SeanR

Courtshark

Any idea what happened to P-9? Website is not working and can't find any info on Google.

Mike, have you dyno'd the car since the turbo install? Hope it's still as much fun as it looks and sounds!

killav

Nah I sure didn't. Car is running strong. Next month will be two years, and no problems at all. Keep detonation at bay, and these motors will handle 5-10 lbs of boost.

I'm sure they would build another kit if there was interest. Anyone interesed can PM for John Thomas' phone number.

Courtshark

Cool, thanks for the speedy response. Torn between this and Victor's new Rotrex set up. I've always preferred turbos to SCs. Not looking for crazy boost, though. Just a nice 6-7 psi and a sharktune and I will be happy.

Lizard928

Go with the turbo!

Courtshark

Hey Colin, I'd love to, but the ease of install on Victor's kit is mighty tempting. Almost hate to say that, but my spare tuning time seems to have evaporated lately. I also don't like that P-9 seems to have dropped off the face of the Earth. Not reassuring! And I know I'm nowhere near as talented as you are in building something like that from scratch. I'm more like 3M... I can make an existing kit better.

Lizard928

JT who is P9 has never really been big on posting here. The local crowd, ATB, Tom M, etc all know him well. I've met him a number of times and he seems like a real stand up guy imo. The kit is built in conjunction with the main rear mount turbo guys.

The tuning is the hardest part. The pluming of the exhaust etc is easy compared to the small details like crankcase ventilation.

The one thing about Victor's "kit" I dont like is the fuel rail pluming, simply put, it scares me.

Courtshark

Ah, good to know. Gotta say I've been mighty impressed with each install.

What about the fuel rail plumbing is scary? Haven't seen any close ups of that.

killav

Well I figured they would sell like hotcakes, but for some reason it appears that nobody else has tried it. At least if they did, they don't know about Rennlist.

I will say this, if you like a mellow, quiet exhaust, this kit is not for you. I have modified my kit as delivered with two Dynatech split flow mufflers, plus a silencer for the wastegate, and I like the sound now. As delivered, the exhaust is pretty loud across the entire RPM range. At WOT as delivered, a nascar fly by mixed in with a wonderful turbo whistle is a good description. The turbo only acts like 1/3 of a muffler or somewhere in that neighborhood. But the sound of the turbo spooling up never ever gets old.....

And finally, I have reviewed the compressor map for the supercharger that Victor sells in his kit. In my opionion, it is very well matched to the airflow requirements of a stock 5.0 liter 32v engine. I won't get into the calculations, but at the pressure ratio, and lbs/min of airflow of a typical 928 engine, that Rotrex model used in Victor's kit is a good match, falling into a "sweet spot" in the efficiency island's between 5 and 10PSI.

In contrast, my 60mm turbo is relatively small, but not by much. At 5psi, things look really good, but at 10 PSI, I start to fall off the effeciency "rings" or islands on my compressor map. It still makes great power, and is running very strong, it's just heating the air up more than the supercharger would at the same PSI.

And, I was offered to upgrade to a 67mm turbo for about $300.00 but I wanted a good streetable turbo with great spool time so I declined.

I hope I didn't just open up a can of worms........

Lizard928

Victor's kit has the fuel rails dead ended.
This means the fuel goes in at the REAR dampner, the fuel then has to travel forward to the front of each rail. This can create vapor lock at higher temps but more so you will find that the front cylinders will start to have detonation where the rears are OK when you get to the upper limits of the fuel pump.....
Not a great idea IMO.

Mike,
I have a billet turbo impeller on my setup and its map is about the same as a T72. I'm needing to up the boost to get ONTO the islands. A 60 is a very small turbo. I put a 62 (again billet imp) onto an S4 and at 5psi I had 450rw ft lbs, and 370 rwhp. I didnt want to go much more than that due to the fuel pump that was on the car...... As it stands, I need to replace my fuel pump and am considering running all new fuel lines to reduce restriction/heat, and add a fuel cooler pre-rails prior to increasing boost.

victor25

FYI.. I have an electronic meter connected to the farthest point of my dead ended fuel rails and there is no drop in pressure. We have tested pressure in 3 different spots and they all rise the at the same rate with boost. I have data logs if anyone would care to see them. Granted if you go past what the fuel pump can handle then your pressure will drop, but it is even across the injectors. Usually the stock pump will make it to 500hp. As far a vapor lock goes, it has yet to happen.

SeanR

I was gonna say, about the vapor lock, you'd figure here in Texas that would rear it's head if it was going to. It hasn't happened.

victor25

Also vapor lock happens at the fuel pump, and realy has nothing to do with the rails or injectors. Thats why the extra pump was added to the tank in later years.

Jim R.

The stock pump will drop off pressure significantly...if I recall mine dropped down to the 25 psi range pushing 500 rwhp. Needed the 044 pump to get safely there. With a new in tank pump and new 044, I still lost a few psi on the fuel logs while tuning.

Need to update with Murf's high flow 044 strainer setup this winter.

Jim

AO

Why wait? We could knock it out this weekend if you didn't have "commitments".