Pretty much as title says. I wanted to go to 550cc injectors and stay around low 300whp, but if I find say 1000cc injectors for cheaper, is there a downside to getting those instead?
What fuel rail are you using? Top feed side feed? And I have the same question as the guy above what ECU.
Stock. I’m planning on dropping a ton of money at once when I have it and getting a turbo (gt3071r?), a fuel pump, downpipe, injectors, a stand-alone ecu, and a tune all at once.What ECU you running?
Side feed is the old style of injector, top feed is more modern usually. You get the type of fuel rail to match the injectors you want.Stock. I’m planning on dropping a ton of money at once when I have it and getting a turbo (gt3071r?), a fuel pump, downpipe, injectors, a stand-alone ecu, and a tune all at once.
I now have two questions.
Why bother with a lower flow injector like 550cc? Why not just get a 2000cc and not use it to its full potential.
What is the difference between the types of fuel rails (side, top)?
If you only need 550cc injectors and you want the "best" possible injectors, you would want to figure out how to get the OEM R35 GTR injectors to work with the 3S-GTE. Those are designed to spray directly into the back of the intake valve for 4V DOHC heads for better transient fueling and have very fine droplet size.Dr Cowart mentioned in his video that the Ford Duratec engines he was calibrating had X of about 30%, and Tau of about 400ms at idle. I’ve found with most Japanese engines that X is only about 15% with standard injectors – although if you have a narrow spray pattern injector like an Injector Dynamics one, and a dual inlet valve head, then often the injector stream points right at the divider wall between the two runners, and a lot of fuel ends up on the divider. This has the effect of increasing X; so an engine that might be 15% on factory injectors might increase to 40% or so with upgraded injectors.
You can get SARD 800cc side feeds so fit the stock rail. The ID1000 or ID1050X only downside is they are top feed meaning a new rail.I can't imagine most people realistically needing more than 600-700cc injectors. Just choose a reputable brand, ID1000 come up a lot. I am going with seimens top feed.
How does a stock ECU control a bigger injector?1000 cc injectors idle fine on a 3S-GTE with modern engine management. A stock ECU is probably pushing it, but if they're a well matched set it'll probably work ok. Just for reference, you'll go from like 10-15% IDC at low load to like 3-6% with the much bigger injectors. This doesn't leave much room for error, and the older ECUs aren't the most accurate.
A stock ecu doesn’t know you changed the injectors, so since it’s a time thing and the “hole” is larger it sprays more Fuel.. I believe that’s where it gets tricky... long ago (late 90’s) on my rotary I went through all this.. I ran 550’s on primary and added 850’s on the secondary with added boost, it didn’t run super smooth through the curve, butHow does a stock ECU control a bigger injector?
So it didn't actually work and you had to get a tuneable ECU to get it running properly.A stock ecu doesn’t know you changed the injectors, so since it’s a time thing and the “hole” is larger it sprays more Fuel.. I believe that’s where it gets tricky... long ago (late 90’s) on my rotary I went through all this.. I ran 550’s on primary and added 850’s on the secondary with added boost, it didn’t run super smooth through the curve, but
It was manageable, especially under WOT.... but it didn’t lean out which is super crucial on rotary motors under boost... The issue still lies with the stock Mickey Mouse ecu’s, you can’t control timing and that’s where the running quality gets goofy.. I first did all this when there was no road map and all we had was the alphabet soup part numbers from HKS and Trust... that’s when I bought a MoTec stand alone... that solved everything...