Anyone NOT happy with the Plenum?
Registered User
Joined: Oct 2007
Posts: 50
From: England
Rep Power: 21
Foofighter,
I don't think there were ANY compromises in the gt3 (other than to keep it "road car" tracktable)
115bhp/litre is not an easy task on a normally aspirated engine.
It shows what porsche can do when they want to.
When you consider peak power @7600 and it can rev almost 1000 higher, it's amazing.
Everything on that engine "looks" how it should.The inlet and outlet manifolds look nothing like that on the Carrera.
Simon
I don't think there were ANY compromises in the gt3 (other than to keep it "road car" tracktable)
115bhp/litre is not an easy task on a normally aspirated engine.
It shows what porsche can do when they want to.
When you consider peak power @7600 and it can rev almost 1000 higher, it's amazing.
Everything on that engine "looks" how it should.The inlet and outlet manifolds look nothing like that on the Carrera.
Simon
Last edited by johnsosn; Mar 28, 2008 at 01:57 AM.
Registered User
Joined: Jun 2004
Posts: 2,597
From: New Jersey(outside Phila)
Rep Power: 126
Great review, but can the plenum do the same for a NA engine.
I would consider the x51 TB, plenum and manifolds, if you did not have to drop the engine to do it.
I would consider the x51 TB, plenum and manifolds, if you did not have to drop the engine to do it.
I took my car to the shop today to look at the part. Here is my final review after all was checked. BTW --I am happy with the plenum. https://www.6speedonline.com/forums/...d.php?t=124082
Registered User
Joined: Apr 2007
Posts: 1,352
From: long island
Rep Power: 87
I'm wondering if I'm in a minority of 1 in being deeply disappointed with this item.
I've read a lot of posts from people who are delighted with this product - 'makes a big difference', 'best bang for buck' are typical of the types of comment. This from people whose opinions I have learned to respect from reading and contributing to this forum.
I put it on the car yesterday afternoon - took about 25 mins. Everything lined up nicely, all the hose clamps tightened, airbox back on, MAF and valve electronics / pipework reconnected. fired the car up. Idles nice and smooth, no air leaks - this I'm going to enjoy....... Errr, not!
The car pulls less well right across the rev band. Not by much, but noticeably. Gone is the big slug of midband torque that appeared when I put on the AWE cats. Doesn't rev quite so cleanly at the top.
Check for leaks again, check everything's lined up, check the elecronics are all connected correctly - no issues. The damned car is just plain slower. I can't think of anything I might not have done correctly - fitting this part isn't rocket science; it's just a t-shaped piece of pipe!
I'm going to do a full DME reset today and see if that helps, otherwise there's a plenum up for sale.
Ian
I've read a lot of posts from people who are delighted with this product - 'makes a big difference', 'best bang for buck' are typical of the types of comment. This from people whose opinions I have learned to respect from reading and contributing to this forum.
I put it on the car yesterday afternoon - took about 25 mins. Everything lined up nicely, all the hose clamps tightened, airbox back on, MAF and valve electronics / pipework reconnected. fired the car up. Idles nice and smooth, no air leaks - this I'm going to enjoy....... Errr, not!
The car pulls less well right across the rev band. Not by much, but noticeably. Gone is the big slug of midband torque that appeared when I put on the AWE cats. Doesn't rev quite so cleanly at the top.
Check for leaks again, check everything's lined up, check the elecronics are all connected correctly - no issues. The damned car is just plain slower. I can't think of anything I might not have done correctly - fitting this part isn't rocket science; it's just a t-shaped piece of pipe!
I'm going to do a full DME reset today and see if that helps, otherwise there's a plenum up for sale.
Ian
Gerry
Registered User
Joined: Mar 2008
Posts: 43
From: Canada
Rep Power: 20
I think it is safe to say that Porsche, like any astute business, would never release an engine that was tuned to peak performance. Thus, it makes sense that we have the different levels of performance from base carrera to S to X-51 to GT3 etc.
