Gearing question

shigawaker

shigawaker

Member
Joined
Jan 7, 2013
Messages
42
Age
35
Location
Nunavut
With 9 tooth drivers. (01 SRX)
what are the theoretical top speeds at 8500 RPM with different gear ratio`s?

Eg.
stock (1.65) : XXX MPH
2.0: XXX MPH
1.9: XXX MPH
1.8: XXX MPH
1.7: XXX MPH

Or is there a formula i could use to figure that out???

Any help would be greatly appreciated.
 
Last edited:
It's a little weird to phrase the question like you have. The engine rpm combined with the clutch set-up shift the primary out. After this shift out happens the gearing and driver teeth determine the top speed. At 8500 rpm, the clutches shifted all the way out, 8 tooth drivers; the following gearing will result in the following theoretical top speeds:
23/38(1.652) = 115.5mph
23/39(1.696) = 112.6 mph
23/40(1.74) = 109.8 mph

Your 01 SRX came with 9 tooth drivers. So at 8500 rpm and full clutch shift out the theoretical top speed was:
23/38 (1.652) = 130 mph

Changing to 8 tooth drivers results in a significant lower top speed. Changing the gearing to 24/36 (1.50) = 127.3 mph, or 24/35 (1.458) = 130.91 mph will bring the overall close to stock.
 
I agree... re-reading my post i didnt quite explain myself well...

I am set up presently for 660Ft snow racing but the track that i have been going to has been rock hard at every race ive been too so far... i was curious if my current set up of 1.9 could be ``Shifted out`` because I seem to be missing a small bit of top end from the 550 - 660 mark.

My engine RPM doesnt climb like it would on grass but im wondering if the ``slippage`` factor would eliminate this symptom unless i actually got to 100 MPH.

And i do have the stock drivers (9 tooth) im not sure why i wrote 8 lol

So i guess my question is: On a hard 660 Ft snow track is a 1.9 Ratio too short??
 
Gear Ratio interesting
http://www.racenssr.com/calc.htm
MPH Calculator
Fill in the appropriate information below, Then click when finished.
Engine RPM
Chain Case Gear ratio
Clutch ratio (1.00 w/o Overdrive)
Driver diameter in inches (7.07, 7.75.) The speed in MPH is miles per hour.
The same DRIVER size and RPM will give the following speeds based on the following gear ratio changes.
1.40 1.45 1.50 1.55 1.60 1.65 1.70 1.75

http://www.vintagevmax.com/vvforum3/viewtopic.php?f=2&t=1529
 
Rpm x top gear / bottom gear x track pitch (2.52) x driver tooth # / 12 / 5280 x 60 = mph

This is speed at one to one shift out on the clutches.

Hope this helps.
 
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