I'm interested to see what set-ups other people are using. I have track/tarmac rally car that I bought thinking that it was fully set-up and sorted. But the fuel system proved to be an issue. Here's the fuel system as it was when I bought the car. It was originally set-up as an endurance race car and had a removal second fuel tank that filled the boot (trunk) space and I assume was connected to pump 1 which was blanked off.



Fuel set-up when I bought the car.

The first time I ran the car on the track it was clear that there was a fuel issue when it had less than a third of a tank. I discussed this with my mechanic and put the car on a dyno and found that the tune was all over the place. The mechanic that I was using is a Porsche Indy and he recommended that he had a tuner that he "had used lots" who could do a good tune for my setup. I agreed to this and left the car with him for what was supposed to take a week. Four weeks later I get the car back and it's still not running right. But now on WOT it's missing and generally feeling like it's running out of fuel regardless of how full the tank is. I won't go into the ins and outs of the discussions I had with the Owner of the Indy shop who recommended the tune, but it's sufficient to say here that I'm not using him any more. I put the car on a dyno with another shop and find that the AFR is leaning out to around 14.5 on full acceleration.
So I start checking the fuel system, I checked the fuel filter, which the mechanic was supposed to have checked when I took the car to him immediately after purchase to have all fluids and filters replaced; the fuel filter was very dirty. I replaced the filter and then opened the fuel tank to check the Porsche in tank pump. I was expecting to find the standard pump which should then feed the Bosch in line pump. But no such thing, clearly whoever set-up the fuel system didn't know what they were doing. The standard Porsche fuel pump was not there. Instead there was just a split tube with a pick-up in either side of the tank. I knew enough to know that this set-up wasn't going to work. The Bosch in line pumps are not designed to lift and that was causing a problem. So after doing a bunch of reading and getting advice from different sources (unfortunately I hadn't found this forum at that time) I came up with this system.






I'm now using a carter diaphragm pump to fill a surge tank and then the Bosch 044 pump and SX filter in-line between the tank and the injector rack.
The challenge that I have is that I am still having problems getting the car to run properly. I believe that the fuel system should be right now but I have a tune that I am not sure of. I am getting an O2 sensor error on bank 1. My new mechanic has replaced the sensor but we continued to get the error message, so he had his auto elec check the wiring back to the ECU and the new sensor and found that it was faulty. This was replaced under warranty and fitted on Friday. He said that he has run the car in the workshop and driven it for 5 minutes and had no faults show up. I picked the car up on Saturday morning and after 10 minutes of driving I got a check engine message again. I'm taking it back to him tomorrow (Monday) to check the engine fault message. If the bank 1 O2 sensor is faulty agin then there is something that is damaging this. So I'm in the middle of trying to sort out what's what. I'll know more tomorrow when I find out what's causing the engine fault message. But I thought I might share my frustration with you guys and also see whether anybody might have some idea whether the tune could be causing this fault.

 

Both setups are too busy.How much power is the car making?You have enough pumps there to support 1200+ hp but it appears (hard to tell from the pics) you are pushing thru the pumps.Thats wrong and potentially dangerous because if one pump inline goes it becomes a restriction.If your car is making less than 1000 hp i would just submerse one pump in each side of the tank and have them feed one line via a y block.I had that supporting 1200 hp before and was fine.

 

man that system looks complicated! i run a walbro 465 e85 pump in the tank. then i tapped the bottom of both sides of the tank and installed an-8 lines all around. the bottom y's to a magna fuel 465 pump. both sides feed from 100 micron filters pre and 40 micron filters post. feeding into a set of billet rails holding 1300 cc injectors running into a weldon for and an-8 return line. this setup will support 900 rwhp

 

My custom fuel system experience consists of adding a Holley electric fuel pump to a Datsun to replace the block mounted camshaft eccentric driven diaphragm factory fuel pump, which I removed and fitted a block off plate to cover the hole in the block/head where the factory pump mounted. Oh and I fitted a Holley adjustable fuel pressure regulator with a larger inline fuel filter and ran larger fuel lines from the pump to the fuel filter and fuel pressure regulator. (I was feeding two dual side draft Weber (45mm IIRC) carbs).

Thus I can only offer general suggestions. First I agree with the others that that is one busy fuel setup. Simpler is best.

Generally the fuel pump wants to be a push type as this keeps the fuel line under pressure which helps prevent the fuel from boiling and creating a vapor lock which can happen if the pump is a suction type.

It is also very important that the fuel supply lines be large enough and the turns/bends be gentle (and few in number) so as to not restrict the fuel flow.

I do not recall how to size the fuel pump, determine the necessary GPH fuel flow rate, but I would expect a fuel pump manufacturer should have this info available.

Fuel tank pick up needs to be well thought out. I used the factory fuel pick up just made sure the pump was mounted below the fuel tank (and in a protected place) so the fuel pump was ensured a sufficient supply of fuel regardless.

