Straight pipe on a TT?
#1
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hey - I drove a buddies 997.2 GT3 RS with a straight pipe in place of the center exhaust and it sounded AWESOME.
Has anybody tried this on a TT? Crazy idea?
Has anybody tried this on a TT? Crazy idea?
#2
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I have it on mine now and swapping to something quiet next week, it's not as loud as you would think, the turbo's are loud and sound amazing, my problem with the setup is drone at low RPM on highway.. i get chronic migraines so it's not a good setup for me personally.
if you wanted to do it, the cats+straight pipe are usually 2k.. i could sell you my setup when i remove for far less to try out...
if you wanted to do it, the cats+straight pipe are usually 2k.. i could sell you my setup when i remove for far less to try out...
#3
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Maybe someone with some exhaust knowledge will chime in - I think a certain amount of back pressure is good - not sure how much straight pipes provide...if needed.
#4
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
i have talked to EVOms about this in length, they said you HAVE to run cats... the systems that eliminate the cats are very bad for the turbo.. 200cell w/ 70mm piping was their recommendation.
#5
Rennlist Member
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I have it on mine now and swapping to something quiet next week, it's not as loud as you would think, the turbo's are loud and sound amazing, my problem with the setup is drone at low RPM on highway.. i get chronic migraines so it's not a good setup for me personally.
if you wanted to do it, the cats+straight pipe are usually 2k.. i could sell you my setup when i remove for far less to try out...
if you wanted to do it, the cats+straight pipe are usually 2k.. i could sell you my setup when i remove for far less to try out...
I was going to go custom on this at the local Bullet Racing shop but let me know what you'd like for it. We can ship it to my Washington address.
#6
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hey - good idea. I do understand the drone - the GT2RS had one to at around 6K rpms. Predicable - what rev range is yours coming in and out?
I was going to go custom on this at the local Bullet Racing shop but let me know what you'd like for it. We can ship it to my Washington address.
I was going to go custom on this at the local Bullet Racing shop but let me know what you'd like for it. We can ship it to my Washington address.
so jealous of the GT2RS... that's my dream car.
#7
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I don't.
Why do you have to run cats?
Why are catless systems supposedly bad? That goes against pretty much everything I know about turbocharged engines, and I've been playing around with turbocharged cars for over 20 years.
Trending Topics
#8
Nordschleife Master
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
i guess HAVE was a strong word, i will replace it now with SHOULD...
i would personally sacrifice 5% power for some longevity.
#9
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Well, the specialists I have talked to- actual turbo manufacturers, not street car tuners- have all said back pressure is bad.
If the tuner says they need back pressure for turbocharger life, find another tuner. The issue isn't back pressure, the issue is proper turbo design.
The other issue is whether or not you are even approaching the rpm limits of said turbo. I highly doubt a stock engined, stock turbocharger equipped 997 Turbo approaches that limit with or without a pair of catalysts. If you are not at the turbocharger limit what would cause premature failure? Vibration (poor balancing, bad tuning)? It sure as heck isn't heat because cat deletes would only lower pressure in the manifolds, not raise them. In fact, lowering the temps substantially by deleting cats may increase life instead.
Unless you have 60k+ miles on your car I seriously doubt any issue of turbocharger life comes into play concerning catalysts, unless the goal is to lower output from clogged cats, and thus lower the rpm they operate at. That is the only way the catalysts can help lengthen turbocharger life.
If the tuner says they need back pressure for turbocharger life, find another tuner. The issue isn't back pressure, the issue is proper turbo design.
The other issue is whether or not you are even approaching the rpm limits of said turbo. I highly doubt a stock engined, stock turbocharger equipped 997 Turbo approaches that limit with or without a pair of catalysts. If you are not at the turbocharger limit what would cause premature failure? Vibration (poor balancing, bad tuning)? It sure as heck isn't heat because cat deletes would only lower pressure in the manifolds, not raise them. In fact, lowering the temps substantially by deleting cats may increase life instead.
Unless you have 60k+ miles on your car I seriously doubt any issue of turbocharger life comes into play concerning catalysts, unless the goal is to lower output from clogged cats, and thus lower the rpm they operate at. That is the only way the catalysts can help lengthen turbocharger life.
#13
Former Sponsor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Our recommendation is on a street car to run, at a minimum, either cats or mufflers. Or both, if you drive the car on the street and value your hearing/sanity.
Running neither gives so little back pressure that the tune has to be extensively rewritten to keep the turbo spool in check. Without it, on a tune that was designed around running an exhaust, you'll get severe overboosting and driveability issues as the car tries to correct itself. We've written tunes for track/race cars that deal with it appropriately, but they were essentially custom tunes due to the other modifications they had going on and drove very aggressively. For a street car, the slight amount of back pressure that cats or an exhaust provides makes the car more driveable at partial throttle.
Edit: Had a customer bring this thread to our attention, sorry for the necro-post.
Sam
Running neither gives so little back pressure that the tune has to be extensively rewritten to keep the turbo spool in check. Without it, on a tune that was designed around running an exhaust, you'll get severe overboosting and driveability issues as the car tries to correct itself. We've written tunes for track/race cars that deal with it appropriately, but they were essentially custom tunes due to the other modifications they had going on and drove very aggressively. For a street car, the slight amount of back pressure that cats or an exhaust provides makes the car more driveable at partial throttle.
Edit: Had a customer bring this thread to our attention, sorry for the necro-post.
Sam
#14
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Hey
i put straight pipes on my 997tt for one day!!! I love loud cars but all it made was noise not sound and it was physically painful! On the highway the drone makes u wanna rip your head off! Thought i would share
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
![Wink](https://rennlist.com/forums/images/smilies/wink.gif)
#15
Basic Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
![](https://www.fabspeed.com/images/997TT_56_1.jpg)
__________________
Porsche Performance Specialist
John@Fabspeed.com
215-618-9796
Fabspeed Motorsport USA
155 Commerce Drive Fort Washington, PA 19034
www.Fabspeed.com
Porsche Performance Specialist
John@Fabspeed.com
215-618-9796
Fabspeed Motorsport USA
155 Commerce Drive Fort Washington, PA 19034
www.Fabspeed.com