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Author Topic:   pure stock exhaust, ???
dirtboss
Dirt Roller

Total posts: 7
posted May 18, 2005 11:53 AM  
We are not allowed to run headers at our track, or center dumps. Right now we are running 2 straight pipes approx 2 feet from the bottom bend. Does anyone know how much it helps to run the 2 into 1 then out the side ?? and if it is an advantage how much length would be needed to get the best back pressure. I also thought of increasing the diamater of the pipe. I have also seen some streeters with the manifolds mounted upside down with the dumps facing up. how can this help ???

Thanks,

DangerZoneRacing
Dirt Maniac

Total posts: 176
posted May 18, 2005 04:44 PM  
They run them upside down because exhaust comes out of the head at a upwards angle. More free flowing then. I run the newer style manifolds from the metric chassis that runs over the top of the spark plugs. Has the same effect as running the manifolds upside down. My exhaust shop put 2" pipe on the manifolds and then went about 3" from the manifold then went to 2 1/2" pipe all the way to the rearend. Duals too i forgot to add. Was thinking about having them put a crossover in so it would be a "H" pipe. I have heard that helps but dont know for sure.

racer17j
Dirt Forum Champ
Total posts: 5390
posted May 18, 2005 09:52 PM  
I normally ran the same dual setup as you mention but this year I ran 2 1/2 off the manifolds and into a y-pipe with a 3" outlet. I was told this by Dr. Gas, they have a website and they seem pretty good. All they do is exhaust and they do a lot for NASCAR, ASA, etc. It's similar to the setup Brzezinski has and they have a lot of info on their website regarding the gains by running 2 into 1 pipes. I hope it helps but I haven't really had a chance to try it yet, our opening night keeps raining out!

[This message has been edited by Speedracer92 (edited May 19, 2005).]

mlpowley
Dirt Full Roller

Total posts: 26
posted May 21, 2005 08:22 AM  
can you run the "stock headder" design of the early 80's metric?

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