jeep 4.0 turbo

Posted By: pnypwr

jeep 4.0 turbo - 10/05/11 04:39 PM

im kicking around turboing a 4.0l out of a cherokee, its going in a gremlin but with the turbo it should be a fun little ride...downside is im turbo stupid so im asking a few questions on where to start...I can weld and fab, im a pro wrench just havnt made any turbo systems...did install a supercharger once but that was a kit. Seeing as there isnt a bolt on kit for a 71 gremlin with a 4.0 l this will be a make it at home deal. any help tips advice direction is appreciated

Posted By: Mr.Yuck

Re: jeep 4.0 turbo - 10/05/11 05:42 PM

good deal. No idea but I'm sure if you have welding skills you could do it fairly cheap. In the last issue of Car Craft there was a turbo straight 6 maverick running 10's. Check it out, it might give you some ideas.

Posted By: Mr.Yuck

Re: jeep 4.0 turbo - 10/05/11 06:14 PM

http://www.jeepforum.com/forum/f22/turbo-4-0l-1054621/

Posted By: Randy..

Re: jeep 4.0 turbo - 10/05/11 06:18 PM

one of the 4wd magazines did one not long ago and it made somewhere around 700hp, think it was 4wheel and offroad.

Posted By: pnypwr

Re: jeep 4.0 turbo - 10/05/11 06:55 PM

id like to do it on the cheap running a stock engine, the fab isnt where my quandries lie, more like what size turbo to use...how to compensate for the map sensor and which fmu to run, its a gremlin and i want a fun driver,,,I have a v8 model but I think I should be able to get decent mpg as the cherokees got around 20 and this wigh alot less and has half as much rotating mass...

Posted By: Randy..

Re: jeep 4.0 turbo - 10/06/11 02:05 AM

a single 67mm should do what you want.

Posted By: Duner

Re: jeep 4.0 turbo - 10/06/11 04:35 AM

If you are going to go with a basically stock engine - a T4 with 60-1 HiFi compressor with a .84 AR turbine works very well. A 35mm wastegate is about all you will need. You can also run a cheap Bosch blowoff valve to keep the cost down.

If you run an aux fuel pump inline with a 12:1 FMU it will be just about perfect with the stock injectors as long as you aren't going for more than 7-8 psi of boost. If you plan on upping the boost more than that, then you will need to upsize to 24# injectors and run a 10:1 FMU plate. The MAP sensor will need a checkvalve / bypass to vent boost but close when in vacuum. The power brake boost check valves work well for this. Move the IAT sensor to the air filter in front of the turbo. An intercooler will help it run on 91 octane in warmer weather and is especially important if you want more than 7-8 psi of boost. If you go to higher boost than that, a boost retard on the ignition is recommended.

Posted By: Bad340fish

Re: jeep 4.0 turbo - 10/06/11 12:44 PM

Quote:

If you are going to go with a basically stock engine - a T4 with 60-1 HiFi compressor with a .84 AR turbine works very well. A 35mm wastegate is about all you will need. You can also run a cheap Bosch blowoff valve to keep the cost down.

If you run an aux fuel pump inline with a 12:1 FMU it will be just about perfect with the stock injectors as long as you aren't going for more than 7-8 psi of boost. If you plan on upping the boost more than that, then you will need to upsize to 24# injectors and run a 10:1 FMU plate. The MAP sensor will need a checkvalve / bypass to vent boost but close when in vacuum. The power brake boost check valves work well for this. Move the IAT sensor to the air filter in front of the turbo. An intercooler will help it run on 91 octane in warmer weather and is especially important if you want more than 7-8 psi of boost. If you go to higher boost than that, a boost retard on the ignition is recommended.

Hey Duner is that your Jeep? If so we need to see your lawnmowers and other cars to see if they all have turbos on them lol.

Posted By: Duner

Re: jeep 4.0 turbo - 10/06/11 08:22 PM

No, not my Jeep. I turbo'd it for a customer 4 years ago. His Jeep was almost glacial at 8,000' altitude so it needed some serious help. He was so friggin' happy with it he was almost beside himself.

Posted By: 2734bbl

Re: jeep 4.0 turbo - 10/06/11 09:12 PM

Duner I know it's all relative but what's a ballpark figure on a build like that?

Can OBDII candle this or is a FMU mandatory?

Posted By: pnypwr

Re: jeep 4.0 turbo - 10/07/11 02:32 AM

judging by the pcm in that pic its an obd2 truck...my donor is a 94 cherokee 4.0 with 150k on it...for now id like to keep it as stock as possible? Did you just run the factory manifold on the left and pipe it over to the pass side to mount the turbo? I dont plan on running more the 7 or 8 psi I Dont think the engine would take it...not saying in the futurea stroker with forged guts couldnt happen...but hey im playing with gremlins so not like im rolling in the dough right now...

