down to 2000 not 2800..(and by the way, by idle I assume you meant idle, 1200 rpm)..I know a couple of guys who actually go to a dead idle but I like to keep it a little up off idle...

Remember generally the farther out you go the more time you need in the stop...but like I said previously I go out .2 or .3...just to make sure I get off and away...

One thing you will also experience is this will be almost like two launches...one at the hit and another when the stop comes back off..I was coming back off in 1st gear so its a rush...shifting on time while on the stop will soften that a little...

So yes at 1:1 you would have exactly the time in the stop that you want to slow down from all out...

nemo963 · 03-20-2009, 10:07 PM

Im running a 1800 lbs hardtail and a 540ci BBC with twin toilets. We have run this combo in super comp (and brackets) since '91. We launch and go on the stop at .5, using a in line stop we drop down to 3800 rpm, shift on time at 1 second, and come back on around 2.5 seconds or so. We run consistant year to year and go rounds at the Div 5 races. We dont run a electronic bypass or anything else, not saying that it wouldn't help, thats just been our experience.

Hustler1098 · 03-24-2009, 08:38 AM

Nemo,

What do you run off the stop in the 1/4?

art leong · 03-24-2009, 04:18 PM

I was just going through this thread. This is for a totally different application. I have a electronicly controled 4 cylinder using LS1 coil over plug setup. I tried using a 2 step that was setup for the LS1 coils. It did what it was supossed to it held the motor at 4200 on the starting line, but the car was off 2 tenths in the short times (compared to just putting it on the floor and using the transbrake, same rpms).
I also developed a lot of blowby when using the 2 step and damaged one of the plugs (broke the porcelain).
I was wondering if the ecu was giving the motor full fuel while the spark was being knocked off a cylinder at a time.
When I read about your fuel problems with the throttle stop. I wonder if the problems aren't related?

Rich Biebel · 03-24-2009, 04:49 PM

Art...mechanical fuel injection and electronic fuel injection don't have much in common. I've run both so I know quite a bit about them. I did win in S/C using the same Terminator Dave Steltz has now....and I went quite a few rounds over the course of 1-2 seasons of running S/C at Div 1 events. I also built an EFI LT-1 Firebird and tuned it myself and got it running decent. The EFI gets various inputs from sensors to adjust the amount of fuel going in the engine. The mechanical injection is dumb.....it dumps fuel simply by rpm and barrel valve position. The biggest issue with a Ron's type unit is that the barrel valve is at wide open fuel flow very early in it's travel...so at part throttle you will likely be way fat on alcohol.....that is not a bad thing sometimes...but other times it will be and that is the problem.....inconsistancy tracked back to part throttle fuel mixture. I had it mostly under control using the electronic leanout. On my Firebird.....I added a 2 step and a finger button intending to try it as I saw so many people using that setup. I tried it once in the pits and really hated the way the engine was loaded as well as trying to hold the finger button and the brake pedal....I never used it and the next year NHRA banned finger buttons anyway. I foot braked that Firebird every run I ever made with it. I have zero experience with coil pack stuff.....and don't want any!!! EFI is great but it sure takes a lot of experience to get them running real nice. My old car has been tuned recently by a racer with a lot of EFI experience.....I'm glad to learn I had it running pretty well down the track....he was able to clean it up some around the pits/staging/burnout and on the launch.....picked up maybe 1/2 tenth

03-18-2009, 01:06 PM	#1
Hustler1098 Junior Member Join Date: Mar 2009 Posts: 8 Likes: 0 Liked 0 Times in 0 Posts	Throttle stopping injection Wondering if anyone out there has had any luck throttle stopping injection... setup is two toilets on a 572, in its current setup should run roughly 7.50 I've talked with James Monroe and he the advice he gave me was to bring the rpm down to about 2800 on the stop and go out a little further than most do in order to burn the fuel that may puddle up on the starting line Any other advice anybody might have or does that pretty much sum it up? Also, does anyone have any approximations as to what kind of time I will have to run in the timers... Thanks...

