Air vs Electric stops

Henry S · 11-13-2007, 04:36 PM

Adger,
Here is my take on the pro's and con's for inline vs. under the carb type stops.
the pro's for inline is:
1. no power loss from adding another set of butterflies i.e. (restriction)
2. adjustability of opening and closing rates to control wheel spin etc.
3. greater adjustability of stop rpm, typically can go lower rpm with an inline vs an undercarb stop
4. hood clearance
5. gets an accelerator pump shot when opening
cons,s of inline
1. carb linkage very important for consistency
2. Air fuel ratio's change while on the stop more than on undercarb type stop
3. carb primary and secondary linkage type important 1.1 vs progressive
pro's for an undercarb stop
1. ease of use electrically
2. air/fuel ratio tends to stay more consistent throughout run.
3. if electric no variance due to bottle pressure and opening closing rates not changing
con's of undercarb
1. hood clearance may become an issue
2. some power loss
3. fuel puddling on the stop blades, can cause inconsistencies.

I have run both types and have won with both types. it usuallly is a matter of preference. a Great resource is to call #1 stops 319-277-5290(Gary) he has a wealth of good information.
As for systems go, you can't beat crewchief pro for prediction software along with altalabs weather stations

slow dragster · 11-14-2007, 01:19 PM

Dont be afraid of the plate stop under the carb. We did some extensive dyno time and found no change in HP. Myth i guess, We have an air plate stop and by far the most consistant. Get a number 1 stop and you wont go wrong.

rod butcher · 11-14-2007, 07:18 PM

On the dyno with plate stop lost 38 hp at the peak and 20 hp on the average. This was on 406 sbc making 754 @ 7400.

Mike Hedger · 11-14-2007, 08:50 PM

I only gave up 16 HP with my #1 base plate stop on a BBC with a 2" super sucker under it and a Dart intake. I think the HP loss has allot to due with the intake configuration.

I have run mine on both alcohol and gas with no changes except slicing the blades below the throttle shafts to keep the fuel from puddling up on the blades when the stop is on.

Also if you have allot of HP spend the extra to put the second air cyl. as well as the extra flow controls on both on and off. If you do this you will be able to get down any track around because you can control both directions of the cyl. action.

As far as air pressure you only need 80-90 PSI to operate the stop so as long as you have 200+ PSI in the bottle you can make a run without any problems. But always have a way to fill your bottle or carry a spare.

But whatever you do, ONLY BUY AN AIR STOP the electric is a good way to get into trouble on a bad track with allot of power.

On the pro stage I turn mine off when .90 racing I want to be the one matting the throttle not the box doing it when I depress the TB button.

Hope this helps, Mike

slow dragster · 11-14-2007, 09:17 PM

I think your going to see more loss at a lower HP motor. I think the intake is the key here. On my 565 it dyno'ed at 915HP 745 lb torque with out the stop. With the stop it was the same. The intake has been ported and hogged out to match the heads. Flowed the heads and then bolted the intake on it. There was a huge dif in flow with the stock configuration of the intake Edelbrock 2927. Spent about $300 on the intake to get the flow numbers back up. Hope this helps.

rod butcher · 11-15-2007, 12:08 PM

I think in my case its the carb thats the limiting factor in the horsepower loss. I am using a 750 holley (old reliable) and feel that this setup is consistant but alot smaller than it should be. I will be trying a new 1000 cfm carb and it should help in the hp loss. If nothing else it should be 20-25 hp stronger up top and the dyno will tell.

NED890 · 11-25-2007, 08:23 PM

Have a #1 stop under the carb and a super sucker back to back runs with and without the stop same ET did this on gas and alky Everyone told me the stop wood slow the car a tenth when running it wide open.
Guess it has to do with your set up. This was done with a 1050 cfm carb one is a ruppert carb and the other is a devince carb

11-14-2007, 01:19 PM	#2
slow dragster Member Join Date: Apr 2004 Location: Spring Hill, TN Posts: 143 Likes: 0 Liked 6 Times in 4 Posts	Re: Air vs Electric stops Dont be afraid of the plate stop under the carb. We did some extensive dyno time and found no change in HP. Myth i guess, We have an air plate stop and by far the most consistant. Get a number 1 stop and you wont go wrong.

11-14-2007, 07:18 PM	#3
rod butcher Member Join Date: Dec 2005 Posts: 252 Likes: 306 Liked 132 Times in 27 Posts	Re: Air vs Electric stops On the dyno with plate stop lost 38 hp at the peak and 20 hp on the average. This was on 406 sbc making 754 @ 7400.

