Turbo?

[Cwish]

How hard would it be to set up a turbo running low boost on 4.0l

[4.3LXJ]

You can do it. But the biggest problem is the dual O2 sensors. I think that you would end up running the exhaust to the other side and mounting the turbo there so you don't have to mess with current sensors. You generally can do a half atmosphere on stock systems.

[Cwish]

How hard would it be to set up and what would I need to change for say..5lbs of boost

[LizardRunner]

I'd use a custom header, a small (230 type) turbo housing will keep the boost on the low end (about 7psi) any larger housing would be tougher to fit under the hood plus would require a waste gate. Mostly it will depend on the innards of your motor, most boosted engines have forged pistions, rods and crank. plus you might find you need a different cam profile for best performance. By using a split header and letting only three cylinders drive the turbo, you can reduce the amount of overall boost available, then meet up at a collector before the muffler. That might help keep the O2 sensors in line.

[Cwish]

So you can boost just 3 cylinders?

[4.3LXJ]

No, you have ot boost them all.

[LizardRunner]

the boost goes to all cylinders, the power (exaust to the turbo which drives the inlet side can come from only three cylinders) the inlet side (the part of a turbo that provieds the extra pressure to the intake manifold through a carberator or TPI injection system must "boost" all cylinders. On our 4.0L jeeps with individual port injectors you will have some adjustments to make since the fuel isn't mixed with air untill it is going into the cylinder. Usually the pressurized air is mixed with the fuel then runs down the intake runner and into the cylinder. Any way, if you tried to just add pressurized air and fuel to only three cylinders the engine would have catastrophic failure of the crank shaft and piston/rod.

[default83]

you ever check out those STS turbo setups? they look pretty cool, i would think the lag would suck, but it might be easier setting it up with the space you have.

turbo setups are fairly easy, the only thing is getting the right exhaust setup, as stated. also some sort of fuel management or upgraded injectors/fuel pump would be mandatory i would think. not sure on the size of the stock ones.

[Cwish]

I read that under 5 pounds boost is about the most you want to go on stock engine. I could do better injectors. I really don't want to do a lot to change for turbo. Its just I got a free turbo so I thought ...heck

[4.3LXJ]

I thought that might be the case. I have a couple laying around too. But the first thing you need to do is a lot of research. If this sounds like "hitting the search button", it kind of is. I would recommend going to Barnes and Noble and getting a basic turbo charging book and reading it. One of the things you will learn is that turbos have to be sized for the application. So, for instance, I cannot use my current turbo that came off a 1.8L on my 4.3. But I can use two of them and be OK. There is literally no wrecking yard parts you can use here. This is something that is doable and a good way to get power and good drivability. But it will cost you. And you will not be able to do it without good fab skills.

[Cwish]

Yeah i see I prob won't end up doing just curious

[default83]

its not as bad/hard as it sounds. it requires some fab skills and basic knowledge, but if there is an exhaust shop around you that is decent, they can build a manifold. and with a tune and the right fuel system, i bet you could get 8 psi out of it, depending on the condition of the motor before you turbo it.

but as far as turbo setups for trail/offroad use, its not that great of an idea, motors that werent factory turbo'd tend to have a lot of problems....

[bluedragon436]

you ever check out those STS turbo setups? they look pretty cool, i would think the lag would suck, but it might be easier setting it up with the space you have.


Actually the STS turbo setups only run as much lag as a unit mounted right to the side of the block, not to mention the air temp back at the engine is way cooler after it ran under your vehicle back to the front.. And you can keep the under-hood temps down a bit, as an under hood turbo heats up even more than our XJ's already do..

[Cwish]

My engine is in really good shape 100k miles well kept not driven hard. What type of fuel stuff would I need like fuel pump and injectors?

[bluedragon436]

honestly if you are running a small 5-6psi you should be good with just upgrading the fuel injectors and fuel pump.. and would look into an adj. fuel press. regulator..

[default83]

honestly if you are running a small 5-6psi you should be good with just upgrading the fuel injectors and fuel pump.. and would look into an adj. fuel press. regulator..

x2, just slap a turbo on it, bigger pump, bigger injectors with a good tune and your set. and make sure you have some kind of way to control it, or go get it tuned.

i beleive and correct me if im wrong, but the ecu wont simply pump more fuel just because the injectors are bigger. its been a long time since ive dealt with turbo cars.

do NOT get an electronic boost controller. once you have boost, you always want more, its not a good idea to be able to control it from inside the car if your losing a race, competition will cause you to pump it up and blow your engine, ive seen it a thousand times.

[bluedragon436]

I have been looking at the RIPP Mods Supercharger (http://www.rippmods.com/RIPP_Supercharger_for_2005_2006_JEEP_Wrangler_TJ_p/0506tj-sds-1.htm) for the TJ.. and this is how they take care of the fuel/tuning part:

For fuel management RIPP feature plug and play Diablo Sport Predator which turns your ECU into a fully programmable fuel and timing system. The system comes with base maps designed to safety, calibrated to an engine running boost, or you can choose to bring it to a tuning facility and get the most out of your system.

They are running 265whp on a stock engine and automatic drivetrain, with no changes to the exhaust.. so you should be good..