Anyone been on a dyno

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lawman
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Anyone been on a dyno

Post by lawman » Thu Mar 15, 2018 8:45 pm

I finished the project, ready for plop. I wanted to test its gearbox under proper load and check the Air fuel ratio so took it to a dyno at Swinton Performance Centre near Rotherham.

7.11 BHP at the wheel, then the float bowl fell off and a fairing bolt fell out. Quite pleased with the power, AF ratio is flattest ive ever seen, neigh on perfect.

All good stuff, better than falling to bits on track and gushing fuel all over and bursting into a fireball and having to run off into the pond.

Tomorrow is loctite day............

I just wondered if anone else had subjected their mighty 90 to the ravages of a dyno and what you got.

https://photos.app.goo.gl/XlI25iyYJz8bQnL92

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bikerbaker
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Re: Anyone been on a dyno

Post by bikerbaker » Thu Mar 15, 2018 8:57 pm

I seem to remember a video of aliengravy with his efi Cub on a dyno, quite a long time ago though! :D

culfy
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Re: Anyone been on a dyno

Post by culfy » Thu Mar 15, 2018 9:55 pm

We've also had our plop racer on a dyno but the results are top secret ,is your bike road legal ?and a good tip is to put some cable ties around your float bowl as it stops the vibration (a little). We did the nifty fifty at Mondello last month and as I was racing I pointed out to a fellow racer that his float bowl was ready to fall off .Just check everything twice before Mallory ;)

lawman
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Re: Anyone been on a dyno

Post by lawman » Fri Mar 16, 2018 8:12 am

Yes lesson learned re the floatbowl and thanks for the cable tie tip.
I think this stock engine is running as well as it can. The only way I can think of to get more power would be to skim the head or fit another head or something which isn't really in the spirit of the event.
I'm happy with it and it sounds mint, just hope it lives long enough to give all four of us a good run!
See you there.. Dave.

It could be on the road with a horn and a daytime mot. But would probably need a Speedo and front mudguard to satisfy construction and use regs. It wouldn't take much effort or cost.

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Ventura
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Re: Anyone been on a dyno

Post by Ventura » Fri Mar 16, 2018 9:14 am

lawman wrote:
Fri Mar 16, 2018 8:12 am
It could be on the road with a horn and a daytime mot. But would probably need a Speedo and front mudguard to satisfy construction and use regs. It wouldn't take much effort or cost.
Having the bike road legal is a big plus for a Plop bike as it allows you do get many shakedown miles under your belt before an event.
As you've already found, there are many small unforeseens which will lose you time and laps on the day.
Simple things like the carb float bowl screws have put paid to many teams good results over past events.
Losing laps to sort such things out can very quickly take you from a top 10 position down to 70+!!!
(Don't ask me how I know! We've all done it!)
We've seen many teams who have gone to a lot of time and effort in their preparations ending up spending more pit-lane time than out on the track as bits fail or fall off.
Taking your bike on a 100+ mile Sunday run will highlight all these little weak points and go a long way in avoiding annoying pit stops on the day.

V.

culfy
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Re: Anyone been on a dyno

Post by culfy » Fri Mar 16, 2018 12:11 pm

As Graeme says get it road legal , it’s the best way ,daytime mot that consists of rear centre reflector , number plate , speedo and horn (look on eBay for Hornit dB 140) A’s it’s battery powered and loud .we used to shake ours down on a very quiet country road just outside Sheffield highly illegal but the only way we could iron out any problems ,see you track side :D

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Re: Anyone been on a dyno

Post by Drew » Fri Mar 16, 2018 5:45 pm

As Ventura said, we lost a fifth place at Mallory because the float bowl nearly fell off and ended up 32nd. It's a common problem.

I have had the bike on the dyno and found over two horsepower just by jetting and filter trials so well worth it if you know how to interpret the results.

Have done five other plops and only had a handlebar end bung fall off all with top ten finishes, the secret is in the preparation ingnore it and be ready to spend lots of time in the pit instead of racing.

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Newtsalad
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Re: Anyone been on a dyno

Post by Newtsalad » Sat Mar 17, 2018 1:31 pm

bikerbaker wrote:
Thu Mar 15, 2018 8:57 pm
I seem to remember a video of aliengravy with his efi Cub on a dyno, quite a long time ago though! :D

lawman
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Re: Anyone been on a dyno

Post by lawman » Sun Mar 18, 2018 1:09 am

Thanks lads. I appreciate your thoughts. I've put it back together with a dab of loctite and added cable ties to boot. I'd be very happy with a top 30 place.
I've the offer of a bike driving school car park so might do a few circles of that to iron any final issues before the big day. It seems a few of you are nearby, we have 2 Barnsley lads and 2 Rotherham lads. None of us has ever raced I've done plenty of track days most recently on cb500.
#74

The Chicken Chasers
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Re: Anyone been on a dyno

Post by The Chicken Chasers » Wed Apr 25, 2018 10:46 am

Surprised you're getting so much. Ours makes 6.5. Only mods are ported E22 head, exhaust and choke removed.

What's this gearbox mod then eh? Surely not a 4-speed... :o

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