jbc426
Well-Known Member
A few years back, I welded on a pair of high-flow, metal substrate racing catalytic converters to my 3" TTi behind the collectors on my '68 EFI'd Magnum based 408 stroker. The overlap on the cam is pretty decent with 246* & 252* at .050" & 108* LSA.
I didn't do any back to back timed runs, but I could not detect any difference in sound or performance. The smell on unburnt hydrocarbons was completely gone though. The car runs clean, and being a convertible, it is a big improvement over the way it was even though the exhaust exists all the way out back.
I just ordered another pair of race cats for my 493" RB based motor in an attempt to repeat this effect. I'm hoping there is no noticeable performance loss on this engine either.
This style racing converter is pretty short at 6" in length with a 3 1/2" inlet and exhaust and a 4 1/2" wide body. I may have to use a tapered reducer for the exhaust side conection, but the inlet side will fit on my reducer, as it is 3 1/2" already. This car has a full 3" TTI exhaust with 2" headers and electric cutouts with ovalized megaphone tips to sweeten the sound.
I'll update the results when I get back from Carlisle and install them. This car is also getting a multi point EFI conversion in another month or two. Both upgrades are an effort to make the car much easier to drive and enjoy more often.
I didn't do any back to back timed runs, but I could not detect any difference in sound or performance. The smell on unburnt hydrocarbons was completely gone though. The car runs clean, and being a convertible, it is a big improvement over the way it was even though the exhaust exists all the way out back.
I just ordered another pair of race cats for my 493" RB based motor in an attempt to repeat this effect. I'm hoping there is no noticeable performance loss on this engine either.
This style racing converter is pretty short at 6" in length with a 3 1/2" inlet and exhaust and a 4 1/2" wide body. I may have to use a tapered reducer for the exhaust side conection, but the inlet side will fit on my reducer, as it is 3 1/2" already. This car has a full 3" TTI exhaust with 2" headers and electric cutouts with ovalized megaphone tips to sweeten the sound.
I'll update the results when I get back from Carlisle and install them. This car is also getting a multi point EFI conversion in another month or two. Both upgrades are an effort to make the car much easier to drive and enjoy more often.