However, if you believe the 26 HP increase that Porsche claims DESPITE THE EXTENSIVENESS of the X-51 kit, one would have to surmise that simple bolt ons would add very little to the net output of this engine. Ultimately, the computer mapping and other non-accessible aspects of engine management will prevail.
For what its worth, I have canvassed some of my less civilized
albeit experienced corvette and ferrari pals who like to tinker with their beasts and they concur that there has been limited DYNO proven benefits from basic bolt mods despite their best attempts.
Let common sense prevail.
However, if you believe the 26 HP increase that Porsche claims DESPITE THE EXTENSIVENESS of the X-51 kit, one would have to surmise that simple bolt ons would add very little to the net output of this engine. Ultimately, the computer mapping and other non-accessible aspects of engine management will prevail.
For what its worth, I have canvassed some of my less civilized
albeit experienced corvette and ferrari pals who like to tinker with their beasts and they concur that there has been limited DYNO proven benefits from basic bolt mods despite their best attempts. Let common sense prevail.
Registered User
Joined: Apr 2007
Posts: 1,352
From: long island
Rep Power: 87
Thank you for your opinion. Forgive those who, in their ignorance, value the input of others with first hand, real world experience on the topic in question. Please add the plenum to your list of current mods and report back. In the meantime everyone seems to have lost track of Ian, who started this thread.
Registered User
Joined: Jul 2006
Posts: 840
From: SoCal
Rep Power: 53
The engine has to be droped for that,, I assume your talking about the manifolds, but isnt ther another way.
Registered User
Joined: Mar 2008
Posts: 94
From: Canada
Rep Power: 22
for what its worth.. I have not seen anyone other then the manufacturer post a before and after dyno sheet for this mod???? The claims remind me of the tornado gasoline saver. http://www.tornadoair.com/
I am doing a bunch of mods at AWE and paying for before and after engine dyno's. I would challegne the manufacture RSSGREG to send one to AWE, and if it meets the claims I buy it, if not I send it back.
My car is due to arrive on wednesday/thursday this coming week. its getting AWE cats-headers-muffler, Evo intake, GIAC chip. Can do the RSS plenum right afer we have dyno'd the car to set the baseline. then after the plenum and then after the AWE/EVI/GIAC mods. That way we will all see how it preforms as a standalone mod, and a mod done with all the rest. GREG are you up to it?????
I will post all dyno charts for all to see.
I am doing a bunch of mods at AWE and paying for before and after engine dyno's. I would challegne the manufacture RSSGREG to send one to AWE, and if it meets the claims I buy it, if not I send it back.
My car is due to arrive on wednesday/thursday this coming week. its getting AWE cats-headers-muffler, Evo intake, GIAC chip. Can do the RSS plenum right afer we have dyno'd the car to set the baseline. then after the plenum and then after the AWE/EVI/GIAC mods. That way we will all see how it preforms as a standalone mod, and a mod done with all the rest. GREG are you up to it?????
I will post all dyno charts for all to see.
Thread Starter
|
Registered User
Joined: Jan 2008
Posts: 407
From: UK
Rep Power: 42
Hi again!
Now I'm properly confused - my butt dyno hasn't a clue if my car's faster or otherwise!
I put my newly acquired AWE mufflers on the car this w/e. Wasn't sure if I liked the sound at first Boom! Drone!......Then I read the instructions! Once I'd moved the rear bumper stays so the mufflers weren't touching them any more, most of the booming and droning went away... idiot!
These mufflers sound absolutely superb at WOT and over 4000 rpm but still a little bit too boomy around town. Not a bad compromise though and one I'm more than happy to live with. I'm just driving everywhere faster now!
Problem is, the sound and character of the car has changed with the new mufflers, as has the power delivery so I no longer have a clue if the plenum is contributing or not to any increase in performance. In fact I don't even know if the car is faster than stock. Shows how reliable the old butt dyno isn't!
