TheSamba.com :: View topic - Porsche Powered Mid-Engine Double Cab Build

Mon Oct 24, 2011 2:50 pm

I'm glad to see this is still in the works! Can't wait to see the final product. I really dig the shift knob made out of walnut and aluminum.

Mon Oct 24, 2011 9:11 pm

What's with the cats? Totally stock engine map to be used here?

(unless those are silencers/resonators, in which case this can be ignored)

Wed Oct 26, 2011 9:52 pm

Hugo Stiglitz wrote: I'm glad to see this is still in the works! Can't wait to see the final product. I really dig the shift knob made out of walnut and aluminum.

Big project build, need much work, take much time.
Thanks, the shift knob was a fun little project as it was easy to finish (umm, needs more coats of finnish, damn)!

Wed Oct 26, 2011 10:13 pm

RennyRB wrote: What's with the cats? Totally stock engine map to be used here?

(unless those are silencers/resonators, in which case this can be ignored)

Yes, they are Magnaflow universal cats.
I use the D.C as my daily and put about eight thousand or so miles a year on it so I consider the the cleaner exhaust a plus part of the engine swap.

The overall exhaust design is very different than the stock 911 so I will get a baseline dyno run to the custom chip guy Steve Wong to optimize the air fuel ratio.

I am hoping the new exhaust will free up 10+ h.p. from the otherwise stock 3.2. (even with the cats).

Thu Oct 27, 2011 12:13 am

Sounds good :!:

Proper tuning is the way to go, and good on you to reduce pollution.
Can't wait to see more updates, this is one of my favorite builds.

Thu Oct 27, 2011 1:15 am

I'm getting that old "aaaahhhh this is going to be so badasss!" feeling again. I dig the cats, sometimes people don't realize how little they actually restrict the flow. I really like how everything is just 1 step above factory in quality with all the fabrication. Best way to go for a daily driver! 8)

Sat Oct 29, 2011 3:14 pm

One side almost done, other side is a little more intricate.

A little more tweaking and I can weld the mid pipe to the muffler and cat, and then start on a crossover, or H-pipe.

Sat Oct 29, 2011 3:17 pm

I'm a little disappointed the exhaust looks so simple in the pictures, but there are a lot of angles you don't really see. Its not just straight with some bends. Almost every bend is off axis from the one before, especially on the PS.

Sat Oct 29, 2011 4:12 pm

Twisted Minis wrote: I'm a little disappointed the exhaust looks so simple in the pictures, but there are a lot of angles you don't really see. Its not just straight with some bends. Almost every bend is off axis from the one before, especially on the PS.

I am not disappointed about anything in this build. I want one.

Sat Oct 29, 2011 8:28 pm

Basically I am just disappointed with the camera pics right now. I need to get the DSLR out of storage. You can't see much detail in these, it looks much better in person.

Sun Oct 30, 2011 9:20 am

Twisted Minis wrote: I'm a little disappointed the exhaust looks so simple in the pictures, but there are a lot of angles you don't really see. Its not just straight with some bends. Almost every bend is off axis from the one before, especially on the PS.

Looking closely at the last picture, the passenger side exhaust shows just how much off axis fabrication this exhaust run entails.

Amazing design, engineering and fabrication! Looking forward to more

BTW, I had an 89 944 S2 for a short time and I loved the gearbox. I regret selling that car.

Thu Nov 03, 2011 11:13 pm

Here are the latest shots. I am basically done with the exhaust now aside from the H-pipe. I needed to finish each side before I can tie them together with the H-pipe. I am pleased with the way it came out.

Fri Nov 04, 2011 6:37 am

dirtsandwich wrote: Twisted Minis wrote: I'm a little disappointed the exhaust looks so simple in the pictures, but there are a lot of angles you don't really see. Its not just straight with some bends. Almost every bend is off axis from the one before, especially on the PS.

I am not disappointed about anything in this build. I want one.

I'm disappointed that I don't have one :cry:

Sun Nov 06, 2011 9:53 pm

Almost done with the exhaust. I fitted up the H-pipe, I just need to cut the holes and weld it in place.

Tue Nov 08, 2011 1:20 pm

Here are some better pictures.

Tue Nov 08, 2011 1:22 pm

Nice work. What's the reason for the cross-over in the exhaust?

Tue Nov 08, 2011 1:54 pm

Virtually all V-8 exhaust systems can be refined by the addition of a balance or X-pipe. These have two potential attributes: increased power and reduced noise. Extensive dyno testing on both of these factors has indicated balance and X-pipes are 100 percent successful at reducing noise. The reductions amount to a minimum of 1 dB to a maximum of 3 dB with 2 dB being common. As far as power is concerned, things are a little less certain. With engines between about 325 to 550 hp, experience indicates that in about 60 percent of the cases (mostly with balance pipes), the engine can deliver as much as 12 additional hp, with 5-8 being the most common. The other remaining 40 percent tested showed virtually no change in output either up or down. Based on such results, we can conclude that a balance or X-pipe is always a positive asset and never a negative.

Balance pipe sizing seems not to be overly critical. The only really influential dimension is the pipe diameter. This needs to have an area at least equal to that of a 2.25-inch diameter pipe (4 square inches) with 2.5 to 2.75 inches being preferable. Though limited to tests on engines up to a little fewer than 600 hp, there seems to be no measurable benefits to using a crossover pipe bigger than 2.75 inches in diameter. As for the crossover length, dyno results indicate that 18 inches responds in virtually the same manner as 72 inches long.

Read more: http://www.popularhotrodding.com/enginemasters/art...z1d9KM4fih

Tue Nov 08, 2011 1:55 pm

Gary wrote: Nice work. What's the reason for the cross-over in the exhaust?

Helps equalize and balance the flow of a true dual exhaust system. Helps with low to mid range torque and minimizes that rasp you hear during deceleration.

Tue Nov 08, 2011 1:59 pm

Thank you both for the explanations. I hope when this build is finished that a video is posted so we can all enjoy the sounds of that exhaust system.

Tue Nov 08, 2011 7:35 pm

I'm interested to see the heat exchangers get plumbed in. The truck should be toasty with those monsters.