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Re: Power/Speed relationship

Posted: Tue Sep 09, 2014 9:26 am
by Lambretta Sash
" by Darrell Taylor » Tue Jun 19, 2012 10:26 pma few of the scoots ive tuned that are 35 to 38bhp are topping out at 85 to 88 mph gps with full bodywork ,the top sprint bikes full bodied are seeing from memory 92-94 mph and at scooter shotout last year i think about 85 was max seen on full body scootsthe cut downs and bsso scoots did 100mph or just overwhats interesting to find out is what lambrettas with engine transplants achieve and power output they have ? what does speed demons 6speed cr250 do? ive heard 95 97 gps ? "

Playing on another dyno I've acquired, it has air resistance built in by rollers turning fans, clever buggas the French, judging by the above Darrell, where would you put 20 and 30 hp ? I've tested a few on it from li 150 bog std hitting 42 mph and Buell 130 mph, interestingly it hit 120 straight off then built up to 130 as it does on road. I'll definitely be adapting this unit for real time fuelling in near future :)

Re: Power/Speed relationship

Posted: Sun Sep 14, 2014 8:35 am
by Lambretta Sash
Id like to try a few more scooters and bikes, results are as follows

GT 200 lammy clubman 70 mph
Vespa 166 sterling 66 mph
Munster Lammy rb225 82 mph
Vespa GTS 250 leovinci 70 mph
Buell 130 mph

The Munster rb 225 in same trim hit 78mph a santapod 1/4's

I know areodynamics plays a part in it but the info from this appears to be close to road conditions which is a positive point on from a straight inertia type i have with 1/2 ton roller!!

If any of you guys with a fast scooter want to try it out its foc till mid October while im setting it up with Dynomec hardware

Re: Power/Speed relationship

Posted: Fri Feb 27, 2015 7:08 am
by onthelam
Darrell Taylor wrote:a few of the scoots ive tuned that are 35 to 38bhp are topping out at 85 to 88 mph gps
I have a formula I gleaned from somewhere which works for sport bikes. The unknown is the aero constant for a Lambretta sat up straight.

Happy to send to anyone who sends me a PM/ email address. It is an excel spreadsheet.

I might have to get to 10 posts or something first though.

Re: Power/Speed relationship

Posted: Fri Feb 27, 2015 9:59 am
by Adyonekenobi
If it is of any help, my scooter info is:

Li150 Special, full bodied.
GP200 gearbox
TS1 225cc 'out of the box'
30mm VHSH Delly
Dyno tested by Al at Diablo Moto at 22.9 bhp
Top speed so far sitting upright (I am 16 stone!) seen as 80 mph on SIP DIGITAL SPEEDO
Speedo had been set up by me with accurate circumference data

I'm well happy

Ady

Re: Power/Speed relationship

Posted: Sun Mar 01, 2015 5:57 am
by onthelam
That gave me a constant of 28.16 a bit low compared to say a PCX but..I'm on the case.

So far the constant looks more like 30.2! But as it is aero based it depends on sat up or prone.

const HP mph kph notes
Li 150 (2T) 30.2 6.6 56.6 91
SX150 30.2 9.38 63.7 102
TV 200 31.5 10.7 69.4 111 Geared higher
SX200 30.2 10.3 65.7 105
GP 200 30.2 11.7 68.6 110 Geared lower?

The more info the merrier

Re: Power/Speed relationship

Posted: Mon Mar 30, 2015 10:38 am
by Lambretta Sash
I've had a few more on there with interesting results, The inertia dyno is used first and i can now predict top speed on resistance dyno.
Gts 250 - 66 mph
Gts 300 with pipe & rollers 70 mph
SX200 with 22mm carb/clubman 51mph 9hp
Ts1 as was 60 mph 16hp, new pipe n tweak 25 hp 75 mph
quatrini mx1 75 mph
T5 with sip road 50 mph, siminoni 58 mph, sterling 50 mph

it takes a bit to get a scooter doing a genuine 80 mph and you are gonna need 28 -30 hp to achieve those speeds
so if you think yore getting 80 mph gps or speedo you may need to think again

Re: Power/Speed relationship

Posted: Tue Mar 31, 2015 8:06 am
by shilloboxer
So sash my two smallframes did 80-82 at santapod over the 1/4 and the same at the shootout over 1/2 mile would you say that these are true speeds? Can't remember what the GPS reading was didn't have time to look.

Re: Power/Speed relationship

Posted: Fri May 01, 2015 2:18 pm
by Lambretta Sash
its as accurate as you are going to get, if you want to come ver this way you can put it on mph dyno foc nd have a play with jetting