GT2871 USERS. SR motor

[codyace]

Originally Posted by jspaeth

1) It seems clear to me that everyone is getting mixed up. Those of you who are saying "15-20" are referring to IN MG, not psi. There is a difference.

Ah derrrrrrrrrrrrrrrr. Homer moment.

Originally Posted by jspaeth

2) Cody, as far as the tune, he did say that it seemed like he was using more fuel than he thought he would have had to.

The reason it is not "leaning out", is because if the pump was also weak during the tune, then he just added as much fuel as necessary while tuning (more than most people need up there?) to get the AFR in check.

I understand this: What I'm saying is that a weak pump would not 'magically' get better by using more fuel. Remember at a certain PSI, that's all the more the pump is flowing...him tuning it rich is not using any more flow from the pump itself (as it's regulated by the FPR). If the pump was weak then, it should be weak now.

I know it may be redundant, but have you rewired the pump?

Originally Posted by jspaeth

It is possible (but I DOUBT it) that the fuel pressure is not going all the way up to 62 psi at full boost (43 +18 psi boost), but I really, really doubt this, as it is a very good FPR I am using, and it works PERFECT in the other direction (i.e. when I pull the vacuum line off at idle, the FP goes up by EXACTLY what my boost controller reads as the vacuum pressure).

On the contrary, if it's throwing MORE fuel at it, it could be a sign for the duty cycle. I doubt this as well though as your car would be exceptionally rich.