Turbocharging a lawn mower

[tschwarting]

A single cylinder governed engine running 3400 rpm would respond to a positive displacement supercharger but you won't get enough exhaust to properly spin a turbo to get any midrange improvement. You need at least a twin cylinder engine for a turbo to work. The kits in your link are for multi cylinder 500cc or bigger engines. Trying to turbocharge a push mower would be very difficult and probably cheaper to just buy a mower with a bigger engine.

Think Tim Allen of Home Improvement fame = MORE POWER!!

 

[Mike88se]

I haven't been here in years and haven't played w/ turbo cars for a long time but when I got the email notification about this thread I had to read it. I figured it would be entertaining and it was. Also sometimes hilarious. Kudos to the posters who mentioned the necessity of pressurized oil and increased fuel flow.
OP: No oil pump = no turbocharger. Other posts made great points such as increasing the fuel capacity to match air flow. FYI, forced induction works by increasing intake air charge i.e. exhaust spins one side of the turbo so that the other side... the compressor side, compresses air going into the intake) and on a carbed engine that's tricky business. EFI engines of course can vary the amount of gas easily bc they have computerized engine managment... along with a fuel pump and fuel injectors and several sensors providing feedback to the ECU (the computer mentioned earlier) so that it can match fuel pressure to intake air, among other things. BTW there is no $75 turbocharger. The last turbo I bought circa 2008 cost about $800 and was not considered particularly expensive at that time. I do remember ebay turbochargers (and devices to make a car sound like it had a turbocharger) available from China which weren't real turbochargers at all but they sold like hotcakes to all the Honda fanboys. Some good folks on here have told you this is a terrible idea. Trust them on this. But part of me hopes you do try this. The results should be entertaining.

 

[Hammermechanicman]

Famous quote "Let's not confuse the issue with facts."

Still waiting for the link.

 

[EatPreyMow]

Those little engines aren't designed for boost, they are designed to be as cheap to manufacture as possible which means they aren't built to handle an extra 30% of power/torque. Even if you successfully tune the carburetor and achieve higher power output then it will at best mow slightly better for a while until the rod breaks or your head gasket blows. If you decide to raise the RPMs then you have the blade spinning far beyond design spec so it could fragment and cause a word of hurt for you or a bystander.

I see two alternatives.

1. Buy a larger displacement engine. It will be designed to produce higher torque at mowing speeds so there will be less bogging, and it will last. You won't mow your lawn significantly faster but it will be less frustrating.
2. Buy a better lawnmower. Get a wider deck or better yet get a riding mower. You will finish mowing far faster and you can sell your old mower since it hasn't had a turbo hacked onto it.

This is a good time of year to find deals on used lawn mowers so that's what I'd do.

 

[TobyU]

Have any of you used any of the following and what were the results?

Boosted Mowers. Lawn Mower Turbo Kit

If you're looking for a way to boost the performance of your lawn mower, a turbo kit is the perfect solution. With the right kit, you can increase horsepower, improve fuel efficiency, and get a cleaner, healthier lawn. Fortunately, Amazon offers a wide selection of lawn mower turbo kits that are...

www.outdoorpowerllc.net

Thanks
TBB

It's absolutely silly and absurd for anyone to be interested in this kind of thing for a lawn mower that's actually used to cut grass.
Even the current horsepower ratings we have, even though they're kind of a joke and erroneously high, still have far more power than we need to cut our lawns!

The only thing I can see this being worthwhile for are the play toys and race or pulling mowers people do.
This is not some makeshift play around kit but a real turbocharger and would certainly give huge power increases but it also would come with other complications with tuning and then with exhaust etc but I'm assuming anyone wanting to build this kind of power for pulling purposes etc is using a custom exhaust of a very large size or rather a dump and using the size to help tune exhaust scavenging etc.

Now in the play around version of Turbo charging lawn mower I've done that several times just for fun.

The quickest and easiest way has always been with a leaf blower but you can also use anything where you have a controlled or consistent flow of air like a shop vac exhaust or compressed air etc.
All you have to do is add an extra fuel source

So you take your handheld leaf blower whether it be gasoline or a battery powered one and then you drill you a hole somewhere around 8 in from the end of they discharged tube there where the air comes out and you pipe you a little hose brass fitting spray tip nozzle etc into there.
You need Subway to control the size of the bottom like a fixed orifice etc but many things can be adapted.
Then you run you a piece of tubing, preferably clear so you can see the fuel flow to a fuel tank source and when you blow the air out the blower it will suck the fuel out and you can adjust everything just right with your speed and with the orifice size so you're blowing a gasoline enriched mixture of air coming out of the end.
Now of course you can take this makeshift design a little further and turn it into a flamethrower too but none of it is very safe.