11-14-2007, 08:50 PM	#4
Mike Hedger Junior Member Join Date: Jul 2007 Location: Kemah TX Posts: 93 Likes: 0 Liked 1 Time in 1 Post	Re: Air vs Electric stops I only gave up 16 HP with my #1 base plate stop on a BBC with a 2" super sucker under it and a Dart intake. I think the HP loss has allot to due with the intake configuration. I have run mine on both alcohol and gas with no changes except slicing the blades below the throttle shafts to keep the fuel from puddling up on the blades when the stop is on. Also if you have allot of HP spend the extra to put the second air cyl. as well as the extra flow controls on both on and off. If you do this you will be able to get down any track around because you can control both directions of the cyl. action. As far as air pressure you only need 80-90 PSI to operate the stop so as long as you have 200+ PSI in the bottle you can make a run without any problems. But always have a way to fill your bottle or carry a spare. But whatever you do, ONLY BUY AN AIR STOP the electric is a good way to get into trouble on a bad track with allot of power. On the pro stage I turn mine off when .90 racing I want to be the one matting the throttle not the box doing it when I depress the TB button. Hope this helps, Mike __________________ Mike Hedger S/C 4646 MPH Racing and Fabrication Last edited by Mike Hedger; 11-14-2007 at 08:53 PM.

11-14-2007, 09:17 PM	#5
slow dragster Member Join Date: Apr 2004 Location: Spring Hill, TN Posts: 143 Likes: 0 Liked 6 Times in 4 Posts	Re: Air vs Electric stops I think your going to see more loss at a lower HP motor. I think the intake is the key here. On my 565 it dyno'ed at 915HP 745 lb torque with out the stop. With the stop it was the same. The intake has been ported and hogged out to match the heads. Flowed the heads and then bolted the intake on it. There was a huge dif in flow with the stock configuration of the intake Edelbrock 2927. Spent about $300 on the intake to get the flow numbers back up. Hope this helps.

11-15-2007, 12:08 PM	#6
rod butcher Member Join Date: Dec 2005 Posts: 252 Likes: 306 Liked 132 Times in 27 Posts	Re: Air vs Electric stops I think in my case its the carb thats the limiting factor in the horsepower loss. I am using a 750 holley (old reliable) and feel that this setup is consistant but alot smaller than it should be. I will be trying a new 1000 cfm carb and it should help in the hp loss. If nothing else it should be 20-25 hp stronger up top and the dyno will tell.

11-13-2007, 04:36 PM	#1
Henry S Junior Member Join Date: Aug 2007 Posts: 83 Likes: 11 Liked 19 Times in 7 Posts	Re: Air vs Electric stops Adger, Here is my take on the pro's and con's for inline vs. under the carb type stops. the pro's for inline is: 1. no power loss from adding another set of butterflies i.e. (restriction) 2. adjustability of opening and closing rates to control wheel spin etc. 3. greater adjustability of stop rpm, typically can go lower rpm with an inline vs an undercarb stop 4. hood clearance 5. gets an accelerator pump shot when opening cons,s of inline 1. carb linkage very important for consistency 2. Air fuel ratio's change while on the stop more than on undercarb type stop 3. carb primary and secondary linkage type important 1.1 vs progressive pro's for an undercarb stop 1. ease of use electrically 2. air/fuel ratio tends to stay more consistent throughout run. 3. if electric no variance due to bottle pressure and opening closing rates not changing con's of undercarb 1. hood clearance may become an issue 2. some power loss 3. fuel puddling on the stop blades, can cause inconsistencies. I have run both types and have won with both types. it usuallly is a matter of preference. a Great resource is to call #1 stops 319-277-5290(Gary) he has a wealth of good information. As for systems go, you can't beat crewchief pro for prediction software along with altalabs weather stations Last edited by Henry S; 11-13-2007 at 06:00 PM. Reason: fogot to add

11-25-2007, 08:23 PM	#7
NED890 Junior Member Join Date: Jun 2006 Location: New Jersey Posts: 39 Likes: 0 Liked 0 Times in 0 Posts	Re: Air vs Electric stops Have a #1 stop under the carb and a super sucker back to back runs with and without the stop same ET did this on gas and alky Everyone told me the stop wood slow the car a tenth when running it wide open. Guess it has to do with your set up. This was done with a 1050 cfm carb one is a ruppert carb and the other is a devince carb