03-18-2009, 03:07 PM	#2
GaryGoFast Senior Member Join Date: Nov 2003 Location: New York Posts: 804 Likes: 0 Liked 1 Time in 1 Post	Re: Throttle stopping injection 1st, I would do what James says, he's got some experience but I know more than one who have their stops go to idle and I think its to control the fuel pump rpm. This usually gives you a 1:1 ratio. Hope this helps. __________________ Gary Federico S/St, S/G 1814

03-18-2009, 03:15 PM	#3
Dave Steltz Member Join Date: Nov 2003 Posts: 323 Likes: 0 Liked 0 Times in 0 Posts	Re: Throttle stopping injection We have some guys doing it here in D1....kill it down as low as possible...(I kill mine to 2000 with a terminator)..that way the pump wont overload you on fuel, and then let it rip..might want to get a electronic bypass to bleed some off... I also kill mine at .2, so not really going out too far... At that low rpm, you will be about 1:1 in your ratio, so if you're looking at 8.90 do the math... __________________ Dave Steltz 135G SG/SP/SST BIAECH Racing Team

03-18-2009, 04:10 PM	#4
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,436 Likes: 776 Liked 700 Times in 204 Posts	Re: Throttle stopping injection With a barrel valve that has a part throttle bypass, you can run it clean at any rpm . ....you can get one from Kinsler.......If you don't want to change the barrel valve,then use the electric bypass, tied in with the timer......without a bypass,you need to get as low as possible on the stop rpm,while going out farther than a carbureted car before going on the stop. .....Tom __________________ Tom Goldman 1500 SG , 1506 STK

03-20-2009, 10:07 PM	#7
nemo963 Junior Member Join Date: Feb 2008 Location: Firehouse 10, Wichita Ks Posts: 9 Likes: 0 Liked 0 Times in 0 Posts	Re: Throttle stopping injection Im running a 1800 lbs hardtail and a 540ci BBC with twin toilets. We have run this combo in super comp (and brackets) since '91. We launch and go on the stop at .5, using a in line stop we drop down to 3800 rpm, shift on time at 1 second, and come back on around 2.5 seconds or so. We run consistant year to year and go rounds at the Div 5 races. We dont run a electronic bypass or anything else, not saying that it wouldn't help, thats just been our experience. __________________ Nemo Duty-Pride-Tradition

03-24-2009, 08:38 AM	#8
Hustler1098 Junior Member Join Date: Mar 2009 Posts: 8 Likes: 0 Liked 0 Times in 0 Posts	Re: Throttle stopping injection Nemo, What do you run off the stop in the 1/4?

03-24-2009, 04:18 PM	#9
art leong VIP Member Join Date: Dec 2001 Location: Richmond Hill, Georgia Posts: 2,003 Likes: 0 Liked 1 Time in 1 Post	Re: Throttle stopping injection I was just going through this thread. This is for a totally different application. I have a electronicly controled 4 cylinder using LS1 coil over plug setup. I tried using a 2 step that was setup for the LS1 coils. It did what it was supossed to it held the motor at 4200 on the starting line, but the car was off 2 tenths in the short times (compared to just putting it on the floor and using the transbrake, same rpms). I also developed a lot of blowby when using the 2 step and damaged one of the plugs (broke the porcelain). I was wondering if the ecu was giving the motor full fuel while the spark was being knocked off a cylinder at a time. When I read about your fuel problems with the throttle stop. I wonder if the problems aren't related? __________________ Art Leong 2095 SS

03-24-2009, 04:49 PM	#10
Rich Biebel VIP Member Join Date: Jun 2007 Location: Northern New Jersey suburbs Posts: 2,275 Likes: 25 Liked 510 Times in 200 Posts	Re: Throttle stopping injection Art...mechanical fuel injection and electronic fuel injection don't have much in common. I've run both so I know quite a bit about them. I did win in S/C using the same Terminator Dave Steltz has now....and I went quite a few rounds over the course of 1-2 seasons of running S/C at Div 1 events. I also built an EFI LT-1 Firebird and tuned it myself and got it running decent. The EFI gets various inputs from sensors to adjust the amount of fuel going in the engine. The mechanical injection is dumb.....it dumps fuel simply by rpm and barrel valve position. The biggest issue with a Ron's type unit is that the barrel valve is at wide open fuel flow very early in it's travel...so at part throttle you will likely be way fat on alcohol.....that is not a bad thing sometimes...but other times it will be and that is the problem.....inconsistancy tracked back to part throttle fuel mixture. I had it mostly under control using the electronic leanout. On my Firebird.....I added a 2 step and a finger button intending to try it as I saw so many people using that setup. I tried it once in the pits and really hated the way the engine was loaded as well as trying to hold the finger button and the brake pedal....I never used it and the next year NHRA banned finger buttons anyway. I foot braked that Firebird every run I ever made with it. I have zero experience with coil pack stuff.....and don't want any!!! EFI is great but it sure takes a lot of experience to get them running real nice. My old car has been tuned recently by a racer with a lot of EFI experience.....I'm glad to learn I had it running pretty well down the track....he was able to clean it up some around the pits/staging/burnout and on the launch.....picked up maybe 1/2 tenth __________________ Rich Biebel S/C 1479