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I think I found the issue. I had a leak in the TCP intake. I'm having a really hard time getting it on without major kinks and didn't get it sealed. I spent another 2 hours on it tonight and it's a little better and I don't think it has any leaks now.
The car feels better and my butt dyno can feel the mods now. Even the exhaust sound is different. It's actually a lot quieter even with the cut outs open it's not obnoxious at all. I'll know for sure when I take it for another dyno run.
I'm thinking of going back to stock or changing to the Mina Gallery intake. I just can figure out the TCP and how to get it straight, without kinks or leaks. It's like a Rubiks cube I have probably 5 hours in it and am giving up.
I'm emailing them to see if they will take a return. If not, anyone want a TCP? Any offers?
Darren, I had the same problems as you with kinks in the TCP intake, but after a couple of goes (and several hours!) at fiddling with the placement of the hoses and clamps I reduced the kinks to an acceptable amount, still some but nowhere near as bad as yours. It just takes (a lot) of patience!
One hint - try pulling the central Y piece out a bit further, ie a bit closer to the S/C pulley/belt but still leave at least 5 mm clearance. This was the most effective fix for me.
I too had issues getting mine right, I'm running the original design with the 5/8 vacuum line plummed into the silicone hose, it seems to fit better than the updated intake with the 5/8 hose plummed into the metal elbow.
All of my performance mods are now complete. I need to get some miles on it for the ECM to adapt and I'll do another set of dyno tests next week. I'm very happy with the sound and flexibility of the electric exhaust cutouts. Silent stock to amazing straight pipe with the push of a button. I'm interested in the dyno test with them open vs closed.
It's hard to tell from the pics, but I have an extremely similar setup (I'm using Race Ready Performance's Patriot Series cutouts), and you might want to try to rotate your tips down a bit, so the exhaust goes down to the ground while you're sitting still.
It's hard to tell from the pics, but I have an extremely similar setup (I'm using Race Ready Performance's Patriot Series cutouts), and you might want to try to rotate your tips down a bit, so the exhaust goes down to the ground while you're sitting still.
Reaxions. mine currently point down and out at about a 45 degree angle. I thought about pointing them down but was worried the sound would bounce back up off the concrete like when your going through a drive through. (not sure if that would happen or not )What would the benefit of pointing them down?
Have you ran yours on a dyno and compared them open vs closed? I'm still chasing down other issues I'm having with my mods but as I sit right now I'm losing between 25-50 whp with them open compared to closed.
Honestly I'm not surprised about a loss of power with an open exhaust.
I have heard from several people over the years about engines losing power / responsiveness when the exhaust is too big, straight through, or even when removing catalysts (which also act as a muffler).
Even the factory active exhausts on some models seem to be only for noise. One of the guys here in Sydney with an XK did some dyno runs with the valves locked open and shut, made no difference to the power on the dyno at all, just got louder.
I also got feedback from one F-Type V8 owner who changed his cats to 200 cells and he was disappointed that it seemed to lose some of the low end response it had before.
Too little exhaust back pressure is also bad from a tuning perspective, so they tell me...
Thanks for the advice everyone. I've been reading all night about exhaust back pressure, velocity and scavenging. Lots of fun.
What I still don't get is that I've virtually duplicated the XFRS exhaust. X-pipe, straight pipes and bypass valves that pass straight through the mufflers which is basically the same as my cutouts. The only thing I did notice is the x-pipe on the XFRS is further back than mine is. I think I might move it further back and see what that does. Should I put the central muffler or resonator back in for a little more resistance?
Reaxions, your cutout setup was my inspiration. It looks so good on your cae and I love having the ability to be very quite when I want and let it loose with some sound when I want. I don't even care if I don't get any gains from opening them, I just would like to not lose so much power with them open. Have you tested to see if you are gaining or losing power with the cutouts?
The supercharged V8 rear cans are not effectively "dumps" when the valve opens.
The valve does not open far enough to allow 100% of the gases to bypass the all the internal muffle material and the gases still have a maze of bends and chambers to go through. (I cut mine out and welded plates in)
So you do still get some back pressure when the valve opens on a "stock" setup.
