Well, my plans for next spring are happening now!

I purchased a set of 370cc injectors and a S-AFC. The injectors are used, which I know may be a bit of a risk, but I'm not too concerned.

Any thoughts on how to set this up? I know Mardi use a 3:1 FMU disc, but that was with a much smaller pully. Do they make smaller FMU discs? Will I be able to pull back enough fuel with a 3:1 disc with the AFC?

2-step colder plugs, or are 1 still ok?

Other tips/advice?

 

on a side note I'd get those injectors cleaned....getting clogged injectors when pushing big power is definently something you should be concerned with.

http://www.cruzinperformance.com/fuelinj.html
I got my 450s cleaned by them, good guys and good prices

 

How much? Link's not working for me right now.

 

$11 per injector...beats the hell outta RCs prices

 

Wow. (Got to their site now...we're having DNS problems)

Can't beat that. I'm going to get them cleaned there for sure. I wasn't too fond of $25/injector, but you're right. $11 is way better.

 

Before I decided to go the JWT route, I planned on using a Vortech super-fmu for coarse tuning, since you can adjust the rise rate of the fuel pressure, and you can adjust the base fuel pressure as well. I think the 3:1 is the lowest disk Vortech makes, which may still be too much with a 3.125" pulley, so having the rise rate adjustability is attractive. You need the base pressure adjustability for proper idling.

Once you get the injectors installed, adjust the base fuel pressure to get good idling and then drive around without boosting for a few days to let the ecu learn the injectors. Once you get good closed-loop performance, you can start boosting and checking EGTs and adjusting the fuel pressure rise rate to get where you think you need to be. After that it's off to the dyno for some dyno-tuning. For fine tuning on the dyno you can use the S-AFC.

This is what I was planning to do. I ended up not going this route, so take this as advice based on what I've researched but not actually done.

If I were you I'd go with the 2 step colder plugs.

 

I've got a SARD FPR, so I can drop the base fuel pressure that way. I like the S-FMU, but that's more than I'm looking to spend at the moment. I could do Maxi's trick and lower the FMU ratio to 2:1.

Sounds like my plan. I like the JWT option, but that's not an option for me.

Without the S-FMU I guess I'm just going to throw a 3:1 disc in there and see what the EGT's are. I'm going to assume that I'll be really rich and try to pull it back with the AFC once I dyno.

If I can't pull back enough fuel, I could just go to a smaller pully.

 

There ya go.

You can also use a boost bleeder valve to trick the fmu into thinking you've got less boost pressure than you actually do.

 

Can't you use that FMU boost-bleeder thing to get one less fuel/boost ratio on the disk? ie, giving you a 2:1 disk instead of a 3:1?

Mardi was the only one who spoke up about it a while ago, but maxi-overdose just recently posted a thread on it.

 

One thing about that, though, is increased charge air temperature and the increased likelihood of detonation. If you do go smaller, you should seriously think about either a charge air cooling scheme or the J&S Safeguard.

 

That's now my spring plan (some cooling option). I wasn't totally serious about a smaller pully.

 

Numbers:

These seem pretty reasonable to me...what do you guys think?

3.125 pully = 11ish psi

Base fuel pressure of 20-25psi. 3:1 FMU disc

Redline fuel pressure would then be 43-45psi. That's very similar to what Matt found to work (post).

Should get me in a reasonable ballpark to tune with the AFC, no?