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Post by muttsnuts on Dec 23, 2016 21:06:52 GMT 1
So, having now got the dyno fully up and running I thought it was time to sort out my 421 with the power dynamo and ignitech fitted, the bike before fitting them was sat at 95bhp (give or take) and went pretty well, although I knew with a fixed ignition curve it was always a little handicapped So armed with 20 litres of petrol and a few spare hours, I decided today was the day to get this all working, or at least get the bike back to what it was doing before fitting the power dynamo and ignitech The initial run showed the bike at 80bhp  , not a great start, but nonetheless not a bad start, after some tweaking and approx 20 runs I got the bike up to 95bhp  , happy days, at this point I decided to print the graphs out and have a closer look at each section in 1000 rpm chunks, after a lot of small but progressive changes, I not only managed to up the power, but I lifted the whole curve and also took 3 secs off the time it takes to reach peak power, which is now 101 bhp, the best run giving up 101.4bhp and a whopping 56ft-lbs of torque (up 6 ft-lbs) The graphs below show the difference on the power curves from the starting point (pre power dynamo and ignitech fitted) and after them being fitted, no other changes have been made BHP Graph  The next graph shows the difference in how quick the engine now rev's up to peak power etc, as you can see a massive 3 secs knocked off it, now ya going to feel that on the road ! Acceleration/Speed Graph  Of course the final proof of the pudding is to ride it I have one other thing to change on the bike which should see peak power come up further, possibly 105bhp, but that is one for next year now ! All in all, a very satisfactory day, although I did use all of the 20 litres of petrol as well - its a thirsty beast ! |
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Post by sparx on Dec 23, 2016 21:10:53 GMT 1
Very very nice dave.
Can you build me one the same please 😳
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Post by marsbar350 on Dec 23, 2016 21:45:07 GMT 1
My bike on to tomorrow
A box of bits is hard to set up on a dyno
17 weeks to donny
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Post by sparx on Dec 23, 2016 22:35:28 GMT 1
Keep telling you my 421 won't be going to donington
Rgv having pipes made now
That is going
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Post by marsbar350 on Dec 23, 2016 22:43:20 GMT 1
OK thanks for the update show pony then?
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Post by veg on Dec 23, 2016 23:34:11 GMT 1
So are you saying a 421 with decent pipes and ignition should see similar? I only ask as I am also building an LC2 with similar motor.
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Post by sparx on Dec 23, 2016 23:56:38 GMT 1
Exactly that veg. Depends which 421 motor you go for though as there a few different types of barrels
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Post by veg on Dec 24, 2016 0:04:43 GMT 1
Kin ell never expected those type of figures I am expecting around 60 ish bhp from my Tz 700 barrelled 350 and thought 70 ish from my ypvs 421.
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Post by sparx on Dec 24, 2016 0:52:08 GMT 1
Depends on a lot of things
Which barrels you have
Which carbs
What reeds
And how well you have it set up.
You can have all the right bits
Not know how to set them up
And get a bike that runs like a piece of shit
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Post by Eyrey1 on Dec 24, 2016 1:20:36 GMT 1
you need to start trying it on a powervalve type engine 421 443 535 cc
just so it will have some sort of midrange and make it more ridable .
like this is probably ok for 20 minutes and a laugh but for a road bike ?
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Post by JonW on Dec 24, 2016 1:30:06 GMT 1
great work! Exciting to know whats in there just waiting to be unleashed  |
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Post by Tobyjugs on Dec 24, 2016 1:40:15 GMT 1
you need to start trying it on a powervalve type engine 421 443 535 cc just so it will have some sort of midrange and make it more ridable . like this is probably ok for 20 minutes and a laugh but for a road bike ? Fair comment Eyrey1, i use my bike on the motorway and moving with the traffic i spend alot of time around the 6000rpm mark and that is where my engine is at its worst just like above. Ive tried alot of different things to improve it but as of yet no luck. Dave how do you think you could improve on that 5500-6500 area of your graph? |
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Post by Eyrey1 on Dec 24, 2016 1:53:08 GMT 1
dont think he can do much really maybe a bit of help with some midrange pipes
i think the porting in the cub cylinders isnt suited to making midrange just for outright power
dave is involved or will be with the serval cylinder bike me and markhoopey are doing
as they are made to produce stonking midrange rather than top end which should also give the crank an easyer life
also we are having tsa midrange pipes made to help it further
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Post by bare on Dec 24, 2016 4:35:25 GMT 1
Certainly impressive numbers. Well done.