So you just pipe the leaf blower into the intake with various plastic hose and adapter assemblies like PVC or Shop-Vac accessories.
You can even get creative and make a little box with a rubber flap that falls down and is open when the engine is running and no air coming from the leaf blower so it sucks air not through the tubing and not through the leaf blower but in reality that's not really a problem because most leaf blowers will flow just fine and don't restrict the flow at all.
This way though when you pressurize the air filter intake and stuff with the leaf blower it will soft close the little box flap so the only air coming through is coming from the leaf blower with the gasoline mixture.

The problem is you really can't give it that much volume until you get up to pretty high engine speeds but if you had a situation where you kept the engine at constant RPMs or even if you eliminated the governor like many race engines do you could get it adjusted pretty decently.

 

[rdedrick]

It is a Murray walk behind mower and the grass is very thick and the mower sometimes has trouble getting through it. I have received numerous suggestions to add a turbocharger and get rid of the muffler. I have been told with this being an OVC that it will double the power and that the muffler is taking away power.

Sharpen the blade and narrow your cut. Or buy a bigger mower.

 

[Hammermechanicman]

Back in a previous century when the 5hp flathead briggs was THE engine guys running the unlimited class were running superchargers and alcohol. Some were centrifugal and some axial flow. Usually a belt drive off the crank. Pretty much aftermarket for everthing but the block, crank and flywheel. They made crazy power.

 

[wineman]

torque x RPM / 5251.1 =HP
In order to add a turbo you would need to also add some sort of pressurized oiling system. I am guessing that the kits you showed are for larger engines.

They said to use 90W differential oil and everything would be fine.

 

[wineman]

I haven't been here in years and haven't played w/ turbo cars for a long time but when I got the email notification about this thread I had to read it. I figured it would be entertaining and it was. Also sometimes hilarious. Kudos to the posters who mentioned the necessity of pressurized oil and increased fuel flow.
OP: No oil pump = no turbocharger. Other posts made great points such as increasing the fuel capacity to match air flow. FYI, forced induction works by increasing intake air charge i.e. exhaust spins one side of the turbo so that the other side... the compressor side, compresses air going into the intake) and on a carbed engine that's tricky business. EFI engines of course can vary the amount of gas easily bc they have computerized engine managment... along with a fuel pump and fuel injectors and several sensors providing feedback to the ECU (the computer mentioned earlier) so that it can match fuel pressure to intake air, among other things. BTW there is no $75 turbocharger. The last turbo I bought circa 2008 cost about $800 and was not considered particularly expensive at that time. I do remember ebay turbochargers (and devices to make a car sound like it had a turbocharger) available from China which weren't real turbochargers at all but they sold like hotcakes to all the Honda fanboys. Some good folks on here have told you this is a terrible idea. Trust them on this. But part of me hopes you do try this. The results should be entertaining.

I am going to work on it today and will report back.

 

[wineman]

I haven't been here in years and haven't played w/ turbo cars for a long time but when I got the email notification about this thread I had to read it. I figured it would be entertaining and it was. Also sometimes hilarious. Kudos to the posters who mentioned the necessity of pressurized oil and increased fuel flow.
OP: No oil pump = no turbocharger. Other posts made great points such as increasing the fuel capacity to match air flow. FYI, forced induction works by increasing intake air charge i.e. exhaust spins one side of the turbo so that the other side... the compressor side, compresses air going into the intake) and on a carbed engine that's tricky business. EFI engines of course can vary the amount of gas easily bc they have computerized engine managment... along with a fuel pump and fuel injectors and several sensors providing feedback to the ECU (the computer mentioned earlier) so that it can match fuel pressure to intake air, among other things. BTW there is no $75 turbocharger. The last turbo I bought circa 2008 cost about $800 and was not considered particularly expensive at that time. I do remember ebay turbochargers (and devices to make a car sound like it had a turbocharger) available from China which weren't real turbochargers at all but they sold like hotcakes to all the Honda fanboys. Some good folks on here have told you this is a terrible idea. Trust them on this. But part of me hopes you do try this. The results should be entertaining.

They said that using an octane booster will also be part of the deal.