GregBBRD

I can relate. We had several different iterations, before we were happy with the sound and had gotten rid of 95% of the "drone".

Seemingly little changes in exhaust design make huge changes in sound and sound quality. Just changing from mild steel to stainless changes the sound. Going from 2.5" to 3.0" is a huge change in sound.

My design criteria was exactly as Rob stated the results were....sound very stock, until you push hard on the gas pedal.

928er

That is a high quality exhaust...... I wish I could afford one... I spent no less than 3 weeks making mine... in dual 3".... the only differences are that I used the Burns Stainless X which is pure art but I'm not sure if I would have gained anything putting it further back.....

again... that is pure art high quality work Greg.....

terry gt

Greg , Your system is a work of art . These systems look simple , but represent a LOT of trial and error work

Jon B.

If Greg's system was available for the early 32V cars I would have bought it YESTERDAY.

Seriously though, I'm going to have to try and find some Lvl. 2 Devek headers, or make the equal length headers that Mark A. sells work somehow. I was already planning on doing a custom setup after the headers, but I need the damn headers! Greg's system would knock out both!

AO

Love that pic with the glowing headers! Very cool!

Didn't know about the Devek L2 headers interfering with the lightweight starters. I will say they are very close to the clutch slave line (within millimeters) and can cause boiling of the fluid.

Rob, got any pics of Greg's headers installed on the car? Particularly the drivers side?

Andy, it's not a lot of juic considering the squeeze, but I "get it.". It's a beautiful piece of pipe work that Greg offers.

andy-gts

I am in for the long haul with this 928 , and the last thing that needs change is the exhaust as the pipes are rusting pretty bad . the only stainless on the system is the borla mufflers....and the crossover is right at the exit of the headers. this system with the cross further back should move the torque up a little more to the upper rpm...

from the dyno numbers the engine was still very much maxing out but not dropping off at 7000 rpm. and greg made the engine to survive 7200 rpm for extended periods....while at the tuners the hp and torque began to fall off around 6400 rpm and the tuner said my headers and exhaust redo would probably get that power back in the curve like you see above...with some other changes (tps was not working quite right above 4500 )

I am just messing around, kinda fun to see this stuff....I just dont want to go from a 3 inch system to a 2.5 inch and loose power. thats kinda what I am looking for.

maybe I will have to have a 3 inch system remade out of stainless so I dont have to look at all the rust when I am under there...hahahahahaha and the l2 headers are yours if you still want when I get around to this change

SMTCapeCod

Very hard to make 3" freeflow system sound anything other than raw/race. But with the power your pushing if it is zero tolerance for losses then that may be what you are in for.

Congrats on the output- I'd be very interested to find the thread describing the work and final configuration.

andy-gts

there are bits and pieces out there , simard cams and with a grind that greg and simard worked on to get the above 400 torque from 3000 all the way to 7000 rpm, simard itb, and gregs 6.5 stroker with dlc coated lifters and his uber head work....I wish every one could drive it ....it is very amazing. 8k miles since getting it last sept 2011. it idles at about a 1000 rpm and in gear drops to 750 , and the bank allowed me time to pay it off....hahahahaha

fbarnhill

Wow, 610hp? I doubt you will be able to feel the difference 5 - 7 hp will make. I would absolutely love a ride in a 600hp shark. I was thinking 400 - 450 would be ideal on the street. I once had a 66 dodge coronet street hemi. It had to stop at nearly every gas station but was just a blast to drive every day. I just can't imagine a streetable shark with even more hp.

Can anyone recommend a thread that explains what these hybrids are and what goes into them?

Oh, and Greg, I agree that your systems are just a work of art. Where do I look for a list of parts that you offer? I am way too far away to visit.

Cheers,

andy-gts

got a new app for iPhone,

db at idle 10 feet from tail pipe 91 db
db at idle in cabin drivers seat--80 db

db in cabin at 2100 rpm 90-91 db

already did dynamap in doors and will do the deck and rear wheel wells.(interior)

now I have work to do to finally quite things down a bit

I will try what louie did first and add long glass paks prior to borlas. the x is way up front and burns stainless said for best power to keep the crossover forward…so I may put a h pipe in after the glass paks and measure sound.

part of me wants to move to california and have greg put his new system on cause I am just shooting in the dark here….

andy-gts

anybody else check db noise level

Rob Edwards

No, but I am dubious of the iAccuracy of your idB meter. 80 dB at idle form the driver's seat is louder than most modern cars at full throttle. Unless you were in a steel garage with the garage door closed and the windows open. In which case you should open the garage door.

andy-gts

been driving this car for 3 yrs now and the loud exhuast wears me out....so I am going to quit futzing around and jump for gregs header exhaust system.... maybe even get alittle more torque across the rpm board....and

AO if you still want the level 2 headers theyare yours...

MattiasH

Hello Andy,

If AO isn't interested of the level 2 headers any more and you can ship them to Sweden, I would interested of them.

BR,
Mattias Hofvendahl

andy-gts

I hear ya, if andrew doesnt want them , you got em