RPI GT Race exhaust...

JCz04Bimmer · 07-06-2009, 04:53 PM

Quote:

Originally Posted by RPIpower

Yeah, we went through this guys. The tips are going to be as it has always been. I dont want to follow everyone else and do the same thing. I think it sets our system apart from all others and it fits the lines of the Z4 well.

Understood. It wouldn't be a deal-breaker for me, really. I could just as easily lob them off and replace them with something else if I really didn't like the look.

I'm most curious to hear what this sounds like a cruising speeds on the highway from inside the cabin. Are videos of this planned? I'd be interested in hearing what it sounds like while holding the revs constant at 2000, 2500, 3000 and 3500.

RPIpower · 07-06-2009, 05:38 PM

Quote:

Originally Posted by Dammmittt

Any word yet on the price of these bad boys?

Intro pricing is $899. We are only making 25 of these so I would get a list going if any of you want it.

Quote:

Originally Posted by Z4MCJJ

So are the dyno results herein valid for these exhaust cans?

yep 8whp and 7ft/lbs.

Quote:

Originally Posted by JCz04Bimmer

Understood. It wouldn't be a deal-breaker for me, really. I could just as easily lob them off and replace them with something else if I really didn't like the look.

I'm most curious to hear what this sounds like a cruising speeds on the highway from inside the cabin. Are videos of this planned? I'd be interested in hearing what it sounds like while holding the revs constant at 2000, 2500, 3000 and 3500.

The car is not loud but definately louder than stock. I drove about 200 miles with the exhaust and I was able to talk on the phone via bluetooth, etc with no problems. I didnt get to do too many videos as I didnt want to have to drive a car with PINK roundels any more than I had too.

chuck159 · 07-06-2009, 05:59 PM

I guess I'm starting the list. Do you want a deposit? LMK
Thanks!

RPIpower · 07-06-2009, 06:01 PM

Quote:

Originally Posted by chuck159

I guess I'm starting the list. Do you want a deposit? LMK
Thanks!

I hate doing deposits. I rather go on the honor system for now. You can start the list if you want and we wont take payment info until its time to ship.

laidback · 07-06-2009, 07:55 PM

The sound is Pure Sex (very Deep and no rasp) ...I've heard quite a few exhaust on the Z4M and this is the reason why i picked this system (with Hp and Tq to boot)...

Quote:

Originally Posted by JCz04Bimmer

Understood. It wouldn't be a deal-breaker for me, really. I could just as easily lob them off and replace them with something else if I really didn't like the look.

I'm most curious to hear what this sounds like a cruising speeds on the highway from inside the cabin. Are videos of this planned? I'd be interested in hearing what it sounds like while holding the revs constant at 2000, 2500, 3000 and 3500.

RussRamz · 07-06-2009, 11:26 PM

Any word yet on the noise readings?

laidback · 07-07-2009, 01:41 AM

Eloy and i just met an hour ago to measure the db meter and i'm sure he'll post the readings and the vid...be ready to order the exhaust

Quote:

Originally Posted by RussRamz

Any word yet on the noise readings?

laidback · 07-07-2009, 01:42 AM

Burn out on 20's FTW

Quote:

Originally Posted by RPIpower

Here is a launch and semi-flyby vid.

RPIpower · 07-08-2009, 06:03 PM

I have the test on video but it doesnt want to upload right now for some reason. The test was done at about 20" from the exhaust tip at a 45 degree angle. In nuetral, revved to 7500rpm, the db is 112. At 4900rpm its 97-98db. At 6000rpm its hovering at the 100db range.

RPIpower · 07-08-2009, 06:22 PM

finally got the vid to work.

The "O" mark would mean that its 100db.

mimsterzx7r · 07-08-2009, 07:20 PM

Does anybody know the stock db readings?

RussRamz · 07-08-2009, 11:44 PM

Quote:

Originally Posted by RPIpower

I have the test on video but it doesnt want to upload right now for some reason. The test was done at about 20" from the exhaust tip at a 45 degree angle. In nuetral, revved to 7500rpm, the db is 112. At 4900rpm its 97-98db. At 6000rpm its hovering at the 100db range.

Thanks for the testing. Is this exhaust mounted to a stock set of headers, cats, and resonator?

RPIpower · 07-09-2009, 11:29 AM

Quote:

Originally Posted by RussRamz

Thanks for the testing. Is this exhaust mounted to a stock set of headers, cats, and resonator?

Its the axle back only. The stock piping is VERY well designed and I couldnt find a cost effective way of improving on it. We have dynoed several aftermarket tubing without significant improvements in performance. Our axle back uses two small resonators.

Chuck I · 07-09-2009, 01:19 PM

Quote:

Originally Posted by RPIpower

Its the axle back only. The stock piping is VERY well designed and I couldnt find a cost effective way of improving on it. We have dynoed several aftermarket tubing without significant improvements in performance. Our axle back uses two small resonators.

