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Classic Bike Trackdays

SDR Cup race brochure

 
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James P



Joined: 31 Mar 2013
Posts: 131
Location: Sydney, Australia

PostPosted: Fri Oct 19, 2018 7:49 am    Post subject: SDR Cup race brochure Reply with quote

This brochure is already available from the internet, but I have yet to find a copy which has been scanned with sufficient resolution to make the text legible. As well as introducing and promoting the SDR Cup race series, the brochure also contains information on modifying the engine for competing in the 'Modified' and 'Expert' classes of the SDR Cup races.

I managed to get hold of a copy of the brochure at a vaguely reasonable price and have translated the information for your collective interest. The PDF document contains scans of the original brochure pages, with the translation pages following. The translation comprises a 'summary translation' of the concept and organisation of the SDR Cup race series, with an almost direct translation of the engine modification instructions in the "SDR Engine Tuning Method" section, along with enlargement (and translation where necessary) of the associated drawings.

Translation was done using Google Translate, along with reference to my kanji & kana book where translations made no sense. If anyone notices any errors in the translation, please let us all know!

https://drive.google.com/file/d/1qKF5xhN1q_A_yBXquHqx_HkMxESVAzFS/view?usp=sharing

SS Ishii was instrumental in compiling the brochure by providing details of the parts and services available for making an SDR200 suitable for competition in the race series. I infer that the shop also provided the information on modifying the engine.
There is another brochure issued by SS Ishii showing all of the parts available for the 'Normal' and 'Modified/Expert' classes along with prices, but I have only found fairly low resolution scans on the internet so far. I'm generally keeping a lookout in case a copy comes up for sale, but haven't seen one yet.

I wasn't sure whether to put this in the Brochures section, but have decided to put it here as it isn't a 'factory' brochure.

Regards,
James
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strokeoneout



Joined: 05 Sep 2017
Posts: 10

PostPosted: Mon Feb 25, 2019 11:41 pm    Post subject: Reply with quote

I totally vacuum up every single bit of SDR info you put out James so thanks so much. Is their anything that can be taken from this info to tweak the performance in your opinion? I know often pushing more power means pushing the reliability but perhaps some nuggets of note?
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TZR125
SDR200
NSR250RR-SP MC28
SDR200
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James P



Joined: 31 Mar 2013
Posts: 131
Location: Sydney, Australia

PostPosted: Tue Mar 05, 2019 8:43 am    Post subject: Reply with quote

strokeoneout wrote:
I totally vacuum up every single bit of SDR info you put out James so thanks so much. Is their anything that can be taken from this info to tweak the performance in your opinion? I know often pushing more power means pushing the reliability but perhaps some nuggets of note?


I'm happy to help by sharing whatever info I have. I would expect that the modifications described would improve performance, but I'm not sure what sacrifices would be made in doing so. It would be handy to find someone who has ridden both standard and modified 'Cup-spec' SDRs who could offer a comparison, but the chance of finding any such person outside Japan would be remote.
I prefer to leave cylinder porting standard unless there are changes which have been proven to increase performance with no loss of tractability and no other undesirable effects. Minor improvements may possibly be had by 'blue-printing' (spending the extra time that the factory couldn't afford during production), modifying the air intake system to be more free-flowing and losing some weight where possible. I have carried out these kinds of modifications to my own SDR but I had no experience of riding it beforehand, so can't offer any sort of comparison.
Sorry if this is not very helpful, but I would need more spare parts, more spare time and more money before venturing into 'experimental' territory Sad !

Regards,
James
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