Electric turbo or big bore kit

[briggsandstratton123]

i have a 125 cc 4 stroke engine for a go kart and i would like some more power, i can get a big bore kit (150cc) or and electric turbocharger kit for a similar price. which option would offer more power, and would be better, i imagine the turbocharger would do more for top end power but i'm not completely sure

 

[Hellion]

By all means, let's see the electric turbocharger kit as well as the 125cc engine.

 

[Bwdeaton]

ELECTRIC TURBOCHARGER IS A SCAM AND DOES NOTHING.

Good, now that's out of the way, what buggy and engine do you have? You may beablr to do a big bore kit but 125 to 150 isn't going to be that noticble, but is it is a GY6 then you cna do a 125 to 180 which is actually noticeable. I've done the 180cc BBK on a 125 and it definitely improved acceleration.

About a year ago someone started marketing the idea of an "electric fan turbo charger" and sold a lot of them and if you look, You will see that there are no changes in the dyno results by adding an electric fan to your intake. You simply cant get enough pressure to make a difference.

 

[bob58o]

I've seen the Electric fans and guessed it is more of a restriction than a boost.
I don't think I've seen them on a small engine.

Get the AMR300 or AMR500 so I can watch and steal info.

 

[OzFab]

Following on from what Bwdeaton said:

An electric fan spins at a constant speed where an actual turbo spins in line with the speed of the engine, ie: the faster the engine revs, the faster the turbo spins...

If anything, you would only see a difference at low end RPMs; once the engine reaches a certain speed, the fan then becomes a restriction (as previously stated) because the engine requires more air than the fan can provide

 

[briggsandstratton123]

ELECTRIC TURBOCHARGER IS A SCAM AND DOES NOTHING.

Good, now that's out of the way, what buggy and engine do you have? You may beablr to do a big bore kit but 125 to 150 isn't going to be that noticble, but is it is a GY6 then you cna do a 125 to 180 which is actually noticeable. I've done the 180cc BBK on a 125 and it definitely improved acceleration.

About a year ago someone started marketing the idea of an "electric fan turbo charger" and sold a lot of them and if you look, You will see that there are no changes in the dyno results by adding an electric fan to your intake. You simply cant get enough pressure to make a difference.
It's one of those chinese semi auto unbranded pit pro/lifan type motors, and the buggy (not acturally finished) is a home built single seater sort of suspension, probably 70-90 kg when finished go kart/buggy. that weight isn't that heavy but therre are a few hills to climb and i would like to be able to comfortably tow a very small trailer with small loads, so more torque/power would be useful

 

[Bwdeaton]

That engine is somewhat limited in what you can bore it to, due to design. Maybe 140cc-150cc max because you the cylinder studs are too close to go larger. It can work to climb hills by being geared low enough to make it up all the hills, but you may not have much top end speed.

Is the motor and automatic or integrated 3 speed/4 speed transmission?

Can you post pictures of the project?

 

[Flyinhillbilly]

I've seen the Electric fans and guessed it is more of a restriction than a boost.
I don't think I've seen them on a small engine.

Get the AMR300 or AMR500 so I can watch and steal info.

AMR300 is the next planned step for my minibike. I'll blow stuff up, you can watch and learn what not to do, lol. I figure it'll be a lot like my learning curve was on turbos. I made a lot of good parts into scrap learning what I know.

 

[Bwdeaton]

By all means, let's see the electric turbocharger kit as well as the 125cc engine.

Hey if I find the free time I'll look into trying to see if the concept works on a Briggs 1450 305cc. I just got access to a small engine dyno and already have a leaf blower and the motor.


Sent from my iPhone using Tapatalk

 

[OzFab]

That's not exactly the same thing... same concept but, a leaf blower can create wind speeds up to 100mph; I doubt a $12 electric fan will go anywhere near that... maybe 10mph... but, by all means, have at it...

 

[bob58o]

AMR300 is the next planned step for my minibike. I'll blow stuff up, you can watch and learn what not to do, lol. I figure it'll be a lot like my learning curve was on turbos. I made a lot of good parts into scrap learning what I know.

I'm just starting to research.

I'm thinking the AMR 300 or 500 on the 420cc, but that's a different thread and pipe dreams perhaps.

 

[Bwdeaton]

I wonder what kind of Hp gains you would see from a small supercharger. How are you thinking about attaching it?

 

[Predataber]

Electric turbos have been debunked. Even the ones based on variable speeds. A fan just isn't enough, I think there was a myth busters of something on this. AND they did wind up using leave blowers too.. Best bang for you buck, maybe a port and polish when you are in there with the big bore kit and index the plug? Good Luck.

 

[bob58o]

I wonder what kind of Hp gains you would see from a small supercharger. How are you thinking about attaching it?

I was thinking draw through carb.

So the supercharger will sit between the carb and intake port.
I'd need some sort of pop off panel so I don't blow up the sumnaB.
The whole supercharger can fill up with fuel air mix.

Or if somebody says blow through is better, I'll go that route.

 

[Denny]

Draw through superchargers have been working successfully for over 100 years now.


Denny

 

[bob58o]

I wonder what kind of Hp gains you would see from a small supercharger. How are you thinking about attaching it?

Lots of compression.
Lots of cfm.
75% to 100% gain????

30+ HP from a 420cc??

 

[Flyinhillbilly]

I was thinking draw through carb.

So the supercharger will sit between the carb and intake port.
I'd need some sort of pop off panel so I don't blow up the sumnaB.
The whole supercharger can fill up with fuel air mix.

Or if somebody says blow through is better, I'll go that route.

IMO when it comes to a roots style supercharger that draw through is superior. I figured I'd mount it the same way I mount everything else. I just put it where I want it and build to the nearest available mounts. I think the percentage of under drive will play a huge role in how feasible this ends up being.

 

[bob58o]

A 212cc 4 stroke engine uses 106cc per crankshaft revolution.
A 420cc 4 stroke engine uses 210cc per crankshaft revolution.

A boosted engine needs 50% more air at WOT?
So a 212cc 4 stroke supercharger should pump 160cc per rev?
A 420cc 4 stroke supercharger should pump 315cc per rev?


The AMR300 pumps 300cc per revolution.
The AMR500 pumps 500cc per revolution.

The AMR300 driven at 1:1 might be right for the 420cc?
The supercharger driven from the TC jackshaft?
Underdriven at 2.5: 1 at engagement?
(will this be a problem? say if the pump is only putting out 120cc per crank rev - instead of the 210cc a NA engine wants? Is this just less boost? Or is this a restriction at low RPMs?)
1:1 driven when TC is in High gear?
Boost will increase with RPMs until TC gets into High Gear.

I'm thinking 9:1 static compression 6-8 psi of boost for around 13 or 14:1 effective compression.

 

[Flyinhillbilly]

something your not considering is the fact that the crank will make two complete revolutions per intake cycle. Boost is kind of a funky thing, ideally 14.7psi in the intake would effectively double your power output given everything else is tuned correctly, but it's not that simple. I figure getting the amount of underdrive right is going to be the trick.

 

[bob58o]

Sorry.