I have 99 Eclipse RS with a Hahn Stage II Kit.

I want to get bigger injectors and a better FPR but am not sure what to get.

Can anyone help, the S-AFC is already ordered so I have a way to tune the bigger injectors. Also Is it worth it to get a better Fuel Rail or is the stock one fine?


On a last note my boost gauge is Only showing about 4lbs. at full boost and 15 vaccuum at idle, I dont think this is normal for a Stage II kit, is this bacause of a boost leak?

Thanks in advance guys....

-Dere

I could answer some questions, you dont' need a better or better fuel rail because your stock one is just fine and it will do the job and get the vortech s-fmu for the fuel pressure regulator with a 1:1 ratio disk.
and for the injectors, I'm not sure how much psi your running but try out this web site by Corbin, http://www.2gnt.com/www/corbin/chooseinj.html

Derek,

I can answer some of your questions. The best choice for a rising rate fuel pressure regulator is the Vortech SFMU. It comes with four calibration disks (a 7:1 - 3.72" disk, 5:1 - 2.62" disk, 3.25:1 -2.47" disk, and 2.5:1 - 2.22" disk), 3 rings (largest disk does not use a ring), and two springs. I also purchased the optional spring -Part ##7X100-050 - which provides a faster rise rate directly from vortech engineering. All the disks and spring combinations allow you to fine tune your system. Although this regulator cost me about $300 dollars, it is well worth it as it holds extremely solid/consistent fuel pressures at idle. You may be able to find a better deal than ordering direct from Vortech - I ordered direct so that I could purchase the optional spring.

To figure out approximate fuel pressures you could use the following formula but make sure when you do the actual tuning on the car you have an EGT gauge and A/F gauge. This formula will only give you approximations to see which disk/ring you should run.

For example, I am running 7 to 8 lbs of boost using the 3.72 disk and hard spring on stock injectors. Hahn Racecraft recommends fuel pressures of over 100 psi.

Idle Fuel Pressure + (lbs of boost * disk ratio)
55 psi + (8 lbs of boost * 7) disk ratio for 3.72" is 7:1
55 + 56 ~ 111 psi of fuel
(this number doesn't take into effect the rise rate of the spring)

I am not sure what size injectors you will be running (I have seen people use the 325cc injectors without a SAFC and others use a 440cc injectors with a SAFC). Also, from what I have read a SAFC advances timing when you use it to lean out the injectors at idle - a big problem for turboed engines - so be extremely careful and only make small changes at a time.


As for seeing only 4lbs of boost, that is definitely not normal. I would double check all hose clamp connections at the intercooler piping (from the turbo to the inlet on the intercooler, from the outlet on the intercooler to the throttle body), all signal lines from the back of the throttle body (to fuel pressure regulator, boost gauge, blow-off valve signal). Somewhere you definitely have a leak.


Hope this helps,
Kurt

i'm planning on running 415 cc/min injectors (the ones from hahn) with a 3:1 disc in a s-fmu with about 30 psi at idle and 70 psi at full stage 2 boost (8-10 psi) on my new rebuilt shortblock. (give or take the fuel pressures a little, i'll have to do some tuning) i'll use the AFC to make minor adjustments, maybe to smooth out idle out a little.

as for only getting 4 psi of boost at stage 2? sounds like you have a boost leak. get a leak tester (you know, the thingies that go over the intake for your turbo when your car is off and pressurize the whole system with like 20 psi or so) and spray down all of your intercooler piping with soapy water. look for lots of soap suds and you'll be able to hunt down boost leaks easily that way.

if you still only get 4 psi of boost, check this stuff out:

a good way to compensate for boost leaks is to run your wastegate pressure signal to the back of the intake manifold instead of the compressor housing. much more accurate boost/vacuum signal that way. makes your turbo spool up a little quicker too.

your boost gauge may be fubar. if you have your wastegate getting it's signal from your intake manifold, you've hunted down all of the boost leaks, and you're still only getting 4 psi then you should probably get a new boost gauge.

if you're STILL only getting 4 psi of boost after you try all of this stuff, maybe your wastegate is messed up. i guess it's best to leave the most expensive option for last.

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