Open Headers
skluv
12-19-2007, 12:05 AM
Hey guys... One of my buddies has recently suggested that I run open headers on my '78 Firebird... I'm not really sure if it is a good idea... Thoughts?
SG007
12-19-2007, 06:42 AM
It's fun (and loud) but not legal. Not where I live anyway.
MrPbody
12-19-2007, 01:00 PM
Open headers reduces back pressure significantly. This is good for a higher RPM range, and capped headers are better for lower RPM ranges.
Running open headers on a street car is iffy. While you're driving down the highway, they're fine. At a stop light, if you have ONE "tight" exhaust valve (or other exhuast valve issues) it can "suck" cooler air into the header, and if it makes it to the valve before it reaches a high enough temp, it can and will warp or burn the valve.
At the track, you may need to richen the mixture significantly, to avoid piston damage from too lean a mixture. It may like a little more timing, too.
Some localities allow it. Most don't. Excessive noise is not a criminal offense, at least the first time, but it's ticket, and you COULD get a "racing" charge, too. I've seeb it happen. Cops don't CARE whether you were REALLY racing if they can make a case to a judge that it "sounded like" you were. I've seen that in New Mexico, where there were NO noise laws at that time. He couldn't bust you for noise, but racing? You bet!
Lastly, avoid trying to "be cool" while driving your hot rod. Instead, be VERY cool by NOT attracting attention to yourself!
So what engine you got in that '78 Firebird? (just nosey... I LIKE Pontiacs!)
Jim
Running open headers on a street car is iffy. While you're driving down the highway, they're fine. At a stop light, if you have ONE "tight" exhaust valve (or other exhuast valve issues) it can "suck" cooler air into the header, and if it makes it to the valve before it reaches a high enough temp, it can and will warp or burn the valve.
At the track, you may need to richen the mixture significantly, to avoid piston damage from too lean a mixture. It may like a little more timing, too.
Some localities allow it. Most don't. Excessive noise is not a criminal offense, at least the first time, but it's ticket, and you COULD get a "racing" charge, too. I've seeb it happen. Cops don't CARE whether you were REALLY racing if they can make a case to a judge that it "sounded like" you were. I've seen that in New Mexico, where there were NO noise laws at that time. He couldn't bust you for noise, but racing? You bet!
Lastly, avoid trying to "be cool" while driving your hot rod. Instead, be VERY cool by NOT attracting attention to yourself!
So what engine you got in that '78 Firebird? (just nosey... I LIKE Pontiacs!)
Jim
skluv
12-19-2007, 07:25 PM
Thanks guys... I think you're right MrPbody, My 'bird is pretty loud now and I've already gotten a few complaints from the neighbors... I think it'd be wiser not to make the vehicle any louder- it seems to me like I'd be asking for trouble...
By the way, the 'bird's got the 350 Pontiac V8... but it's far from stock. Comp Cams, Heddman headers, Moroso valve covers, K&N air filter, Edelbrock carb...
By the way, the 'bird's got the 350 Pontiac V8... but it's far from stock. Comp Cams, Heddman headers, Moroso valve covers, K&N air filter, Edelbrock carb...
MrPbody
12-20-2007, 08:05 AM
sk,
Cool cars. Let us know when you're ready to take it to "the next level"... GREAT chassis for a performance car! The little Pontiac isn't the best engine to pump up, but it surprises most non-Pontiac people when it is pumped up. Wait 'til you see what 400s and 461s can do...
Jim
Cool cars. Let us know when you're ready to take it to "the next level"... GREAT chassis for a performance car! The little Pontiac isn't the best engine to pump up, but it surprises most non-Pontiac people when it is pumped up. Wait 'til you see what 400s and 461s can do...
Jim
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