Good twin-turbos for 4.0L/stroker?

[Dr. Dyno]

1 turbo should be enough......psshaw heat just put the turbo outside

That's fine until it rains. Then the contact of cool rain with a glowing hot turbo will result in cracked turbo housing and expensive damage. Not a good idea unless you only drive the Jeep on sunny days.

 

[olympicgold]

it rains very little down here.....I could have easily kept the turbo under the hood by simply making the turbo mount tube a little shorter but I chose not to.

after looking around under the hood I think the best place for turbo would be on the driver side right where mine is except under the hood. If anybody thinks the ecu getting hot is a prob you could relocate it....I would not place the turbo on the manifold since our engine also has the intake manifold on the same side and would create far to much heat causing "hotter" intake temps <detonation> sure detonation could be worked around with a little tuning by retarding timing a little but then you wouldnt be making the power that you "should" be making. I would not recommend header wrap if you plan on doing any offroading in the water(river crossing,beach) because it'll pretty much trash your headers with rust...I personally experienced this on my previous setup. A form of heat shield would probably help with lowering the temps a little but I get the feeling it'll create an "oven" effect by simply holding all the extreme temps of the turbo.
It could probably also be placed on the passenger side by relocating the battery. To remedy partial turbo lag from the further location a smaller crossover tube could be used like 2-2.25" to keep exhaust velocity and temps high.

 

[jbeoughe]

Trust me, I understand what's at work. To spin the compressor, the impeller uses the heat from the car's exhaust. In the process of compressing the air, it is heated up as well. This is Boyle's law (PV=nRT, aka "Pivnert").

This is the ideal gas law, not Boyle's Law. Boyle's law states that pv=k, which means pressure times volume equals a constant at a constant temperature.

The turbos do not run off of the heat from the exhaust, they run off of the kinetic energy of the exhaust moving the turbine as it is being pushed out of the engine by the piston. Kinetic energy=mass times velocity^2 and has nothing to do with heat.

 

[Purple]

do you offroad that vehicle? or is it just for show?

 

[ROBZ95Xj]

How much HP does that beast have?

 

[BrettM]

Jose! you got it finished! looks awesome!

I recognize that knob you still liking the shifter? I finished the auto/manual version, email me.

do you offroad that vehicle? or is it just for show?

He sent me video of him dirt drag racing, that was before the turbo.

 

[olympicgold]

I still think the shifter is awesome.....I'm now going to bump up my shift points to about 5K and whenever I get a dyno run probably average out a good shift point. I still havent purchased the trans oil cooler but will probably be doing so within the next month or so......hey Brett did you see the blue switch next to the shifter knob??? turns on power to the trans for launching.....brake the engine in the switches' off position accelerate to about 3-4K rpm and when the light turns green BAM!! turn the switch on and go. I'm probably going to have to work on beefing up the drivetrain first before I try any launches above 3K. In the sand you wont break stuff as easy since you'll probably just spin....usually big tires/paddle tires and lockers will start breaking stuff under hard launches.
The XJ was down for about 3 weeks cuz I blew a headgasket but its been back on the road now for about a week,now with beefed up headbolts a severe duty headgasket and ported and polished head. So far from what my butt tells me the XJ is back with a vengeance!!! : )
I'm staying off of boost right now because when I blew the headgasket my wideband 02 sensor went along with it so I have no idea what my A/F is. I'm running a slightly modified tune from my turbo TJ setup so I shouldnt be to far off but better safe than sorry.
It was a daily driven XJ until I started the turbo project since then its just been parked......its ultimate goal is for sand drag racing and sand hill climbing with occasional trips to the beach.I want to build up some tube doors and go doorless for racing that alone should free up a few pounds. I'm not sure what HP #'s I have now but I'm hoping for at least 350 BHP out of the stock bottom end once all tuning has been done. Theres a few local turbo guys running turbos and all are running 12+ psi 2 have forged and stroked bottom ends and the other has a stock bottom end with 12 psi. I'm thinking 12psi should yield about 330-350 bhp on an "efficiently" intercooled setup of course as the engines VE improves that number would increase as well allowing the use of less boost and still make that power.

 

[krakhedd]

Wow man, that's a wild setup!

I wondered about the water/turbine housing thing, I figured a good ceramic coating would be able to protect the turbo - am I wrong to think this? Should I start making plans to mount the turbo above the hood, instead of closer to the exhaust? Is there any other way to keep the turbo safe from warping/cracking apart from encasing it in a "box"?

I guess if the water is as high as the turbo, my main concern should be getting air into the motor instead of water......