My gut feeling is that the X-pipe is causing the dramatic drop in torque at 3-4000 rpm. There's plenty of anecdotal evidence to suggest that the flat-6 doesn't respond well to this configuration. I'd be VERY inclined to have this changed for pipes that don't mix the exhaust streams from the opposing banks (i.e. crossover pipes, rather than an X-pipe). Can your exhaust maker weld your free-flow cats into seperate crossover pipes instead of an 'X' configuration? Your peak power figures shouldn't be compromised as the increased flow from the cats is where most of the power comes from, but the hole in the torque curve could disappear.

 

Has this issue been solved? i installed fabspeed comp air intake and fabspeed mufflers.

Noticeable drop in torque low end like before 3000 rpms

echo if u fixed this issue please let me kno how, i kno this thread is a while back soz

 

I am also interested to find out if you solved your low end torque loss with an ECU flash

 

Someone asked me if I resolved my issues with the low end torque and I just thought I post it for all that's interested.

I did install the Softronics ECU flash and didn't seam to make any difference on the low end torque below 4000 rpm.

I was convinced that a plenum would help so I had an IPD Plenum would help so another $1000 for the Plenum and that didn't seam to make much difference on my torque below 4000 rpm.

At the end of the day, a lot of money spent, the car is definitely faster above 4000 rpm but I was not able to recover the loss of torque at the low end. I did not try separating the exhaust pipes by removing the x-pipe as someone had suggested and by that time, I didn't want to sink any more money into the car. I did learn how to drive it faster around the track to carry more speed through the corners and made slight changes to where I shift.

I know this was no help in providing you any solutions but it might save you some money by putting it in other areas that perhaps I have not tried yet in recovering my low end torque. I still enjoyed driving the car very much because it drives like no other base 997 and it now belongs to my brother in law.

 

Hi echo:

I was the one who sent you the private message requesting an update. Thank you so much for your very complete response as I am sure it will help a lot of people who are in the same boat.

I am very disappointed to hear about the lack of success after the Softronic flash, but I am not surprised. After reading many threads in this and the other forum, I started to realize that getting back that low end torque would be very hard.

I installed a FVD Sport PDK exhaust system in my 2012 C4S 997.2 about 1 month ago. I am very happy with the results sound wise and torque-and-hp-gains-above-4k wise. The sound coming from this exhaust is good enough to justify the expense, and at least so far, I would do it again knowing what I know now about the low end torque loss.

Interestingly, I talked to Rhonda @ FVD in Miami and she told me that the torque wasn't lost but that the torque curve had moved to the right and that an FVD software flash would rectify this situation. Even though they have a 30 day money back warranty/no questions asked on this software flash, I am hesitant to do it because of possible warranty issues (even though the flash is reversible, I've learned that Porsche can tell at least that the the ECU was flashed without authorization - please correct me if I am wrong); if I had confidence that the FVD flash (or any ECU flash for that matter) had at least an 75% chance of succes to rectify MY specific problem, I would do it and live with the consequences, but according to my findings I doubt it. I am tempted to call Rhonda and ask her to let me know when ***** Brombacher (owner of FVD) is back in town so he can test the car and give me his opinion; he was at the warehouse when I picked up the exhaust and he even help me load it in the car. Very nice guy.

Maybe others with the same problem can chime in with their insights/solutions?

Cheers;

Moises

 

Yeh this torque loss at low rpms is very annoying, i would be goin up a slight uphill and if i wanted to accelerate it would feel really sluggish unless i push deep into the pedal

 

Moises, You can search on a few forums and find info on our software and the low end. Here is one for example....

 

This is spot on I reckon!

I tried a cat less xpipe with scavenging effect, the fabspeed one.

My peak power went from 368BHP and 305lb/ft upto 392BHP and 322lb/ft with biggest gains around 5500rpm, approx 40bhp and similar torque more.

But at 3000-4000rpm the car lost 40BHP and 45lb/ft, hugely noticeable, it also hesitated at low rpm with too much throttle. All issues many have seen with x-pipes.

Also the noise with PSE was stupid loud and horrible! I put my cats back in!!

Got some 200 cel straight pipes to try and shall dyno next month, shall be interesting to get the results.