However, I did run with a Subaru Impreza FQ360 yesterday. (I don't know if they're available in the US or elsewhere but this is a factory 360BHP Impreza on STEROIDS! The FQ stands for 'F***ing Quick' by the way - a manufacturer with humour)! We ran from a dead stop all the way to 100+ and he couldn't pull an inch on me. The driver was genuinely surprised he couldn't pull away - we spoke afterwards and he reckoned he could normally walk a 997S. From what I can remember the Subaru is a 3.9 sec to 60 car so I can see why! Maybe this was a more reliable test than the butt dyno - I simply don't know and haven't ever run against a similar car when mine was stock. Maybe the driver was good, maybe not.
My car is an enjoyable drive now and sounds amazing for most of the time. I think I'll treat the old girl to a pair of AWE headers then live with that setup for a while.
dduncan - I'm looking forward to your dyno results and would be very impressed with Greg at RSS if he'd take you up on the offer.
Edit: I found this apparently independent dyno test of a plenum added to a 997S. Don't know anything about the site but the test appears to show the plenum giving 11bhp peak on top of gains of 20 bhp with a full exhaust. http://www.europeancarweb.com/tech/e...a_s/index.html
Ian
Now I'm properly confused - my butt dyno hasn't a clue if my car's faster or otherwise!
I put my newly acquired AWE mufflers on the car this w/e. Wasn't sure if I liked the sound at first Boom! Drone!......Then I read the instructions! Once I'd moved the rear bumper stays so the mufflers weren't touching them any more, most of the booming and droning went away... idiot!
These mufflers sound absolutely superb at WOT and over 4000 rpm but still a little bit too boomy around town. Not a bad compromise though and one I'm more than happy to live with. I'm just driving everywhere faster now!Problem is, the sound and character of the car has changed with the new mufflers, as has the power delivery so I no longer have a clue if the plenum is contributing or not to any increase in performance. In fact I don't even know if the car is faster than stock. Shows how reliable the old butt dyno isn't!
However, I did run with a Subaru Impreza FQ360 yesterday. (I don't know if they're available in the US or elsewhere but this is a factory 360BHP Impreza on STEROIDS! The FQ stands for 'F***ing Quick' by the way - a manufacturer with humour)! We ran from a dead stop all the way to 100+ and he couldn't pull an inch on me. The driver was genuinely surprised he couldn't pull away - we spoke afterwards and he reckoned he could normally walk a 997S. From what I can remember the Subaru is a 3.9 sec to 60 car so I can see why! Maybe this was a more reliable test than the butt dyno - I simply don't know and haven't ever run against a similar car when mine was stock. Maybe the driver was good, maybe not.
My car is an enjoyable drive now and sounds amazing for most of the time. I think I'll treat the old girl to a pair of AWE headers then live with that setup for a while.
dduncan - I'm looking forward to your dyno results and would be very impressed with Greg at RSS if he'd take you up on the offer.
Edit: I found this apparently independent dyno test of a plenum added to a 997S. Don't know anything about the site but the test appears to show the plenum giving 11bhp peak on top of gains of 20 bhp with a full exhaust. http://www.europeancarweb.com/tech/e...a_s/index.html
Ian
Last edited by Ian_UK1; Mar 31, 2008 at 01:42 AM.
Registered User
Joined: Apr 2007
Posts: 1,352
From: long island
Rep Power: 87
Hi again!
Now I'm properly confused - my butt dyno hasn't a clue if my car's faster or otherwise!
I put my newly acquired AWE mufflers on the car this w/e. Wasn't sure if I liked the sound at first Boom! Drone!......Then I read the instructions! Once I'd moved the rear bumper stays so the mufflers weren't touching them any more, most of the booming and droning went away... idiot! These mufflers sound absolutely superb at WOT and over 4000 rpm but still a little bit too boomy around town. Not a bad compromise though and one I'm more than happy to live with. I'm just driving everywhere faster now!
Problem is, the sound and character of the car has changed with the new mufflers, as has the power delivery so I no longer have a clue if the plenum is contributing or not to any increase in performance. In fact I don't even know if the car is faster than stock. Shows how reliable the old butt dyno isn't!
