FEDREX

I have the Bonez hi-flo cat with DP and Greddy catback. I also have the Walbro in now and I have an FCD that I'm not currently using because I don't hit fuel cut because of the hi-flo cat.
My question is - will it be OK to put on the racepipe and FCD since I have an upgraded fuel pump?
90 TII

Keith

FEDREX - in answer to your question, yes and no. Will a Walbro fuel pump deliver enough fuel for your setup? No question, it will and then some. However, there is another consideration here - the FCD. The way this thing works, it tells the ECU that there is never any higher boost then 8PSI (approximately), no matter how high the actual boost gets. Now lets say, for the sake of example, that you get up to 10PSI boost in third gear. At that time, the ECU is getting a boost reading of 8PSI from the boost sensor. Therefore, it will inject the correct amount of fuel for 8PSI. Since you are really running 10PSI, fuel will be insufficient, and the worst possible thing that can happen to a rotary may happen - detonation (pinging)! Sadly, you now have a blown engine.

Now, having said that, you may never reach sufficient boost for fuel cutoff, or you may only reach 8.7PSI (only .7PSI above the FCD value). If you are going to use an FCD, I would at least invest in an Air/Fuel ratio guage, so I would be sure this never happens. Better yet, get a modified chip for your ECU or an aftermarket engine management system. Both cost way more than an FCD, but they do a better job.

Of course, this is imho.
Irv, Keith's dad

BLUE TII

iTrader: (9)

I don't want to tell you it is safe and then have it blow up, but here are my findings. I have an '86 TII w/ RB downpipe/midpipe (stock catback currently), turbo inlet duct mod w/ open filter of course, very ported wastegate, FCD and Walbro w/ pump rewire. Using my Greddy gauges I have found that at full .65 Kg/cm2 boost (about 9.4psi) I am still running 11:1 A/F ratio at this boost and obnoxiously rich at all other times (Note that the stock pump w/ rewire started to lean out in 5th gear at .5 Kg/cm2 -7.25psi-before the TID mod.). I still think it would be best for you to have a way to monitor A/F and boost accurately on any modified turbo car!

BLUE TII

iTrader: (9)

It was cold and misty last night and A/F gauge indicated 12:1 w/ full boost in 5th held for a little past 100mph. So I would say this setup is JUST adequate, of course running rich at all other times is far from optimal.