15 more MPH

[alexanderfoti]

Hi all

My bike is great around town, but as soon as I get out of the city its scary as hell to ride on, geared top speed is 56mph, and its just too slow.

Now, I avoid riding it out of town and take another bike if im going to. Im wondreing what the easiest way to get 65mph out of the bike is. I think maybe 3 more bhp would do it.

Keen to keep fuel economy, Turbo is out as singles never turbo well (as people have seen on here). Back to supercharging then? Any other ideas?

[pietenpol2002]

Sell a kidney and then click on the link below.

http://kemotorsport.com/sc.htm

Or their home page for everything else you'll need to go with it.

http://www.kemotorsport.com/

[coachgeo]

This link is their motorcycle S.Charger build

http://www.kemotorsport.com/cafe.htm

[alexanderfoti]

Hmm I have grown quite attached to my kidneys I think the main reason I have stayed away from forced induction is complication.

I have read that the pcv system in the head needs to be blocked to prevent oil being injected into the intake, are there any other things I need to take into account? And amr500 with a v pulley would be quite easy. A bracket, a belt and some intake piping.

[gearhead1951]

Scavenge a turbo from a scrapped car , remove the exhaust driven turbine and replace with a pulley (after you establish how fast it will have to spin to provide the boost you want) and mount it up !

[alexanderfoti]

Scavenge a turbo from a scrapped car , remove the exhaust driven turbine and replace with a pulley (after you establish how fast it will have to spin to provide the boost you want) and mount it up !

That's seems like a nice cheap idea. How to figure out how fast it needs to spin though?

[Eddy Wane]

There are a few options to get more speed.
1. Lose weight.
2. Only ride downhill.
3. Tweak the gearing.
4. Add some streamlining.

You could get a little more power if the head was worked on i.e. polish the ports to improve gas flow and breathing.

[alexanderfoti]

There are a few options to get more speed.
1. Lose weight.
2. Only ride downhill.
3. Tweak the gearing.
4. Add some streamlining.

You could get a little more power if the head was worked on i.e. polish the ports to improve gas flow and breathing.

1. No can do, like my pies too much
2. I wish!
3. Gearing is perfected for this bike right now, as much posisble with the big jump from 3rd to 4th. I am in the power band constantly with this gearing.
4. That could do, but I dont think I would gain 15mph purely with streamlining?

[pietenpol2002]

And amr500 with a v pulley would be quite easy

Actually, the AMR300 is perfectly sized for your engine.

An additional 15 mph is quite a stretch. To increase your speed (in round figures from 55 mph to 65 mph) is a 15% increase. However, as the demand for power increases exponentially with speed, you would need something on the order of 16 hp. And that's not going to happen.
That said, you could gain a bit by fitting a less restrictive header pipe, which is the one area that limits the Yanclone the most. It's an abrupt turn directly at the head and almost appears to pinch down the ID. Were it not for shipping and taxes to the UK, you could have the propane fumigation system I built for my Yanclone. Only good for an 11% increase on a NA engine. Add a supercharger to the propane and you might see 65. But then you'd need the titanium trousers to shield the jewels.

[tappy]

Have a look on fleabay for Aisin 300 and Aisin 500 superchargers. They're a small roots type blower designed for use on 600cc kei car engines in Japan. There are quite a few of the superchargers going cheap - usually in Australia but shipping's not horrendous. Roots type super-chargers are reasonably efficient at low boost pressure and don't have complicated lubrication requirements.

This will help increase engine power output, but will not improve economy. The power absorbed by the supercharger at low pressures will be very low, but you're still using crank power to pressurise the intake and it takes the piston more power to then compress the denser charge. You do then get a far bigger power stroke, but with the same expansion ratio (fixed piston stroke) you do then throw away more energy out of the exhuast.

Increasing the overall pressure ratio will make it quite knocky at idle, so you could consider a small centrifugal clutch so that it only engages above 2krpm.

For an idea of supercharging power:
A 600cc engine revving at 3600rpm consumes 18L of air /second. This is 0.022Kg/second at atmospheric conditions.
Let's say you pressurise it by 3psig. P/P(14.696+3)/14.696 = 1.2 T'/T = 1.05. Assuming 75% efficiency the temperature rise will be 20deg C.
M*Cp*delT gives 0.022*1.2 * 1.004 * 20 = 0.53Kw, i.e. 0.7 horsepower.

I've long fancied making an electric super charger. Take the impellor from a hoover for example - they can absorb up to 1600W and generate 2 or 3 psi. People have been known to use them to make very basic gas turbines The flow coming out the back is so hot because they use it to cool the electric motor. Note - this is a very different proposition to the electric super charger kits touted on ebay etc, which are frankly a load of crap, especially in context of car engine flow rates.
OK, so you've then got to find a small motor (RC aeroplane or helicopter motor?) & 500W of electric power, but it might be an interesting experiment to see what difference a few psi can make.