Adding in a central resonator will increase back pressure as stated above, but it will change your tone a bit, but form always follows function when it comes to cars.
BTW - I LOVE THIS THREAD.
Keep at it and thank you for your research and willingness to share.
It's been almost 5 years since I did all of my exhaust work, so I hope I'm remembering it all correctly...
I left the first/front resonator, listed as "1" in red on the attached diagram, in place. I think it's essentially under the front seats and I didn't want to incur excess cabin drone. I initially replaced the second/rear resonator, listed as "2" in red on the attached diagram, with just an X-Pipe, but didn't like the tone or how loud it was, so I immediately installed a Magnaflow X-Pipe with a muffler built around it where the rear resonator had been. The muffled Magnaflow X-Pipe I have installed is Magnaflow #12468 (see attached pix). It took down the volume and the harshness significantly, and I've loved it and gotten countless compliments on the overall exhaust sound/feel all of these almost 5 years.
As I added the cutouts primarily for sound, and I don't race my rig, I never felt the need to drop coin on a dyno. So, as much as I'd like to and will try to help, I'll have to present anything I might mention with the caveat of pure speculation. To that point, I'm not sure what, if any, effect my X-pipe or it's location might have, or if the cutouts are potentially responsible for some differences between our cars, especially since without a dyno, we can't really compare them scientifically enough to provide any reliable certainty. Hell, assuming that everything else is the same, including our cutouts opening to the same degree, maybe I'm actually also losing HP every time I open them (which is 99% of the time), and I just don't notice. Having said that, even though I've never noticed a "seat of the pants" difference between having the cutouts open or closed, if I'm being honest, I doubt I'd really notice a difference of 25 HP with everything else that's been done, anyway. Although, my ego would like me to believe that I'd notice a difference of 50 HP in my "butt dyno." Ha-ha! If I were ever to actually dyno my car, I'd probably ask them to measure with the cutouts wide open, completely closed, and several positions in-between, to best calibrate optimization.
I'll be the first to admit that I don't know very much about the science of exhaust dynamics, but, prior to making any of my exhaust mods, I did read a ton on both sides about back pressure, etc., and, without vouching for the validity of this next statement, I even remember reading at one point that supercharged cars aren't "as" dependent upon back pressure to determine performance as normally aspirated cars. Specific to my setup, I'm ultimately not sure if opening the cutouts means that the path of least resistance is so great that the exhaust gasses completely bypass the dual rear mufflers, or if some of the exhaust is still channeled through them, thereby keeping some of any required back pressure. Again, it's been half a decade since I researched any of it, but I do remember thinking that with my existing setup, because the exhaust is still going through the cats, the first/front resonator, and then the muffled Magnaflow X-pipe before it hits the cutouts/Y-pipes, that any loss of back pressure should be negligible (assuming it mattered very much in the first place). As always, I reserve the right to completely wrong.
Unfortunately, and as I'm sure you're aware, without matching runs on the same dyno (at roughly the same time) to get a decent baseline, and without a true apples to apples hardware comparison, I just don't know how to troubleshoot any of it based on my setup. If it might help you narrow down some of the other potentially dependent variables between our cars, I've currently got 42K miles on my '11 XFR, and, in addition to the exhaust setup, I've got a TCP intake and K&N panel filters, a Mina pulley, and an ECUTG tune. Even if we're running the exact same hardware, which it sounds like we probably aren't, the tune alone could potentially determine the whole ball of wax; even if we're still assuming that I'm actually not losing any HP/TQ with the cutouts open, which I may very well be, my ECUTG ECU tune might potentially take advantage of more of an open exhaust. Maybe it's a stretch, but, everything else being equal, I guess it's plausible that the ECUTG tune could possibly require less back pressure than the factory tune (assuming it's of significant importance to the factory tune), as I remember a freer-flowing exhaust being one of ECUTG's prerequisites for the tune.
Whew! I'm all speculated and counter-speculated out. Please PM me if you'd like to chat on the phone about some of this. Good luck tracking it down - I'll be watching the thread.