it aint gonna stay NA

[1977cherokeechief]

before i really start buying parts for the motor in the Cherokee i want some serous opinions. I am planing to either go into a supercharged or a turbo charged applications with it.

i do not want it to remain NA (naturally aspirated). i know that the jeep is already different from anything around here, but i want some more go out of it. i drive a LOT of highway, but still need power for the bottomless mud holes around here, it will also be used to tow with occasionally.:fsj:

so put up opinions, and a vote.

nate

[mattmopar440]

Procharger :thumbsup:

[YellowJeep]

Supercharged if you want the power right off the line. Personally, I've done quite a bit with turbos and there is way more potential in a turbo vs supercharger, but you almost always end up with some turbo lag.

[billyrb]

the turbo lag issue is almost non-existent these days, with turbo timers, blow-off valves, etc. Even a single turbo now can get past that. You should pick up Corky Bell's turbo book as it is a great primer on turbos, systems, engine needs, header choices, etc. I hope to turbo my Wicked Woody one day, but have to get the rest of the motor wrapped up and a few other projects done before I can start down that path. Superchargers do have less plumbing, take up less space, and are more simple, but you will have to have a bracket built and convert to a serpentine belt drive if you want to keep it from slipping / having problems.

[men in black]

Turbo Turbo Turbo.

[bushwood44]

Roots,killer torque:thumbsup:

[YellowJeep]

the turbo lag issue is almost non-existent these days, with turbo timers, blow-off valves, etc.
A turbo timer keeps your engine running for a few seconds after you turn the key off so the oil doesn't cook in the turbo. Not sure how that is going to help you with turbo lag. A blow off valve only helps with lag between shifts by keeping the turbine spinning by releasing existing boost in the intake system.

All turbos are driven by exhaust flow. If the motor is not flowing much exhaust volume (off idle for example) it takes a little bit for it to spin up and make power...aka turbo lag. So, when you are crawling around on the rocks, or just taking off from a stop light your turbo is going to be doing very little.

You can get around some of the lag with a smaller turbo, but like anything there are trade offs such as not as much air volume or lower possible boost PSI.

Super chargers are driven by a belt and don't have this same problem.

EDIT: I should add that putting a turbo or a procharger on a carbed motor will require special modifications to the carb. A roots charger can be more carb friendly because it is drawing air through the carb instead of forcing boost through it.

[billyrb]

true, the timers don't reduce lag, they do however make them last longer. THe waste gates do the same, keeping them working for longer and relieving pressure when it starts to get too high, and you are right that they also help reduce lag between shifts. For the "lag" (boost response), you can get rid of most of that if you design a system for lower, more instant-response, but it does mean you won't be running a 1,000 hp engine as you'll have to sacrifice some of the top-end (which most FSJ's wouldn't see anyway). There are also turbos that reroute some of the incoming air to help keep the turbo spinning at higher rpms while the engine is at idle & low speeds, and there are also electric motors built in to some turbos that keep them spinning, but those are usually outside the $ reach of most folks and aren't necessary with this type of application. There are also downpipes that due to their size and how much exhaust they can flow, can quickly get the exhaust through the turbo and exit to air, which in turn helps spool the turbo a little faster which in turn reduces lag, and you can also use a high-quality turbo with ball-bearings (versus sleeved bearings) which helps them spool up much faster.

Most of the lag that people hear or know about is from cars in the 80's, which were older & less-efficient designs and were also mainly on 4-bangers, sometimes on 6-cylinders. On a V8, there is considerably more exhaust flow at lower speeds than most of the 4-bangers, meaning they'll spool up much faster as well. Now if you use an oversized turbo and don't properly size it to your engine, exhaust system, driving style & use, then yes, you'll get a lot of lag and then the power will hit like adding another motor all at once, making it unrealistic for daily driving / off-roading.

Basically, if you don't know anything about turbos and buy one on ebay that came on a tractor, and don't spend some time researching them and how to design a system properly, then you're going to experience a good bit of lag. But, if you research them and design a system to fit your rig and your needs, then you can minimize the lag to the point that you most likely won't notice much (if any).

For the carb, YellowJeep is correct that you'll need to set your carb up for a blow-through application if you use a turbo. If you go draw-through, you don't have to do as much, but it will still need some work to get it set up properly for the power. Oh, something else to consider is fuel requirements. You will need to think about a boost-referenced fuel system to keep up with the added requirements, as if you run short on fuel and run lean, you'll toast your motor quickly.

