FastKat

iTrader: (10)

What is the largest available (and affordable) injector I can use on an E40 ECM without having to scale? I understand the ECM is limited to 63.5#.

So far the largest I have found is the LSA/LS9 injector running 52# at 58psi. Is there anything between that at 63.5# at 58psi?

eaglegoat

There are a few different injectors between that and 63.5. There are a couple issues though.
1) The highest the flow rate the table can go is 63.5. This means your injector can only be 58# because in vacuum out to 80kpa it'll hit that limit. Unless you switch to a manifold pressure referenced system. If you do that
2) Most injectors have no data or crappy data. The Ford racing injectors can be mathematically converted to GM format with good success, GM injectors can be converted from one format to another with good success, ID has developed good data for their stuff. The only injector I know of that fits in the range you're looking for is from deatschwerks and their data is sketchy at best.

If you need injectors big enough to to worry about this you might exceed the airflow limits of the pcm anyway. Why not just scale the tune?

SLOW SEDAN

iTrader: (13)

G8 has an E38 ECM. E40 is older 24x.

A few companies make a 50lb @ 3Bar which flows pretty close to 61lb @ 4 Bar.

FastKat

iTrader: (10)

Thanks guys. So Deatschwerks and who else? I saw FAST has some 50s but not sure if that is at 3 bar or 4 bar. I could not find any Bosch or Siemens in that range at 58 psi.

I want to avoid the complexity of scaling and want things like my MPG and DTE to work. I'm working on a mild SC build so I don't think this should be a problem. LSA injectors are my fall back plan.

eaglegoat

What's the power goal and what fuel?

FastKat

iTrader: (10)

I don't really have a power goal per se. I did a small cam and I have a set of 1-3/4 tri-y headers, a CAI, and an Aeromotive Stealth 325. I want to get an LSA SC and with either a stock or slightly smaller pulley. Whatever I get with that is what I get. 550whp on 93 octane pump gas is my best guess. The car is a daily with almost 200k miles and I don't want to poke the bear with a ton of torque. So far all is well.

SLOW SEDAN

iTrader: (13)

The FAST 50lb are rated at 58PSI so a bit small. The Deatschwerks are at 3Bar so flow a bit more at 58PSI.

Really the LSA/LS9 injectors work up to about 600hp on pump @58PSI which is inline with the goals and should be fine. Plus the injector data is as easy as copying stock tables. Long as the fuel pump keeps up which I think it should. We used to use a 250lph pump on a boost activated BAP which kicked up voltage to the pump over 3PSI or so. The 300 should be close to the same performance.

Some say they get more out of the stock injectors but the cars equipped with them stock also had a FPCM which we don't have in the G8. The FPCM can kick the pressure up to 88PSI to extend the injector and allow the small injectors to support more hp.

eaglegoat

You'll be cutting it close on LSA/LS9. I'd recommend SD60s and simple scaling on a speed density tune.