Sorry for yet another Greddy topic. Bear with me.

I'm considering adding a head gasket and upping the boost on my Greddy kit. I have 3 questions on this.

1) 2mm or 3mm:

How do you calculate the right size? I'm assuming it depends on your intended boost level and that there is a formula for it. I've seen a lot of comments that claimed you should go one way or the other but they sounded more like gut feelings than facts backed by math.

2) Similarly, at what boost level will the 550cc injectors in the kit max out?

I used this site:
http://www.rceng.com/technical.aspx

However, it seems to significantly over estimate the size injectors required. Is this really accurate for our application? If i'm using their calculator correctly, the 550cc ones that come with the kit are already too small for the base boost.

3) How much boost can the T518Z 18G reliably make?

I believe the consensus is the limit is 15 psi. Is it safe to assume this is the case?


So essentially, I want to know what my limits are with the kit. If I wanted to go 15psi would that call for 2mm or 3mm HG. Would the 550cc be able to do that or would I need 650cc? 750cc??

I'm getting tuned in about 2 weeks. I dont have easy access to the tuner (we're flying him in) so it's kind of a one shot deal to get it right. I was going to run it like it is now, but then thought I should take advantage of having the tuner available and just go ahead and max it out.

Thanks for tolerating yet more annoying Greddy questions

PS: I've already done as many supporting/safety mods as I could think of. Oil cooler, radiator, IM gasket, Water/Meth injection, Wideband A/F, EGT Gauge, ceramic coated manifold, profec boost controller, blow off valve.

 

i sadly cannot answer your questions, but im interested in seeing what others say. free bump

 

Check the greddy question thread near the end...someone stuck a headgasket on his greddy kit and said it was worse with it becasue the turbo falls flat on its face after 12psi or so.

Its not worth it, you'll need to get a different kit if you want to make more then ~300rwhp.

 

you dont want to exceed the efficiency range of the turbo..

for ap1, it seems to be 9psi; for ap2, 7/7.5 psi... these are the CFM flow limits for the greddy turbo on each engine..

 

Where did you get this data from?

Do you have efficiency charts for the turbo? Thanks.

 

[QUOTE=TRBOKEV,Apr 15 2008, 12:59 AM] Where did you get this data from?

 

goodluck with everything, just wanna add if you didn't already know, s2kart is running meth/water injection with his greddy kit and put down 331whp.

>300whp achieved.

 

Yeah I want to know where you guys are getting your turbo info from. I know theres guy with wrx's running this turbo at 18psi all day no issues making nice power.

 

if you guys want more power out of the Greddy, I suggest you get a bigger turbo.

 

more psi will equal more power; it's just an issue of diminishing returns..

also, we can't compare the sti engine to the f20/f22.. even among the s2000 engines there is a difference..