Cost and fabrication wise, would it be better to put in a higher output and heavier engine, at the cost of fabrication...
Or the time spent setting up a FI GS500 engine, and putting a small output turbo on it? (like, the chevy cruise)
I know the 2 websites about the turbo'd gs's, and the general idea that it results in a grenade. Small turbo + low boost (4-7psi, stock impreza turbo), and a properly tuned fi setup, should at least insure I dont melt the pistons...
The most expeditious and probably the cheapest route is probably to buy a higher output engine along with the rest of the donor bike and ride that bike instead of the GS.
If your goal is the project then pick the one that most appeals to you.
My goal is the project. :thumb:
Turbos on a bike this size are bad news... Lag can kill you, ie you hit a corner and halfway through your boost kicks in and your rear tire lets go...
Honestly I would build the engine... you can get 70HP from a GS500 engine... Do that... it will be more useable on the street than a turbo and handle better than a 600 engine in the 500 chassis...
Agree with the turbo. Could be dangerous if it lets go.
I have read about people trying FI. The biggest issue is getting the mapping just right. Not an easy feat. Most just get an engine with the FI already configured and go that route instead of taking an existing carb bike and trying to throw on FI.
the chevy cruze turbo would be far too large for this application. you wouldn't start building boost until redline. have to do some serious research into turbo efficiency maps to find one that would work with such a small engine.
if you got a smaller turbo and an FI setup, it might work. you can tune the sudden onset of boost out of the system by correctly managing the wastegate and blowoff/bypass valve settings. i think megasquirt has provisions for managing boost. you would most likely need to add several sensors to get it set up correctly, including EGT, o2, knock, boost, etc.
the other thing to consider is packaging. you'd have to sort out where to put the turbo so the engine still cools, how to package the BOV/BPV, how to route the wastegate dump tube, construction of an intake manifold, and charge air piping.
not trying to scare you, but just slapping on a turbo is no small task, and you'll put a hole in your block the first time you get it wrong. and that block sits under your nuts.
It seems to me that a turbo plus the GS's air cooled engine would be a bad idea. The engine already consumes a little bit of oil on a good day, and with the extra heat that a turbo would create it seems to me that you'd be running dry and hot very quickly.
I think the main issue is blow-by, which would most likely get much worse with turbo. Oil gets pressurized out of the crankcase breather and then burned or lost to the atmosphere.
A properly rebult engine with total seal rings and the right pistons (there are pistons designed with little ports that allow the compressed mix to push onto the rings and squeeze them against the wall of the cylinder) you can eliminate that issue, most of the oil burn from any engine is from the valves not the piston rings.
Quote from: crzydood17 on December 21, 2012, 11:51:03 AM
A properly rebult engine with total seal rings and the right pistons (there are pistons designed with little ports that allow the compressed mix to push onto the rings and squeeze them against the wall of the cylinder) you can eliminate that issue, most of the oil burn from any engine is from the valves not the piston rings.
That assumes that the rod and crank bearings can take the stress from the additional compression and torque.
http://gstwins.com/gsboard/index.php?topic=62003.0
Stock Crank = strong... Just cant handle a lot of RPM