Or alternatively, use a hoover impellor with a gear drive off the crank - you'd need quite a steep gear ratio tho'.

[alexanderfoti]

I actually had a amr500 floating around that I never got round to doing. 13-14hp wouldn't be too much of an ask, I would be sure to measure egt and oil temperatures. It would be nice to have a clutch on the pulley to have a switch for fuel economy or power! Hmm

[gearhead1951]

Gasoline engine leaf blower impeller and scroll + Electric motor sized for the application = electric supercharger ! Good for sudden acceleration but not for constant high speed running !!

Hook that impeller and housing up to your crankshaft and you have a setup for constant boost that IS good for cruising !

Google "turbonique"

[Blunt Eversmoke]

Scavenge a turbo from a scrapped car , remove the exhaust driven turbine and replace with a pulley (after you establish how fast it will have to spin to provide the boost you want) and mount it up !

That's seems like a nice cheap idea. How to figure out how fast it needs to spin though?

Around 120 000-180 000 RPM for about any the run-off-the-mill Euro car turbo, a few 10 000 RPM give or take. Of course, then, there are the exots like the ones mounted on Smart turbodiesels that spin as fast as 290 000 RPM
For turbos found on small to medium trucks, 100 000-130 000 sounds about right; I belive, turbos used for US V8 also spin about as fast.

If one were to drive the compressor section of a turbo from the engine crank, problems due to side-load on the impeller axle could arise - there is supposed to be very little side load on the axle of a turbo, after all, and at the RPMs we are looking at, the smallest disbalance will chew up the impeller bearings faster than you can say "Dagnabbit!", possibly sending pieces of the impeller or the pulley flying through the air, bike parts and your gonads.
Has anyone (heard of anyone who has) driven the compressor of a turbo off the engine crank? How is that problem handled? Is it a problem at all (might be just me being overly careful)?



Regarding turbos on singles: Most of the problems result from the singles giving their exhaust (and taking in their air) with heavy pulsations. Now, common car turbos are constant-flow, so they are hard to get to work even on double-barrel lumps (according, among others, to users on this site).
However, there are turbos that are specifically made to work WITH pulsations (I don't know if they are actually called pulse turbines or what); while all of these are also made with multi-cylinder engines in mind, I can imagine one could get them to work on singles as well, and easier that a constant-flow turbo, provided one knows exactly what one is doing and the math is done properly.
Alas, I have never looked into this topic in any depth, so don't know if there are any car turbos of that ilk and if yes, what makes they are and what cars they are used on

[gearhead1951]

When I was young one of my insane neighbors took a turbo off of a road tractor diesel and turned it into an engine driven supercharger for a 300 cid ford I6 , He put the compressor driven pulley (the one on the compressor shaft) in between two High speed bearings so that the compressor did not see any of the side loads you refer to !

This thing was geared to be 8 to 1 ( 7000 engine rpm = 56000 impeller rpm)

Get the largest displacement turbo you can fit to start because it can provide the boost you need at a lower rpm than the little ones !

Good luck and please keep us posted !

[tappy]

Has anyone (heard of anyone who has) driven the compressor of a turbo off the engine crank? How is that problem handled? Is it a problem at all (might be just me being overly careful)?

There are loads of crank driven centrigufal supercharger kits available for car engines, but yes they do have different - but not exotic - bearings. If you were wanting to use compressors salvaged from exhaust driven turbos then you could use two compressors back to back and this would generally cancel out the pressure loads.

However, there are turbos that are specifically made to work WITH pulsations

There are indeed, but they're designed to have lots of pulses coming in quick succession from a multi-cylinder engine. It's more designed for good cylinder scavenging than a conventional turbo set up, but I don't think it would be any more successful than the ordinary turbos people have tried.

[albertaphil]

Did I miss the thread that concluded that our little singles and twins cant develop boost with an exhaust driven turbocharger? I thought the issue was that they needed to be intercooled too. 4 years ago I remember that guys were getting 5+ psi of boost but that power would drop off after a bit, presumably due to heat soaking of everything.

So, have we had an example here of an unsuccessful turbo/intercooler setup?

[tappy]

Scavenge a turbo from a scrapped car , remove the exhaust driven turbine and replace with a pulley (after you establish how fast it will have to spin to provide the boost you want) and mount it up !

That's seems like a nice cheap idea. How to figure out how fast it needs to spin though?

