SCCA Turbo 5.0L MJ (Comanche Eliminator Project)

[nick]

Today marks the beginning of the SCCA Twin Turbo 5.0L MJ (Comanche Eliminator Project). I purchased a Comanche for the purpose of racing in SCCA events, mainly autocross. I'll give some history before I delve further into the project.

I am Gradon's brother, Nick. Both of us have been working on Jeeps for over 10 years. Back in '02 I purchased a turbo to throw in my XJ. I really wanted to do this project, but it kinda got set aside for other more important things in life. Then 2 years later I was beginning to gather parts to stroke my XJ. I had the crank, rods and bearings. I then entered the military and in '07 I gave everything to Gradon for use in his XJ. I came back in May of '08 to begin tearing down his Jeep and rebuild it to what it is today. You can view his project here http://www.jeepstrokers.com/forum/viewtopic.php?t=147.

I still; however, wanted to make good use of the brand new turbo I still had collecting dust in the shed. I have returned from the military and have since been enjoying life in an Acura NSX (my dream car), but I still wanted to do a turbo project on the Jeep. I finally decided to sell my XJ with Euro full leather interior and just dropped in the Euro 4.0 which I might add is the strongest 4.0 engine I have ever had IMHO and I have owned 4 Jeeps myself and Gradon has also had 4 plus all the Jeeps him and I work on.

SCCA events won't allow SUV's so I decided to get a vehicle that was already SCCA certified and guess what, the good ole MJ (Comanche) is. Today, as stated above, is the beginning of this project. This will be a pretty detailed thread with lots of pictures. Wish me luck and hopefully all will go smoothly.

*Disclaimer* I do not want to hear bashing about lowering this MJ. There are no mountains or mud bogging or many rocks to climb in the DC Metro area. So with that said this is a racing machine designed to be super light and dog anything within reason.

This is my Inspiration

[nick]

Reserved for project details and checklist

List of things to do in no particular order:

Engine

• See 2nd post

Drivetrain

• Centerforce clutch
  Hurst short throw shifter (only for temporary AX15)
  Light Aluminum flywheel (still researching a fab CNC flywheel)
  Exchange Dana 35 for Ford Explorer 8.8 w/3.73 LSD Rear disc brakes
  BBK front with dual piston calipers (poss WJ if fits)
  Delete brake booster and install Hydroboost from F350 or H1 Hummer
  Big tires (275 on 15x10 rear and 245 on 15x8 front)

Suspension

• Custom lowered 800 in/lb leaf springs and coils
  Custom traction bars

Body

• Firberglass hood
  Front air dam
  Wide body
  Class-3 hitch (helps add rear end weight and for towing my NSX and bikes to events as well)

Weight Reduction

• Carpet deleted
  Spare tire deleted
  Rear bumper deleted
  Hood
  AC
  Bench seats (exchange for light buckets)
  Gas tank (exchange for fuel cell and relocate)

[nick]

Reserved for dyno charts

5.0L Engine Specifications

• '96 block over-bored .062 (3.937")
  Custom Ross 3.935" slugs w/ 1.265" pin height with ceramic coated 34cc dish and nitride coated skirts
  Custom Eagle 6.125" nitride coated H-beam rods
  Custom offset ground 4.2L crank to 4.060"
  '96 0630 head ported and polished (Combustion chamber 64cc)
  2.02 in 1.60 ex ceramic and nitride coated Ferrea valves by offsetting guides bringing them more inward
  505 Adjustable 1.6 roller rockers
  '99 ported intake
  Direct (geared) timing
  Start off with single T3/4 Turbo for 8psi and then move to compound turbo setup
  Water/Air Intercooler
  Start off with Renix with FTC then move to Megasquirt with HEI, GM sensors (Temp, MAT, IAC) and NGK wide-band O2
  Dodge throttle body w/Renix TPS
  Oil cooler
  Custom fab fuel cell (former spare tire location)

505 Performance Camshaft Specifications @.050

• 230* roller camshaft (285 advertised)
  114 lobe separation angle
  544 lift

[nick]

Reserved for pictures of ongoing project

090829 - Day 1 - Purchase







090829 - Day 1 - After wash and quick clean up



090829 - Day 1 - Carpet delete and scraped floor pan of surface rust




090831 - Day 2 - Engine pulled









090902,03 - Day 3,4 - Junk removal part 1 (Removal of leaf springs, exhaust, AC system, spare tire rig)




090910 - Day 5 - '95 0630 port and polish part 1 (Gradon put in 3 hours this day)




090913 - Day 6 - '95 0630 port and polish part 2 (Gradon put in 2 hours this day)

[dwg86]

There is a perfect 1988 Comanche in pull-a-part, south Atlanta. Shiney blue paint, not even a scratch. No dents inside the bed. I can't believe it's in there. It is labeled a "clunker" vehicle, and there is a tag on the engine that says "do not sale" because its locked up do to some sort of silicon added to the oil.

