I need help choosing injectors for new turbo set-up

[Snow White]

I just recently changed my turbo setup over to a Evo 3 16g on my 1998 GST eclipse with the new 7bolt engine I rebuilt. My plans are to upgrade my fuel system and go with a 190 Walbro fuel pump and 550 RC injectors will this be a good choice for 15 to 20 pounds of boost and I have a dsm link to tune with.

 

[98_tsi_]

That would be plenty for 15-20 lbs.

 

[WES_393]

You want a fuel system that can handle more than the maximum airflow and pressure your turbo can produce, even if you don't plan to max out the turbo. Otherwise one wastegate malfunction and you'll be rebuilding the engine again.

If you have a legit Evo 3 16g (not Small or Big) then you need a fuel system that can support over 45 lb/min at about 30psi. The 550's will only safely support a little over 30 lb/min, which isn't even enough to run a Small 16g. A 190lph could support about 45 lb/min at 25psi, which still isn't enough for an Evo 3 16g.

I would suggest a Walbro 255 with at least 650cc injectors. But if you have DSMLink, why not go with something around 1050cc? It'll be a while until you have to upgrade again and you'll have the option of using E85.

 

[BCDSMatt]

I have a similar setup and bought a 190lph, my mistake because a 255 walbro was needed for good flow. 650cc Injectors are a good idea as well.

 

[Snow White]

Due you think evo 560 injectors would be better ? There a little cheaper to or should I just go with 650 injectors and yes its a real evo3 16g.

 

[95talongirl]

I'd recommend the 650's with a 255 and a regulator. That's what I have currently. At 20-22psi, the car is showing 70% duty cycle via dsmlink. So there's still some wiggle room.

 

[Nicklepage1010]

Buy the biggest injectors your wallet can handle.

 

[NWHTanK]

Im going baby steps. 16g ,560 injectors,255 with a rewire,fmic,15 lbs boost Max,link,3 inch exaust,and other parts.im not hungry for power till I learn more and do a awd swap.

 

[99ECLIPSEGSXDSM]

Buy the biggest injectors your wallet can handle.

+1 Go big

 

[Snow White]

My only problem is the motor is freshly rebuilt but it was a stock rebuild. What would be a safe amount of boost to run thats why I didn't wanna go crazy with boost.
Thanks for the fast responds.

 

[snowborder714]

Don't base injector size on break-in boost levels, as it sounds like you might be doing. Go with the biggest injector your wallet can afford, as link can account for them and make (most of) them idle and run like stock.

 

[95talongirl]

"safe" boost varies, depending on what you have to support the turbo... and preventing knock.

Without any tuning or fuel mods, I wouldn't go over 10psi. But then, that's really a waste of going with the larger turbo. My car is currently tuned running 18psi. Granted, its not perfect, and sometimes it will spike to 20 or so on really cold days, but I consider this safe because I know there's enough injector to handle it, and there is no knock issues. (Even on the cold days with slightly more boost the injector duty cycle would not go over 70%)

 

[99ECLIPSEGSXDSM]

Turn the boost up until you see knock (with tuning upgrades). I've seen people only being able to tune 18psi up to 24psi on pump

 

[snowborder714]

^Bad approach. The last thing to tune is timing and this will vary based on when you see knock.

You should know how much airflow your injectors can support while still maintaining a safe IDC%. You should also know approximately how much airflow you'll see from your turbo at your target boost level. If the target airflow is higher than what your injectors can support, you should consider larger ones (unless it's just slightly over) or dropping your target boost level. If it's under, then you're safe to tune for that boost level.

 

[95talongirl]

^Bad approach. The last thing to tune is timing and this will vary based on when you see knock.

You should know how much airflow your injectors can support while still maintaining a safe IDC%. You should also know approximately how much airflow you'll see from your turbo at your target boost level. If the target airflow is higher than what your injectors can support, you should consider larger ones (unless it's just slightly over) or dropping your target boost level. If it's under, then you're safe to tune for that boost level.

+1

The guessing method.... of just turning the boost up until it knocks, is too much of a gamble. All it needs is to knock bad enough for a split second, and you'll be rebuilding again.

 

[99ECLIPSEGSXDSM]

My bad guys. It's been a long day for me and not thinking 100% right now

 

[Snow White]

Okay I guess im going to go with 255 fuel pump and 650 injectors with FPR.

 

[toppertopper]

go with a 255 and 1200 cc injectors (could be 1250),you can control them with link ..You will always want more so why do it 3 or 4 times ...I went with big 16 g ,link ,750cc injectors, frp ..This spring i will be going with 1200 or bigger (parked for the winter)

 

[99GS_Turbo]

I'm actually in the same boat as the OP. I picked up a new DSM and the turbo was blown, but I still had a small 16g that I never used from my past DSM way back. My friend from work has an EVO 9 is about to upgrade his injectors and will sell me his for $80. Should I buy those and will they be good enough or should I go bigger? I don't plan on going with a bigger size turbo

 

[snowborder714]

A small 16g will max out around 36-38 lbs/min for airflow. The 560cc Evo injectors will support 32 lbs/min at 80% IDC's and 40 lbs/min at 100% IDC. Technically, yes, you could use them. Something a bit larger would be a better option for sure.

Also, it depends on what you plan to tune with as to what size injectors you can run.

 

[clipto]

If your running ecmlink and staying on pump gas just get 1000cc injectors and call it a day. Might as well go big you can always fine tune the injectors with ecmlink that's what makes it so good. The bigger the injectors anything more like 1200-1450cc injectors might run ruff on pump gas but great on e85. So hopefully that will help you calculate somethings.

 

[kpoage20]

Better to have to much injector than having high duty cycles

 

[99GS_Turbo]

thanks, I will go bigger...Also I heard that the 190 is plenty for the small 16g and that the 255 might be too much. I'm a noob when it comes to this so I want to do it the right way. Should I go with the 255 or would you recommend the 190

 

[bonusboy]

1000cc FTW

easy to tune
and never upgrade again!

 

[WES_393]

thanks, I will go bigger...Also I heard that the 190 is plenty for the small 16g and that the 255 might be too much. I'm a noob when it comes to this so I want to do it the right way. Should I go with the 255 or would you recommend the 190

The 190 could only fully support a Small 16g once rewired. Yes, a 255 would be more than enough pump for a s16g, even with E85. But that's the point, you want your fuel system to be oversized.

1000cc FTW

easy to tune
and never upgrade again!

Well, I wouldn't say never. I swapped my 660's for 1150's to run E85 with my 16g. I thought they would be the last injectors I'd ever need. But now that I'm installing an HX40, I wish I had gone even bigger.