New E85 Convert - How do things look?

[Ttype6]

Ttype6 - my pressure is 43 with line off.

What is it at idle with the line on?

 

[kkash48]

ttype6 - if I am reading this right, it shows a lil over 41 with hose on

 

[kkash48]

Hey Keith - thanks for the reply - just hooked up the wideband so honestly not really sure what "the number" is .. I read on a few posts to aim for 11.4, but maybe 12 is ok? .. more reading in store for me. My other problem is that I got a volt booster installed, but it isn't showing up on the powerlogger on WOT runs (I see no volt increase - so gotta doublecheck the connections for a 3rd time, otherwise I got a defective one and will have to replace). Thanks for your input - much appreciated.

 

[turbo89]

Ttype6 - my pressure is 43 with line off.

Turn it up

 

[Ttype6]

ttype6 - if I am reading this right, it shows a lil over 41 with hose on

It should be lower with the line on. With the line off,see how low you can get the pressure to go by turning the adjustment screw.

 

[turbo89]

It should be lower with the line on. With the line off,see how low you can get the pressure to go by turning the adjustment screw.

what are you trying to have him do ?? he already had it set at 43 psi line off ... I would even start with 45 psi line off .. why are you having him lower it ???

OP .... Set it to 45 psi line off .. START to tune it from there with the chip .. leave the FP alone @ 45 .. report back your results ..

 

[Ttype6]

what are you trying to have him do ?? he already had it set at 43 psi line off ... I would even start with 45 psi line off .. why are you having him lower it ???

OP .... Set it to 45 psi line off .. START to tune it from there with the chip .. leave the FP alone @ 45 .. report back your results ..

I asked him to lower it with the line off to see how low it would go to see how accommodating the return line is. I didn't ask him to leave it there.
TT asks you to set the pressure to 43 with the line off. Being able to get to 43 line off doesn't mean we aren't overwhelming the return line. With the line on,the engine vacuum will lower the pressure 6-8 psi typically to 36 ish. If the pressure doesn't move downward by this amount,I suspect the return line is unable to send the unused fuel back to the tank at idle. Since the a/f ratio is adjusted to 14.7 to 1 at idle based on input from the O2 sensor,the extra fuel pressure won't effect idle a/f ratio. The problem that can be created by the line on and off pressures being too close to one another is a stumble during the tip in period the split second when the throttle is first opened from the idle position. The program is based on a sudden upward spike in fuel pressure when the throttle is opened and the vacuum signal falls. If the fuel pressure doesn't rise enough,the lean mixture could cause a stumble.

Also,10.8 to 1 would be a good starting point for full throttle operation.

 

[kkash48]

Thanks Turbo89 and Ttype6 - will get some car time in tomorrow night and will report back results. Appreciate both of your feedback.

 

[turbo89]

I asked him to lower it with the line off to see how low it would go to see how accommodating the return line is. I didn't ask him to leave it there.
TT asks you to set the pressure to 43 with the line off. Being able to get to 43 line off doesn't mean we aren't overwhelming the return line. With the line on,the engine vacuum will lower the pressure 6-8 psi typically to 36 ish. If the pressure doesn't move downward by this amount,I suspect the return line is unable to send the unused fuel back to the tank at idle. Since the a/f ratio is adjusted to 14.7 to 1 at idle based on input from the O2 sensor,the extra fuel pressure won't effect idle a/f ratio. The problem that can be created by the line on and off pressures being too close to one another is a stumble during the tip in period the split second when the throttle is first opened from the idle position. The program is based on a sudden upward spike in fuel pressure when the throttle is opened and the vacuum signal falls. If the fuel pressure doesn't rise enough,the lean mixture could cause a stumble.

Also,10.8 to 1 would be a good starting point for full throttle operation.

I totally disagree with the 10.8 to 1 .. It depends on the car .. I've run a lot of cars where 11.6 was the sweet spot ... others have been far richer .. way too many variables to put a specific number on.. I also suggested the 45 psi as a starter as MOST cars ive done seem to like this number .. TT can suggest whatever value but I am suggesting based on a significant number of
personal experiences that 45 seems to work best with similar setups as the OP.

FYI .. I typically only see the line on off pressure differential by 3-4 psi .. NO TIP IN STUMBLE @ 45 psi ...

There is a reason I am pointing him to 45 psi at idle ... put it on the clocks and you will see why too

 

[Ttype6]

I totally disagree with the 10.8 to 1 .. It depends on the car .. I've run a lot of cars where 11.6 was the sweet spot ... others have been far richer .. way too many variables to put a specific number on.. I also suggested the 45 psi as a starter as MOST cars ive done seem to like this number .. TT can suggest whatever value but I am suggesting based on a significant number of
personal experiences that 45 seems to work best with similar setups as the OP.

FYI .. I typically only see the line on off pressure differential by 3-4 psi .. NO TIP IN STUMBLE @ 45 psi ...

There is a reason I am pointing him to 45 psi at idle ... put it on the clocks and you will see why too

The more power you make,the richer it needs to be. I'm recommending a safe starting point for E85. The higher the base pressure,the more taxing it is on the WOT demands of the fuel pump. As we run higher pressure,the output volume falls. These are things to think about as we try to get the most out of any pump. I'm offering information to make more informed decisions. No steadfast numbers.