18 g turbo

[mattspyder]

I was told that a 18g turbo requires atleast 780cc injectors. I have 680s w 190lph pump. Will that work or do I need bigger injectors.

 

[seefour]

Whoever told you that is an idiot. I'm running 650's with my 18g at 22psi and my IDC's are only in the high 70's low 80's.

 

[mattspyder]

well the shop doing my 6 bolt swap told me that, cus my t04b vtrim took a shit and i wanted to put a big 16g on and he has a 18 g but he said I would need bigger injectors.
what should i do. bottom line i need a new turbo..

 

[SonySlave]

650s, 660s, or 680s will work perfectly fine for an 18G. Leave your injectors in there.

 

[mattspyder]

I will be running around 20 psi so those 650s would work fine, he said I would run to lean and burn a whole in the cylinder.

 

[mattspyder]

also does it matter what My mods are, cus Im rebuilding the block, arias pistons, eagle hbeam rods, b/s removal, would any of that affect the injector size?

 

[bmwisthekey]

what compression ratio are the pistons gonna be?

 

[mattspyder]

Well I decided on this, told the mechanic to leave my 650s on there and also leave my t04b vtrim turbo on there, that way I will know for sure if the turbo is shot when i pick it up. (smoke) also I dont really want a 18 g I really wanted to go with a evo III big 16g, so if my turbo is shot for sure I will buy the big 16g that way I know what Im getting, and I can still tune with my safc II and 650s. Will that hurt my new set up at all if i leave the turbo on and it is shot??

 

[brandonzero0]

I'd personally get that turbo rebuilt sorry if its off topic but before i had my BR 20g i ran the to4b v trim and it was great.. but you can tune with the SAFC II and 650's but I would think twice about running a blown turbo long, butjust to see if its blown or not you're fine as long as you don't run it long if it is blown then you get oil in the intake and intercooler piping if it is it just makes more of a mess. ju8st my opinions but i would go with a EvoIII 16g also a great turbo.

 

[mattspyder]

ok so Im set on this, having him put the 18g turbo on with 780cc injectors. Later on down the road I do plan on going the dsm link route. i would sell my datalogger palm pilot and safc II right now (if anyone is interested)

 

[daren_p]

ok so Im set on this, having him put the 18g turbo on with 780cc injectors. Later on down the road I do plan on going the dsm link route. i would sell my datalogger palm pilot and safc II right now (if anyone is interested)

If you plan on running those 780 injectors with just an SAFC you will probably run into tunning issues. You need to remove too much fuel with the SAFC & the result will be too much timing advance & more then likely causing knock issues. If you just have the SAFC, stick to the 650's until you can get DSMLink. If you already have an eprom ecu & are running a eprom chip to compensate for those injectors, forget what I just said.

 

[Dream On]

I wouldn't get the bigger injectors until you get dsmlink either. As said above, you'll be ok to run around 20 psi or so with 650's, and you can still tune with the SAFC with those.

 

[dsm-onster]

The 18G comes in a couple of flavors. Which turbine and turbine housing does it come w/? A set of 780s would be a good idea, but of course you'll certainly have issues w/ timing and the safc. And also The safc can only compensate for up to 800cc, right? that only leaves 20cc difference to tune your fuel curve.

Again though, the 780s would be good as this compressor wheel has a bit larger inducer than the evoIII 16g (evo3, 18g, & 20g have the same exducer diameter). 650s can match around 400 hp at a good 11:1 tune (80% idc). I was running at 95% IDC w/ my PTE 650s and 25psi w/ FP cams and a td05H 18G. I wish I had kept the turbo and swapped in an 8cm^2 housing. Or gone to a td06H turbine wheel and machined out my 7cm^2 housing.

At the end of the 18g potential, you'll likely need to upgrade your 190 lph pump. It doesn't flow quite as good at high fuel (boost) pressures. It should be great for around 400 hp though, just like the 650s . If you're interested in an eovIII turbo, then I think that will be quite satisfying.

Why don't you want an 18G? I've seen an 18G yield higher hp than any evo3 16g powered car of which I've ever heard.

 

[Dream On]

The limit for the SAFC is supposed to be around 650cc (ish) injectors. Much more and you'll get too much timing advance.

 

[dsm-onster]

Right. And even you were brave enough to go over 650cc compensation (around -30% airflow compensation w/ the SAFC), you still couldn't run, let's say, 900cc injectors and expect to be able to tweak the fuel curve. Add that to terrible timing advance and you'll not be happy.

 

[mattspyder]

well I decided to go with the 780s and 18g, hes tuning it on a dyno anyways, and hes giving me a afpr. later on in the future I will be getting dsm link. so hopefully everything works out.
thanks guys

 

[JOEY A]

You need to get your eprom chipped for big injectors either way

 

[MoparTurbo]

Hey OP, just wondering why you would ask a question and not take any of the given advice in. You don't NEED bigger injectors, and your tune WILL be shit. IMO stick with your injectors now. You aren't going to overrun them. More money for parts to make your car run disfunctional and eat more gas is no good in my book.
Not trying to be an ass about it all, I just think noone in this thread posted +1 FOR your ugraded injectors.