A couple of questions for the force-fed guys...

[XJRocket]

Hi I am new here. I am buying a 1995 xj country. This is not my first jeep, as I had a 78 CJ 304. I waqnt this one to be a street performance SUV as I need a daily driver and I have a trail only rig. My XJ has the np 242 t-case and aw4 tranny. MY question is this. I am designing a low cost intercooled supercharger kit for it. I have made kits for other vehicles that were mass-air vehicles. I have never made one for a speed density setup. I plan on using a fmu to enrich the fuel supply. How did you guys enrich your setups? I am interested in what ratio of fmu you used. also, I am curious if there is a way to make the computer enrich the setup rather than using an fmu. Is there a way to use a different map sensor and injectors? Will the computer compensate? I know I could play with it and find out, I just thought hat perhaps those of you that had force-fed your 4.0s may have a bit of advice that will save me time and money.

also, do you think that the aw4 will survive the blower? If not, do you know of a tranny upgrade? I know alot about chevys, fords and mopars, but not so much about late model jeeps. I have an amc pattern th400 I was thinking could be adapted with a chevy tailshaft and a syclone t-case. As for the rest of the drivetrain I have a Versaillies disc brake nine inch and a set of seventeen inch mustang gt wheels and Cobra front brakes I want to use.

Does this sound like a viable recipe for a haul-a$$ xj? I would appreciate any info you guys have for me.

P.S. I did search.

Thanks, Arin

 

[JJacobs]

Welcome to the forums.

I think you'd probably do alright with a 2 bar map sensor and a boost referenced pressure regulator but I haven't actually done this with a 4.0.

Some friends of mine just came out with a wideband tuner/ boost controller that will piggyback onto the stock ECU and control the A/F ratios to your target specs. www.advancedinjectiontechnologies.com I hope I don't get in trouble for pimping their product.. however it does have new capabilities that nothing else on the market can do, I'm just spreading the word.

As for the AW4, it'll probably hold up just fine. I raced my MJ for a season with the AW4 holding 380 rwhp, and it did start to slip some. I don't know the history of that trans though, it probably had 150K before I got it.

 

[XJRocket]

where would I get the map sensor? is there a part number?

Thanks

 

[87manche]

might want to build a map sensor adjuster. The stroker guys could help you out with adjusting the mixture. take's about $10 in parts and a soldering iron. I'm doing the research for a stroker, but haven't really done any of it yet, so all I can do is give you my bookmarked link.
http://www.angelfire.com/my/fan/MAP_adjuster.html
The AW4 is super stout, same trans used behind twin turbo supras and such.

 

[db209_2000]

also, do you think that the aw4 will survive the blower?

Toyota used the AW4 in some of the cars 87manche mentioned, and behind some of their V8 light trucks. It's pretty bullet proof, except for the 300 some odd dollar range sensor. I've lost track of how many Jeeps I've failed for inspections because their backup lights were inop. I'm glad mines an AX15, it's backup light switch is only $25.

 

[czb83]

Toyota used the AW4 in some of the cars 87manche mentioned, and behind some of their V8 light trucks. It's pretty bullet proof, except for the 300 some odd dollar range sensor. I've lost track of how many Jeeps I've failed for inspections because their backup lights were inop. I'm glad mines an AX15, it's backup light switch is only $25.

I've had that happen to my cherokee. A simple cleaning of it fixed the problem years ago, hasn't happened again. This would probably do for most cases.

 

[5-90]

Toyota did use the AW4 behind the turbo six in the Supra - so as long as you're not getting too nuts, it should be fine.

The 2-bar MAP should be available from Jeg's or Summit - but if neither of those pan out, Google "Marren Fuel Injection" (injector.com, I'm inclined to think,) since I know they have it - and for not too many $$$. About $50, IIRC.

5-90

 

[XJRocket]

Thank you for that. Ok so I have a 2 bar map sensor. Now, how do I get the computer to understand that it is talking to a 2 bar map sensor rather than a 1 bar map sensor when they have identical voltage ranges of 1-5 volts? Maybe up the injector size or lower the fuel pressure? am I even on the right track?

My thinking is this. A 1 bar map sensor at zero vacuum or standard sea level atmospheric pressure should read 5 volts. A 2 bar map sensor at the same pressure level would only be 2.5 volts. The stock injectors are 19lb/hour, right? So if I installed 38 lb/hr injectors with the 2 bar map sensor in theory the computer should supply the same amount of fuel as the stock setup. right?

I have had way too many beers to be thinking this hard on a saturday night.

 

[Cjmartz2k]

MMMMMMM...... Beer........

We aren't allowed any alchohol here:rattle:

 

[XJRocket]

MMMMMMM...... Beer........

We aren't allowed any alchohol here:rattle:

Now that is a travesty. Put your ass on the line and can't even enjoy a frosty barley pop.

I'll just have to drink one for ya man.

 

[XJRocket]

Does a XJ use a Bosch style map? I haven't memorized who makes what on an XJ yet. By that I mean like on my CJ7 I had a starter off a SBF, distributor cap and wires off a 460 ford, PS pump off a chevy, ignition module from a granada, Chevy alternator, TH400 tranny, etc. Most of the parts were made by someone else for AMC. I figure the XJ is probably the same. I already know it has a chebby steering column.

 

[5-90]

It uses a Chevvy style MAP - I don't recall if that's a Bosch sensor or not, but I think most Chevvy parts were made/designed by Bosch. I'd have to do some more digging to be sure, and I may not have that book.

Most of the RENIX AFR management sensors were GM - as has been said, AMC saw no need to "reinvent the wheel" - they just designed engines and chassis. The later sensors may have been GM - I think ChryCo used a lot of GM parts as well.

5-90

 

[Cjmartz2k]

I'll just have to drink one for ya man.

Thanks!! We are sitting here working airplanes watching the superbowl over the internet--but at least we get to see it, eh? BOO STEELERS!!!

 

[XJRocket]

Yeah go hawks!

 

[Cjmartz2k]

Funny, we are giving updates to the airplanes flying through our airspace on the game.