Mechanical WI and Tuning
 

I am have a problem with finding the right tuner for my FD. I've spoken to several tuners to determine the maximum boost I can safely run on my car. I've been reading the forum quite extensively and ran across a couple of threads regarding WI, some cars here are boosting 22+ psi with pure WI only. I've spoken to several shops and most of them seem clueless, all have said that because I'm running on 91 octane, max safe boost is around 18 psi. 1 particular tuner even said that 15 is probably the max due to 91 octane. I've tried to explained WI will allow the engine to run higher boost without success in making them understand. Am I wrong here, or is there really no tuner with WI experience Southern California? My mods are below, please let me know how much boost I can safely/reliably. My main goal is maximum SAFE boost. I want a reliable tune. My mods are below:


Engine rebuilt by Howard himself
Intake
BW S362 .91 a/r divided
Wannaspeed pre turbo WI
FMIC
Twin Power ignition and 10mm wires, NGK Plugs 9s (I think)
850/1680 fuel setup with KG Rails
Walboro 255lph fuel pump
Full Exhaust sytem
Dual Oil Coolers
Will be running premix

Is 23 psi safe?

Your fuel pump is limiting factor. Without some voltage booster it would support about 450 HP@crank max. Your turbo can support about 600 HP.

Amount of boost you can run, assuming that ignition system is up to task, depends mostly on water injection rates and extend to which engine running parameters are compromised - non-ideal fuel mixtures and retarded ignition timing.

With high water flow rate, you can run engine at more optimal ignition advance and fuel mixture and vica versa. You can run modest amount of water with retarded ignition and very rich fuel mixtures or use large quantities of water to bring engine to more otimal operation parameters.

Ignition power is critical and I think that you will need better solution with far more ignition energy than Twin Power, at least if you want exploit full potential of your setup and water injection.

I'm sure that many won't agree with this point with assertion that this and that combination doesn't misfire to certain power/boost levels, but at such point, ignition energy is already compromised and so are tuning parameters with it.

get a Walbro 400 with a new sock

Fuel - As mentioned the Walbro 400 will provide more flow. I am running an Aeromotive Stealth 340lph with great results. Its proven to 500whp with stockish base pressure. You could always add another Walbro 255 with a dual setup. I always preferred one pump, but depending on your power goals, duals may be best.

Ignition - The twin power will get it done with the right support. The PFC's restriction is the stock ignition and coils. AEM coils are a new development but they provide pretty much the same power as the stock coils with a twin power. I pretty much copied Brent's ignition as he was making 540whp with no breakup. Pick up a new Leading coil to make sure its fresh. From there I Highly recommend NGK race plugs. Banzai Racing sells them. I'm running 10's on all 4. With a good set of wires, you should be good for 500whp. Water only is more demanding on the ignition. 50/50 meth will help also as its an easier mixture to ignite.

Tuning - 50/50 water meth is what I am using. My tuner was more comfortable as it helps cool the intake temps which picks up more power at a lower boost level and adds a fuel so its less stress on the fuel system. Tuning with water injection is the same as tuning without. A conservative tune throughout, and let the boost make the power. If you have to explain water injection to a tuner then I wouldn't consider them . Search around the Southwest forum of the club. You may have to travel a bit.