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So I got some stainless steel OBX headers in the mail today with the pipes unbaffled
Just out of curiosity would it be possible to run just the open headers for a bit without the actual side pipes because at the moment Im waiting on the hardware for the pipes to get connected and I really wanted to get these headers on. I know it'll be ridiculously loud I'm just curious if there will be any issues running just the long tube headers for a bit (maybe paint burning or something?)
Last edited by rednrebel; May 23, 2022 at 04:39 PM.
Nothing really functionally, but it will be crazy loud and you might get some popping / soot on your doors as you will have absolutely no back pressure
You’ll do no damage to the engine.
If you drive it at all, don’t be surprised at the noticeable loss of bottom end to mid range power.
I’ve run open headers on boats since the early 70’s with no issues.
You’ll do no damage to the engine.
If you drive it at all, don’t be surprised at the noticeable loss of bottom end to mid range power.
I’ve run open headers on boats since the early 70’s with no issues.
is there anyway I could mess around with the idle mixture screws to make the loss in power through the range less noticeable or is it entirely based on the fact theres zero backpressure ?
is there anyway I could mess around with the idle mixture screws to make the loss in power through the range less noticeable or is it entirely based on the fact theres zero backpressure ?
It is not neccassary, every race CAR in the country is running with open headers because there is more power not less. Whereas it is necessary to have some back pressure, the headers alone supply all that is needed. If you were trying to win a big race, you would want to fine tune it.
Most only run only headers on Dyno,,
No worries,,,,
I've been waiting for sidepipe hardware for over 12months already.. I just made my own hookups from local suppliers,,,,
Idle mixture screws will only richen or lean the air fuel mixture in the idle circuit at idle and have no effect on the fuel mixture once you crack open the throttle.
With open headers you will gain hp above a certain rpm depending on the engine build, tune and header design.
That’s what headers are designed to do and why race engines are designed to run at the higher rpm ranges.
At low rpm, you will notice a slight decrease in power with open headers.
You can’t tune it to gain the loss in power at lower rpm’s.
It’s the same reason you will notice a slight loss in power running side exhaust.
They are designed to flow at higher rpm’s and that’s why you see them on many race cars.
I always noticed an increase in low end and mid range torque and horsepower running modified baffles in my drag boats and motorcycles.
Check out Engine Masters on Hot Rod Magazine show. Very informative dyno comparisons. At least three episodes on header variables compared to power curves. One on collector extension length; about 18” was best (yours looks pretty close, but I don’t know about the variable of side pipe headers). One on pipe diameter. One on dented headers; they beat the sh.t out of them and it made no difference.
Overall, the amount of directly usable information on that show is incredible.
Check out Engine Masters on Hot Rod Magazine show. Very informative dyno comparisons. At least three episodes on header variables compared to power curves. One on collector extension length; about 18” was best (yours looks pretty close, but I don’t know about the variable of side pipe headers). One on pipe diameter. One on dented headers; they beat the sh.t out of them and it made no difference.
Overall, the amount of directly usable information on that show is incredible.
I was unable to locate the series you referenced, would you please give a Reader's Digest version, as you did for the dented ones. If pipe diameter is not significant, we wasted a bunch of money in the 60's/70's. I like the looks of what Corvette calls off-road exhaust despite the negative of melting ladies' hosery, but the slightly smaller diameter was a no go for me. Thanks in advance.
One of The Unwritten Rules of Hotrodding is that, when you install headers, you have to take the car for at least a short little spin with open headers. Kinda like how, if you remove the hood of your car for any reason, you have to take it for a spin with no hood.
I was unable to locate the series you referenced, would you please give a Reader's Digest version, as you did for the dented ones. If pipe diameter is not significant, we wasted a bunch of money in the 60's/70's. I like the looks of what Corvette calls off-road exhaust despite the negative of melting ladies' hosery, but the slightly smaller diameter was a no go for me. Thanks in advance.
Pipe diameter matters! Bigger is usually better, but it can depend.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
I say give it a try, but my guess is with side pipes you won't do it for long...WAY too loud next to your head. I run open headers and drive to the track from the house, it IS damn loud for sure, but sounds damn nice! Reminds me of the 70s running at the track. Like mentioned, 17-18", 3" collector is about right for max torq. I don't really care about the HP side so much, but it's the torq that launches you out there and gets you moving quickly.
I wouldnt do it for long believe me it will get old real fast!! plus the fumes right there-
You could always search for a temp baffle, has to be something out there.
Ran open headers just long enough to get to the muffler shop. Brand new engine...was expecting it to be loud when I started it but shees..made me jump.
It felt lazy but damn did it sound good!! Doesnt smooth out due to the cam til 3k...loving it.
Primary length & diameter has a lot to do with making torque, collector length etc. Cant help but wonder in a 1/4 mi situation the smashed vs good headers would do.
On a higher output engine Id imagine youd see a difference.
Running open headers
I run open headers and drive to the track from the house, it IS damn loud for sure, but sounds damn nice! Reminds me of the 70s running at the track. Like mentioned, 17-18", 3" collector is about right for max torq. 
