for anyone that has ever wondered what an LT-1 sounds like with open headers, here is a video of mine racing a 2000 SS. the video is very dark, only headlights can be made out for the most part, but my car is closest to the camera. I had Hooker Long tubes, with an 18 inch piece of pipe bolted to it so I had a mounting place for the O2 sensors and a turndown! You might have to turn up your speakers to hear this, but it sounds very wicked (too loud for a daily driver, so I put on some exhaust!!)


http://osr.albeeno.com/images/LT1ws6.MOV

 

some FYI-
your probobly going to be faster with backpressure at this point.
your motor doesn't rev high enough to take advantage of the open headers

13.6 REPEATDLY with no muffler and long tubes
13.2 REPEATEDLY when i bolt the muffler back up

 

some FYI-
your probobly going to be faster with backpressure at this point.
your motor doesn't rev high enough to take advantage of the open headers

13.6 REPEATDLY with no muffler and long tubes
13.2 REPEATEDLY when i bolt the muffler back up


I wondered about this, as I always race with open headers. The only run I made with full exhaust was 1mph and .2 slower, so I assumed that it was good to run stock internal engine with open headers. But, I'm not very consistant right now, especially with street tires. Would I have overall quicker times with full exhaust, at least until I install a hot cam?

 

FYI- If you run a good free flowing exhuast you will not see much or if any loss in power and et's. I personally run exhaust to be able to hear any kind of problems. I just don't think it sounds all that great running open headers. If run look at the NMCA cars they all run exhaust and those cars RUN. All the classes me and my friends run all require exhaust. My buddies car (Project X) which runs factory leaf springs and exhaust runs 8.50's @ over 165mph, not bad for an ole 65 Chevy II. This is just my .02.

 

So the Corvette C5R engine that only revs to 6400rpm max in sprint form, isn't being as efficient with its dual 4" open exhaust as it would with a muffler. It has nothing to do with how high it revs, but the volume of air that it is moving out, there is also a sound wave that moves from the valve to the end of the pipe and back, this also creates a scavenging effect so more than anything it moved his RPM range up on the scale.

 

well-
if the bottom end is the same...

the C5-r's cam and heads might be a bit different from the LT1's

 

What was the MPH on those runs? I have yet to see a bolt-on LT1 run better w/exhaust than w/out. Less exhaust on a LT1 the better.

 

I really did not have time to look at the speedo on that run, since if you listen to the end of the video you can hear the brakes lock up a few short times. Since the cam, header install I have not had the car back to the track to see if my times got any better or worse, however, I do still have the short sticks of piping that were on there (I have exhaust now), and I plan on running at the track to see if there is a difference. I figure 3-5 runs each way should give a decent amount of info to judge weather or not open is better or more hurtful. Of course, the point of this thread was only to provide a sound bite for an LT-1 with open headers, but performance is always in the mind of an F-body owner!

 

103-104.5 to 106

in an auto