nothing else to add, picture speaks for its self.

 

Sweet. By far, the best improvement I've made to my car; at least 50 lbs lighter. X-pipe?

 

Who made it?

 

Dave Lomas, MotorSports SLC. Here's the original thread from Roger. Carl sells them too.

https://rennlist.com/forums/928-foru...7-to-95-a.html

 

Sean, I am jealous, that looks so good buddie.

 

I need to do that one of these days. Looks great!

 

Nice!!

Now we just need a dual 3" version that fits the 16V cars

 

Sweeeet!

'89 S4 GP White/Black
'76 912E Silver/Black

 

Hacker, I did a single 3" version for 16v cars that turned out to be too much for all but the 300+hp euros. 219 & 240hp both lost torque. That prototype is now on a Lemons race car. I couldn't see much of a market for it other than you! (maybe a couple of others out there too) Dual 3"? You don't take just one Viagra at a time do you? lol

 

Since this can of worms has been opened....

I have heard opening up the exhaust on the 16V reduces torque.

can you clarify? my impression was it reduces low end torque. but got the impression it benefits the high end HP.

I have also seen a note about advancing the timing a bit to increase high end HP with an impact on low end torque. but could never find a thread the suggested how much advance is beneficial.

I had to replace my CATs with a Y pipe, as the CAT had a leak. since then I replaced my resonator and pumpkin with free flow mufflers.

my pumkin probably had the baffles rusted out as my exhaust sounded like it was exiting through an empty garbage can. just could not stand it any more. now I manually shift a lot to hear the engine rev. now it sounds great but maybe a tiny bit loud. I can live with that.

PS. and what about the exhaust if you install a SC kit on a 16V.

is there no end to the stuff we think about doing to our cars?

 

I'll post a chart later, but my stock 79 with MSDS headers and single 3" exhaust with no mufflers has a lot of low end toque, which is useless on the track since I'm never low enough in the RPM band to use it. I would gladly give up 50ft/lbs across the board for more HP up top.

I've only tested the back-pressure on a couple of supercharged 928's, but all of them had way too much back-pressure. The lowest was Andrew Olson's with DEVEK Level 2 headers and a nice 2.5" exhaust & custom X-pipe. IMO his back-pressure is still too high with that setup but probably "good enough" for most people.

My supercharged 81 with stock exhaust manifolds, custom SS-Y and 3" exhaust had over 10psi of exhaust back-pressure. The gauge only went to 10 and was maxed out by 4,500rpm. This was measured after the Y collector so the pressure in the primaries would be even higher.

 

Hacker needs dual 3" because of the boost he is running.

I guess he is sick of seeing his backpressure rise 1:1 with his boost.......

 

that's a lot of mufflers Sean ... are you sure you need them all?

 

its really only 1.5 mufflers since he's missing the left side connector pipe to the rear muffler..... It will be a little louder? Ride with all the windows down Sean!!

 

LOL Chuck