I installed this part & eliminated the cat. convertor.The car in sig. lost 2.5 10th,s just in the 60ft,s& also lost drivability,throttle response,etc.This mod just didn,t workThe car et,s @ track were also off by at least 2 10th,s& hp gains in 1/8 mi. were up by maybe 3-4 hp.The trap speed also went from av.of 101.15 to a best of 100.95 so even there not much gain.Does that mod need further tuning,etc.Any opinions would help.

 

There is no logical explanation for what happened. Should have been a tiny gain, if anything. Is the "pipe" significantly smaller in diameter than the rest of the system?

 

I noticed all your best times/speeds were all in September. Is it possible that weather/track conditions are a major contributor to the lower speeds and such?

Something as minor as an off-road pipe shouldn't hurt the car. Throw your cat back on and see if you gain it back for some reason. If not you might have another issue going on that just happened to be at the same time as your cat-pipe swap.

And on a side note- I wouldn't expect to gain monster time or speed with just an ORP. Cats are efficient these days and are not the major plug in the exhaust that so many people think they are.

 

The ad for that part says it,s 3" dia.but i will measure it to be sure.Thanks for the reply.

 

As a matter of fact i have reinstalled the Walker hi flow cat& it,s definitely better;one drive around block confirmed that.The weather cond. could have played a part but the car felt poor during different cond.I,m going to run the car again in Sep.(last race of season)& hopefully see some improvement w/ a 52 mm tb.Btw that cat. didn,t have any issues as i held it up against the light & i could see thru. it,it was also a 3" dia. one& much better than stk.Thanks for your reply.