So I make sure I understand... these are stainless and the entire unit will be polished.. correct? Thanks, Chuck I

RPIpower · 07-09-2009, 01:26 PM

Quote:

Originally Posted by Chuck I

So I make sure I understand... these are stainless and the entire unit will be polished.. correct? Thanks, Chuck I

They are T304 stainless, polished and come with our standard limited lifetime warranty.

rcodea · 07-09-2009, 02:18 PM

did i read this correctly, sub-98dB readings? I too would like to see some drive-bys, and interior audio clips. any thought on drone?

~Ryan

RPIpower · 07-09-2009, 03:32 PM

Quote:

Originally Posted by rcodea

did i read this correctly, sub-98dB readings? I too would like to see some drive-bys, and interior audio clips. any thought on drone?

~Ryan

Held at 4500-4900rpm the reading in nuetral hovers 98db. I dont have any readings during cruising, etc as there was an LASD deputy watching us very closely as we did this test. This system does fall into our GT series category so quiet wasnt one of our main priorities.

rcodea · 07-09-2009, 06:06 PM

Quote:

Originally Posted by RPIpower

Held at 4500-4900rpm the reading in nuetral hovers 98db. I dont have any readings during cruising, etc as there was an LASD deputy watching us very closely as we did this test. This system does fall into our GT series category so quiet wasnt one of our main priorities.

and there are no plans for a more sport/quiet exhaust, correct?

~Ryan

RPIpower · 07-09-2009, 06:20 PM

Quote:

Originally Posted by rcodea

and there are no plans for a more sport/quiet exhaust, correct?

~Ryan

No, not at this time as power becomes an issue when you try to suppress the db levels with this particular application.

mimsterzx7r · 07-09-2009, 10:06 PM

I got these readings from Edmunds test drive of an 06 M Roadster. It doesn't state how they obtained these readings, so I don't know how valid they are.

Db @ Idle: 52.5
Db @ Full Throttle: 83.4
Db @ 70 mph Cruise: 71.5

Here is the link.
http://www.edmunds.com/apps/vdpconta...4/pageNumber=5

jonanator · 07-09-2009, 11:42 PM

An in cabin vid with sound would be awesome

RPIpower · 07-10-2009, 11:44 AM

Quote:

Originally Posted by jonanator

An in cabin vid with sound would be awesome

laidback? Care to make a quick video?

07-06-2009, 05:59 PM	#399
chuck159 New Member 0 Rep 20 Posts Drives: 07 Z4 M coupe Join Date: Sep 2007 Location: SF iTrader: (0)	I guess I'm starting the list. Do you want a deposit? LMK Thanks!
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07-06-2009, 11:26 PM	#402
RussRamz M Slut 18 Rep 564 Posts Drives: 2011 M3 Coupe Mineral White Join Date: Sep 2007 Location: Adenau, GE via 3 years in dreadful El Paso, TX iTrader: (0)	Any word yet on the noise readings? __________________ You have to be 100% behind someone before you can stab them in the back. David Brent
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07-08-2009, 06:03 PM	#405
RPIpower Captain 49 Rep 857 Posts Drives: F97 X3M, G80 M3 Join Date: Aug 2007 Location: PA iTrader: (0)	I have the test on video but it doesnt want to upload right now for some reason. The test was done at about 20" from the exhaust tip at a 45 degree angle. In nuetral, revved to 7500rpm, the db is 112. At 4900rpm its 97-98db. At 6000rpm its hovering at the 100db range.
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07-08-2009, 06:22 PM	#406
RPIpower Captain 49 Rep 857 Posts Drives: F97 X3M, G80 M3 Join Date: Aug 2007 Location: PA iTrader: (0)	finally got the vid to work. The "O" mark would mean that its 100db.
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07-08-2009, 07:20 PM	#407
mimsterzx7r Private First Class 5 Rep 161 Posts Drives: 07 M Roadster, 03 Pathfinder Join Date: Oct 2007 Location: Houston, TX iTrader: (0)	Does anybody know the stock db readings? __________________ ZHP knob/Zeckhausen CDV/ESS Tune/More to come
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07-09-2009, 02:18 PM	#412
rcodea Private First Class 17 Rep 104 Posts Drives: 19 M2C Join Date: May 2009 Location: Goodyear, AZ iTrader: (0)	did i read this correctly, sub-98dB readings? I too would like to see some drive-bys, and interior audio clips. any thought on drone? ~Ryan
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07-09-2009, 10:06 PM	#416
mimsterzx7r Private First Class 5 Rep 161 Posts Drives: 07 M Roadster, 03 Pathfinder Join Date: Oct 2007 Location: Houston, TX iTrader: (0)	I got these readings from Edmunds test drive of an 06 M Roadster. It doesn't state how they obtained these readings, so I don't know how valid they are. Db @ Idle: 52.5 Db @ Full Throttle: 83.4 Db @ 70 mph Cruise: 71.5 Here is the link. http://www.edmunds.com/apps/vdpconta...4/pageNumber=5 __________________ ZHP knob/Zeckhausen CDV/ESS Tune/More to come
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07-09-2009, 11:42 PM	#417
jonanator Private First Class 6 Rep 105 Posts Drives: '08 E93 335i, '06 Z4MC Join Date: Nov 2008 Location: Calgary, AB, Canada iTrader: (1)	An in cabin vid with sound would be awesome
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