As observed there is "some" merit for some amount of backpressure caused by an exhaust system. Unfortunetly this kind of thing is only observable by experimentation, it is impossible to accurately calculate beforehand. It is affected by everything from the effiecincy of the intake breathing to the camshaft, timing, etc. That is why when you buy something from a reputable vendor they have done measurements so you can expect certain results, not the case when you go off on your own and fabricate your own parts. Unless you start with baseline measurements and document and test everything you do you are "out there all alone". That is why you pay more than just for the fabricated parts. Testing is expensive along with some kind of warranty. IMHO the slight gains in the exhaust are not worth the expense and the added noise. On a long trip the noise can get to you and increase the fatigue. The catalytic converter does a lot to quiet the exhaust but is also a large contributer to backpressure. As for low end power, IMHO the gearing of the trans (automatic OR 5-speed) is not optimally designed to the PRV for the car at it's stock weight. I am guessing now but there is probably more to be gained by changing the gear ratios than anywhere else. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxxxxxx, "denverdelorean" <denverdelorean@xxxx> wrote: > Thanks for the review! I am a little disappointed that you lost > some low end tourque, but the car is a Grand Tourer, and benefits > from midrange power. I think I'll hold off for a bit because if > anything, I want more low end power. It doesn't help matters that > To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/