However, I did run with a Subaru Impreza FQ360 yesterday. (I don't know if they're available in the US or elsewhere but this is a factory 360BHP Impreza on STEROIDS! The FQ stands for 'F***ing Quick' by the way - a manufacturer with humour)! We ran from a dead stop all the way to 100+ and he couldn't pull an inch on me. The driver was genuinely surprised he couldn't pull away - we spoke afterwards and he reckoned he could normally walk a 997S. From what I can remember the Subaru is a 3.9 sec to 60 car so I can see why! Maybe this was a more reliable test than the butt dyno - I simply don't know and haven't ever run against a similar car when mine was stock. Maybe the driver was good, maybe not.
My car is an enjoyable drive now and sounds amazing for most of the time. I think I'll treat the old girl to a pair of AWE headers then live with that setup for a while.
dduncan - I'm looking forward to your dyno results and would be very impressed with Greg at RSS if he'd take you up on the offer.
Edit: I found this apparently independent dyno test of a plenum added to a 997S. Don't know anything about the site but the test appears to show the plenum giving 11bhp peak on top of gains of 20 bhp with a full exhaust. http://www.europeancarweb.com/tech/e...a_s/index.html
Ian
Now I'm properly confused - my butt dyno hasn't a clue if my car's faster or otherwise!
I put my newly acquired AWE mufflers on the car this w/e. Wasn't sure if I liked the sound at first Boom! Drone!......Then I read the instructions! Once I'd moved the rear bumper stays so the mufflers weren't touching them any more, most of the booming and droning went away... idiot!
These mufflers sound absolutely superb at WOT and over 4000 rpm but still a little bit too boomy around town. Not a bad compromise though and one I'm more than happy to live with. I'm just driving everywhere faster now!Problem is, the sound and character of the car has changed with the new mufflers, as has the power delivery so I no longer have a clue if the plenum is contributing or not to any increase in performance. In fact I don't even know if the car is faster than stock. Shows how reliable the old butt dyno isn't!
However, I did run with a Subaru Impreza FQ360 yesterday. (I don't know if they're available in the US or elsewhere but this is a factory 360BHP Impreza on STEROIDS! The FQ stands for 'F***ing Quick' by the way - a manufacturer with humour)! We ran from a dead stop all the way to 100+ and he couldn't pull an inch on me. The driver was genuinely surprised he couldn't pull away - we spoke afterwards and he reckoned he could normally walk a 997S. From what I can remember the Subaru is a 3.9 sec to 60 car so I can see why! Maybe this was a more reliable test than the butt dyno - I simply don't know and haven't ever run against a similar car when mine was stock. Maybe the driver was good, maybe not.
My car is an enjoyable drive now and sounds amazing for most of the time. I think I'll treat the old girl to a pair of AWE headers then live with that setup for a while.
dduncan - I'm looking forward to your dyno results and would be very impressed with Greg at RSS if he'd take you up on the offer.
Edit: I found this apparently independent dyno test of a plenum added to a 997S. Don't know anything about the site but the test appears to show the plenum giving 11bhp peak on top of gains of 20 bhp with a full exhaust. http://www.europeancarweb.com/tech/e...a_s/index.html
Ian
Gerry
Registered User
Joined: Nov 2006
Posts: 546
From: Birmingham, AL
Rep Power: 41
I put my newly acquired AWE mufflers on the car this w/e. Wasn't sure if I liked the sound at first Boom! Drone!......Then I read the instructions! Once I'd moved the rear bumper stays so the mufflers weren't touching them any more, most of the booming and droning went away... idiot! These mufflers sound absolutely superb at WOT and over 4000 rpm but still a little bit too boomy around town. Not a bad compromise though and one I'm more than happy to live with. I'm just driving everywhere faster now!
I wish I would have the instructions then I may have kept my AWE mufflers. I bought them used w/o instructions.
These mufflers sound absolutely superb at WOT and over 4000 rpm but still a little bit too boomy around town. Not a bad compromise though and one I'm more than happy to live with. I'm just driving everywhere faster now!I wish I would have the instructions then I may have kept my AWE mufflers. I bought them used w/o instructions.