what size injectors to use with evo3 16g?

[ShapeGSX]

Uhh, 550s with increased fuel pressure is equivalent to using larger injectors when it comes to the AFC. Both are just as easy/hard to tune with the AFC. You will get increased timing advance with both solutions.

It is really best to correct for larger injectors or higher fuel pressure inside the ECU.

 

[sweet97]

I use the MAF-Translator for fuel control. Let's say I have my base fuel pressure at 40 psi. If I have the trans. set on "X" and that adds timing and I raise the base fuel pressure to 45psi timing should still stay the same but I may eliminate knock due to the extra fuel at the same "air" setting on the translator. That's been my take on it. mark

 

[qwkdsm2]

just get a wideband and it'll make yourtuning a whole lot easier with either safc,dsmlink,etc.

 

[sweet97]

If you have a 1G you can get a Scanmaster from fullthrottle. I can watch boost, EGT, A/F on widebamd, 02 voltage and knock(Scanmaster). I can switch the scanmaster to timing and set the timing advance all in real time and you can record on a palm if you like. With so much to watch I have to remember to watch the road!!

 

[TsiTalon9587]

Unless I have missed it, I didn't see anyone mention the fact that you can just go straight to 950's with the use of DSMlink. This way you'll never have to upgrade again, unless of course you need 1600's at some point. I would say just get the 950's, and be done with it. You won't have to worry about going to high with your IDC on that turbo.

 

[GPTourer]

Unless I have missed it, I didn't see anyone mention the fact that you can just go straight to 950's with the use of DSMlink.

What is idle like on such a car, and how would mileage be affected, compared to a 550/660 equipped DSMlink car?

 

[ShapeGSX]

What is idle like on such a car, and how would mileage be affected, compared to a 550/660 equipped DSMlink car?

It should be the same. The pulsewidth resolution can go small enough to control 950s without issue.

 

[TsiTalon9587]

Josh got it, you can compensate for the size of the injectors within DSMlink, and it will idle like stock 450's

 

[XtReMeToYz]

It should be the same. The pulsewidth resolution can go small enough to control 950s without issue.

Yep, thats what I plan to do Should only be another week or two before I have a really pretty DSMLink box as a paperweight because of winter

 

[DSMSpyder99]

Know one has brought up another important issue...quality of gas. I know my friend back in NJ only uses Sunoco 94 and he pumps out 20PSI on 550cc his IDC is 85%. I know it is a little high but it works. As for me i am going to go 660cc since i have crappy Cali 91

 

[killab443]

So if i get a non turbo 1g fuel pressure regulator, it would boost my fuel pressure from 39 to 47. Since im not running the stock 39 fuel pressure, and i increased the fuel pressure to 47, does that mean my injectors will flow more (un tuned or tuned) because of the increased fuel pressure? Someone said before if you run higher than 43psi from a fpr then the amount the injector will outflow what its suposed to flow. That was on 550cc injectors, does this apply to the stock 450s

 

[XtReMeToYz]

So if i get a non turbo 1g fuel pressure regulator, it would boost my fuel pressure from 39 to 47. Since im not running the stock 39 fuel pressure, and i increased the fuel pressure to 47, does that mean my injectors will flow more (un tuned or tuned) because of the increased fuel pressure? Someone said before if you run higher than 43psi from a fpr then the amount the injector will outflow what its suposed to flow. That was on 550cc injectors, does this apply to the stock 450s

Your theory is right, they will flow more at a higher fuel pressure, but nonturbo fuel pressure regulators are not rising rate like turbo fuel pressure regulators. This is important because for every 1 pound of boost increase, fuel pressure increases 1 pound. If you wanted to go that route you would need some sort of an AFPR that can reference boost, and a logger/safc combo or something to tune the injectors back down to stock like conditions for your part throttle.

 

[ShapeGSX]

Turbo DSM FPRs are not rising rate FPRs. Rising rate indicates that for every 1psi of boost pressure, fuel pressure will increase by >1psi. Maybe 2psi or 1.5psi. It is a dirty way to ensure that you don't blow up an engine that has a fuel computer that is made for naturally aspirated engines.

N/T DSM FPRs will match fuel pressure with boost pressure, though.

I just think that tuning by using fuel pressure is like playing with fire, though. Do it right or don't do it at all. Doing sloppy mods, particularly when it comes to your fuel can and will come back to bite you in the ass later.

If you leave the base fuel pressure at 43psi, and tune the fuel inside the ECU, it all just makes sense. The calculated A:F ratio that the ECU thinks it is delivering really IS the A:F ratio it is delivering if you do it right! Go figure!