Posted By: Duner

Re: jeep 4.0 turbo - 10/07/11 06:23 PM

That was about a $2,500 job.

Posted By: Duner

Re: jeep 4.0 turbo - 10/07/11 06:27 PM

Yes. It was pretty much all stock including exhaust manifold. The Jeep exhaust crossed over to the passenger side from the factory, so I just redirected it to the turbo, then tied back into the stock exhaust system out of the turbo. Just the aux pump and FMU for fuel duties. I also built a heat shield for the turbo to keep from cooking the battery in the stock jeep location.

Posted By: pnypwr

Re: jeep 4.0 turbo - 10/08/11 01:58 AM

what kind of power did you get out of it? do you mind if I pm you and ask some stupid questions...im a turbo novice, but i am a mechanic by trade

Posted By: Duner

Re: jeep 4.0 turbo - 10/08/11 03:44 AM

I'm more than happy to answer any questions I can.

I have no clue how much actual power it made, other than the customer was thrilled. He drives it at high-altitude and it was completely gutless before adding the turbo. Now he says he can accelerate quickly enough to get on the freeway! LOL (he might have been exaggerating how slow it was before...)

Posted By: pnypwr

Re: jeep 4.0 turbo - 10/08/11 04:13 PM

mybe not if its lifted and has anything bigger than a 31 on it...we lift tons of jeeps and with 33s they are nutless without a regear

Posted By: 2734bbl

Re: jeep 4.0 turbo - 10/10/11 04:03 PM

Thanks Duner. Thats seems like a very reasonable price for that job.

Posted By: WO23Coronet

Re: jeep 4.0 turbo - 10/13/11 03:44 AM

Quote:

If you are going to go with a basically stock engine - a T4 with 60-1 HiFi compressor with a .84 AR turbine works very well. A 35mm wastegate is about all you will need. You can also run a cheap Bosch blowoff valve to keep the cost down.

If you run an aux fuel pump inline with a 12:1 FMU it will be just about perfect with the stock injectors as long as you aren't going for more than 7-8 psi of boost. If you plan on upping the boost more than that, then you will need to upsize to 24# injectors and run a 10:1 FMU plate. The MAP sensor will need a checkvalve / bypass to vent boost but close when in vacuum. The power brake boost check valves work well for this. Move the IAT sensor to the air filter in front of the turbo. An intercooler will help it run on 91 octane in warmer weather and is especially important if you want more than 7-8 psi of boost. If you go to higher boost than that, a boost retard on the ignition is recommended.

In your description of what you did to the Jeep, you mention a 12:1 FMU plate and a 10:1 FMU plate used with the aux inline pump, what are these? And from what I understand you didn't need a tuner for the computer, the stock tune would do it? Can you go into this a little more, I'm really enthralled with the turbo stuff and want to build one some day

Posted By: Duner

Re: jeep 4.0 turbo - 10/14/11 03:57 AM

Quote:

In your description of what you did to the Jeep, you mention a 12:1 FMU plate and a 10:1 FMU plate used with the aux inline pump, what are these? And from what I understand you didn't need a tuner for the computer, the stock tune would do it? Can you go into this a little more, I'm really enthralled with the turbo stuff and want to build one some day

The FMU Explained

An FMU delivers supplemental fuel to the engine when in boost. An FMU is often referred to as a boost-dependent fuel pressure regulator. The FMU is essentially a variable/rising-rate fuel-pressure regulator that automatically raises fuel pressure as boost rises. This is done mechanically without any electronics or programming other than swapping different size plates inside of it to vary the rate.

A booster pump is used in conjunction with the FMU and pumps in a loop. When not in boost, the FMU routes the fuel back into the system instead of to the fuel rails. The FMU is downstream (after) of the stock regulator. As boost pressure begins to rise, the FMU starts restricting the flow of fuel returning to the loop. Like a garden hose, if the flow is restricted, the pressure increases. The increase in restriction results in an increase in the pressure of the fuel being delivered to the factory fuel injectors. Higher fuel rail pressure enables the fuel injectors to deliver more fuel in the same amount of time than they do at the static stock fuel pressure. The limitation to this system is that you cannot continue to raise the fuel pressure beyond reasonable levels. Most people try to keep the fuel pressure below 100 psi. Generally, if you need more pressure than that - you should go to the next larger size injector and lower the rate of the plate.