Zoomies on a n/a dragster

November 24, 2018, 06:20 PM

Bob Murphy Jr

Hey. I been thinking of trying this and I’m not sure if anyone has. I have a 555 big duke in a Racetech that can run high 7.20s to low 30s. I usually set up the car to be a 7.50 player (4.80s). The car is naturally aspirated on alky carb. I been running the down swept dyno techs but wanted to put 2 in trailer with ease. I know it will probably hurt et some and I don’t mind that bc I’ll setup for 7.50s. But I just wanted to know if could possibly hurt the motor anyway or after I do burn out and go to clean carb out will it back fire or pop threw pipes. I know ppl that run them but they are all pro charger or blower setups. But has anyone tried on a n/a setup? Any feed back would be awesome. Just wanted to try something if possible will work and don’t wanna do upswepts

November 24, 2018, 09:06 PM

Dave Koehler

I have room na w zoomies for years.
No issues.

November 25, 2018, 12:15 AM

BP758

On a 358 SBC comp style motor ( B/ED) it was right at a tenth slower with zommies. This was years ago... Doubt if it would hurt anything other than power.

November 25, 2018, 06:56 AM

sst5167

I know a couple guys out of division 5 that run zoomies on their bbc super comp cars. They've been doing it for years. So I'm assuming there's nothing to worry about. To me, they sound terrible at low rpm, but once they do a burnout, or head down track, they sound very similar to a blown car.

November 25, 2018, 08:09 AM

Quick Dawg

On my 555 in an altered I much prefer zoomies. First, they look cool, second, my car doesn’t sound like a door car (no offense anyone), third, the ET difference is negligible (yes I have done back to back), fourth, the plugs are much easier to get to. I have a few friends in this area that run zoomies also with no ill effects what so ever.

It shouldn’t backfire thru the pipes unless you are rich and putting raw fuel into the pipes. I don’t understand wacking the throttle after you back up from a burn out. If your car is jetted right, there should be no need to “clean it out”. I have never done that, but each to his own.

November 25, 2018, 08:40 AM

wideopen231

1st you mean there is another type of exhaust? PM sent on a set.

November 25, 2018, 12:06 PM

fatpack

509 BBC hat injected with 2 1/8 tube zoomies works fine for me! I'm making my second set now, these will be sorta like weed burners. The ones I was running come straight out of the port then kick up and back. I bought the tubes with the bends I wanted and the flanges from A C P's Stahl Headers!

November 25, 2018, 12:15 PM

Bob Murphy Jr

Idle sounds ok? Yea I’m thinking a smaller set that don’t come out far and has nice lean back as well. Or a set like disco had on his maybe.

November 25, 2018, 02:08 PM

bill masiello

Bob I did an a to b to a test with zoomies on my injected small block and found that the zoomie was a little faster ! I think mostly because they are 20 lbs lighter ! I went from a 1 7/8 to 2 inch step header with a merge collector to a 2 inch zoomie 20 inch long !

November 25, 2018, 03:28 PM

Ron C.

It will only matter power wise if your running a carb ( other than weight reduction).

Fellow racer and servant of the Lord of Lords
John 14:6
"Creekside Racing Ministry"
MFI system, ProCharger Non-intercooled [6.02 @ 229 or 3.91/660' soft tune and killing power above 6K rpm]
Ron Clevenger

November 25, 2018, 03:54 PM

Bob Murphy Jr

Alky Apd 1250 carb. Like I said if car slows a tenth so be it. But don’t wanna hurt nothing or not idle right at 900rpm. I wonder if anyone ever had mesh welded in tubes or something for rocks. I was just told they can get in zoomies with ease

November 25, 2018, 03:54 PM

wideopen231

Na on bbc and Hemi with injection never issue. I know few guys say with carbs they cost hundredth or so.Lil brother ran with carb on gas and no issues.

November 25, 2018, 07:43 PM

67TSCHEVY2

Ran a 598 with 2/4 carbs on gas for several years with and without zoomies ...ZERO difference in performance to me .

November 25, 2018, 08:08 PM

Quick Dawg

You don’t have to worry about rocks getting in your pipes as long as the pipes point down from the exhaust ports for a few inches before you start your upsweep. I would recommend you don’t put pipes that go straight up from the ports. If you look at all the classic zoomie shaped pipes you will see that most of them point to the ground at about a 45 for 8 to 10 inches. Of course, no rock will ever get in the pipes with the motor running no matter the angle of the pipes.

November 25, 2018, 09:35 PM

27Keith

If you like to coast your car in the pits and there is any gravel, i can see something getting in a tube !

November 28, 2018, 11:33 PM

BP758

quote:
Originally posted by Bob Murphy Jr:
Hey. I been thinking of trying this and I’m not sure if anyone has. I have a 555 big duke in a Racetech that can run high 7.20s to low 30s. I usually set up the car to be a 7.50 player (4.80s). The car is naturally aspirated on alky carb. I been running the down swept dyno techs but wanted to put 2 in trailer with ease. I know it will probably hurt et some and I don’t mind that bc I’ll setup for 7.50s. But I just wanted to know if could possibly hurt the motor anyway or after I do burn out and go to clean carb out will it back fire or pop threw pipes. I know ppl that run them but they are all pro charger or blower setups. But has anyone tried on a n/a setup? Any feed back would be awesome. Just wanted to try something if possible will work and don’t wanna do upswepts

Ever think about a stepped zommie? I bet on a combo like yours there is some et.

November 30, 2018, 07:48 AM

wideopen231

I have looked at a step zoomie idea. WIth shortness of the pipe and zero restriction flow wise I doubt there would be any gain,but hey been told being wrong happens to folks. Smaller tube would possibly have a gain,but would require 3 or more sets to see what works best and still probably very small change,but hey it adds up.

If someone does try I would love to hear results.Thinking if any gain so minor you would only see on dyno.