Anyone NOT happy with the Plenum?
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Ian
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I have been bored today! As a consequence, I decided to clean my engine bay.
After removing the airbox, and a little more study, I think it's possible to fit an X51 intake manifold without dropping the engine!
You would have to remove the alternator and move the compressor and then i think I can get my hands all round the intake manifold right up to the head on the furthest one in.
I would however have to get a little braver before I decide to do this.
If any of you get the time, have a look.
Regards
Simon
After removing the airbox, and a little more study, I think it's possible to fit an X51 intake manifold without dropping the engine!
You would have to remove the alternator and move the compressor and then i think I can get my hands all round the intake manifold right up to the head on the furthest one in.
I would however have to get a little braver before I decide to do this.
If any of you get the time, have a look.
Regards
Simon
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I see alot of chat of added HP but what about the torque gains? That's where you feel the pull on the seat of the pants!! I heard the plenum reduces the torque in certain pockets on the torque curve. Maybe that's why he feels his car is slower.
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I believe the discussion of low end torque loss was w r to headers pipes. There is no sense of lost T w plenum in my experience, rather the opposite. Gerry
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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
So you completely removed the rear bumper stays? In my directions from AWE it had said to bend them out of the way, but I could not even bend the damn things and bending them would cause them to not align with the holes. So I assume its ok to remove them altogether? My mufflers have a rattling sound that comes at low low rpms and I assume it is the mufflers hitting those damn metal bumper stay bars, so that is why I ask.
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So lets think about this: dduncan has requested a plenum from RSS for dyno testing at an independent dyno (AWE) to see if there are any gains to be had from the plenum versus a stock baseline dyno. But RSS has not replied and does not want to send him one for testing? Did I read this right? I sure hope not because if this plenum makes even 5whp this would be great marketing for RSS...so please lets get this done!
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Why should RSS send him a plenum to test, when they've already tested it and posted the dyno results?
And why again can't dduncan pay for it like everyone else and return it for a full refund if he's not satisfied?
I think RSS has met their obligation.
And why again can't dduncan pay for it like everyone else and return it for a full refund if he's not satisfied?
I think RSS has met their obligation.
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From: Tucson, AZ
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I think the second option of him buying it and returning it if not satisfied is fair enough. Do you always believe dyno numbers that the manufacturer puts out? Independent dynos are more reliable than those by the manufacturer...of course a manufacturer is going to show gains, it is marketing.
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