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Bracket Racers using Sniper or Holley & no Mufflers Q #3092570
11/08/22 01:56 PM
11/08/22 01:56 PM
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Taxes & Virus's R-US, NY
Dragula Offline OP
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So I got a price on a new billet carb, and I am thinking of running my Sniper 4500 on my bracket car instead....But it has short 4" header collectors and no mufflers....Can you still tune it without mufflers?

Anyone bracket race one of these?

Last edited by Dragula; 11/08/22 01:59 PM.

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Dragula] #3092588
11/08/22 03:12 PM
11/08/22 03:12 PM
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Pattison Texas
CSK Offline
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If you run a LONG header extension it will work


1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5

Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: CSK] #3092598
11/08/22 03:46 PM
11/08/22 03:46 PM
Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline OP
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No chance of that...

DSC06963.JPG

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Dragula] #3092616
11/08/22 04:40 PM
11/08/22 04:40 PM
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Pattison Texas
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you can put the o2 in one tube, some will disagree with that but just keep an eye on the spark plgs, My Holley HP efi only has 1 o2 on the left bank,


1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5

Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Dragula] #3092624
11/08/22 05:32 PM
11/08/22 05:32 PM
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Originally Posted by Dragula
So I got a price on a new billet carb, and I am thinking of running my Sniper 4500 on my bracket car instead....But it has short 4" header collectors and no mufflers....Can you still tune it without mufflers?

Anyone bracket race one of these?


Yes it can be tuned with a short collector and no muffler. Put the O2 sensor in one of the header tubes about midway between exhaust port and the collector. That will give you a good reading for anything above 2000 rpm. You might be able to tune the idle also, or you might have to manually tune the idle. I tune several fast bracket cars (8.50 chassis cars) and that is the way we do it. Usually best if you can put the O2 sensor in the #1 or #2 pipe but any pipe can be made to work if you can't put it in a front pipe.

In your picture you might want to go into the #8 pipe up near the valve cover but it depends on your harness layout. I'd use the #1 pipe if possible but sometimes you have to do what you have to do.

Last edited by AndyF; 11/08/22 05:34 PM.
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Dragula] #3092628
11/08/22 05:47 PM
11/08/22 05:47 PM
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Just from my experience with an o2 data logger, if you run it in the collector, it will read lean at idle and normal at WOT. As mentioned, put it in one of the tubes. I would use cylinder 5 or 7 just because they usually run the leanest. Unless you have a 5 7 swap camshaft. The other thing is I would call Holley, I don't think the O2 sensors tune much at WOT, they mainly are used for part throttle and cruising, that is where they learn and adjust the fuel maps. At WOT they are good for a data logging function.

Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: jwb123] #3092636
11/08/22 06:14 PM
11/08/22 06:14 PM
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Pattison Texas
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Originally Posted by jwb123
Just from my experience with an o2 data logger, if you run it in the collector, it will read lean at idle and normal at WOT. As mentioned, put it in one of the tubes. I would use cylinder 5 or 7 just because they usually run the leanest. Unless you have a 5 7 swap camshaft. The other thing is I would call Holley, I don't think the O2 sensors tune much at WOT, they mainly are used for part throttle and cruising, that is where they learn and adjust the fuel maps. At WOT they are good for a data logging function.


They tune at WOT


1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5

Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Dragula] #3092641
11/08/22 06:21 PM
11/08/22 06:21 PM
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Central TEXAS!!!!
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Not hard, under "system ICF" open close loop/learn click "enable closed loop above XXXXX" (2000?)The closer the O2 to the collector, the higher the RPM. Then just manually tune the idle.


Joe


Without Data, you’re just another guy with an opinion.
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Dragula] #3092652
11/08/22 07:00 PM
11/08/22 07:00 PM
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Yes, it will work .Yes, you need to read plugs and know what your o2 is reading compared to your plugs but, yes, it will be fine, even in closed loop.
Lots of guys running well over 200 mph with holly systems and o2 bungs in places that make a fella scratch his head wondering "how the heck does that work" ? But, it does.May take a little work to get everything dialed in but, to my understanding and, seeing what people are successfully doing , I would sure give it a shot.
Andy F. has done quite a bit of work with the holley systems now, feel sure he would be a reliable resource.

Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: RustyM] #3092653
11/08/22 07:00 PM
11/08/22 07:00 PM
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Oops- I see Andy already replied , my bad, missed his post.

Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: RustyM] #3092663
11/08/22 07:31 PM
11/08/22 07:31 PM
Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline OP
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Next dumb question, it has no provision for E85, but can I run it if I multiply the engine size by .67?


'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Dragula] #3092669
11/08/22 07:50 PM
11/08/22 07:50 PM
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Posts: 2,842
Pattison Texas
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If the injectors flow enough yes, the Super Sniper has 8 injectors & so does the 4500

Last edited by csk; 11/08/22 07:53 PM.

1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5

Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: CSK] #3092711
11/08/22 10:48 PM
11/08/22 10:48 PM
Joined: May 2004
Posts: 12,379
Taxes & Virus's R-US, NY
Dragula Offline OP
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I think that calc of .67 is inverted, I think I would have to use 1.33...


'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Dragula] #3092731
11/08/22 11:59 PM
11/08/22 11:59 PM
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Lake Villa Il
INTMD8 Offline
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Not sure the best way to change for E85. Can you change injector flow rate?

If you can change something to compensate for the additional fuel required, next question is, are the injectors large enough to handle that additional flow?

Also, are they stainless internal injectors? If not, can be gummed up rather quickly on E85, even if using the right filter. (6 micron fiberglass)


69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: INTMD8] #3092761
11/09/22 08:58 AM
11/09/22 08:58 AM
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Central TEXAS!!!!
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Originally Posted by INTMD8
Not sure the best way to change for E85. Can you change injector flow rate?

If you can change something to compensate for the additional fuel required, next question is, are the injectors large enough to handle that additional flow?

Also, are they stainless internal injectors? If not, can be gummed up rather quickly on E85, even if using the right filter. (6 micron fiberglass)








Changing for e85 is not hard, in the sniper software,go fuel, target A/F ratio, make sure table is in 2d mode, highlight the entire table, Left click, select "Offset selected" Enter *.67. Now everything is at the E85 ratio, you have a starting point.

Joe


Last edited by sr4440; 11/09/22 09:04 AM.

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Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: sr4440] #3092806
11/09/22 11:18 AM
11/09/22 11:18 AM
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Would that not only work if you can change the stoich value for the fuel? (maybe you can).

Otherwise if programmed for gasoline stoich, richening target a/f ratio would just make it very rich.


69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: sr4440] #3092811
11/09/22 11:29 AM
11/09/22 11:29 AM
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You'll also have to change the fuel type to ethanol in the software. If you don't do that, just changing the target AF tables will make it too rich.

Reading up on it from a couple different forums, it sounds like E85 isn't suggested on most of the Sniper systems due to the injectors they use not being compatible with E85 and also the uncoated/bare aluminum parts inside the unit itself.


'18 Ford Raptor, random motorcycles, 1968 Plymouth Fury III - 11.37 @ 118
Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: Blusmbl] #3092920
11/09/22 05:58 PM
11/09/22 05:58 PM
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Originally Posted by Blusmbl
You'll also have to change the fuel type to ethanol in the software. If you don't do that, just changing the target AF tables will make it too rich.

Reading up on it from a couple different forums, it sounds like E85 isn't suggested on most of the Sniper systems due to the injectors they use not being compatible with E85 and also the uncoated/bare aluminum parts inside the unit itself.


Yep, forgot that part, it's when you do the initial engine setup.

Joe


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Re: Bracket Racers using Sniper or Holley & no Mufflers Q [Re: sr4440] #3092999
11/09/22 11:36 PM
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You could probably tune it by ear for idle and part throttle and get pretty close. Just pretend its a carb and you don't have an air fuel meter. Once you get to 3000RPM or so the 02 sensor readings should work fine.

I don't know how the sniper stuff works but you will need to get it tuned in to where you feel it is good at idle and low load and then lock the table and turn any learning off so it doesn't just keep dumping fuel trying to hit a target that cannot be achieved.


68 Barracuda Formula S 340
87 "Chrysler" Conquest






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