Topic: Superchargers anyone running them?

[oakesmi2]

Hey I was wondering if anyone is running a supercharger on there 2.5's out there?
What kit are you running or where did you get parts from?
What do you think?  Where do you see improvments? Any short comings?

Thanks for the input.

Mike

[Jeffy]

There are only two official kits out there and one is out of business.  The Rimmer Engineering Kit was the first.  The second, Avenger Supercharger.  They took a lot of stuff from Rimmer and made it their own.  Rimmer used to use M45 and M60 superchargers but change to AutoRotors in later years.  Avenger just went with the AutoRotor.  It's not a big company but is sorta known in the Tuner world.  Way back Don-A-Vee used to have a Paxton kit.

There is one member who has a old Rimmer with the M45 compressor on the forum.  He recently bought it from another member who bought it from another member.  I don't believe there is anyone on the forum who's got the Avenger but there are a few on the Mailing List.

You're only choice these day's is the Avenger Kit though.  This is specially true of you live in CA as it's the only C.A.R.B. certified kit.  If you live in a non-emission zone then you might consider a homebrew Turbocharger though.

For the cost, you could do a engine swap in a non-emission state.  If you wanted to go by the books then a engine swap would require a lot more work and money.  A Avenger can be installed in a weekend.  There is a one year warranty on the kit but only if it's installed by a certified installer.

With a blower, you'll still want to have correct gearing to take full advantage of the compressor which will also cost money.  They you'll really want to consider beefer axles that will hold up to the torque.

Another thing to think about is that you'll have to run Premium gas.  You could run Plus but you risk retarding the timing too much.  With the Avenger you'll probably get decent gas mileage.  From what Trailblazer95 went through, you'll be lucky to get close to what the engine was getting, pre-supercharger.

[trailblazer95]

yep, I ran one.   I'd say if you bought one of the newer Avenger kits, you'd be set.  Those kits seem to be top-notch, and I've really never heard any negatives regarding their kits.  (other than the price).   Within the first month when the blower was on, I blew out my clutch due to the added torque, saw a complete decrease in fuel mileage (from 18mpg before to about 11mpg), spent way too much time adjusting fuel/air ratios & tuning it, and spent a lot of money feeding it premium gas.

BUT, yes, I did see an increase in HP and torque.  It drove like an I6.  The only thing that I didn't like was that I had I6 power with 4Banger parts, so it had to be babied a little bit, especially after the clutch incident, which cost me $800.  

Now keep in mind, I had an older kit, which hardly had any of the refinements of the well thought out Avenger kit.  I didn't have an intercooler, or the fancy computer things the new ones do.   Given the price of the kits out there, if you're going to drop that kind of coin, I'd say you'd probably be better off doing an engine swap.

[oakesmi2]

I really appreciate the well thought out responces. This is exactly the type of infromation that I was looking for.  I guess the old saying still applies "there is no replacement for displacement"  I have done all the normal mods and was hoping that a supercharger would provide power without adverly effecting other parts but as you all have said that is not realistic.  I think I will leave it the way it is and if I feel that I need more power (so fare there have only been a few time I have needed more power) I will sell this Jeep and go to one a 4.0.

Thanks for the responces.

[Jeffy]

Well, you will also want to take into consideration how old the Jeep is and how many miles are on it currently.  If you've got a newer Jeep or one with low miles, then I don't think strength will be too much of a problem.  You won't want to drop the clutch but you should have to baby it either.  It's probably good to replace it if it's old anyway.

The tranny should hold up ok even with the extra power.  The main concern is the rear axle if you have larger tires and/or a locker.  More torque will increase the chance of shearing off the splines on the axle shaft.

Another option to a Supercharger or a larger engine would be propper gearing.  Some people thing 4.88:1 gears are perfect for 33's on a 2.5L but in all honesty, you'd want to be at least 5.13:1 which means new axles.  If you're running 35's then you'll want a minimum of 5.13's and better yet 5.38's.  With propper gearing, the Jeep will be a lot more responsive and maintain higher speeds better.  You want to gear it low to keep the RPM's up but the only problem is having it geared too low if you want to eventually do an engine swap or a SC.  So you've got to make some plans ahead of time.  This is the delema I'm facing right now.

