Contour Enthusiasts Group Archives Forums Modifications Duratec Performance To DemonSVT or anyone else Exhaust Question

Please check my post on nov.14 under Duratec performance.Why has no one else gone 2.5 inches throughout like I did.Instead of spending money on a new Y-pipe and low flow Cat get the best low restriction setup my way. No rasp , sounds great and performs even better. BAT ,Sho Shop, ETC. are just scamming you out of money offering systems that are a little better than stock but not as good as my system since my system offers as low restriction as you can get for much less money. Just find a good exhaust shop.

Was that really one entire sentence? A few carriage returns please.

BTW. 2.5" single exhaust has been done by several folks before. However most of the were smart enough to use mandrel bends and not sacrifice a good chunk of performance.

I even did a 2.5" single to dual F-body style exhaust as my first exhaust. All mandrel bends of course. Performed quite exceptionally even if a bit loud.

BTW - you may want to check the other post you did...

Firstly, thanks for your reply. I've admired your responses to other members that's why I posed the question to you. You obviously have vastly superior knowledge in this area than I do. BTW, I never mentioned that my car was a 99 se sport not an SVT.When the exhaust shop removed my original exhaust I did notice that it was made using crush bends. However, unlike the new system they installed, The bends showed an obvious decrease in diameter at all the bends. It had "clamp-like" marks on all of the bends. I did a bit of research last night and noticed several sources mentioning that the oe system on many cars is produced using crush bends. Also, that a good crush bent can be better than a poor mandrel bend if the mandrel bend is welded anything but perfectly flush and without any holes in the weld. In my particular situation the bends not not look to diminish in diameter at all compared to the factory system. Honestly, I've noticed a significant increase especially in the mid-range.Also the tires are willing to spin much easier from a start. The car reminds me more of another car I own A 2002 Maxima se 6 speed. Of course, that car is faster than any contour svt or not and in refinement is like comparing a dinner a Denny's to a steak dinner at Burns. Thanks again for your response.

I resemble that 2.5" exhaust remark. Also a Non-SVT, with 160hp/157tq before most of the new mods.

I had 2.5" crush bent piping on my car for a long time. The whole system was kinda pieced together, and it was way too loud inside the car (not outside, though). All in all, it gave me a good kick in the pants.
However, I have changed to a mandrel bent 2.5" system. Why? (I worked hard during the summer...wait, no!) cause I wanted that little extra bit of hp. I wanted that little extra flow.
I think the arguement here is that crush bent pipes are good enough for some people, and not good enough for others. I think it's been proven time and time again that mandrel bends will outflow even the best crush bends. So, do what suits your needs, and to each his/her own.

Have you had any performance problems that DemonSVT eluded to. My system seems to perform well.

performance problems? well, the first time I dynod I only pulled 165. I was a little sad, yes.
Otherwise, if you're just looking for an improvement over the stock straw-for-an-exhaust-pipe, a 2.5" crush bent system should certainly net you some hp gains. If you're looking for the best flowing system, mandrel bends are a MUST!

Derk2000, have you had any performance increases since you changed to madrel bends. BTW, my exhaust seems very well put together much better than the oe exhaust. the guy even took the time to spray all the welds.

Thanks for your info bro. I've decided to stick with stock on my other cars and have a new BMW M3 on the way. Can't wait for that. Should have it next week. I had a 1999 328is which I loved but the M3 should put that to shame. Thanks again for your response.

I would like to say "yes" for certain, but I can only use the seat of the pants dyno. My before dyno had the crush bent system. 165hp. My most recent dyno I added the mandrel bent system, catco cat, and the ProM MAF. 171hp. The ProM was added at the beginning of the summer, the new exhaust and cat added at the end of the summer. So, I didn't dyno the exhaust gains, but rather all my summer mods' gains. The new exhaust does feel like it has a little more up top, though (again, only seat of the pants testing).

I must say, though, that I'm so pleased w/ my exhaust setup. I know it flows well, and it's soooo much quieter inside. Plus, as the new mufflers get broken in...they sound cooler and cooler.