remove the speed/rpm limiter and lighten up

[Spliffotticle]

I am SLOWLY closing in on my WJ project. Removing the speed limiter is obviously my first topic in this post to address. Also, what is the highest STABLE rpm increase that any low buck strokers have seen? I'd like to see a limit @ 7k. I almost dread reading the replies to this post, expecting everything from "Why would you want to go that fast in a WJ?" to "If Jeep wanted the limit higher, it would be". This IS the Jeep MODDING forum, right?
I'm assuming Hypertech Power Programmer III 50012 will allow these things. Anyone use it? It breathes so well, I think it will handle a little more. It hits the rev limit faster than any jeep engine I have ever seen periodddddd. I'm cutting weight everywhere I can and dropping the body a little but having bags to raise it if need be. Looking @ C5 Corvette magnesium rims. ordered aluminum rotor hats for composite brakes (front anyway). I'm interested in what else can be done to lose weight. Are aluminum control arms an option outside of fabrication? I don't plan on off-roading it. I'm already fabbing a new rear axle mount support thingie out of aluminum. ANY WORD ON THESE ALUMINUM BLOCKS? I'm ready to see aluminum everything; block, head, pan and cover. Are there any forged aluminum rods? They are coming out with stronger alloys every day. I'd like to be casting custom valve covers and pans next year. I have easy access to a cnc machine so I can put any design in the sand molds I want. My first casting will be one that says "Stroker" maybe in a sexy font Messing with an old porsche, I was also inspired to cast an oil pan with heat sink fins. Maybe next year we will all have custom stroker covers and pans

[CobraMarty]

IIRC the 4.0 engine has a bad cam harmonic at 5600rpm. Cam breaking in fact. Having said that, the rpm limit and the speed/mph limit can be changed in the ecu by christunned.

How about a cast larger capacity/deeper, finned AW15 trans oil pan. With drain plug and hole for temp sensor.

How far are you willing to go on the 'removing weight'? Remove interior, rear seat, passenger seat, spare tire? AC bypass/removal, HESCO alumn head -30lbs for $2000. It gets expensive fast.

[SilverXJ]

I wouldn't touch a hypertech is someone gave it to me. Biggest waste of money I have ever spent.

Get a retune by christune. Don't increase the rev limiter as there is a cam harmonic. While it hasn't broken a cam that I know of it will damage bearings and snap timing chains.

No aluminum block. Solid axle suspensions don't lend them selves well to air bags, especially the front where the track bar will move the axle left and right. I have seen a company that was working on aluminum control arms for TJs IIRC, but never saw a production arm.

[Spliffotticle]

In order, my truck has a bit of a shake between 50-60. smooth before and after. Makes me wonder (about my Jeep's harmonic situation) if I could get away with not dwelling in that specific rpm range. I couldn't find christuned (so I don't even know what it is...) but if you guys have a link that would be awesome. I also can't find AW15. Will you order it for me and install it too? Let me know when it's done As for willingness to remove weight, spare tire. That's about it aside from hitch and I'm probably going with some kind of lighter gas tank holding setup. I even pondered putting a custom aluminum one in the tier area. And I wand A/C. So, control arms it is. I have been looking @ rectangle stock
@ Silver, I had one for about 30 seconds once but returned it based on not being able to do what I wanted... like anything. But Now all I want is the limiters removed. Surely I can't get that done for less than $220. What didn't it do that you were after? Shift points? That was what did it for me. Also, had an acquaintance get a different tuner (not hypertech) and it kept the VIN lock on a micro sd card and he just erased it and was ALLEGEDLY ably to upload tunes into whatever from that point. I'm kinda curious for the dissection

[SilverXJ]

In order, my truck has a bit of a shake between 50-60. smooth before and after. Makes me wonder (about my Jeep's harmonic situation) if I could get away with not dwelling in that specific rpm range.

if its speed related its something in axle/axle shafts/tires. Being that its is at that specific speed its probably the tires.

I couldn't find christuned (so I don't even know what it is...) but if you guys have a link that would be awesome.

[email protected]

I also can't find AW15.

As for willingness to remove weight, spare tire. That's about it aside from hitch and I'm probably going with some kind of lighter gas tank holding setup.

IIRC the WJ gask tank has a bit of a skid over it. I don't know if that skid holds it in place as well or not. If not, then remove it, but I wouldn't given how low it hangs. Also, some WJs came with a thinner skid than others.

But Now all I want is the limiters removed. Surely I can't get that done for less than $220.

Don't bet on it. I would not remove the rev limiter. to begin with. Removing the speed limiter is neat, but really, when you would you go above 120 mph. If al you want to do is remove the limiters don't. Your wallet and engine wil thank you. Better spent elsewhere.

What didn't it do that you were after?

It made no difference in anything aside from making the engine ping. Sold it and got an apexi instead. It wouldn't touch the shift points as that is controlled by a seperate module on the XJ, TCM. However that brings up a good point. Your 42RE (I believe the RE stands for retarded) is controlled by the PCM, not a TCM, even more reason for a retune if you want to change the shift points and other stuff.

[superstingray77]

superchips=crap

Silver... can you point me in the direction of more info on this cam harmonic deal? Would my fully balanced and built engine with the Lunati cam still have the same harmonic? I dont Usually push mine anywhere over 5k but my combo pulls hard and has a peak near 6100....

[Spliffotticle]

lmao @ re = retarded
but in response to:
"Don't bet on it. I would not remove the rev limiter. to begin with. Removing the speed limiter is neat, but really, when you would you go above 120 mph. If al you want to do is remove the limiters don't. Your wallet and engine wil thank you. Better spent elsewhere."

On the strip of course. That is really the whole point of this project. An attempt to answer the newer SRT8 with the classic, beloved straight 6. No ridiculously expensive forged things. Simple mods combined with good math that can make a daily driver more fun. I am really pressing for a 10 second WJ. I think it can be done with between 4-500 hp (based on the weight and drag coefficient) which is all I am trying to make. I just want(ed?) to make it in the rpm range that is the worst harmonically apparently. I wonder if aftermarket cams have the same balance issues or if it was just whatever came from Chrysler. I have a comp something or other. This will be the third jeep 6 I have blown. First two were bought that way (XJ and WJ) and took a lickin before flying apart.

[gradon]

My experience to date:
Jet2 in 94=awesome
Jet2 in 96=meh
Hypertech 50012 in 96: +500rpm redline didn't work, unsure of 128/+12mph topspeed, chose 93 octane tune and had full tank of 93 octane=pings and CELs. OK, chose lesser 87 octane tune with tank still full of 93 octane=pings and CELs. So the programmer didn't work on my 4.0l 96--the good thing was that it was able to reset the codes it caused and revert to stock tune. Sold it ASAP.
I have a vehicle speed sensor kill switch that lets me get past the 116 stock limiter and a couple years ago I took it up to 136mph(brother paced me on YZF-600). Now it is has a stripped interior save for passenger seat and it weighs in the high 2900s.