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Chain v short prop & diff mid engined car
Autoflock Motorsport - 23/12/14 at 09:43 AM

Just been looking at another thread on this forum and noticed a short prop to a normal diff setup. Can anyone shed some light as to the pro's and cons of this set up?

Is it a lot heavier than chain? lower geared? smoother? slower? etc

Any help would be great

daniel mason - 23/12/14 at 10:11 AM

Gearing is easily adjusted on a chain drive setup. Front or rear sprocket change is all that's needed!

JAG - 23/12/14 at 10:24 AM

Conversely; chain and sprockets will wear out and need replacing.

theprisioner - 23/12/14 at 10:24 AM

It is not uncommon for prop adapters to come off. There are various solutions and the AB Racing approach is the one I am trying at present. Basically bike o/p shafts are designed to drive chains, loading at 90deg to shaft. The prop adapter takes this shaft and converts it to 180 deg. Unfortunately there is a lot of vibration at this joint and even when the best adapter in the word is fitted the bolts on the flange can still come loose (well that is my experience). I have also seen it many times at race meetings. My bolts are wired now.

russbost - 23/12/14 at 10:51 AM

quote:
Originally posted by JAG
Conversely; chain and sprockets will wear out and need replacing.


Well, yes, but given typical kitcar mileage, not very often. I run a fairly short chain run with a small drive & driven gear (which you would therefore expect to produce high wear rates) & I'm coming up towards 3000 miles now, probably 50% of which has been aggressive use, 50% cruising, there is no noticeable wear on either sprockets or chain. I have adjusted the chain probably 3 times after the initial 100 mile or so bedding in period which requires a couple of adjustments.

The upside is it's a lot lighter, more compact, & wastes less power than a crown wheel & pinion - downside is it is messier

Autoflock Motorsport - 23/12/14 at 11:26 AM

thanks for the responses, confirmed what I was thinking but just needed to hear it from someone else. I quite like my chain setup not only for the simplicity but the overall characteristics of it, the clunkyness give a proper race feel if that makes sense.

CosKev3 - 23/12/14 at 11:35 AM

quote:
Originally posted by Autoflock Motorsport
Just been looking at another thread on this forum and noticed a short prop to a normal diff setup. Can anyone shed some light as to the pro's and cons of this set up?

Is it a lot heavier than chain? lower geared? smoother? slower? etc

Any help would be great


You would need to turn your engine sideways to fit a prop?

As mid engine cars that run chain drives have the engine sat the same way as they are in a bike,where as a front engined bec has the engine turned so the output shaft faces backwards

dhutch - 23/12/14 at 12:42 PM

quote:
Originally posted by CosKev3
You would need to turn your engine sideways to fit a prop?

I would presume so. Unless you use a 90deg shaft-drive type system (CWP and both ends) which seems a little pointless.

I guess the engine would prefer to be the right way in terms of oil management, although you still have the issue that bike engines (sumps there of) often cant take much sideward g forces.


Daniel