high boost in 4th?

[embler]

put in a mbc and set it to about 17#. holds good in first through third. does spike a hair. when I get into 4th, it'll go right up to 20# and when it does, it feels like it bogs down. any idea why? I'd like to see at least 17 or 18#. with the bcs hooked up, it'll only do around 13 to 14 in premium.

[embler]

fuel pressure is fine, have 93 octane in the tank. I don't have the problem until 4th gear when it spikes to 20# forgot to add, it is an ihi, maybe at 20# its just out of steam. don't want it to run at 20, just around 17 or 18

[SVOeric]

Trying to help, and you're getting grumpy....
You REALLY think that gas in your tank is 93 octane ?
and you know the fuel pressure is fine how?

far as it only hapening in 4th, do you think it might be load related ? (we do)

[embler]

Trying to help, and you're getting grumpy....
You REALLY think that gas in your tank is 93 octane ?
and you know the fuel pressure is fine how?

far as it only hapening in 4th, do you think it might be load related ? (we do)

how am I getting grumpy? lol. I have a fuel pressure gauge on it. hope its 93 octane or more since I fill up with it 93 octane and added a couple gallons of 100 octane to it also (i have a station close by that sells it). how does fuel pressure and/or octane affect boost pressure? not trying to be grumpy, just trying to understand. these 2.3t's are still new to me and I'm learning new stuff all the time.

[SVOeric]

Can you read your fuel pressure gauge while the car is under boost ?

That 100 octane, Are you sure it's unleaded ? leaded fuel will kill your oxygen sensor.
Fuel quality is a real pain for me, There's really only one station in town I can relilabily get something close to 93 octane... most of the time, it's crap.

I read it as grumpy because you say the fuel pressure is fine. Do you know what 'fine' fuel pressure is?

[embler]

Can you read your fuel pressure gauge while the car is under boost ?

That 100 octane, Are you sure it's unleaded ? leaded fuel will kill your oxygen sensor.
Fuel quality is a real pain for me, There's really only one station in town I can relilabily get something close to 93 octane... most of the time, it's crap.

I read it as grumpy because you say the fuel pressure is fine. Do you know what 'fine' fuel pressure is?

yeah, its 100 octane unleaded. I can get 116 but its leaded and super expensive. one benefit of living in nc around all the race shops and tracks. I taped the gauge to the windshield. I do have a holley afpr. I have it set at 41 with the vac disconnected. I was seeing about 60 psi at 15# and saw it go up to about 64 when it hit 20#. as soon as it hit 20 and bogged (not in it even a second) I lifted.