[The PIG Smith]

...quote is from the first Mad Max movie when The Goose takes max down in to the garage to show him the car!
Goose (http://www.imdb.com/name/nm0001950/): [describing the supercharged Interceptor that's idling, in particular the supercharger itself] You can shut the gate on this one, Maxie... it's the duck's guts!
Barry, MFP Garage Mechanic (http://www.imdb.com/name/nm0131540/): [excitedly] She sips nitro... with Phase 4 heads! 600 horsepower through the wheels! She's meanness set to music and the ***** is born to run!
Goose (http://www.imdb.com/name/nm0001950/): [looking at Max just staring at the engine] He's in a coma, man!

Thanx for Bigun for educating me about this.

Blowers are off scale kewl!

Here is an AMC 401 that is blown
http://www.youtube.com/watch?v=DmvzACSpQVM

[grand_wag_85]

Turbos can put out a helluva lotta power if you set it up right. A buddy of mine had a 93 Toyota RN with the 22RE and we equipped it with a MAck dumptruck turbo. No power off the line but when it got going faster it would haul azz. We ended up putting a smaller turbo before the Mack turbo to get it spooled faster. That motor bit the bullet so we put in a 327 from a '63 Stingray Corvette, 375HP stock. We had both turbos on there but the smaller turbo, Chrysler New Yorker IIRC, would boost the motor rigt until the bigger one kicked in. One mounted on each exhaust manifold made for a heck of a kewl sound.:drivin:

[1977cherokeechief]

i will be putting on an EFI system, i was thinking about calling edelbrock and seeing if they could be help me out with that part, does anyone else make a multi-point injection system that would work?

[The PIG Smith]

...having said that, turbos maybe the way to go.

Four cycle Diesels are all turbo charged.

[YellowJeep]

true, the timers don't reduce lag, they do however make them last longer. THe waste gates do the same, keeping them working for longer and relieving pressure when it starts to get too high, and you are right that they also help reduce lag between shifts.

The waste gate controls boost only. It has nothing with turbo longevity. Without a wastegate, the turbo would make boost progressively until it spun so fast it or the motor flew apart.

And billyrb brought up another great point. DO NOT buy a turbo off of ebay and just expect it to work. Most of those are from huge diesel engines or made to make BIG hp and won't work well for this app...or for those poor ricers who try to slap it on their honda!

Ball bearing turbos are nice, but pretty expensive and people argue how much better they really spool. Do your research before throwing down big $$ for one.

I've never seen or heard of a turbo with an electric motor in it. If it exists, I would have to be one heck of an electric motor because turbos get really hot!

If you really want to run a turbo, check out a VNT turbo. These have a fins inside them can change their pitch to work like a small turbo off the line, then a big turbo once you are moving to reduce lag. A small turbo used to spool a 2nd larger turbo would be a great setup too.

[The PIG Smith]

Turbo's on an AMC can be done!
This is Hankrod's setup.

"Turbonetics T72 big shaft with 1.0 P trim tubine- 1400.00
turbonetics racegate-325.00
2 intercoolers, Ebay-440.00
9 3"180 degree ubends-200.00
flowmaster..custom job,steel and other exhaust pipes,coupleings,clamps,paint,and hardware about- 600.00
TCI bonnet, Ebay-160.00
EFI, heads,valvecovers, manifold, grank trigger, MSD dizzy-about 7000.00
milodon oil pan and dual pickup-480.00
remote oil filters,trans and engine coolers-400.00
plus a 401 shortblock and 300 hours,,,and counting of work... tell me is it worth it?
checking my sanity. Hankrod"

http://i2.photobucket.com/albums/y29/bulltear/PHTO00041.jpg

[1977cherokeechief]

is there more information on his setup?

[billyrb]

Without a wastegate, the turbo would make boost progressively until it spun so fast it or the motor flew apart.

That was my point, as without one, the turbo won't last terribly long. With it, the turbo will last longer :)

For the electric motors, I had read about them a while back from an article with Garrett, and as I recall they are only about an inch long, and can run the turbo up to 150k rpm, and sustain over 200k rpm continuous speeds.

