Hard on Fuel - MPI S/C What am I to do

[Yummy]

I have 600 miles so far on my S/C stage III, running 10 psi, gear 25/38. I average 75-80 miles per tank and that not even pushing hard.

My A/F indicate between 13 and 16 on idle/slow. 12/13 mid and 12.4 at wot.

I understand more power...more gas but If you cruise along 7-8k rpm with the boost at 1-3 psi. Should I not getting better fuel millage?

Before (stock) I was getting 100-120 miles per tank.

What you guys are getting? What else can I check, because I can't go on big trips. Need to do atleast 100 miles per tank minimum.

Thank you

 

[tko47]

well my stage 2 apex is not alot better about the same although I just had some work done at Ulmers like he installed a BOV and he did some other fuel work it runs spectacular but I haven't gone to far to check milaege, give a better report after this weekend....

 

[millstreet]

BOV is supposed to help with fuel economy, although I can't get mine to run properly with it installed. Mine's a pig also - 70-80 miles/tank - might be a thumb problem though

Good Luck

 

[Yummy]

Thank you for replying.

Forgot to mention, but I have a BOV.

I been reading Turbo/SC articles for the past three years on TY before making the jump in the boost world. I never reed that fuel consumption was that high. I guess Turbo/SC sledders do not go on big trips or carry spare fuel on theirs backpacks.

Not sure what will be my next move #%$@%$!@

 

[kinger]

I always read around 100-110 miles on a tank with a stage 1 carbed sled and worse then that on a Apex, your running a stage 3 blower which is significantly larger. What BOV are you running? I would think you need to be at vacumn when running down the trail say on "cruise". That is why the Vortec is so highly reguarded it comes on with very little amount of vacumn, ie light throttle going say 50-80mph but not in boost.

 

[Anonymous]

We are currently working on a set up to control the boost on high boost aplications with our prologger with a bov. In testing we are seeing better mpg,lower intake temps,drives better. If you guys have any more questions please call me 888-649-4609 ext 121, thanks skyler

 

[Yummy]

I understand I'm running stage III, but I have two air deviation valve, so I can run the stage III at only 10psi --- like a stage I. Yes Yes I know I'm wasting a lots of CFM......

Is the Stage III harder to turn than a stage I at the chank? I would imagine a bit harder but not much. I remember reading that running S/C take away some HP...I believe it was something like 20HP, I imagine that is at WOT. Not sure how much HP a SC is eating away when cruising??

While in cruising mode at 7500 rpm, the speedo is showing 65mph, the boost gauge is at 3 psi, the Gem controller is showing 1 green light and I'm getting 14.5-16.0 at the A/F.

I'm not sure of the make of my BOV. Are you saying that when cruising they should be no boost at all. I though that was possible on turbo but not on SC.

 

[millstreet]

Are you taking a boost reading from the intercooler? If so, it will read higher than what the engine actually sees. I take a reading from between the carbs and the head - it's quite a bit different from the intercooler #s. You can ride it and keep it in the vacuum side (not much fun) although you still have the parasitic drag of turning the SC. Slowing down - riding in the vacuum range should(will) help with fuel economy, and get you home with lower octane fuel if necessary.

 

[mulot30th]

I understand I'm running stage III, but I have two air deviation valve, so I can run the stage III at only 10psi --- like a stage I. Yes Yes I know I'm wasting a lots of CFM......

Is the Stage III harder to turn than a stage I at the chank? I would imagine a bit harder but not much. I remember reading that running S/C take away some HP...I believe it was something like 20HP, I imagine that is at WOT. Not sure how much HP a SC is eating away when cruising??

While in cruising mode at 7500 rpm, the speedo is showing 65mph, the boost gauge is at 3 psi, the Gem controller is showing 1 green light and I'm getting 14.5-16.0 at the A/F.

I'm not sure of the make of my BOV. Are you saying that when cruising they should be no boost at all. I though that was possible on turbo but not on SC.

You run a stage III at... 10 psi?

What gears are you running?

On 1-1 gear ration I get 16 psi boost with the bypass valve fully open.

 

[Yummy]

No, it's connected at the ICS. I don't see myself driving it on Vacuum...
That would be NO FUN AT ALL!

 

[Yummy]

I understand I'm running stage III, but I have two air deviation valve, so I can run the stage III at only 10psi --- like a stage I. Yes Yes I know I'm wasting a lots of CFM......

Is the Stage III harder to turn than a stage I at the chank? I would imagine a bit harder but not much. I remember reading that running S/C take away some HP...I believe it was something like 20HP, I imagine that is at WOT. Not sure how much HP a SC is eating away when cruising??

While in cruising mode at 7500 rpm, the speedo is showing 65mph, the boost gauge is at 3 psi, the Gem controller is showing 1 green light and I'm getting 14.5-16.0 at the A/F.

I'm not sure of the make of my BOV. Are you saying that when cruising they should be no boost at all. I though that was possible on turbo but not on SC.

You run a stage III at... 10 psi?

What gears are you running?

On 1-1 gear ration I get 16 psi boost with the bypass valve fully open.

Hi MulotTurbo,

I have 2 bypass valves fully open and running 30-28 pulleys. It ain't pretty but run pretty good!

 

[mulot30th]

30 bottom 28 uppper?


or 28 down and 30 upper?


Does not sound too good to me.


I run 27/27 (1 to 1) and single bypass valve fully open, I get 16 psi.. fully closed I get 20 psi

I can't imagine it going much lower than 12-13 psi even with two valves fully opened.

I take my boost signal BEHIND the TB btw... so boost would be even higher in intercooler.

 

[Yummy]

30 bottom 28 uppper.

Sorry about not being a pro, but that was I have. I'm not complaning about performance..Just fuel consumption.

How many miles do you do on a full tank?

 

[mulot30th]

With the same gearing as you have my stage3 mpi blower push nearly 25 psi....

There is something I really don't understand there....

 

[Ted Jannetty]

30 bottom 28 uppper.

Sorry about not being a pro, but that was I have. I'm not complaning about performance..Just fuel consumption.

How many miles do you do on a full tank?

Flip the pulleys to slow the blower down a bit you have way more blower than you need for what your doing.