Hpi baja pinion/spur gear ratios

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Danrox90

Well-Known Member
Messages
53
Hey guys, I'm just wondering what the best gear ratio would be for me I am looking for much more top speed, the acceleration is already heaps and I'm more then happy with that. So what I want to know is what the best pinion to spur gear teeth ratio would be for me. At the moment it's at the stock 57 to 17 teeth. And how much teeth on the spur/pinion gear can the stock clutch hold? I did find this chart aswell but not sure which one would suit me... Any info is accepted thanks ;)
SPUR....PINION....RATIO......SPEED.......POWER.... .TOTAL TEETH
58........16..........3,63........-8 %.........+8 %.......74 (correct mesh)
57........16..........3,56........-6 %.........+6 %.......73
57........17..........3,35.........0 %...........0 %.......74 (correct mesh)
57........18..........3,17........+6 %.........-6 %.......75
56........18..........3,11........+7 %.........-7 %.......74 (correct mesh)
55........18..........3,06........+9 %.........-9 %.......73
56........19..........2,95........+12 %.......-12 %......75
55........19..........2,89........+14 %.......-14 %......74 (correct mesh)
54........20..........2,70........+19 %.......-19 %......74 (correct mesh)
53........21..........2,52........+25%........-25%.......74 (correct mesh)
52........22..........2,36........+30 %.......-30 %......74 (correct mesh)
 
How much extra speed would it give the 56 - 19 give me in km roughly, and would that spur gear and pinion fit on the stock clutch bell.
Thanks heaps
 
If I went for 54-20 would that put too much stain on the stock 26cc engine.
Thanks again
 
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The 20-54 would be a big strain on the stock engine.
My suggestion for a stock 26 engine would be 18-56.

And

With those gears the buggy, if properly tuned, should run about 53 MPH.
 
The 20-54 would be a big strain on the stock engine.
My suggestion for a stock 26 engine would be 18-56.

And

With those gears the buggy, if properly tuned, should run about 53 MPH.

I agree. MAYBE 19-55 but no farther down the list than that. Other thing to keep in mind is the farther down the list you go the harder it will be on the clutch. If you are running a stock clutch and non-vented bell I would stick with 18-56 or 19-55 (preferably the 18-56 unless you keep spare clutches on hand).
 
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At the moment I'm only getting 50km for some reason not sur of the pipe I'll send a picture later think it's a Dom , and I took the car to the tuner shop and he tuned it aswell, I did buy the baja second hand, not sure if that has anything to do with it.
Thanks
 
50 kph is way low.
I ran my stock Baja on radar several times, and stock with the stock can exhaust it would run 79 kph - 49+ mph.

With additional gears 18-56 it should run about 85 kph.

Seems like a tuning issue for sure.

Is this a true HPI, and is the engine a CY ?
 
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These are some images of my baja the guy that I got it from not long ago claimed it was hpi they engine does say Chung yang on it and 26cc, what pipe has it got on it and is it real. He also said he converted it from a short course truck to a 5b aswell.
Thanks
 
If the guy said it was real, I would have to take his word on it.
Without really digging in, one that has been modified like yours has is VERY hard to tell if it is Not HPI.
It is obvious it has had many additional hop-up parts installed on it, and that is good.
The pipe is either a V1 Dominator, or clone of one.
That is actually a good pipe for high rpm.
Having an engine with chrome covers, it will be interesting to see what numbers you find one the side of the cylinder head.
Those numbers will help tell for sure if you have a 26cc or not.
There are a number of factors that can change the speed of a car, but still it should be very close in the range, if tuned well, and having stock gears.

It is all bout having fun, and you need to keep that in mind !
 
On fan side lower base of the cylinder head, there should be some numbers that tell you crank length and piston diameter, which will determine the engine displacement.
These numbers will be stamped in.

Thanks to O'Bros (O'neill brothers ) for this image.

28cc6.jpg

28-32 is 23cc
28-34 is 26cc
28-35 is 27cc
28-36 is 28.5cc
 
It says r260 but it's in a different spot just below that screw hole, my brother has a baja and his is hpi and it says the same thing, it also says chung yang ... Would the cdi have anything to do with the speed issues?
Thanks
 
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