In the case of the Turbo with its goofy tank shape, there are two fuel pick ups, siphon jets. Even in street cars one of these can fail and the car essentially runs out of fuel at about a half tank. It occurs to me the fuel pump has to have considerable extra capacity to drive these jets sufficiently to siphon fuel from the basins. If the tune requires even more fuel the pump may not be able to keep up.

The stock Turbo has a fuel cooler that is operational whenever the A/C is on. For a track car you may have to fit a fuel cooler but of course one that doesn't rely upon A/C for its cooling.

Last but not least, can you visit the track when events are being held for cars similar to yours and check out what the competition is running? Talk to some of the other entrants?

As for the sensor error what is the error code?

Without the error codes all I can offer is first, of course, the correct sensor must be used. Some engines take a narrow band sensor and some require a wide band sensor. The Turbo comes factory with wide band sensors in the #1 sensor position of both banks. However, the custom tune may change the sensor requirement from what the engine came with stock. Probably not but one never knows.

Sensors can be damaged by improper installation. The tip should not be touched. No attempt to measure resistance through the tip should be done.

No thread lube should be used.

Intake leaks can affect sensor operation because the fueling is wrong to begin with. Turbo intake systems are complicated and it is easy to end up with an intake leak.

Exhaust leaks can affect sensor operation. For my stock Turbo every time the exhaust system is removed to service the engine the tech uses new exhaust (metal) o-rings the tech fits new ones to ensure a proper exhaust/turbo seal.

Oh, and leaded fuel should not be used. Even some lead substitutes can foul sensors.

 

Powerhaus performance in NJ has a pre made fuel kit, all custom stuff, fuel rail....etc. Pretty good price, here is one of their versions. Incorporates a Radium surge tank, you can go bigger pumps too.....


https://www.flickr.com/photos/radium...57631877842400

 

so how does someone remove the filter for cleaning and not dump fuel all over the inside carpet of the frunk? looks cool but in reality not the optimum setup thats why i installed all of mine under the car in the tunnel that housed the awd. draining for cleaning is no longer any issue. btw the radium setup can be purchased direct from radium, adding lines is simple enough

 

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personally I'm not a big fan of using dual 044's as a main fuel supply.i use dual in tank o44s to supply my surge tank and then a weldon to supply the engine.That Radium surge tank imo is not big enough for a big power 996 turbo.

 

Matters which one. I do not run 044's fyi. I also added an additional pump to the radium surge tank setup, just makes it for a clean setup and no loud droning.

 

I'm not sure what setup you think i have. mine is an-8 from front to back billet rails 1300 cc injectors and magnafuel, walbro and and weldon components. its setup for exactly the power i plan on building for.
i never implied it was your setup but honestly thought if your posting it you might have a clue as to how it works. obviously you don't. running a single filter isn't anywhere near a big power setup. pre filters post filters are mandatory in a large power setup. as for surge tanks the only reason they are even used is to ensure fuel demand to the pump is there when the main tank may be low and sloshing the fuel. running lines from the bottom of the tank vs running them from the top ensure adequate fuel at all times.

i was asking a question and its obvious you don't have an answer so you lower yourself to demeaning comments. sorry i actually build most of my cars so i do know a little bit about what i post.

 

Agreed it has ended up complicated, but I was trying to fix a system that was already in place versus starting from scratch.

 

Not much horsepower (yet). As purchased the car was only producing stock power when I dyno'd it, even though it has a free flowing exhaust, centre of cats removed and free flowing airfilter. I've added Forge Diverter valves and f pipe. Put it on the dyno but stopped the run when we saw that it was running real lean (on the original setup with no pump from the tank to the Bosch in line pump).
I'm only using one of the Bosch 044 pumps at a time.
As I'm setting up the car for tarmac rally I thought it would be good to have a spare pump.



The pumps have switches on the dash so I have a main and a spare marked AUX. I'm running check valves on each pump so there's no flow back through the pump that's no being used. The line from the filter and the return line are as were and are -6 not -8.
I'm thinking I'll go to K16 billet system with injectors, don't know enough about this yet. From what I can see Markski has a record setting 16 billet setup that would work for me. I'm only looking for 500-550 rwhp.

 

Thanks for the advice. I'll have to keep an eye on the fuel temp without a cooler.
Re error codes, I'll have to get that checked today. It was an O2 sensor on bank 1 error code previously, but as I mentioned we replaced that (twice). We thought that the new sensor we got was just a dud, but now I'll have to see when my mechanic checks it. I need to get a Durametric to check this stuff myself.

 

ok now i see what u are doing .I didn't realize you were using one for a backup.Did u log the tune and what codes are u getting?

 

I'm taking the car to my mechanic today to find out what the error codes are now. On Friday the codes that I was getting was O2 sensor (in front of cat) on bank 1. I don't have the log info. I need to get a Durametric logger I think. The mechanic that I'm no longer using has a log from the first dyno run, I'm trying to get it but he's not playing nice.