had to set base FP at 54 psi with TT E85 chip

[Flyin Brian]

I am finally getting my E85 setup tuned close to right. I had to set my base fuel pressure at 54 psi to get my blm's close to 128. This seems high as the instructions call for 43 psi +/- some but the car is running right. I am sure the FP gauge is reading correct. Is 54 psi base ok???
Thanks,
Brian

 

[Eric Stage I]

For most people, you would not want to do that because the fuel pump will run out of volume. In your case, you won't run out of volume due to your pump setup. It won't necessarily "hurt" anything, as long as the car is running right. However, there is no particular reason to get the BLM's right on 128. The low end air/fuel ratio is the same whether the BLM is at 138 or 128.
You might end up making some other part of the tune too rich.
Excessively high BLM's are typically caused by vacuum leaks, or a bad MAF.

 

[Flyin Brian]

Thanks Eric.
Should I turn the base FP back down then and see what happens? I have chip # 6827. My wideband says around 10.4:1 on the gas scale near the top of third at 17 psi boost. I am pushing 90% duty cycle at this point with fuel pressure around 70 psi. I am afraid if I turn down the base pressure I won't have enough fuel flow up top. I was hoping that I could get to 20 psi boost with 80 lb injectors but it seems like I am out of room. Car is making power and I get 6 mpg around town driving it fairly hard. No vacuum leaks but the MAF flakes out sometimes at WOT. Is there an advantage to going with the wideband SD chip?

 

[Eric Stage I]

With E85, you can run leaner than that. I would target around 11.3 to 11.5 AFR. If you turn the boost up to 20psi, you should end up in that area.
The duty cycle will get high at high RPM, which is not necessarily a problem. What RPM are you seeing the 90% DC? It was probably up around 5800 or higher.
For now, I would leave the fuel pressure where you have it, and start creeping the boost up.

 

[Flyin Brian]

Thanks again Eric. I have been running it on the rich side because I was having some false knock issues and wanted to be sure I did not blow up my nice motor. Re-adjusting the tie down strap so it was not hitting the MAF and getting a new ECM (got some prom socket errors and wierd data with old ECM) seems to have solved my false knock issues. You are right about hitting 90% DC, it happens right around 5800 and above. I will start turning up the boost as soon as I get a bigger spring for my wastegate. I think a good tune at 20 psi boost with my setup should be very fast and fairly friendly to engine parts.