that is the right idea for sure. fluid will follow path of least resistance so you will lose to much flow to the jet pumps if you do not restrict them instead of sending it up to the rails. we also did something similar on my car with some metal restrictors. with larger pump it will be plenty to keep the basket full.

 

What size restriction did you use? The stock pump had about 1/4" hose. I was thinking the 450lph is much more powerful plus it will be feeding both jet pumps 100% of the time, I thought 3/6" would be MORE THAN enough flow, but could probably smaller.

 

I am confused, I thought the 450lph pumps fed the engine (balanced fuel between the sides as well) and the low pressure jet pumps fed the fuel basket. If that is the case why would you have to restrict the flow to the 450lph pumps? Isn't that handled by the FPR up the stream?

 

The stock pumps had 5 outlets, pump 1 has 2 on top and 1 on the bottom, pump 2 has 1 on top and 1 on the bottom. The Walbros only have a single 5/16" outlet each, you have to get fuel to the engine and both jet pumps off a single outlet ( or to 1 jet pump per walbro). I've opted to feed both off a single pump leaving pump 2 to give 100% of its fuel to the engine under full throttle.

 

i honestly dont remember because for us it was an after thought. we literally had the car on the dyno and decided to swap in the walbros "real quick" well that turned into a PITA quick. the check valves and restrictors were done last and we didnt get too hung up on the sizes math as it was plenty either way.


they do feed the engine and whatever is not used comes in the return. however they ALSO feed the jetpumps which keep the basket full and thats where the pumps actually pull fuel from ( the basket). jet pumps are fed off special outlets in OEM pumps which no aftermarket pump is going to have so you have to improvise and go back to the way it was on a 996TT.... where after the pump there is a Y and one side of the Y goes to the fuel rail and another side of the Y goes to the Jet pumps to pick up more fuel for the basket.

 

Is running the return to the basket not enough?

 

It should feed the basket first. If the pumps can't get fuel, there will be nothing to return. I think that feeding the basket via the return would be counter productive. The more fuel you require, the less it would return to the basket.

 

I guess I need to get mine apart and it will make more sense.

Ive seen it done all sorts of ways. But on single pump configuration, ive put the pump in a sump with baffled doors (bottom of tank) and then ran the return to the sump to keep it full.

 

The return does go in to the basket as well as the jet pumps filling it. Here's another picture of the basket so you can see how it looks. (The return line has the white connector). The other large yellowed tube comes from the fill line. (I guess if you run out of gas, when you put gas in the tank, it will run into the basket so the pumps get fuel to start pumping again). Porsche made sure the basket can always get fuel. I'm waiting for some fittings (6 AN to 8 mm barb). I'll show the completed assembly once they arrive.

I got the restriction fitting made. I still have to clean it up before I install it. It has 1/8" NPT on each end with a 3/16" hole in the center. I also got all of the fuel line completely ran now (Tank to engine and back to tank). It took a bit of time getting the lines to the top of the gas tank but it was done without dropping the tank at all.

I checked out the fuse/relay panel I got from Switzer. I wanted to see how they had their pumps wired. It appears they ran both pumps together full time. There are only 2 wires from pins 85/86 making it impossible to have run the factory pump configuration. I'd imagine this made A LOT of fuel return to the tank. I'm going to separate the pumps and have them run the way Porsche designed the fuel system.

The car is getting really close to being finished. I'm starting to see the light at the end of the tunnel.

Of course there will be more updates......

 

I'm getting close!!!

The Syvecs is all pre-wired and ready for the ECU to be connected. I've been waiting to lower the car on the hoist a bit so I can open the roof and get at the ECU without a ladder. I modified the headers and decat pipes for the external waste gates. They turned out beautiful. I went through the waste gate springs and waste gate combinations I had and came up with the best I could for spring settings. I'm going to have the turbo waste gates to open at 16.65 psi and the exhaust waste gates to open at 21.85 psi. Switzer left me one last surprise for this install. I remember reading the AMS instructions on installing their Alpha 9 kit and they mentioned the Tial turbos sit back 3/4" from stock and that you had to be selective in your exhaust to make sure it could be shortened. One would expect that Switzer would build their own exhaust to work on their own kit with Tial turbos? No, is the answer. I assume the exhaust systems are all pre made and they just bolt it on regardless of what kit is used. The exhaust was sticking out away from the factory mounts by you guessed it, 3/4" and the muffler was "tilted" back to try and shorten the gap. It was still sitting tight against the rear heat shield. While I had the waste gate welding done, I had the tig welder shorten the decat pipes 3/4" as well. I straightened the muffler back to how it should be and it is a perfect fit in the factory mounts now. The tips also sit perfectly for my liking. I don't remember pics of Anthony's car, but I assume the tips stuck way out the back.

I'm having a difficult time getting the new fuel line tubing connected to the 8 mm - 6 AN barbs. I pressed so hard on the tubing trying to push it onto the fittings that I rolled the skin off 2 of my fingers leaving nickel sized blisters. I'm using a heat gun and heating the ends as much as I can before they distort and I'm still struggling to get the ends on. Does anyone have a suggestion on how to make this easy to do?

Here are some more pics.....

 

Hi vr6 , first of all a big fist pump for tackling this project ! just curious how many man hours do you roughly have into this project ( we're you a mechanic in another life bc this seems like not a project for the avg diy ) and also if you don't mind sharing a rough dollar amount i should budget for similar mod

 

Thanks dDesimone, this project has been bigger than I expected. I could have bolted the existing Switzer kit up in much less time but didn't want to have to re do it all again when it fails or when I decide to take it to the next level. As far as what I have in the project..... Honestly, I don't want to add the receipts up, I'm just happy knowing it cost more than it should have. I'm not a mechanic but have worked on cars/trucks/heavy equipment for a long time. The 997 is very tight to work on assembled. No matter what you try to do, it always seems like there is not enough room to get your hands in to do it.

A project like this would be really tough without a hoist and I'd have $30-35k planned out for the job. Outside of the major components it's $250 here, $500 there, $1000 somewhere else start-finish. Again, there are cheaper ways of doing it. It depends if you plan on getting near or just past the limit of each stock part.

 

How was it wiring the Syvecs?

 

It's really easy. You only have to wire in the Aux sensors you add. For me, that is Flex fuel, boost, and bluetooth.

 

exhaust tips look weird the inside ones are usually the longer ones and the outsides ones are shorter to follow the contour of the bumper...