Well, i just started up my 12A turbo and went for a drive with a broad band lambda. The following modifications are what i have made:
- Huge intercooler up front
- Fuel pressure regulator
- Modded intake
- Big custom exhaust
- 8 psi of boost on stock Hitachi HT18
- probably somethings i have forgotten.

We got readings from 12,5 up to about 13,5 at full boost..

So what is it? I know its rich, but are the readings ok?

 

Ported and higher boost rotarys like 11.5-12.5 max afrs. They like a really rich mix in the peak torque/hp range, to prevent detonation. It's a trade off between hp and rebuilds. Timing is critical too. You will get better info and response in the single turbo section, if they don't frown on the 12A.

Robert needs to come in on this one, he's boosted 12A guru.

 

12A is more response to me. its the same as a 13B, just a tiny tiny bit smaller. trochoid is right, robert knows more about the 12A then most in here.

 

I kinda knew that it should be lower, but seeing that my 12A still has stock ports and standard turbo, i guess i should be allright for now.

The fuel pump cant handle the pressure either, the pressure flattens out at about 6K rpm instead of increasing like it should with a rising rate FPR installed. It goes like a rocket though.

I guess that a bigger fuel pump is on my shopping list next week, i might as well go big now, seeing that the plan for this winter is rebuild, extend port, and a bigger turbo! Around 400 rwhp is the goal, so i might as well opt for a pump that can supply fuel for that.

Took some pictures too, tonight. Turned out pretty well, but it wasnt my camera so i cant post them before tomorrow! Its 5 in the morning here now, so i guess im off to bed..

 

Pics are up, have a look under visuals/audio and norwegian rotarys

 

i can tell you from experience, if you keep running it at 13.5 under full boost she's not gonna last much longer. with a stock port you can get away with around 12.0 but nothing higher than that. even then, your timing will play a big role in this. your fuel pressure is probably leveling off because your boost is. if you havent made full boost by 6k rpms with that turbo then something is severely wrong.

regardless you are on the right path of getting a better pump. easiest solution is a supra pump, much more reliable than the junky *** walbro's and they pump the same if not more lph.