99+ Intake Manifold & Unichip Mods w. Dyno Results

[Comanche91]

Just got back from Hesco regarding the slight stumbling I had w. the Unichip when the AW4 was lugging under load in O/D at around 2000 RPM as they are prone to do. They leaned the Unichip out in the 1950-2100 RPM range and left the rest of the RPM band as is. Nice you can do that w. the Unichip instead of just retarding or advancing the timing for the whole RPM range. All's golden now.

Regarding mileage: have run three tankfuls thru since the intake manifold and Unichip, and have averaged 16.5 city, 20 highway. That's an improvement of about 1.5 MPG overall with my foot in it as usual most of the time.

[John]

That's pretty good gas mileage, What do you think it would do if you came in off the hood....
John

[Comanche91]

That's pretty good gas mileage, What do you think it would do if you came in off the hood.... John

Good question John. When I first put the stroker in almost fours years ago, mileage was around 13/17. I attributed this to the usual new engine pre-breakin crappy readings. After breaking in, it went up to about 14/18, and basically stayed that way until I swapped diff gears (3.55 to 4.11) a couple of years ago. I had 31" tires all along. The gear change (and a calibrated speedo) improved the mileage about 2 MPG across the board, due to the higher overall and I think more efficient RPM when cruising. I think if I kept it at 2400-2600 RPM max and accelerated gently, it would do over 20 MPG highway. But who wants to do that?

[John]

Not me!!!! On the hood and on the pipe is the stuff smiles are made of. What is this chrome thing you list in your signature.
John

[SilverXJ]

Off the hood? On the pipe? WTF??

Anyhow, going from 3.55s to 4.11s on 31" tires really made that big of difference in mileage?

[Comanche91]

What is this chrome thing you list in your signature.
John

Lol. Starts here:



Ends here:

[Comanche91]

Anyhow, going from 3.55s to 4.11s on 31" tires really made that big of difference in mileage?

Yes. The gears got me back to close to the original final drive ratios w. the 225 x 75 tires, albeit at a more efficient higher RPM than stock. Regearing mostly eliminated the AW4 "seeking gears" going up long grades, and the 2000 RPM AW4 O/D common bog downs in traffic. To completely get rid of the unwanted shifting, I'm working on adapting an electronic manual AW4 shifter to control the solenoids. It's based on the GM Hydra-Matic 4T65-E four-speed automatic transmission manual shifter found in Chevy Malibu SS models, and others. I have the parts that I need, am now working on cosmetics so I can keep my OEM column shift and toggle between the two when I want it. Work in progress...........

[John]

Nice, they don't fare so well here in the rust belt.
John

[Muad'Dib]

The chrome looks good IMO.

[Comanche91]

The chrome looks good IMO.

Thanks. I just finished putting in some 98 ZJ factory hood vents to help the underhood temps, and I even thought about chroming those; but that would have been overkill.......

[John]

Beautiful truck, chrome em......
John

[Comanche91]

Nice, they don't fare so well here in the rust belt. John

Hey John; WV isn't really part of the rust bet, is it? It can't be as bad as Ohio and points further north, or VT where I'm originally from. It's basically impossible to find a rust-free MJ (or any other Jeep) in these areas. I found my MJ back in 1999 in Brookneal, VA. Bought it from the original owner's daughter for $1K even, and it had 72K miles on the clock. The old gent used it around his farm for light duty hauling. I've completed many modifications on this truck, but dropping in the Hesco stroker crate was the best thing I ever did.

This forum is the best, and I really appreciate the hard work from the sys admins that went into creating it and keep it running smoothly. And the stroker knowledge base who post here are second to none.

[gradon]

Man your ride is clean. I've been meaning to ask why you have 4.5l listed when you had it bored .030" over. And then you have the 4.6l badge. Do you like to puposefully underrate it? Also I've been effin around with the PSC1 and I dig on being able to control the fuel and do my best to get the trims to 0 and WOT to 12.5:1 AFR, but I must say that in the 2 or so years reading about strokers, you have surprised many with what the Unichip was able to tune out of it. I'm always gonna be curious what a little timing here and there can do for my baby.

[John]

"WV isn't really part of the rust bet, is it?"
Here along the Ohio river, cars are white coated in the winter from all the road salt, and summer time high humidity in the river valley makes it hard on vehicles.
John

[Comanche91]

Man your ride is clean. I've been meaning to ask why you have 4.5l listed when you had it bored .030" over. And then you have the 4.6l badge. Do you like to puposefully underrate it? Also I've been effin around with the PSC1 and I dig on being able to control the fuel and do my best to get the trims to 0 and WOT to 12.5:1 AFR, but I must say that in the 2 or so years reading about strokers, you have surprised many with what the Unichip was able to tune out of it. I'm always gonna be curious what a little timing here and there can do for my baby.

The motor was listed by Hesco on my receipt as 4.5L, p/n HES4.5, so I ASSuME it's 4.5L. The 4.6 badge on the tailgate is actually from a Mustang 4.6 Hi-Po (closest I could find).