550cc Injectors ???

[Crankwalker]

Does anyone have any information on how many CFM's 550cc injectors can support?

[ProjectGSX]

There is more to it than CFM, though. I assume you have a 2G, based on your screen name.

A 2G with anything larger than a small 16G will need larger than 550CC injectors. The reason being is that the 2G ECU is rather stingy with timing advance. As soon as it starts seeing large amounts of HZ from the MAS, it will cut timing. So, if you have a large turbo, you need to use a SAFC (or other fuel computer) to lean out the fuel mixture. What the SAFC literally does, is intercept the MAS signal, modify it, and send it to the ECU. So it tells the ECU that the MAS is seeing less air than it actually is.

With 550s, you cant lean it out enough to make the ECU happy enough to award favorable timing.

Dont get me wrong, 550s can offer enough FUEL for a good sized turbo. But you wont get the timing, due to high air flow numbers. This is 2G specific, as well.. 1G's dont have this issue apparently.

[ecoli]

Originally posted by Crankwalker
Does anyone have any information on how many CFM's 550cc injectors can support?

Enough on race gas, not enough on pump gas. I hope that is specific enough.

[Crankwalker]

Actually I dumped the 2g and went with a 1g. I understand there will be a lot of variables but isn't there a base rating? The calculator on the RC site seems to think 550's arent enough for a 14b. I just want to figure out how far 550's can carry me. A few of my local club members have used 550's on fast 20g set-up's and I know Archer used 550's on the race cars and those had huge Garrett indy car turbo's.