Turbocharging....Questions

[The Lorax]

Has anyone actually put a turbo on their XS? I have a mitsubishi turbocharger that I am getting ready to remove from a dead volvo, and I am debating on what to with it. would I have to fuel inject it? how does one go about dealing with the additional compression generated by the turbo? I am just in the concept stages at this point as I was considering rebuilding the engine in the volvo, but have decided to junk it, but I want the turbo...for what I don't know yet, but I want it. any thoughts? thank in advance

[DiverRay]

The Volvo turbo is probably too BIG for the XS1100. I'm looking into a turbo for my winter project, and DO plan on fuel injection.
Yamaha had a 650 Turbo in '83. The system worked well, but it had a LOT of lag, almost 1.5 seconds IIRC. I owned and rode one until I was met on the freeway by a drunk driver.....
It would pull the front end up in 3rd and 4th gear, just with the throttle.
There is a GREAT book on turbocharging, by Hugh M., if I remember. I will look at the book shelf when I get home, and post the exact info on it. It is THE book for anything turbo,. I would start with a read, and then choose a turbo size after.
Ray

[The Lorax]

Secondary thought....what if I removed the blades on the input shaft, installed a pulley and belt drove it...essentially making it a supercharger...no low end lag...I don't know, I'm just kind of kicking around ideas here. it would be fun to make it work, and I could gear down the "Supercharger" so as not to overboost my little beastie and make a mess out of a fun toy....like I said, just kicking around ideas....thoughts?

[HobbyMan]

Whats the difference between a turbo and supercharger? Yes, you would need a fuel injection system. Carbs work on (-) manifold pressure. With a turbo, you have a + pressure. How about a fuel injection maifold from a newer yamaha? The only problem is that new manifolds with all the goodies from a new bike will probable runn about a grand. (at least thats what some of them cost) What effects would it have on the transmission gears?

[The Lorax]

as I understand it, the difference between the two is that a turbocharger is driven by exhaust gas turning a propeller...turbine...whatever it's called and a supercharger is belt driven off of the crankshaft or some other place to run a belt. you don't get the low end lag with the supercharger that you get with a turbo because when you hit the throttle, the belt drving the supercharger spins it up immediately, giving virtually instantaneous boost. as opposed to having to wait for the exhaust gas to spin up the unit and create boost. I was thinking, if I could get a pulley mounted to the crank on thetiming side, machine a new timing cover that allows for a belt to be looped through and fed to the boost drive, make or buy an EFI system...with O2 sensor feedback. and see what I get...if nothing else, could be fun to figure out. Still a lot of thought and development work to do. just thought I'd get some opinions. what the hell right, I mean, what's the worst that could happen??????

[TopCatGr58]

Hey Andrew,

If you were paying attention, in Lorax's second post he talks about not having the Turbo driven by the conventional method....which is from the exhaust gases, but putting a pulley on it and driving it directly from the engine, crankshaft, kinda like this!


This was posted to the Yahoo group a couple of years ago, I have NO SPECS!!!

However, a guy that races his TURBO'd XS finds himself twisting driveshafts every season! YMMV!
T.C.

[jeffe]

Just a thought. A turbo or a supercharger will work with a carb. If you go back and look at the early years of performance cars you will see many that were supercharged and used a carb. Bugattis, Alfa Romeos, Mercedes, Auto Unions, ERA,BRM's Studebaker Avanti's and Super Hawks. One of my favorite unreachable classic cars is the Blower Bentley. It had the blower mounted out front of the radiator with just some screen to keep rocks out of the carbs. IIRC the 650 Turbo Seca used carbs. Some of the carbs were mounted with the supercharger blowing thru the carb, some had the supercharger mounted pulling from the carb. There were even some that had the carb mounted in "box" so the whole system was under presure. But I do think that a FI injection unit that took into account the air pressure would be the best way to go.

