Turbo on a 2.5

[SWJeep]

Has anyone put a turbo on a 2,5L?  Is there a lot involved?  Someone was telling me that you could get them off of some old Doge mini vans, that would fit.

[Jaguar]

As far as I know, Avenger makes one for the 2.4L, and the 4.0L. Other than that I haven't seen any other super/turbo kits for the TJ.

[SuicidalPenguin]

I think Avenger is working on a soon-to-be-released supercharger for the 2.5L. I could be thinking of the 2.4L, i don't remember.

[BUKI]

I am putting one together soon for my 2.5l (could be early next year though).  My friend is a cnc machinist and has made me several turbo manifolds in the past.  We are trying to put together someting that will develop around a 100 hp increase thats very reliable.  There is alot involved (ie. tubo sizing, fuel managment, high volume fuel pump, FMU and or pressure switch with coldstart injector,boost friendly map sensor, oil supply and or coolant supply, boost pipes, intercooler [if you want more than 4-5 psi], blow off valve.  If you are still  interested, or for more info PM me.
Mike

[4low]

Just a thought for you guys, have you looked at the bottom end on the 2.5?!?!? The big end of the rod, is not that big, not to mention, Isn't the 2.5 roots, based in the old AMC? made to produce something like 90 HP? we've already upped it too 115-125-ish..........i'm not sure about the engine's ability to accept the boost necessary to basically double it's horsepower output.
A 20 HP increase....I could see that being reliable.....but that's just my 2 cents.....

[Bnine]

Just a thought for you guys, have you looked at the bottom end on the 2.5?!?!? The big end of the rod, is not that big, not to mention, Isn't the 2.5 roots, based in the old AMC? made to produce something like 90 HP? we've already upped it too 115-125-ish..........i'm not sure about the engine's ability to accept the boost necessary to basically double it's horsepower output.
A 20 HP increase....I could see that being reliable.....but that's just my 2 cents.....

You are right that a 2.5 is an old 4.2 with 2 cylinders cut off. As simple as that.

But,

That same crank and rod desing and size is whats used to build today's 4.5, 4.6, and 4.7 litre strokers that push as much as 500hp and 650lbs of torque. 500hp being the blown, and stroked motor they put out.

There is a guy who built a natural 2.5 to put out 220 plus hp. His right up is on the 4 banger jeep forum.

Avenger has been putting blowers on the 2.5's for a few years now. No word of it being an issue.

Built right, there should be reason a tuned up little 2.5 wouldnt last.

[NS-jeeper]

some of the 80's dodge cars came with turbos maybe you could adapt somthing. My 87 Dodge colt had a turbo (but a mitsu. engine) and some late 80's and early 90's shadows and lasers came with turbos.

[4low]

Thanks for the insight....
My automotive experience is limited....
I had a 2.5 throw a rod, and when I took the engine apart, I couldn't believe how small the big end was. not to mention the total weight/heft of  the piston/rod assembly.
My experience comes from Superbikes and such, and when I was lookin' at the 2.5, it just looked soooo archaic.....

[BUKI]

The rods seem to be much thicker than my hondas (60 thou bigger).  And a good rule of thumb is at double atmos. press. (1bar) which is 14.7 psi you double your hp output (engine, not wheel).  good tuning to keep your a/f ratio at stoic. or even a little rich (self assurance), can get you a little more or less depending on the situation.
Now my honda (1.6l DOHC VTEC) put out naturaly asperated 167 hp (engine) boosted to 10 psi with very good tuning (wide band O2, computer crap, running perfectly stoic.) put down 313 wheel hp.  Now 10 psi boost on 10.5:1 compression ratio is  the very limits of that engine.
The rods on the 2.5l are thicker and the compression ratio is much smaller at 9.5:1, should accept boost nicely (theoreticly).  I want to run between 7-10 psi safelyand intercooled (ruffly 185- 205hp).

[Bnine]

Interesting stuff.

What will you do to make the power at the bottem? Is there a way of tunning the turbo impeller or something else to eliminate, or minimize lag?

How will you address mud? Jeeps are a SOB to keep cool, and thats 10 fold when you start packing mud into the rad. An intercooler in front will compound that issue.

What kind of money do you think you will be looking at? You think this will be a one off, or something you might start doing for a people locally for a few $ on the side?

My wifes is a 2.5 and could use a bit more pep, although it does fairly well offroad.

Might be interested in this if you come up with a clean system that works well.

[BlackYJ]

I thought the 2.5L was a whole new engine, because the 4.0L was based on the 2.5L, hence the interchangeability of parts.

[Bnine]

Other way around.

The 2.5 is literally a 4.0 with 2 cylinders chopped off.

The 4.0 is only a slight variation from the old 4.2. Again, why mostly everything is interchangeble there as well.

[BlackYJ]

Actually Bnine, in JP a few months ago it stated the 4.0L was based off the 2.5L

[Bnine]

Have to be carefull how you take what you read.

I thought it was the 4.2, but wasnt sure where the 2.5 came from.

Anyways, the 2.5 is a 6 with two cylinders cut off.

When they re vamped the 4.2 to the 4.0, they mimic'd some dimesnions from the 2.5, but.....

You can still take everything off of a 4.2, exhaust, intake, crank, rods, cylinder head, etc etc etc, and bolt it on to a 4.0

The 4.0 still excepts the same camshaft used in that basic 6 cylinder design since 1956. You can go to cranes site and look up 4.0 cams. The specifics are "AMC 6 cylinder, 1956 and up"..........lol

THe only thing they did was change the bore and stroke on the 4.0, the same as they did when they designed the 2.5

So its kind of a chicken before the egg thing, but basically, the root design of the 4.0 is 30 years older then the original 2.5

Saying the 4.0 was designed based on the 2.5 is a bit misleading IMO.

[yjcanibul]

I dont know much about the 2.5L - if I ever replace my willys Fhead I would look here first to keep it jeep;

I had a 4L in my long gone cherokee    ,  missed it so bad my old yj engine top is now a 4L HO --  I put as many 4L parts I could find on my 4.2L   ,  I run a prep'ed 91 4L HO head (water jackets closed ) with same year headers, MPI intake and distrib off a '95 , 4L head gsk, 4L thermostat & housing etc, reused old 4.2L pushrods and all stock there down .... thats where the canibul comes from ..scavenging some of the better parts to keep the old yj going ...


there's something about turbo's vs. superchargers that comes to mind, if I got it right superchargers make torque (offroad=good) and turbo's make horsepower (onroad=good) ... ?

I think avenger is only building superchargers for jeeps

http://www.rockcrawler.com/features/newsshorts/01july/avenger.asp

I did a trail two years ago with a tj from G. Prairie that had one installed similar to pic .. only 1 I have ever seen , .... it was spinning '37's pretty gooooooooooood ....