What kind of engine and setup are we talking about?
Fab simplicity or parts availability can also be drastically different.

 

Turbocharger. No belt system to worry about. No front drive bracketry to hack and fight with. You are taking wasted energy and putting it to work creating more power.

Tap into the oiling system, alter fuel/timing as necessary, mount and plumb, done.

Furthermore - junkyard turbocharger options outweigh junkyard supercharger options by at least 500-to-1, and turbochargers are actually very simple to repair. Of course it is very easy to spend a lot of money, and it is possible to use some very finicky, high-zoot stuff - but turbochargers don't HAVE to be that way.

A little more background on what you are doing would be helpful. As in, base engine, target power level, fuel type, what is it going into?

EDIT: wanted to also make the point; Every modern over-the-road truck in use today is supercharged by a very reliable turbocharger.

 

Turbocharger....You are taking wasted energy and putting it to work creating more power.

It takes exhaust pressure to spin the turbine. 10 psi of boost requires 15-20 psi exhaust pressure. Generating the exhaust pressure takes work. Turbocharging is not free horsepower. My guess is that generating any positive manifold pressure takes the same amount of HP from the engine +5-10%, whether it be rotational losses from a belt or pumping losses due to increased exhaust pressure. The difference would be in the efficiency of the compressor.

I say roots type. An Eaton M90 from a ford supercoupe would be easy to adapt to any engine and could be set up with an intercooler easier than a traditional intake mounted blower. But remember that the low air speed generated by wheelin won't make the intercooling that effective.

 

I was looking for generals, but mine is,

2.5L multi port fuel injected 4 cyl.
200:1 crawl, 4000lb rig.
Shooting for a reliable 200-250hp at the flywheel.

Street time, trail riding, and occasional rev limiter, Not much high speed stuff.

I have access to a few M90 superchargers, and a range of turbos. I have a few skills to build all the bracketry, and I can figure the electronics, just tossing around which direction to go.

**Edited to M90 because I'm a dumbass.......

 

how easy is it to pull oil pressure off your motor? if you have any oil pressure sender, bungs, etc it will be fairly easy. if not you might even have to do something like tap the block. then a drain into the side of the oil pan or maybe the block. I'd generally consider a turbo a bit cheaper to fab up since it can be a mostly DIY affair with tube and plate, no real tolerances to build to other than flange sealing whereas a supercharger you'd have to have some machining done for pulleys and alignment is critical. an M90 wont have to have a big drive ratio to get the pressure you want, but the eatons are known for pushing some pretty hot air. probably a must to intercool or water injection. also M90's are pretty big taking up lots of room under hood when mounted off the side of a motor and have a really long snout making you mount it way back. for your power goals an M62 is a lot smaller and cheap to buy but wll push hotter air at the same cfm's than the m90. an m38 is too small for a 2.5L imho. there is info on the net somewhere to help calculate what drive ratio to use.

 

Ok, that helps. And now I can see the dilemma. Just hanging an M38 up there in the neighborhood of where the AC compressor would have gone would make your life pretty easy.

However, I still vote turbocharger.

 

That, and no extra exhaust plumbing, it has a self contained sump for the oil, and will still reach the power numbers I need.


But thanks

 

Can I get some more info on these M38 sc's? a google search yielded this thread and a bunch of stuff on old jeeps. I'm looking to sc my 22r and the Camden roots setup is about all I can find. I like the self-contained oiling system you are describing, as it looks like all (e) ports on the 22r/ e are pre-filter.

 

They came OEM on the old T-bird supercoupes. I've got a ton of links to builds using them, I'll try to dig them up in a couple.

Dammit........M90. Same as the sc3800s.

 

I saved these links because I'm playing with the idea of a twin supercharged junkyard big block.

http://www.toohighpsi.com/ Click on the t-bird pic in the supercharged header.

http://www.thirdgen.org/techboard/fabrication/541544-twin-m90s-under-firebird.html

http://www.jalopyjournal.com/forum/showthread.php?t=271245


And apparently I had a brain fart, I meant M90. Might help your search a little more......

 

If you watch any of the BTG videos you can watch Carey from Got Propane wheelin with his turbo 22re buggy. You'll see he sits at the bottom of climbs and spools up the turbo before hitting a wall. Don't have to do that with a supercharger.

However a turbo will boost based on load. So more load gives more boost. A supercharger is based on rpm. More rpm gives more boost.

Leni

 

But if you're only looking for 10psi, the turbo wouldn't have to spool far, and the supercharger wouldn't help any once it hets the blow-off.

 

I prefer roots blowers. Turbo is nice as long as it on the small side to keep lag at a minimum. But no matter what to make power you always have to spool the turbo.

As for a roots blower

Builds tons of low end torque.= Good for crawling
More friendly power delivery. = No spike in power as boost comes on.
No lag. = Just mash the pedal as its always there right off idle.

 

I think it totally depends on what you are doing with the motor. If you are going to keep it strung out at high RPM's regularly, then the turbo is going to lend itself to that. But if you place value in a smoother, wider powerband, then I would go blown.

I spent the weekend riding shotgun in a desert car with a cracked out little turbo Ecotec on propane turning out over 500 hp. It's just crazy how violent the acceleration is once the power comes on, but that delay is ever present. The owner is just waiting for that little guy to finally blow up so he can toss in something bigger that makes power everywhere, not just up around 8500.

