^ you seem to know a little bit yourself

 

check this: http://naxja.org/forum/showthread.php?t=1031285

 

yeah, he sure did a solid job. too bad its an auto...

 

excuse me, but I ran one on a car I did at work years back, tied it into the stock ecm. I used to modify engines as part of my job. Machine shop/race for dirt track. we were playing with 300+hp 2.3 ford motors. Fun stuff. Yes, I only say what to do, I don't give facts. READ THE SIG.

Apexi is good, however when we tried tuning with it we ran into glitches, not bashing them just our experience in what we were trying to accomplish.

small turbo=fast spool= more power for the low end.

in the shop we got 1700Hp or so running a smallish turbo with a big turbo after it. Diesel Cummings, pulling tractor.

YOU ARE LIMITED BY THE V.E. ANYWAY in the 4.0 why bother

 

Limited to what? Lol

 

volumetric efficiency of the engine. how much air the engine pumps. Thats all an engine is a giant air pump, the more air in and out, higher VE more power possable

basic of basic engine modification jargon

 

I know what it means. Don't patronize me.

But you say its limited, which its not.

A lot of power can still be made on a low ve engine when you're talking about forced induction.

 

Got a 88 turbo coupe, those 2.3 fords can handle a CRAP load of power.

 

I built a few boosted m20 strokers, a m50 turbo and an stroker m50 turbo (both with and with out vanos) done a few things nothing fancy

 

you where letting the megasquirt run the fuel and letting your stock ECU run the timing? you must have not heared about the megaspark add on...

 

I have to chime in. I've been researching turbo information a bit, cuz I have one I plan on putting in my jeep. I will know a lot more when it's done! What I do know is you definitely need to upgrade your injectors and figure out some way to manage injection pulse and timing. For all the sensors going into the computer, those are the most pertinent outputs. My jeep is a RENIX so it has a knock sensor, which may come in handy to keep me from burning it down. The turbo kits available are about 4 grand, I figure I can do mine for under 1000.
My big plan is to build my own header and come out to the side more so the turbo isn't hanging under my engine. After that, a positive pressure sensor to replace the map and something to trick the ECM to give the right pulses to the injectors. You can actually make a manual device with a variable resistor to control the timing and injectors. Not as high speed as having a chip but it might work. I will definitely make a thread when I get going on that little project.

 

I still don't get why people want to turbo charge the XJ. Why not centrifugal supercharge it? The necessary complexity of the exhaust, wastegate, turbo placement, etc... is just unnecessary for this vehicle. Not to mention the stacked manifolds. If anyone ever wants to supercharge one, give me a shout. I am a Rotrex OEM and although I can't offer you a warranty I CAN beat any and all competitive pricing. Once I get the time I will undoubtedly go that route.


I do love how the guy who boosted his on NAXJA used a water cooler. That IS the way to go if you got the FI route.



Nice! I love a boosted bimmer. My experience is with RWD imports. Currently I own and operate a 500hp 2.0L 240sx that I built for drifting. boost is addictive and so the XJ, although it doesn't really need it, will get FI at some point. Suspension and gearing is the priority for mine at the moment.

 

Its cummins, was it the 5.9 or the 6.7? What did you do to it to get 1700HP.

I have one

 

Id love to know that also, if I did that much work to a motor, id know how to spell it

 

Exactly, I have a 6.7 with about 7 grand into it, and its not pushing near 1kHP yet. 682 hp and 1307 ft/lbs.


Airdog fuel system, s&b intake, 90hp injector nozzles, modified CP3 injection pump, arp head studs, tune from h&s performance, htt mani and a sb66. Also have a DPF delete, cat delete and a EGR block.

Its not as easy as it sounds to get a cummins to 1kHP.