Jeep Strokers

Hey all,
I thought a 10K update might be in order. I haven't posted for a few months as I lost my business at the beginning of June, been unemployed since. Kinda' changes those "work-in-progress" aspirations. Anyway I did a few things after the "badness" anyway and here's where things are. I went to UniChip in July and had the chip tuning done. The air temps were in the consistent 100's that week. I had also added a water/meth. system a month or so before that and had the pinging under control on 50%/50% mix, but it was still stuttering around 4700-4800 at WOT. When UniChip went through it, the fuel was rich all across the rpm range on the 24LB Ford injectors, so fuel was reduced accordingly. This was with the wa/meth. turned off.
The five position switch that the UniChip uses has the following settings: #1-Three degrees minus timing, my daily driver setting. #2-Two degrees plus timing. #3- Four degrees plus timing. #4-Five degrees minus timing, for regular or bad gas. #5-Same as #1, but with 50% of the original fuel curve added back. When they were dynoing it, the temps were going up to 220-230 and they felt the stock radiator (NEW) was not enough. The tech. also commented that the stock analog gauges might be 10-20 degrees behind actual internal temps and he didn't want to cook the engine. That said, on the #1 position running premium in 100 degree weather it made around 210 WHP, and around 270 WFPT. It was at about 3K miles when this tuning was done. I ran it with about 2.5-3 gallons of 110 octane mixed with 15 gallons of premium on the +4 degree setting at Sand Lake in Oregon in August. Running 12 psi in my 31"s, I climbed everywhere I wanted to go pretty easily and it would slid like a rally car! FUN!!! I'm gonna' contact UniChip and see if I can bring it in for some adjusting though.
Now the weather here in Oregon is in the 20's-40's. I have noticed a few changes. As the temps. began to come down in October, I started to have pinging again under WOT in the #1 switch position! This seems odd since the ambient air temps are lower than when the tuning was done and engine cooling from the stock rad. was likely a little to little. I thought it would run better as the air temps went down. A friend has suggested it might be the denser air combined with the "winter" fuel formulation, making it run a little lean. So I've been running in the -5 position and it still feels mighty strong.
In trying to deal with the temp. stuff, I've been running a 180 degree T-Stat. As it's gotten down in to the 40-50's in the air temps, it runs stumbly when it's cold and the mileage has gone down a bit. I thought about going back to the 195 T-Stat, but the article Dr Dyno just posted suggested that one of the ways of dealing with higher compression is to keep the water temps down around 170. It does come up to around 180-190 when I get on it a bit and then when I'm in around town traffic stays around 180.
Another concern is that it's been using a bit of oil. I talked to the machine shop that built the short block and did the assembly. The machinist commented that if it had been over fueling for a long period of time, it may have had some negative effect on the Moly rings and caused them to wear too quickly and/or not seat properly! Ugggg! I'm doin' an oil change today and will note oil consumption over the next 1k to see. I'm hoping it's just taken a while to seat the rings all the way. I've been using the Comp Cams additive as extra insurance and I'm switching to Brad Penn oil this change. Does the ZDDP in these kill cat. converters? If so, that's a bit of a catch22.
For those considering the Keith Black pistons, they are a bit noisy when cold, but seem fine otherwise. The Lunati cam is still a bit of a noisy cam too. I still think it's the profile and the strong spring pressure. No biggy.
I figured out that with 4:10's and 31"s, I'm about 5% underdriven from stock gearing, so that contributes to it being both quick and getting less than ideal fuel mileage. Oh well. The power is still fun and it's as smooth a stocker otherwise. A good choice and worth the investment.

Keep Jeepin'
crusT

I got gypped--my Unichip only has a two position switch

Hey Gradon,
That's weird. Marinus, who is the sales guy for their North American branch, said "sorry for the cheesy switch" before they did mine. It's pretty plain lookin', but it works fine. How long ago was yours done?

Mine hasn't been custom tuned yet--it currently has a the 4.0 w/ K&N FIPK, all header, and all cat-back tune. I installed it and verified that it works and found that the "1" setting makes my setup ping more than the "0" setting does. I have an 01 XJ that I'm selling in the next 2 weeks and the proceeds will go to the custom tune and some shorter bilsteins. I still need to find a tuner that'll be willing to do it--I'm currently at strike 4 for "Unichip Custom Tuning" shops willing to tune a Jeep(one does only Porsches, one prefers Nissans/Infinitis, and the other two prefer imports). I have this picture in my head of a quirky computer savy guy that is just anxious to see how much power he can tweak out of whatever setup he gets to touch, but have yet to find him. It must be nice to be able to turn $100-175/hr down because you don't feel like soiling your @$$ to sit in a Jeep. Rant over.

Hey Gradon,
What year is your Jeep? It should be relatively easy for them to tune since you haven't changed much. If it's OBD II, that's even easier. Mine was really more of a custom tune that required a lot of stuff set up to get the A/F ratios correct. OBD II uses the O2 sensors to give them all the info they need to adjust the fuel and timing.

crustodd wrote: OBD II uses the O2 sensors to give them all the info they need to adjust the fuel and timing.

Not quite. It only does that in closed loop.

gradon wrote:Mine hasn't been custom tuned yet--it currently has a the 4.0 w/ K&N FIPK, all header, and all cat-back tune. I installed it and verified that it works and found that the "1" setting makes my setup ping more than the "0" setting does. I have an 01 XJ that I'm selling in the next 2 weeks and the proceeds will go to the custom tune and some shorter bilsteins. I still need to find a tuner that'll be willing to do it--I'm currently at strike 4 for "Unichip Custom Tuning" shops willing to tune a Jeep(one does only Porsches, one prefers Nissans/Infinitis, and the other two prefer imports). I have this picture in my head of a quirky computer savy guy that is just anxious to see how much power he can tweak out of whatever setup he gets to touch, but have yet to find him. It must be nice to be able to turn $100-175/hr down because you don't feel like soiling your @$$ to sit in a Jeep. Rant over.

Maybe you should talk to Hesco, they sell you a cable so you can load the tune into the unichip. They email you a tune based on your setup. Since they have done a ton of these they can get close. You can usually get a few pulls for $150, then send hesco the data and they will send you a file. It will take longer but probably end up costing about the same.

I didn't go w/ Hesco in the first place because I would be paying $750 for a tune that wasn't ran on the dyno in my Jeep. With all the different variables such as cams, p&p head, lt1 injectors, exhausts, sensor tolerances, etc, there is no way to correctly tune it unless you do multiple pulls on a dyno and tweak as you go. I'll drive up to one of these shops instead of calling/emailing them and hopefully I'll find that guy. Mine is a 96 obd2 and hopefully the Unichip can intercept the o2 signal and tell the pcm that it's 14.7:1 a little before open loop, when it really is 13.5-14:1, cause that's where mine needs more gas(right when torque is plateauing), or else back off on the timing. If the Unichip can't do anything with closed loop other than zeroing the fuel trims, then I'd rather use the psc1, throw the jet2 in, disco the cts, road tune the whole map myself, and sell the Unichip for the $400 I got it for.