[jeffe]

Sorry meant to put this on the other post. It is true that a carb on a unsupercharged engine needs - negative pressure or a vacuum to operate. That is how the airflow is created to cause the fuel to be mixed properly with the air. We get the vacuum from the downward intake stroke of the piston. SO other than the issues you may have with getting fuel delivered to carb against + positive presure or supercharging ,it would not make a difference. It just needs a flow of air thru it to provide the explosive charge needed. As an example. Tractor pulling used to be pretty much a county fair thing with stock tractors. some diesel some gas powered with a carb. A guy installed a large air compressor tank and connected it to the carb on a his tractor. The fitting was a large hose the same diamenter as the carb and held with a couple of hose clamps. He would open the valve just as his pull started. Whether it actually gave him more power, who knows. But it at least it did not make it run worse.

[mro]

go for it

From what little I've read, stock rings may not hold up to a turbo and with the stock compression, engine would not last too long with a boost of more than about 5 or 6 pounds. Missed a deal on a couple of 650 turbo's a year ago. Would have been nice to get most of the compoents at the same time. Right now a turbo XS for me is way down the road.


mro

[Mathh]

Originally posted by jeffe
SO other than the issues you may have with getting fuel delivered to carb against + positive presure or supercharging ,it would not make a difference. It just needs a flow of air thru it to provide the explosive charge needed.

In order to get this setup working you have to pressurize the carbs otherwise at boost the fuel will be pushed back into the fueltank! Sucking through carbs requires special seals within the turbo or charger.

[oseaghdha]

I don't know that you could drive the turbo to an adequate RPM with an external belt. They generally operate in the 70-150K RPM range.
And the ratio on a turbo is not linear, as with a supercharger.
The boost increases the exhaust gas flow volume over and above the flow generated by the pumping action of the engine, which in turn, drives the turbo faster.

$.02

[DiverRay]

The book I think you should read is Turbocharging by Hugh MacInnes.
This will give you all the information you need.
Ray

[xsivepower]

When turboing the xs11 you can use the stock carbs(blow through) or use one "larger" carb and put it in the intake of the turbo and have a "suck through".I personaly am building mine to be a "blow through".I have the help of my brother-in-law who used to be a mechanic for Harley's drag racing team. So with his help I should have it on the road by summer.
Things you must know or have for this setup
A new intake manifold(I made my own)
A turbo header( I made my own)
A turbo (got one off John Deere 244J,small AR .35 outlet,builds boost fast on this 1.5L 3 cyl. but is oil cooled)
Check Aerocharger or Raja for sealed turbos
Fuel pump (electric adjustable-0 to 10 psi) gravity just dont do it
Fuel pressure gauge
Blow off valve (adjustable -0 to 20 psi)
All the ducting
Boost gauge (0 to 25 psi)
Lots of Jets of all kinds and sizes for these carbs
The big thing is to make the hole system sealed tight
The list goes on
I got the turbo for free and am in to this about $600 so far
My brother-in-law says to not go over 5 psi of boost on the stock internals or BOOOOMMM
Oh and the jetting is the bigest thing we are working on.I got it runing but its to lean in the upper RPM's and starves for fuel at 3 psi and 5000RPM.
I also have experience turboing my 68 Pontiac LaMans with a 250 inline6 and my 2004 Neon 2.0 4 banger

[Mathh]

Originally posted by xsivepower

My brother-in-law says to not go over 5 psi of boost on the stock internals or BOOOOMMM

You can run it safely up to 8 psi with stock internals and gain 25-30 hp that way. Everything above requires modifications.
That's what American Turbo Pak told me in 1980 and that's what I rode the first three months. After those three months the itch starts to screw in the wastegate and soon after that you will be the proud owner of your first set of four melted pistons
Tip: buy a better clutch anyway (plates and springs): you will need them!

[mro]

getting XS'ive?

Check this out.......
http://vmaxoutlaw.com/tech/dyno-mikuni.htm

can drill out your mains to get the fuel flow you need.

DynoJet jets are marked according to the diameter of the hole in the

mro