whats the issue with FI on these new v6's?
 

I have been thinking about getting a new v6 and Turbocharging it so i will have twins, but I keep reading about this fueling issue, however i can't any info on what the problem is.

can someone point me to a better explanation of it?

The high pressure fuel pump can't keep up. It looks like we have found a pump that will work as a replacement, but we can't seem to find a supplier that has any and the manufacturer doesn't sell direct. This does not mean that once we get over that hump other fueling issues won't pop up, though. For example, the in-tank pump or the injectors may be the next piece that can't keep up. However, the in-tank pump should be an easy fix. The injectors are expensive, but they are most likely not the problem. Most other DI cars have found that replacing the high-pressure fuel pump fixes the problem.

okay. whats the base fuel pressure on these cars?

my car runs about 45 and 60 under boost

I do have 2 pumps in the tank to keep up though lol

I don't remember what the in-tank runs, but the high-pressure pump is about 1700-1900 stock and it looks like we can bump it up to 2100+.

:confused0068:

so it runs booth and in-tank, witch feeds the high pressure, then the high pressure bumps it(psi) up?

that seems redundant to me....... no ownder there are issue.

i assume the injectors need this to fire because they are Di-erect injection?

Exactly. The pressures in the cylinders are much higher than in the intake manifold. To overcome this pressure you need to inject the fuel at a much higher pressure than normal port injection.

jesus! sounds like a damn diesel injection system.. well technically it is..

yeah.

is there any other company that makes a high pressure pump that could be fabbed/retrofit to work?

Yes, BMW has one that looks like it will bolt right up with little modification. The problem is we haven't found a supplier that has one they will sell us. The new one for the VWs looks very similar and there's a guy working on retro fitting those to up the flow. He says he'll work on ours next, but can't give a firm estimate.

This is an example of our stock HPFP.

RPM x Fuel Pressure.

RPM FRP_C psi
2599 1055.87
2798 1421.37
3047 1575.11
3047 1575.11
3214 1659.23
3544 1694.04
3749 1714.35
4147 1699.84
4354 1705.64
4771 1708.54
4955 1705.64
5399 1720.15
5589 1734.65
5994 1723.05
5994 1723.05
6364 1723.05
6531 1721.6
6727 1801.37
6126 2021.83
5095 2036.33
4628 2063.89
3760 2076.94
3409 2097.25
2843 2107.4
2586 2121.9
2586 2121.9
2076 2140.76
1583 2148.01
1362 2121.9
1240 2043.58
1187 1884.04
1136 1789.77
1124 1596.87
1073 1504.04
1042 1318.39
997 1237.17
997 1237.17
968 1070.38
929 994.96
918 841.22

Yeah, exactly what we are seeing. We get a sharp drop at about 6100-6200 RPM and it goes lean. It should steadily increase, just at a slower rate after peak torque.

Could this be the part:iono:
http://www.google.com/products/catal...d=0CLEBEPMCMAo

I'll have to check with Tracy to see if that is the right part number. Thanks man.

That does not appear to be the one....the one we are sourcing has 3600 PSI peak and feeds a 2012 v8 twin turbo production car.

From the 2012 M5? I've been trying to look for the pump also for you guys with no luck either. You wouldnt happen to have the part # would you.