Turbocharged 4.0's
10-28-2011, 12:53 PM
#78
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Year: 1993
Model: Cherokee
Engine: 4.0
i might get an fmu for a basic tune because i cant afford any type of computer or anything right now. so i was asking what are people's opinoins on running an fmu?
10-28-2011, 06:16 PM
#80
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Model: Cherokee
Checking in to say hi: So Hi!
I see alot of questions and answeres being brought up. So I thought to check in and give you the details of my set up.
(YEAS I know its a YJ, but its the same motor we all run. . )
So: I did start out with just a basic 2 BAR MAP sensor, Adjustable FPR from Hesco, 30lb injectors.
I also run and MSD BTM. (Its a box that can pull timing out as you transition into boost) I use it on extremely hot days or when I cannot get premium fuel, OR if I get a hint detonation. Lately, I have not needed to use it. More on this later.
So I started with the basic 2 bar, but then it failed on me after 18 months of use. Rig started running stupid rich and no power. Before this, I was making good power, 8 lbs boost, with a bit of detonation. Reason for the MSD BTM. kept it under control.
Then I went to a PSC1-002 from split second, Installed a AEM wideband, and gained about another 20 HP. I was averaging 13.2:1 AFR @ 4k+ RPM @ 8 lbs boost. Also running cold spark plugs, gapped to .028". All problems gone at this time.(so I thought
)
Then I started destroying coils. Had to upgrade to a MSD unit due to higher spark demands from smaller gap.(this also controls detonation)
I see alot of questions and answeres being brought up. So I thought to check in and give you the details of my set up.
(YEAS I know its a YJ, but its the same motor we all run. . )
So: I did start out with just a basic 2 BAR MAP sensor, Adjustable FPR from Hesco, 30lb injectors.
I also run and MSD BTM. (Its a box that can pull timing out as you transition into boost) I use it on extremely hot days or when I cannot get premium fuel, OR if I get a hint detonation. Lately, I have not needed to use it. More on this later.
So I started with the basic 2 bar, but then it failed on me after 18 months of use. Rig started running stupid rich and no power. Before this, I was making good power, 8 lbs boost, with a bit of detonation. Reason for the MSD BTM. kept it under control.
Then I went to a PSC1-002 from split second, Installed a AEM wideband, and gained about another 20 HP. I was averaging 13.2:1 AFR @ 4k+ RPM @ 8 lbs boost. Also running cold spark plugs, gapped to .028". All problems gone at this time.(so I thought
)Then I started destroying coils. Had to upgrade to a MSD unit due to higher spark demands from smaller gap.(this also controls detonation)
10-28-2011, 06:23 PM
#82
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Model: Cherokee
So at the current time:
I have a solid tune. It runs safely. I don't have to use the BTM. With my small 35" tires, I can roast em from 1st gear all the way THROUGH 3rd gear and I chip em going into 4th(AX-15 trans)!
I maintain a solid 12.8 AFR at 8.5 lbs of boost all the way to 5000 RPM( I don't go above that)
Full boost will come on at 1900 RPM. Boost will begin as low as 1100 RPM
I run premium 93 octane fuel
I get 5 MPG
When running around town on 40's. It will move with authority with no issues. Its not muscle car fast on 40's, but will move. But when I put the 35's on. . watch out!!
Gearing is 5.38's in the axles running DANA 60's
Hope this info helps you all out.
I have a solid tune. It runs safely. I don't have to use the BTM. With my small 35" tires, I can roast em from 1st gear all the way THROUGH 3rd gear and I chip em going into 4th(AX-15 trans)!
I maintain a solid 12.8 AFR at 8.5 lbs of boost all the way to 5000 RPM( I don't go above that)
Full boost will come on at 1900 RPM. Boost will begin as low as 1100 RPM
I run premium 93 octane fuel
I get 5 MPG
When running around town on 40's. It will move with authority with no issues. Its not muscle car fast on 40's, but will move. But when I put the 35's on. . watch out!!
Gearing is 5.38's in the axles running DANA 60's
Hope this info helps you all out.
10-28-2011, 06:25 PM
#83
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Yeap yeap! Im thinking of changing the tune at idle. trying to get in the 13:1 range. It sucks on the trail crawling seeing 10:1 all the time. Thats at 13 in/hg range at idle.
10-29-2011, 12:11 AM
#84
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Year: 1993
Model: Cherokee
Engine: 4.0
smokeing the tires? geez, mines no where near that and i have 31"s...somethings wrong. i dont spool till about 3000rpms, and it doesnt really pull that hard, dont got any boost leaks or exhaust leaks, i think it my managment. today after work it was cold, and i started the xj, and went to leave and it nearly stalled out, its better once it warms up, but i think its just too rich. should i get the split sec psc1001 or an apexi safc? i dont got much money...maybe the cheaper 5 **** apexi afc?
10-02-2012, 11:30 AM
#85
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Year: 1998
Model: Cherokee
Engine: 4.0 I6 torque monster w/ a supercharger
10-02-2012, 11:44 AM
#87
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Year: 1998
Model: Cherokee
Engine: 4.0 I6 torque monster w/ a supercharger
10-03-2012, 08:06 AM
#90
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Year: 1993
Model: Cherokee
Engine: 4.0
Originally Posted by bpas328xi
Haha. Whoopsie. Guess this wasn't the thread the OP was talking about in my build. LOL.