Here is a link to one type of electric assist motor:
http://www.propulsiontech.com/turbo.html

VNT's (also called Variable Vane Turbos, Variable Geometry Turbos, Variable Vane Geometry Turbos) are sweet, but typically cost a heck of a lot more. I recently started looking at them, and was surprised to read that Borg-Warner is and has-been making a VNT for Porsche.....pretty cool.

[YellowJeep]

That was my point, as without one, the turbo won't last terribly long. With it, the turbo will last longer :)

For the electric motors, I had read about them a while back from an article with Garrett, and as I recall they are only about an inch long, and can run the turbo up to 150k rpm, and sustain over 200k rpm continuous speeds.

Here is a link to one type of electric assist motor:
http://www.propulsiontech.com/turbo.html

VNT's (also called Variable Vane Turbos, Variable Geometry Turbos, Variable Vane Geometry Turbos) are sweet, but typically cost a heck of a lot more. I recently started looking at them, and was surprised to read that Borg-Warner is and has-been making a VNT for Porsche.....pretty cool.

LOL! I guess that counts as longevity!

The VNTs are getting more common. Lots of the bigger diesel like International are running more of them now. They've been around for a while...Dodge was putting them on cars starting in 90/91. I'm pretty sure those were garretts.

[jeepjerry]

Superchargers look way cooler!!!! Turbos are for ricers and big diesels.

[billyrb]

I've been drooling over the STS turbos for a while, and think they might be very cool for FSJ's. Although they mount remotely (typically under the rear), the FSJ's have lots of areas where they could go, one specifically would be where the spare tire currently resides. They also have snorkel kits and relocation kits for the air filter, meaning they could avoid being in submerged conditions. Although on the Wicked Woody, I have a fuel tank where the spare use to be, but I can probably mount one of their TT kits in front of the rear tires since I no longer have the stock fuel tank, and I've converted over to a 2wd setup. Just need to save up some $$ and convince myself it's worth it :)

[shackwrrr]

http://www.superchargerusa.com/amc_bk_street.htm this would be nice

[BarryL]

Forget the super/turbo, put in more CI's.

[1977cherokeechief]

Forget the super/turbo, put in more CI's.

i would, but i feel like using the motor that it has.

[JeepinPete]

Here is one thing to consider. When you are driving through that deep mudhole, do you really want a block of iron that is near 1000*, with a turbine spinning near 100,000rpm, being doused in cold water? Doesn't seem like a good idea to me ;).

[billyrb]

fully submersed, it would take some time for it to cool enough quickly enough to crack. But then again, if you are deep enough to submerge the turbo, you have a lot of other issues to worry about :)

[1977cherokeechief]

what i planned on doing is building a box behind the rear seat/axle that is inside and is COMPLETELY sealed on the inside.

this would allow protection for the turbo, and a nice little heater in the winter...:rolleyes:

i have been putting serious thought about the turbo cracking because it got hit by water, tree stumps, branches, ect.

i do think that it would be easier to put one back there instead of cramming it with everything else in the engine bay. ya there would be more pipe, but here are some different looks on it.

good
less heat
easier mounting
no major need for intercooler, but it would be a good idea
longer turbo life (cooler exhaust)
more places to mountbad
longer spool time
more piping
more exposed vitals
a little more price because of the pressure line, oil lines, ect.

[slackin']

I can see you've given this some thought.
but I think you should do a little more homework on turbos.

no offense but nothing in your "good" column makes sense.

first, turbos use heat energy in the equation of power output. you WANT that sucker to be as hot as can be. a cool turbo will not produce anywhere near the rated boost, and will lag like no tomorrow.

air heats up by compressing it. THIS is the reason you want an intercooler. an intercooler is used secondarily to combat the exhaust temps. so you should run one anyway. if not, you'll need a water/meth injection system.

longevity is based on good oil lubrication AND water cooling not cooler exhaust. (make sure you get a water and oil cooled turbo)

there is plenty of room to mount a turbo in the engine bay. why re-invent the wheel?

I'd suggest running a roots style supercharger... but if you're dead-set on turbo, I'd personally go smaller sized twin-turbos to spool up quicker.

anyway, I wish you luck in your quest. :thumbsup:

[billyrb]

slackin, check out www.ststurbo.com (http://www.ststurbo.com) in the FAQ's, as you can see a few things explained about running a turbo out back and how it makes power (pretty cool stuff). Been looking at them for a while, just waiting for my wallet to catch up to my dreams :)

[1977cherokeechief]

the reason i said no need for intercooler, is that fact that the pipe of compressed air will be running long enough to in theory cool it down,

the less heat part is, less heat in the engine bay, as you know how bad our jeeps can be in the summer time.