Flow characteristics (chics) are available for most turbo-chargers, with a chic for the compressor and a chic for the turbine. This will show the relationships of speed, pressure, flow rate and efficiency.
It's easy to work out what flow rate you need at a given pressure, engine speed and an assumption for efficiency. The problem you'll have is that with the engine drawing pulses of air through the compressor the flow rate will rarely be what you calculate and most often be either stalling the compressor or totally unloading it. This is not likely to do the geared transmission from the crank any good.

If you've got an old Aisin supercharger I really would use that - at low boost pressures it will be far simpler to implement, more efficient, more predictable and more effective.

[coachgeo]

stealing from some of the ideas presented here already I searched the net for some info about smog pumps as superchargers. Apparently its done semi-often at least in the Go Kart MiniBike world

http://www.diygokarts.com/vb/showthread.php?t=2579

http://www.youtube.com/watch?v=p3bQ8xKfBAU

http://www.youtube.com/watch?v=gERfFq8eAK0

http://www.youtube.com/watch?v=tCQLo8EvGPU

http://www.youtube.com/watch?v=cL9HARsn2mg

German with website that sells them? Close look at the blower on the website makes me think it is a belt spun vacumme cleaner set up.
http://www.youtube.com/watch?v=s4v5OX60e48
http://www.f-tech.ch/

Aisin Supercharger
http://www.youtube.com/watch?v=tCURXinXoEg

Side note- Turbo converted to supercharger
http://www.youtube.com/watch?v=ILlk9yPyHZ0

[alexanderfoti]

Thanks Coach, lots of info there!

After seing Tims turbo'd Z482 at the Big knock im convinced thats the best option going forward. I had a ride on it around the roads near the bat and ball and accelreation was really great, only coming on boost when accelerating, then back to nearly no boost at 50mph on flat ground, its a great combo becuase It gives you cruising capacity, and if you put a manual box in it, keeps the efficiency.

[coachgeo]

Well for sure bumping up to a higher HP engine like the Kubota Z482 is going ot get you the ponies you were seeking. W/turbo should work out great.

[alexanderfoti]

OK revisiting this. I'm not going to have time any time soon to change engines so I am re visiting the smog pump supercharger idea.

I have a 1995 sl 500 belt driven secondary air pump (vane type) on its way. After I get the pulley off, it will be interesting to see what sort of shaft arrangement there is. Hopefully I will get a taper lock bush on there, then easily mount an spa pulley.

I have read about small engines making 5-7 psi of boost, but they are normally 50cc jobbies. Interesting to see if I can generate any boost on a 400.

Any ideas how to test boost making capability before welding on the mounts etc?

[Diesel Dave]

Strap it to an electric motor, run it up to speed with a closed chamber attached with a pressure gauge to read the boost.

BTW on a single I'd go for 3x enine capacity for a plenum chamber (or better still an intercooler).

[alexanderfoti]

Strap it to an electric motor, run it up to speed with a closed chamber attached with a pressure gauge to read the boost.

BTW on a single I'd go for 3x enine capacity for a plenum chamber (or better still an intercooler).

Thats what I thought. Im going to just put it in the middle of my primary drive belts (hold it there) and see what it makes that way,

[Diesel Dave]

Try and be a little careful...it will take at least half a horse power to generate any meaningful pressure and you won't hold that in your hand.

Even if your built like Arni Scwartzerfella.

[alexanderfoti]

Try and be a little careful...it will take at least half a horse power to generate any meaningful pressure and you won't hold that in your hand.

Even if your built like Arni Scwartzerfella.

thats a point.

Its a catch 22 isnt it, cant check the boost pressure without building a mount for it, and, dont want to build a mount for it incase it doesnt build enough boost.

[Eddy Wane]

Just an idea after reading your posts. What about fitting a small compressed air cylinder and a release button on the bars to inject air when required, a bit like the nitrous add on. Or for a lesser effect of supercharging move the air intake to the front of the bike and funnel more air into the engine the faster you go.

[alexanderfoti]

Just an idea after reading your posts. What about fitting a small compressed air cylinder and a release button on the bars to inject air when required, a bit like the nitrous add on. Or for a lesser effect of supercharging move the air intake to the front of the bike and funnel more air into the engine the faster you go.

Good idea, but I want to increase the overall top speed so it would have to be a constant boost type scenario.

[boutje]

Why a turbo or supercharger?

I think with a good design exhaust system , a open airfilter and a little bit of port flowing you get the extra power needed.

[alexanderfoti]

Why a turbo or supercharger?

I think with a good design exhaust system , a open airfilter and a little bit of port flowing you get the extra power needed.

I don't think it will give another 15mph although my air and exhaust pipes are pretty open flowing.

[tappy]

I have a 1995 sl 500 belt driven secondary air pump (vane type) on its way.
Any ideas how to test boost making capability before welding on the mounts etc?

Any idea what speed these normally turn at?