Horsepower sells cars, but torque wins races.

 

What transmission do you have?

I have two wheeling rigs right now. A turbo charged one and a supercharged one.

I like the turbo with a manual trans. You can drive around the lag without really noticing it at all.

If it is auto, the supercharger would be my choice for sure. Power right off the line for climbs. And I am assuming thats what you want the extra power for since you mentioned you didn't do too much fast. Hope that helps.

 

spidr go turbo -

our buggy runs a 2.5 that we put a turbo on that is running 7 psi. it is a diffrent animal.

it has a klune 4.1 dana 300 2.7 (whatever stock is ) and 5.13s with 42s - with a slight stall converter.

it has verry little lag and is compact. it would not spin the tires in 2.7 it the tranny was cool it might spin them but not really. after the turbo it will smoke them into 3rd. i can shoot you some pics if you like. autos are great with turbos, just power brake them a little, get the spool and it just goes. blowers need rpm - turbos can build boost without the rpm it sized right

 

It's got a manual, it won't be going to an auto, I like a clutch. 231-300 doubler, getting a 4:1 kit soon enough.

The big issue is that it is lacking on climbs as was suggested^^^. It's currently got 4.10s and 35s, but will be going 5.88s and 40s. Running double low, it will bounce off the rev limiter in 3rd, but bog out at 3000rpms in 3rd. Just needs more power.

What 2.5 are you running? I'll pm you my email if you could send me some pics and details.....

 

I have a turbo'd 2.5 as well, but it being diesel it probably isn't that relevent to you. :laughing: With a clutch you can drive around the lag. Makes a turbo probably the right choice for you. As long as your drivetrain is up to the occasionaly clutch drop.

 

rotary muffler is the only way to go.

 

i turbod my lexus crawler about 4 years ago. currently running 10lbs of intercooled boost on a 4.5L 24v DOC yota 4.5L 1fzfe. i am on my second manifold, a rebuilt turbo, 3" exhaust, added water jacket, highflow cat, and a rebuilt head and headgasket. she even passes smog better than ever.

I bounce her off the rev limiter on a regular basis. she gets 50w racing all the time, and tranny has an extra filter and gets cjanged synthetics regularly.

since the turbo has been installed i have run 31's, 35's, 37's, and now 42's. she had 4.11's at one time but now has 5.86's and tons. the tcase has new gears from Marks in Australia.

only has around 325hp but on paper should have 375lb/lbs. no race car but nice

i have wheeled her in lots of rocks: moab, hammers, st george, dusy, dunes, miles and miles of rockcrawling in the sierras by my home.

the turbo is good for only 3 things: on the flat road, climbs, and in the sand. it is not cool for technical wheeling at all. when she had 4.10 gears she was not low enough. on steep climbs the torque converter would start to load and the engine would start to load, then the rpms would start to build and all of a sudden BAM she would boost and i go flying over the rocks.

Once i regeared her she was 50percent lower and now i never get enough load on her to enter boost wheeling. but sand and long rocky climbs are much more fun.

i wouldn't trade the turbod 1fzfe for a stocker ls1 but my new rig is all ls3.

take the money you will spend on forced induction and buy a SBC with tbi. you will be dollars ahead and faster

 

take the money you will spend on forced induction and buy a SBC with tbi. you will be dollars ahead and faster

Not an option. But thanks.

 

then take the turbo. it is more reliable and likely cheaper.

turbo build here
http://forum.ih8mud.com/80-series-tech/88793-turbo-build.html

 

turbo

 

I knew you where going to say that.........And it's the way I'm still leaning. But I had this option open.

 

I have been wondering the same thing... contemplating between a Nissan VG30ET and a VG33ER, both on propane. I'll be watching this thread. :smokin:

 

A M90 would be a good choice, mount it in any orientation, make good boost on that smaller motor and it's easily enough modified to fit.

 

air to water super cahrger has my vote m90 m62 are cheap. instant torque and hp, in order for a turbo to do that a smaller turbo is required which means lets say at 4500rpm it's maxed out vs supercharger keeps on making power.

power differecne is like big block vs 2 stroke

 

How does one inter-cool a blower that is normally mounted directly to the manifold?

 

Uhhh, you sure you want to stake your claim on that?

 

Man, I'm a turbocharged guy all the way--and on an engine that size, turbocharging would be the cheaper route if you can do it yourself. But no way I would turbocharge a crawler that wasn't at least a v8 if I could afford to put a positive displacement blower on it instead. On the upside, it would be easier on parts.

 

I like the instant, predictable power of a roots style forced induction system then a turbo charger off-road.

 

Supercharger, root style, boost at low RPM for crawlin' and the majority of wheeling in which you are not banging off the rev limiter.

I run 8lbs max and get 5 or 6lbs off idle under load. You don't need an intercooler at 10lbs, though cooler air means more power.

I haven't run a turbo but ran a turbo style supercharger, got no boost till about 2,500 RPM, the roots style is on when you mash the pedal!

This on a small block Ferd, Powerdyne blower then roots style Kenne Bell.

 

I love centrifugal superchargers for some reason

 

Dude chuck a v8 in and save your self the headache.

I have seen your rig wheel and know the train in your area.