I've got a low mileage 2.5L and haven't touched the T-case or tranny.  The rear axle has been swapped out and the Jeep regeared.  So a Supercharger would be a good choice.  One the other hand I would swap my front axle then regear the rear once again and I should be set...

[Jeffy]

Saw this on Avengers site.

[wildman4x4nut]

Well I am the guy who bought the old Rimmer kit off of Trailblazer. I have not started on the project of installing it yet. I am going to try a few things different. I have a PC diagnostic program that tracks the sensors & what the computer is doing. I also have a wide band O2 sensor that I will install to track the air/fuel ratio.

I missed out on a Avenger supercharger that was for sale while I was in Iraq. I have also done a lot of reading and research on forced induction. Both turbos & superchargers. I have a V-8 sitting here if I find out that the supercharger doesn't work.

Something to understand is when doing anything that will increase the HP & torque is that other upgrades need to be made in your drivetrain. I am installing new axles this winter. A HP44 in front & a Tera CRD60 in the rear with 5.13 gears. I have done the 4 to 1 upgrade  in my t-case & a SYE. If I install the V-8 I am also switching over to a auto tranny.

[jpcreep]

I have over 60k miles on an Avenger supercharger.  All was not rosey but the kit does provide as advertised.  I have spent countless hours and many calls to Avenger to exercise the jeeps new demons.  In the end a piggy back computer from Split Second (FTC1 w/ 2 bar map) did the trick.  Dont know if the new kits come with fuel/timing managment, but the old kit did not. The kit I have relies on the ecu from the jeep to compensate for fuel and timing during boost.  The main problem with that is the map sensor does not see boost only vacuum so the idea was that during any boost conditions the jeep will go full throttle which is not always the case which leave you in a lean (very bad) condition. All said and done it was a rollercoaster ride.  Fuel economy hovers around 15-16 on socal doing 65-70 mph so I cannot complain.  Hindsite would have me sell and by a 4.0L. I learned a lot from the kenne bell site, which does not sell kits for 2.5l another good resource is a book by Corky Bell ISBN 0-8376-0168-1 design testing and installation of supercharger systems.

[wildman4x4nut]

jpcreep,
Nice to hear that you got everything working. I too have been talking to Split Second and am planning on getting the FTC1 when I get the supercharger on. It will be interesting to see who my engine does without the cooler. I am also running 4.88 gears right now but when I swap axles I'll be running 5.13 gears. I am hoping this with the supercharger will give me enough power on road. I have never really had any issues off-road.

[jpcreep]

wildman4x4nut,

I have a 3" suspension and 1"body (required fo my supercharger installation) I'm also running 4.88 gears with 33" BFGs, which puts me mathmatically back to the stock gear ratio that came with the jeep and no speedo gear change is required.  jeep runs great on the freeway 3k @70mph which is the beginning of the power band.  I never need to leave 5th gear. I can provide the fuel mapping for my jeep which may give you a head start in the calibration of the 2  bar map in the FTC1.  I'm intercooled and have no timing retard while under boost.  Without an intercooler you may need to add retard to prevent detonation.  

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[wildman4x4nut]

jpcreep,
The fuel mapping would be GREAT!! That would give me some place to start. I am sure I'll need some timing retard with my setup. I'll be ordering my FTC1 next month & want to start on this project soon after that.
I have a 4" lift & 1 1/4" body lift on mine right now w/35" tires. I really enjoyed having all that power back when I had 33" tires but then got the
I NEED BIGGER tires.!!!
 
Thanks again for the offer.

[jpcreep]

wildman4x4nut

PM sent with fuel map attached.

[Jeffy]

What?  The rest of us don't get to see it? :(

[jpcreep]

Jeffy,

Sorry for keeping secrets.  The map itself is a data base file (.mdb) which is opened using split seconds R4 software.  It is nothing more than sequentionally increasing numbers in respect to pressure and RPM.  The numbers coorespond to a voltage and are used to calibrate a 2 bar map sensor which is installed in place of the stock 1 bar map.  Thats a better answer than "I cant seem to figure out how to post a screen shot of the map"  Hope your not to dissapointed.

[Grundar32]

I went to the Jeep rally in Somers CT last sun. and i saw a 4cyl running a supercharger there ... wish i had takin some pics :(  :(