Which injectors for my turbo?

[totalazneclipse]

Hey guys, I was wondering what injectors to run with my Greddy 18g. I've read a number of threads on the forums saying to either get 550's or 660's. I'm planning to get dsmlink and a afpr once I have enough saved up, but for now I just have a s-afc and the rest of my mods listed in my profile. My question is how much boost can I push on my stock motor safely, cause I'm approaching 120,000 miles and how much boost will that turbo supply? Also, which injectors do you guys recommend for those boost levels.

Thanks

 

[dsm-onster]

First, you said in your profile that an 18G was gotten at a deal so it was worth it. . . You'll be pleasantly suprised.

Second, probably better to ask how much horsepower can a 120K block take; not psi. The stock 2g block can handle around 400 hp reliably from my experience and from my research; and from my friends experience and from what others here have been demonstrating. I've seen them go farther and I've seen them break earlier. Mileage really didn't play that much a role in the demises that I've seen. No smoking from overly exerting the rings (other than a block that had wore out rings before any mods). Not many spun bearings other than faulty oil supply. I HAVE seen bent rods beyond 450 hp.

I wouldn't go over 650cc injectors only because of your form of fuel management. 650s flow enough fuel to match about 400 hp at 80% idc (assuming a good 11:1 tune). I've seen TD05H 7cm^2 housing 18Gs go well beyond this. I'm under the impression that a Greddy 18g can be had w/ a 6, 7, or 8cm^2 turbine housing. If you have the 8cm^2 housing, you're definately capable of more than what the 650s can handle.

SO, will 400 hp make you happy? If not, then you need better fuel management w/ a set of 750s or so. If you get better fuel management, then going to 1000cc injectors would be your likely choice because, why not; you have the fuel control and the bigger injectors can be had for the same price.

The 18g didn't give me 30 psi on pump gas (but what turbo will). But it WILL take you to 30 psi to the redline (assuming a proper tune) w/ stock cams. I did take it there w/ pump gas and water/meth injection. You'll just have to push it and see what happens. Anything else is bench racing .

 

[totalazneclipse]

Sweet that's good to hear. 400hp should do well until i can get the ipt tranny and all of the other drivetrain mods. But it is a daily driver so its not like i'll be going wot all the time. I just want the power to be there cause I have the potiential so i might as well get all of the supporting mods. So for now i suppose i'll go for the 650's and wideband until i get the dsmlink.

 

[RipperXX]

I don't see how you think 650's can support 400whp. My FIC 750's get around 80-85% duty cycle @ 20psi and all I have is an Evo III 16g.


I should add that my car has not been tuned yet... I am just using the default settings for 750's on DSMLink.





P.S. IMO if you KNOW for a fact that your going to get DSMLink then why buy injectors twice? Just buy 750-1000cc injectors an set them to the side an wait untill you get your DSMLink to install them. Thats just what I would do but if you must have some now and have the money, who am I to tell you otherwise.

 

[totalazneclipse]

That is true about buying injectors twice. Roughly how much power are you running with the base tune with dsmlink?

 

[Eastwood95]

You should probably worry about getting an AFPR and clutch kit first.....

Another option is to pick up a set of cheap EVO 8 injectors for now with the wideband.......that will allow you to up the boost some.

Then buy the other injectors when you get DSMLINK.....

 

[dsm-onster]

I don't see how you think 650's can support 400whp. My FIC 750's get around 80-85% duty cycle @ 20psi and all I have is an Evo III 16g.

RR racing Fuel injector calculator- calculates at 100% idc. So, do 650cc X 4 X 80% = 2080cc.

See also DSM_Tuning_Sheet_v2.1.xls. This does the math forfuel flow using your target A/F ratio as well. Note that running stock 9.4:1 at peak airflows will push 750s to 80% IDC at around 395 hp.

I know of ShapeGSX maxing out his EVO3 16G w/ 650s and countless others. . .

I should add that my car has not been tuned yet... I am just using the default settings for 750's on DSMLink.

Like I said, my math is assuming a decent 11:1 tune. You'd be suprised at how much leaning out your fuel will affect % IDC. See the spreadsheet.

P.S. IMO if you KNOW for a fact that your going to get DSMLink then why buy injectors twice? Just buy 750-1000cc injectors an set them to the side an wait untill you get your DSMLink to install them. Thats just what I would do but if you must have some now and have the money, who am I to tell you otherwise.

Yes, I agree. I didn't want to tell him what to do w/ his money either.

 

[dsm-onster]

You should probably worry about getting an AFPR and clutch kit first.....

Another option is to pick up a set of cheap EVO 8 injectors for now with the wideband.......that will allow you to up the boost some.

Then buy the other injectors when you get DSMLINK.....

Since everyone is deadset on spending this guys money for him. . . This is a good suggestion. It costs a little money. But since you have the SAFC and the turbo now, why not? You'll get some practice at tuning w/ a logger and you'll be able to get a little something now out of the mods you have. If you bought the injectors used, you could use them for a while, then turn around and resell them for practically the same price. . .

 

[totalazneclipse]

That's true. I guess it depends on how long I can wait. I'm already bored of the power I have right now. I bought a set of 660's a while ago from this local guy off craigslist, but I looked up the write up on how to clean the injectors yourself and found out two were dead. I was wondering why my car barely idled and stalled itself.

As far as what I'm going to do, I appreciate everyone's ideas. It gives me more options to think about and how to go about it right.

 

[totalazneclipse]

You should probably worry about getting an AFPR and clutch kit first.....

That is my main concern right now. That and I'm trying to gather some money together right now for the wideband sale that's here on the forums.