Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

New 928 Headers with Merged Collectors

Thread Tools
 
Search this Thread
 
Old 05-15-2015 | 12:52 PM
  #16  
Carl Fausett's Avatar
Carl Fausett
Thread Starter
Developer
 
Joined: Dec 2001
Posts: 7,005
Likes: 60
From: Horicon, WI
Default

I know with the right location for the holes, you could probably reasonably center the header over each 16v exhaust port. But I can't come to terms with that large of a transition right at the head. That much turbulence dumping small port into a bigger tube like that will probably (IMO) ruin all the scavenging action that was available...

And BTW: these 16v heads have been massaged a wee bit. Their ports are actually slightly larger than stock!
Old 05-16-2015 | 10:12 AM
  #17  
atb's Avatar
atb
Rennlist Member
 
Joined: May 2001
Posts: 4,869
Likes: 33
From: Puyallup, WA
Default

Any chance of mounting the headers backward (collectors pointing forward) for the purposes of getting a dyno reading?




Originally Posted by Carl Fausett
That's the rub. I had every intention of running these headers on the engine dyno when I broke in my motor (pic below) and then was slapped in the head by the fact that the dynamoter occupies the very space the headers have to be in (duh). The 928 is a Torque Tube car, and the exhaust is aimed down the center line.
Rats. No engine dyno possible.

So - then chassis dyno results? Right. Imagine this; someone has to bring me a 32v 928 with stock MSDS headers on it so I can take it to the chassis dyno for the baseline. Then I would have to swap out the early open-collector header for the merged-collector header, and dyno again.

That situation has not yet presented itself, so I do not have any dyno charts for you.
Old 05-18-2015 | 11:48 AM
  #18  
Carl Fausett's Avatar
Carl Fausett
Thread Starter
Developer
 
Joined: Dec 2001
Posts: 7,005
Likes: 60
From: Horicon, WI
Default

Not reasonably, no.
Old 05-20-2015 | 03:33 PM
  #19  
Carl Fausett's Avatar
Carl Fausett
Thread Starter
Developer
 
Joined: Dec 2001
Posts: 7,005
Likes: 60
From: Horicon, WI
Default Update on 16V headers with merged collectors

Doing a count of 16v headers in stock - we find there aren't that many... so development has begun today on transferring the merged collector system over to the 16v headers too.

I'd like to do a before-and-after dyno pull for these new headers.

So this is a call out to someone who has MSDS headers currently installed on their 16v 928 and would like a "free" upgrade. Bring us your car and we will do a baseline dyno pull on it. Then we will swap out your Gen 1 headers for the new Gen 2 headers with merged collectors, and dyno it again.

Here are your costs: The headers will be no cost to you. You will not have to pay for the dyno time either. You will be charged 50% shop labor rate to swap the headers.

Let me know!

PS: same deal is available for somebody with a 32v 928 and a set of Gen 1 MSDS headers installed....
Old 05-20-2015 | 03:38 PM
  #20  
hacker-pschorr's Avatar
hacker-pschorr
Administrator
 
Joined: Aug 2001
Posts: 1,631
Likes: 2,249
From: Up Nort
Default

If no one jumps at the offer, we can use my track car but I'm not driving my 79 to Horicon. A lot easier to just ship the headers up here.

Here is the before:
https://rennlist.com/forums/928-foru...t-exhaust.html

This is assuming the new headers will bolt up to my exhaust.
Old 05-20-2015 | 05:34 PM
  #21  
vze2jshn's Avatar
vze2jshn
Rennlist Member
 
Joined: Aug 2003
Posts: 634
Likes: 9
From: Woodbridge, New Jersey
Default

Is there room on the reconfigured 16v headers to allow dropping the clutch out without the detach headers at the heads rigamarole?
Old 05-20-2015 | 07:06 PM
  #22  
MjRocket's Avatar
MjRocket
Drifting
 
Joined: Oct 2012
Posts: 2,157
Likes: 3
From: Fort Wayne IN.
Default New 928 Headers with Merged Collectors

Roughly what kind of HP increase could one expect to see with these over stock headers on an 87?

The car is supercharged if that makes a difference.

Thx
Old 05-20-2015 | 08:12 PM
  #23  
mark kibort's Avatar
mark kibort
Rennlist Member
 
Joined: Feb 2003
Posts: 29,958
Likes: 180
From: saratoga, ca
Default

Originally Posted by vze2jshn
Is there room on the reconfigured 16v headers to allow dropping the clutch out without the detach headers at the heads rigamarole?
i always wondered why the headers on the 2 valvers were designed that way.... replace the clutch, and you have to remove the headers (or header )
is there an other reason why they cant angle around the lower bell housing like the S4 style?
Old 05-20-2015 | 09:24 PM
  #24  
Ducman82's Avatar
Ducman82
 
Joined: Nov 2009
Posts: 6,983
Likes: 18
From: Marysville WA
Default

"trying" to keep "equal as possible" lengths maybe?
Old 05-21-2015 | 10:55 AM
  #25  
Carl Fausett's Avatar
Carl Fausett
Thread Starter
Developer
 
Joined: Dec 2001
Posts: 7,005
Likes: 60
From: Horicon, WI
Default

all these things are in the design parameters. equal length primaries or close to; clutch service (at least not worse than present)

I think what makes them angle in so aggressively is the attempt to meet up at the stock exhaust before the catalytic converter.
Old 05-21-2015 | 10:57 AM
  #26  
Carl Fausett's Avatar
Carl Fausett
Thread Starter
Developer
 
Joined: Dec 2001
Posts: 7,005
Likes: 60
From: Horicon, WI
Default

Roughly what kind of HP increase could one expect to see with these over stock headers on an 87?

The car is supercharged if that makes a difference.
I'll guess 10 HP over stock headers on a SC'd car, depending on the restrictions in the exhaust system downstream. 15 HP over stock headers on an NA car
Old 05-21-2015 | 01:20 PM
  #27  
terry gt's Avatar
terry gt
Burning Brakes
 
Joined: Nov 2008
Posts: 908
Likes: 2
From: West Vancouver B.C.
Default

Any thought of the headers having a V band clamp instead of the 3 hole plate ? or at least going up to 3/8 inch material . my MSDS headers always leak .
Old 05-21-2015 | 03:33 PM
  #28  
Carl Fausett's Avatar
Carl Fausett
Thread Starter
Developer
 
Joined: Dec 2001
Posts: 7,005
Likes: 60
From: Horicon, WI
Default

About a year ago, there was a thread on here about some China rip-off MSDS headers on eBay... and you may recall, toward the end of that thread the conversation had turned to merged collector headers
Correct. And that was the impetus for this development.
Old 05-21-2015 | 03:35 PM
  #29  
Carl Fausett's Avatar
Carl Fausett
Thread Starter
Developer
 
Joined: Dec 2001
Posts: 7,005
Likes: 60
From: Horicon, WI
Default

Terry, a good dead-soft aluminum flange gasket will help, and some of us use two of them stacked.

Otherwise, buy the v-band clamps and have your local exhaust guy weld them in!
Old 05-22-2015 | 12:00 AM
  #30  
terry gt's Avatar
terry gt
Burning Brakes
 
Joined: Nov 2008
Posts: 908
Likes: 2
From: West Vancouver B.C.
Default

Carl ,I tried the aluminum flange gasket . they got so hot they deformed and leaked


Quick Reply: New 928 Headers with Merged Collectors



All times are GMT -3. The time now is 08:54 AM.