[nick]

There is a perfect 1988 Comanche in pull-a-part, south Atlanta. Shiney blue paint, not even a scratch. No dents inside the bed. I can't believe it's in there. It is labeled a "clunker" vehicle, and there is a tag on the engine that says "do not sale" because its locked up do to some sort of silicon added to the oil.

That is too sad. That vehicle will never be able to be sold and will likely be crushed into a small cube. It's not for sale because it was sold to the Cash for Clunkers program. A program that ruins perfectly good vehicles by draining oil and adding liquid glass (Sodium Silicate) into the oil so that it destroys the motor internals. All you have to do is drop a new motor in and the vehicles would work again. Thanks Obama.

[YJason]

One mans Clunker is another mans treasure

Can't wait to see how the project progresses, I like MJ's

[nick]

Engine pulled out. See pics above.

Gradon will begin working on the 7120 head from my '95 engine and start porting the head before I take it to the machine shop for 3 angle valve job and bigger valves.

I still haven't decided whether I will use the Renix '89 block due to nickle content? or use the '95 block. Anyone know if the '89 is stronger because of the increased nickle content?

The Engine will be the first thing to get worked on and get back in the vehicle so I can start getting it broken in before I turbo it. My XJ will be sold by October so I will need a winter vehicle so that is why the Engine is getting worked on first.

[Flash]

The way i have understood it, the Renix block is stronger then all the rest.

with the least favorite head, intake and exhaust.

Mine has over 300,000 and still running strong! Still no oils consumption ether.

What years do you here of, that the ears braking off, on the block, for the motor mounts.............there not Renix.

[Flash]

Are you sure you want to go with a 2.02 intake valve.............. with all the shrouding it cause?

[gradon]

From what I gathered from all the different builds around, 1.97in and 1.62ex is the way to go. 2.02s haven't been of much use do to the shrouding and the fact that the intake runners are the restrictions. However on a forced induction build. . .

[nick]

Are you sure you want to go with a 2.02 intake valve.............. with all the shrouding it cause?

I don't foresee a problem. I will also be offsetting the guides and move the valves more inward.

[Flash]

I will also be offsetting the guides and move the valves more inward.

Ahhh, problem solved!!!!!!

[seanyb505]

Sounds like an amazing project! Finish it, cause too many people dont. My excuse is money fow now. A couple thoughts:

One the multiple turbos: you would do a stage setup or two identical turbos?

I believe you can modify WJ (dual piston) front brakes for XJs, have you looked into compatibility with the MJ?

What tranny are you planning on using?

Turbo the NSX?

Ive been thinking about modifying some prerunner fiberglass fender flares to give more like a road course oriented look to them. The SCCA trucks just used a deeper front air dam, I think wider fenders would complete the package. This sounds very close to what I want to do with mine, only I dont think I will be using it in any organized events so bah with rules!

[nick]

Today I updated the engine specs 3rd post

Sounds like an amazing project! Finish it, cause too many people dont. My excuse is money fow now. A couple thoughts:

I will finish this by Spring time. Engine will be built this winter (prob mid-Nov). Mainly waiting on the custom crank and cam to be built. Body on the other hand; along with suspension, should be completed this year. Roll cage I may wait until spring time to do that. Oh color scheme will be burnt orange with twin black stripes. Haven't decided how I want them to run yet.

One the multiple turbos: you would do a stage setup or two identical turbos?

They will be staged two different turbos one small one for fast spool up and the other for the high HP, but for now I will be starting out with just the T3 I have collecting dust.

I believe you can modify WJ (dual piston) front brakes for XJs, have you looked into compatibility with the MJ?

I am going to attempt this and if works yes, if not then oh well. I will also be getting a Hydroboost setup from F350 or H1 Hummer.

What tranny are you planning on using?

For now the AX15 since after the Engine is built as I won't be boosting or hitting any super HP until I get a Sequential T5 built. I also need to do some research about a lightweight driveshaft. The stock MJ one is a tank!

Turbo the NSX?

Right now it is completely stock. I will be fabing my own turbo setup with GT4088R turbo with separated entry spring '10. I will also (when I intentionally blow up the 3.2) stroke it to 3.5 and make a bullet proof bottom end.

I've been thinking about modifying some prerunner fiberglass fender flares to give more like a road course oriented look to them. The SCCA trucks just used a deeper front air dam, I think wider fenders would complete the package. This sounds very close to what I want to do with mine, only I dont think I will be using it in any organized events so bah with rules!

I will definitely have the deeper front air dam and will likely do some light wide body modifications to include the fender wells to make my large tires not look so insane.