[Lindel]

Turbos make more HP than they use, might not be the case with Superchargers.

Turbo would be much easier than a charger would, especially with an AMC in a Jeep. Either way will be a custom build, but the turbo should be a lot less fab work.

You CAN mount the turbo where you want to, not the case with the charger (and heat is NOT the turbo's friend). Take a look at the "off the shelf" systems for the Chevy trucks. http://www.turbo-kits.com/silverado_turbo_kits.html

Keep in mind, turbos and chargers don't live quiet, sedate lives, and they don't die quietly either. They tend to die with great vigor and enthusiasm. With that in mind, it might be a good idea to move the turbo to a "better" place to die! ;)

[Ghinmi]

Why not just plumb in a nitrous system? Cheap, easy, simple. No extra parts spinning around to break. Power when you need it and a basic reliable motor when you don't.

[1977cherokeechief]

here in kansas if you get caught with a nitrous bottle in your vehicle it will get impounded, and not only that but you will get fines, and maybe jail time.

in the town that i work in, since they are so tired of all of the ricers they passed a law that if you even have the hoses ran, and hooked up to your engine they will do the above.:eek:


so, that is out of the question.

[snoopy]

Aeromotive makes a remote mount turbo kit for GM's that usually mounts back by the rear end on a camaro, it could be mounted where you want to. As Corky Bell mentioned in his book turbo lag only comes with a big turbo, in the meantime you will still be running on a healthy V8 untill the turbo hits and that's not a bad place to be. In the last few years a company called Rotrex has started making a planetary gear drive (step up) supercharger using turbo style compressor wheels that are more efficient. Too bad about the nitrous attitude there. It really is a good power source. I've been thinking about recycling a tubonetics ball bearing unit I've got on the shelf one day for Snoopy. It's the right size for a 258 and it has water cooling on the center section which is something you want if you go turbo. I would suggest strongly that you intercool no matter which way you go, both forced induction systems will make your engine prone to detonate, that intercooler may save your bacon. Really, intercool it, I promise I've scattered more engine parts on the drag strip than you have from going just a little too lean or you wouldn't doubt it.

[1977cherokeechief]

i was actually planning on intercooling, but, the "kit" says that you dont have to if you do not have the space, but i have the space, and my turbo(s) will be closer than behind the rear axle most likely... but like i have said. i am still going to decide, in the morning i will crawl under the jeep and take some pictures and decide where i will mount it.

as for the NOS, i would, but also the closest filling place for it is an 45 minute drive, and the laws, and you have to have a strip license to buy it.

[Charlie_B]

without an intercooler, you'll be running much less boost. And have alot more chance of knock. You need an intercooler on any aftermarket type turbo application. I know there are alot of non-intercooler stock turbo applications out there. But why skimp out on something that will drastically hold you back.

And I second the comment about heat not being a turbo's friend. It will get hot, no matter what. But you want it to be as cool as possible. And I dont think its a good idea to have a 1500-2000* turbo sitting right underneath the floorpan, next to gas tank, etc..

Two smaller topmount turbos would probably be the best bet. And it seems to me that it would be easiest to plumb. Main issues I can think of would be getting the custom manifolds made, most likely tossing the heater box, and doing one heck of a good job heat wrapping all of the brake components. Some nice louvers in the hood would work great too.

Ive got a book called "Forced Induction Performance Tuning" by A. Graham Bell that I use as a reference all the time. It has a ton of info about selecting appropriate turbine/compressor sizes and A/R sizes. I picked it up from Amazon. I think its a good buy, you should check it out.

Some form of methanol/water injection would be cool too. Especially if your thinking of going EFI. Most can get you up to around 110 octane w/ 91 or 93 oct pump gas. That is unless you want to run E85. 104 octane from the pump! :) I dont know what the options are with MAP switching with your planned EFI setup. But with my car, it is setup to run 2 maps, with a switch on the dash. 1 map for high boost w/ methanol (or E85, race gas, etc), the other for crappy 91 octane, low boost. Ive got the software, now I just need the money tree to allow the hardware. 100+ hp with the flip of a switch is about as cool as it gets to me.