clean 3" exhaust on a c3

[grumpyvette]

ajrothm posted this

its a good example of a well done exhaust system design

Finally getting the car's final bugs worked out and got the exhaust system finished. Came out pretty damn good I thought. Even used the stock tips(although modded for 3") to keep that stock look.

The exhaust is 3" mandrel bent, stainless steel with a Dr. Gas x pipe, Hooker Aerochamber mufflers(center in/out) and stock 71 tips that we cut the back out of and welded in a 3" oval piece to attach the tips to the mufflers. We have good ground clearance through out, spare tire holder will open and nothing is contacted by the exhaust system. I am pretty happy with how it came out. The header flange is the lowest part of the whole system.

On another note, I weighed the car last night at the strip(didn't run it though). With 3/4 tank of fuel it weighed 3515lbs and with me in it was 3695lbs. Only thing left to install in the car is the Sanden AC compressor and brackets...maybe another 20lbs. So with a little less fuel, I should have a raceweight of a hair under 3700lbs.....Shes a porker...



Anyway, here is some pics and a vid:

Hopefully I will get some good halfshafts in it by Feb. and get it to the strip while we still have good air.



***Please excuse the current valve covers***

I had stock chrome valve covers that kept hitting the rockers even with 3 gaskets so I ordered some of the stock appearing, 3/4" taller "cheater" style covers but they haven't showed up yet so I am running the cheapy tall covers until the new tall stockers get here..

 

[Rod75]

Also notice that he's replaced the stock transmission crossmember with an aftermarket piece. That alleviates the problem of possible pipe contact/alignment inside the stock crossmembers exhaust pipe through holes. And I imagine the use of the pipe crossover piece may have also forced this change.

On a side note: one of the best mod's you can do for your engine is letting it breathe with a low restriction dual exhaust. Be sure the bend angles are as gentle as possible to achieve the goal.

 

[Randy_W]

That is a sweet system, I hope he's got the 650 h.p. to go with the that size mandrel bend pipes. Even at 650 h.p. he'd be overkill below 4500 rpm and likely be hurting torque on the street if that matters at all. Back in the mid seventies when we were SCCA racing my Firebird Formula we found dual 2.5" into a single 4" side outlet Herb Adams designed system improved mid range torque off the corners and the 6500 rpm power was no different than 2 3" pipes. Of course that was a 366 Pontiac with only 575 H.P. Newer head designs etc... may have made those big pipes work better than they use to.