The fuel injection is calibrated for the diameter of the throttle body, not the size of the engine - changes to the intake and exhaust will affect the fuel injection, but it will have to be hooked up to a dyno and re-calibrated by an experienced tuner with a program compatible to the electronics.Hello all,
I would like to discuss performance upgrades for a Polaris ranger 150 EFI 2021 model. I bought the new Ranger for my kids and noticed that the ground clearance was not as advertised. I love all the new features and think it’s perfect for my kids. I recently purchased a new set of rear tires that are 14 inch rims with 26 inch tires. I have a lift kit ordered that I plan on only using the on the front end to kind of level the UTV a bit And leave stock 22 in factory tires on the front.(2 in) This has significantly increased the ground clearance in the rear by about 2 inches. (Was around 6.5 now 8.5)
I took it out with the kids on about a 30 mile ride and had no issues with him hitting anything. I did however notice that the larger tires had trouble in sand and would like now to increase the performance of the machine. After doing some searching I found a few performance clutch parts that I plan on installing. Namely a performance torque driver and clutch. I’m also getting some smaller rollers.
now I’ve been looking at big bore kit’s and crankshaft and wondering if anybody has any experience.
I can tell through research that this UTV has the GY6 motor with serial number jl1p57f. It is an a model that I verified by measuring the bolts on the cylinder head.
with the a model GY6 the largest I can safely go is the 63 inch big bore kit. Then I will have to bore out the case. I can also get a +3.5 mm stroker crank shaft that will put me at a 191 cc engine.
has anyone done any of these mods on the Polaris ranger 150? I’m specifically wondering if the electronica fuel injection is enough fuel for this size and if boring the case makes it too weak.
my kids are too small for the 570 and I really want to make this machine work until they’re old enough.
thanks for any of the comments.
Boring the engine will give a bit more low end grunt and revamping the variator will change the engagement characteristic, but you will need to get a high lift cam to get back some of the top end you lose when you increase the bore. Likewise the stroker crank will boost the low end grunt wile lowering the redline RPM limit.
Have fun - engine building is great if you have the time and money - if you have the time, you might get it all done in a 2 to 4 week to month time frame. If you are going for maximum performance allow about 6 months to a year for disassembly, machining, clearance checking, head porting, recutting the valve seats for the larger valves, checking the clearance between the piston and the valves and the overlap clearance between the intake and exhaust valve (one is opening as the other is closing and they have to miss), finding an over sized exhaust system to match the enlarged exhaust port, final assembly and the dyno runs to fine tune the EFI.
Now get the variator tuned for the performance curve of the engine, possibly consider a heavy duty driven clutch assembly and a heavy duty belt.
Whew! I think I would just consider a Chinese 250 instead of all the work of building a Chinese 150 into a 160+, but on the other hand, if you have free time, go for it and let us know how it progresses