Tuning Experts Come In - I Need Your Help!!!

[Bigdough666]

Alright, im gettin my car ready for TX2K6 this weekend so Im turning up the boost and tuning it with my AFC.

Ive got a full fuel system - Lex AFM, 550s, Walbro, Aeromotive AFPR. Im have the boost set ~21 psi on my 60-1 CT and Im hittin fuel cut around 4500 RPMs.

So, how can I, if I can, tune around this fuel cut. Fuel pressure is at about 30 psi at idle, and Ive taken 6% out across the board in the high throttle map on the AFC. Its gotten a lil better, but I need it to be gone, or at least up around 6200+ so I can shift out at around 6000 RPMs and not hit fuel cut. Do I need to lower the boost a bit, say 17-18 psi, or can I tune it at 21? Id like to keep it at 21, so help me if you can.

Thanks in advance. :bigthumb:

 

[suprahero]

This is not an educated answer and you may not want to hear it. I thought that you had to turn the boost down to get around it. I have the lexus afm, etc. and I'm running 12.5 without fuel cut. I think I read somewhere that you would hit it around 18 pounds. If you can run 21 that would be awesome. Maybe some of the smart people around here can help you. How much horsepower are you running on your car now? I just had mine dynod at 317 rwhp with 12.5 lbs. of boost. If you supposedly get 11 hp per 1 lb of boost that would put me at over 400 hp. More than likely it would put me in the shop on blocks replacing a motor. Goodluck Bigdough. Hope you get it tuned right. I also read on here that the maft pro helps get rid of fuel cut. Sorry for the long post and useless info, wish I knew as much as other guys on here but I don't....lol

 

[dbsupra90]

no matter what you do, you want to do it w/ a wideband. whether that be on a dyno or in car.
easy thing first- where is your bypass screw on the afm? if you didnt already, you can drill out the cap over the stock screw and adjust it out for more unmetered air. what i found out is if you drill a hole in the cap just big enough to fit a screwdriver in there but leaving the cap intact you can back out the screw as far as you want w/o the fear of it falling out.
next- you can take more % out on the afc. to counteract that you raise your base fuel pressure. this will keep your a/f the same if you get the right balance of - % and + fuel pressure.
again, please do this w/ the wideband for safety.
i was able to run 18psi on my ct upgrade and never hit fuel cut w/ a similar setup and eric was able to run 25psi+ on a t66/lex/afc.

good luck

dave

 

[Bigdough666]

Yea, Im tuning with a wideband.

The screw on my Lex AFM is backed almost all the way out.

I dont really want to turn down the boost, im tryin to tune with the AFC to get raise the fuel cut outta my way.

Any idea on what my base fuel pressure should be? And about how much should I be lookin to take out with the AFC as far as %??

Like I said, right now the base FP is 30 with vac on, and Ive taken 6% out across the board.

 

[tissimo]

Pull the vac off your fuel pressure regulator and see what its set at.. stock is ~43.. you can raise it some.. but remember.. say 50 base fp + 21 = 71 psi at the rail at full boost.. make sure pump is in good condition..

Your out of room, you cant really do anything about it cept raise the fuel pressure a little bit and see if you can get away w/ that..

 

[Bigdough666]

anyone else?