Lynx

OK on a turbo RX-7 like mine raising the boost seems to be a prob because of lack of fuel. I always see people getting bigger injectors (assuming you have a better pump). WHY, wouldnt just be easier so increase the fuel pressure by useing a adjustable regualtor. The stock pressure is only like 38psi max i think. Thats low, you should be able to pound out at least 45 with a good pump. Plus it helps atomize the fuel better. Couldnt you just get one of those regulators that have increase with boost for the people that want to run like 12psi with the stock ECU. Always assumming you have a upgraded pump which $135 from K2RD is cheap for a better pump. What do you guys think?

Lynx

Also just for my info I have ordered a new Walbro pump form K2RD and will have it installed soon. With that installed with just cleaned and balanced injectors. What would a Safe boost pressure be for my 87 TII with out a Super AFC and what would it be with a Super AFC?

scathcart

The stock fuel pressure regulator bumps the fuel pressure from 40 psi to 50 psi under boost, FYI.
Sean Cathcart

Ranzo

Raising the fuel pressure with a aftermarket regulator is a good way to give more fuel in your mix. Be careful not to exceed 60 psi because injectors don't work well above that. You will need a strong pump if you do this as fuel pressure seriously diminshes a pumps flow rate.

Tuning with a higher pressure will be different because your actual flow rate from the injector will be different. There are formulas available to figure this. You will need to use the STATIC fuel pressure, which is what the regulator cause with no vacuum/boost line attached to it. The pressure increase seen under boost is only there to make the fuel pressure the same as manifold pressure otherwise gas would not go into the engine. This holds true with the stock regulator or a 1-1 aftermarket.

there are 1-2 and 1-3 ratio regulators which will give a bouble or triple incresase under boost..

if you are using a SAFC or tuning device you might need to make adjustments for the increase in fuel flow.

Randy....