ptuomov

Here are some photos of the turbine downpipes. These are only the main turbine circuit. The wastegate circuit that is much more difficult is still work in progress. The punch line is that these are going to just flat out flow. The old more restrictive pipes had less than 0.5 psi of back pressure at 700 rwhp, so these should accommodate what the compressor can push thru and what the engine can burn.

Imo000

The pipes looks like they are hanging a little on the low side. Or is that an optical illusion?

ptuomov

I think it's mostly an optical illusion created by the cuts. They'll fit under the stock belly pans like the old downpipes.

ptuomov

This video shows some details about the downpipe construction:

ptuomov

More on the turbine housing modification:

andy-gts

WOW Kuhn is doing some awesome work !!!!

BC

Is cutting the housing a normal thing ? No, right?

ptuomov

He is.

Fitting these turbos under the 928 V8's wings requires a lot of surgery. The earlier smaller turbos had the compressor cover cut and rewelded to a different shape. These bigger turbos require at minimum cutting and welding the turbine housing for a wastegate circuit. There's no alternative way to route the wastegate circuit while meeting the clearance spec.

Fabio421

There are housings that have this done at the factory. This housing isn't available with that option. Here is an example.

ptuomov

The design intent is similar to the housing in Fabio's photo. That housing would likely not fit in this spot, the space constraints make everything a custom job.

The wastegate priority ended up working very well, the flow path is close to ideal:



The fire-breathing bastards staring at you below. V-band clamp flanges are pretty:



The wastegate location is designed to be easily serviceable and tunable. The spring can be changed without much work at all. The wastegate is also placed high enough such that it is comfortably above the lowest point of the chassis:



Here's how it all fits on the driver side, installed on the car:

BC

Does Taxachussetts have speed bumps? That's where speed bumps hit when you go over them somewhat quickly but not quickly enough and not too slowly.

Tony

ptuomov

The wastegate is at a higher level than the lowest points on the chassis. The belly pans also fit. I am really happy about this being at the right height.

MA has top income tax rate that is almost exactly 1/2 of CA's. Also, we're not bankrupt here. So much for Taxachusetts.

There aren't many speed bumps here. People have a healthy disrespect for the traffic laws in MA, people driving with MA plates in the North-East are called "Massholes". Massholes would just run over the speed bumps and launch their beaters to a nice jump. I lived in East Cambridge for five years and they had one of those "jumps" on 3rd street close to our loft apartment. Evel Knievel show for free, every day.

Although there are not many speed bumps, there are obstacles that someone might casually mischaracterize as "potholes." These in reality are giant holes on streets that would fit a tank, but if you hit one of them potholes you have bigger problems than your wastegate. I once took a right turn in heavy rain hit one of those pretty hard, the left front tire popped off the rim. (The wastegate on the Saab 93 was just fine.)

ptuomov

Passenger side hot parts:

Lizard928

Man that is tight in there!

Going to send it all out to be re-coated once its all done?