Show off your SICK turbo exhaust pics!

[onboost]

Chris,

Thanks for posting.. that is the shot of this beauty I have been dying to see! Nothing like an "outlaw" with a nasty tude!

Paul

[911st]

Brian,

I thought this was a first peak at your new system! Great minds...

Originally Posted by Dai

Bob Holcombe's special.

[RarlyL8]

My new system has some things in common with the Holcombe system pictured. After I designed it I started seeing a lot of convergent evolution. Makes since as we are after the same results. I should have some pictures to post this week.

[mb911]

here is my finished shot

[voitureltd]

Not as noisy as you might think, however I can't get in late undetected.

[RarlyL8]

Work in progress:

[911st]

Very nice Brian!

Keep up the good work!!!

[Stefn1]

dual 38mm

[930gt-40r]

Here is the setup going on my car this year. 1" 3/4 primaries into 2" 1/4 secondaries into a divided T-4 flange.

[911st]

Nice!

[kenikh]

That is CLEAN!

[DonE]

Kris - that's the nicest performance stuff so far- nice short pipes, great looking collectors, great wastegate circuit. PLEASE tell me you won't put a 180 degree pipe off the muffler tho....

[kenikh]

A question on header design for turbos. Is shorter length always better on equal length headers? For example, say you have some headers that have tuned runners for your displacement and rev range (NA).

[kenikh]

Originally Posted by 930gt-40r

Here is the setup going on my car this year. 1" 3/4 primaries into 2" 1/4 secondaries into a divided T-4 flange.

Any shots of the underside?

[911st]

Originally Posted by DonE

PLEASE tell me you won't put a 180 degree pipe off the muffler tho....

+1

[911st]

Originally Posted by kenikh

A question on header design for turbos. Is shorter length always better on equal length headers? For example, say you have some headers that have tuned runners for your displacement and rev range (NA).

On a turbo I suspect you can not tune the length to create any type of scavenging or tunning effect w a turbo. The turbo creates back pressure inhibiting any beneficial savaging. Further the type of cams we run on turbos w little to not overlap dose not benefit much from scavenging.

The goal is more to allow the exhaust pules to exit in an orderly more efficient progression. This helps more in the upper rpm operation.

The advantage to the shorter unequal length is packaging and reduced header volume that has to be pressurized to accelerate the turbo.

The unequal length primaries also create a convergence of the exhaust pulses that can also help accelerate the turbo quicker.

On the header system you show it looks like each side is kept separate. This is to help turbo spin up. It is more effective to do this on a 4 cylinder. Not much advantage on an 8 cylinder. On a 6 it is not as big a deal I hear. Still, I would go for it.

At least that is how I think it works.

[930gt-40r]

Thank you guys for the compliments

Don: F--- no, not to worry, there will never be a 180 off that system. I am going to fab a muffler for it in the next month that will entail a 3 to 4 transition, a burns 4" muffler, 4" 90 degree out the back of the car, and finally a 4 to 3 transition to keep some of the pulses canceled out as to try to keep the cops away. Yes, the days of original exit exhaust are long gone haha

911st: I agree, I never understood how scavenging could be even remotely effective in the case of having a good amount of back pressure (the turbo). I also didn't have giant equal length headers made because its a hell of a lot of work for the fab guy.

Kenikh: thanks for your compliments

Now a word about the fabricator- I specified what I wanted in these headers (1 3/4" primaries, 2 1/4" secondaries, twin V44s, and divided T-4 flange) but this is where my input ended.
All the fab work you see was performed by John at 666 Fabrication in Milford Connecticut. John took my specs into consideration and ran with it to create what you see in the picture. When I tell you this guy does some serious work I mean it- he makes intake plenum's as well that are to die for (not for our cars....yet...).

[RarlyL8]

Fabricators would not go to the tremendous trouble and expense of creating equal length headers for no reason ...

[mb911]

Originally Posted by DonE

Kris - that's the nicest performance stuff so far- nice short pipes, great looking collectors, great wastegate circuit. PLEASE tell me you won't put a 180 degree pipe off the muffler tho....

His system is nice but not truely equal length which lends to not the best performance . I find this baffeling as many many tuners do this but does not hold up to theory.

[JBL930]

My old girl is in having some detailing done, back end was looking scabby! I wouldn't class this as a "SICK" exhaust pic, but tell me how many other stock looking 930's you've seen with 993tt engines in