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Install and go. The X pipe has little cat simulators welded into the "after cat" 02 sensor bung. One of the attractive things about this super pricey exhaust is that a tune is not required. Charles was adamant that you don't need to tune the car as he designed it to work within the stock fuel trim parameters. So I guess there is some "savings" there. Although some people turn off the cat warm up cycle on cold start because it makes the car extremely loud when you first start it. I haven't done that personally.
Under certain conditions (low load, continuous cruising at 40-50 mph, ~1500-3000 RPM) it will give you a check engine light. But i've had it on for 2 years now and have only had the CEL come on twice. One time it was cold and I was driving slow looking for a place to do donuts, the second time my boss called me on my cell phone so I had to keep the engine quiet for a 10 minute conversation.
I have a durametric, which I think everyone should buy. So clearing the code is no problem. The exhaust is extremely pricey, but is also extremely awesome. Its basically a full one off racing exhaust with stepped headers and rebuildable little mufflers. The material its made out of is 321 stainless, so its thin wall and super light. That, I believe, also contributes to the sound it makes.
Charles says its a 70-80 lb weight reduction because you delete the stock muffler hangers, which are total boat anchors. Unfortunately I have not independently verified this.
It has more mid range punch than a center exit exhaust, but a little less peak HP. I knew there was a beautiful sound in there behind the stock 996 crap, so I bit the bullet and ordered it. I actually had to convince Charles to start making the exhaust again, he said it takes a long time to fabricate and 321 stainless is extremely unforgiving to weld. But the end result was excellent. I think the exhaust is a major reason why my car is now knocking on the door of 2XXX lbs. Exhaust, seats, steering wheel, carbon doors are my weight reduction mods. And I'm currently running the cheap-but-heavy Ate 2008 Cayanne Turbo front discs.
Originally Posted by Wind911
I have the same Dundon exhaust. Love it. getting compliments many times at track.The net weigh saving over stock is 63 lbs. (with muffler brackets removed)
Did either of you happen to do before/after dynos for the exhaust?
Do you have the front Tarrett end links that mount to the pinch bolt or the more expensive extended links that mounts to the shock body? The former will bind when the steering wheel is turned in tight corners. Also causes understeer/ inside wheel lift. I had them and hated them, switched to the extended ones much better.
I have the same Dundon exhaust. Love it. getting compliments many times at track.The net weigh saving over stock is 63 lbs. (with muffler brackets removed)
I think I have the shorter (less expensive) ones that go on the pinch bolt (picture below). They didn't seem to bind up after I installed them and loaded up the suspension and turned lock to lock... However, when I bought them I did speak to Ira from Tarrett and he said there was another product they made that does a better job of preventing preload through the motion of the suspension. Those are probably the ones you have.
Agree on the exhaust. On the first day, someone came up to me and said my car sounds better than "most of the new stuff out here." The price has gone a little mad, but its a really nice setup. Looks like you were an early, early adopter of that exhaust.
Did either of you happen to do before/after dynos for the exhaust?
I have a before dyno (picture 1), but I haven't done an after yet. The Dundon website has dyno graphs (picture 2) that show stock, dual exit, and center exit exhausts.
My car did 358hp/271tq to the wheels when I dyno'd it. The baseline car on the dundon graph is 358hp/268tq, so it seems representative. My number is on a dynojet and Charles's number is on a dynapac.
Allegedly, 13 peak HP gain and 20 HP gain at ~6000 RPM
I think I have the shorter (less expensive) ones that go on the pinch bolt (picture below). They didn't seem to bind up after I installed them and loaded up the suspension and turned lock to lock... However, when I bought them I did speak to Ira from Tarrett and he said there was another product they made that does a better job of preventing preload through the motion of the suspension. Those are probably the ones you have.
Agree on the exhaust. On the first day, someone came up to me and said my car sounds better than "most of the new stuff out here." The price has gone a little mad, but its a really nice setup. Looks like you were an early, early adopter of that exhaust.
Yes, What you have are the shorter ones that are really designed for regular 996's. They are not really bind up per se on the GT3, but I can feel the steering gets heavier the more I turn the wheel when the car is parked. This means they're preloading the sway bars and I can actually see the inside front corner lift up higher in tight corners (COTA 13-14-15 for example). The stock GT3 links and the Tarret extended ones dont have this behavior.
03-23-2019, 12:06 AM