Both runs on the SAME dyno?? though.
Dynos can be wildly irregular/unreliable contraptions.. until into mega bux units which are religiously recalibrated.
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Post by muttsnuts on Dec 24, 2016 10:42:44 GMT 1
the dyno's concerned are both in sync as we only verified theat on Tuesday, but I do agree with the sentiment Bare, but have been very careful to make sure both dyno's are using the same rotational ratio's etc, the bike will also go on the other dyno just to double check, but I a 100% confident they are aligned
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Post by tsa on Dec 24, 2016 10:55:33 GMT 1
Great work Did you try the others Dave?
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Post by muttsnuts on Dec 24, 2016 12:43:48 GMT 1
Hi Kenny, no not yet, think there are some more ponies in there as discussed, will wait for your little magic to arrive and then we will get it sorted  Just set the rev limiter and knocked the power off a little this morning, so doing a nice steady 98bhp now - like to be safe ! |
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Post by boost on Dec 24, 2016 16:43:37 GMT 1
hi dave for the ignorant among us (namely me) could you tell me what a 421 is ? does this relate to cc, is it a bored out motor ?? I realise that I may be opening myself up too a little piss taking but hey its Christmas  |
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Post by stusco on Dec 24, 2016 17:14:17 GMT 1
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Post by paulincayman on Dec 24, 2016 17:34:57 GMT 1
CPI Serval cylinders , same folks as Cheetah but advertised as more torque less peak hp ?
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Post by muttsnuts on Dec 24, 2016 18:03:36 GMT 1
hi dave for the ignorant among us (namely me) could you tell me what a 421 is ? does this relate to cc, is it a bored out motor ?? I realise that I may be opening myself up too a little piss taking but hey its Christmas yes, it relates to the cc, basically bigger bores and longer stroke crank, the barrels are Trinity barrels, which is basically a Cheetah Cub in today's terms |
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Post by muttsnuts on Dec 24, 2016 18:06:08 GMT 1
you need to start trying it on a powervalve type engine 421 443 535 cc just so it will have some sort of midrange and make it more ridable . like this is probably ok for 20 minutes and a laugh but for a road bike ? Fair comment Eyrey1, i use my bike on the motorway and moving with the traffic i spend alot of time around the 6000rpm mark and that is where my engine is at its worst just like above. Ive tried alot of different things to improve it but as of yet no luck. Dave how do you think you could improve on that 5500-6500 area of your graph? yes the 5500 to 6500 is a key area to sort, the biggest issue with my bike in that area is the exhaust design, they just don't lend themselves to good mid-range, so a set of exhausts designed for that would help (would knock some peak power off), but everything is a compromise anyway and with that type of powerr on hand losing a few ponies to pick up the mid-range would be a good compromise if you ask me - well that is where I am going with it anyway ! |
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Post by ozzysbikes on Dec 24, 2016 18:13:04 GMT 1
Very impressive maximum horsepower, I did wonder about the wisdom of losing the power valves from power valve engines but Eyrey1 said what I was thinking, doesn't anyone do a big bore kit that retains power valves ? what capacity can you get with rebore and stroker crank on a power valve ? for a well used road bike that could be the answer,
Muttsnutts, sounds like your bike is fantastic for track days, racing or a quick blast (possibly too quick !) on the road, I noticed that the air pressure is higher (nothing worth noting) and the air temp is lower with the higher power readings,
Veg, you should get more than 60HP with TZ700 cylinders as even a 350A made 60HP and by the time the 350 finished they were nearer 70HP and from what I am told the lads running 350TZ,s in classic races now are at 80HP (chinese whispers though)
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Post by muttsnuts on Dec 24, 2016 18:24:18 GMT 1
Very impressive maximum horsepower, I did wonder about the wisdom of losing the power valves from power valve engines but Eyrey1 said what I was thinking, doesn't anyone do a big bore kit that retains power valves ? what capacity can you get with rebore and stroker crank on a power valve ? for a well used road bike that could be the answer, Muttsnutts, sounds like your bike is fantastic for track days, racing or a quick blast (possibly too quick !) on the road, I noticed that the air pressure is higher (nothing worth noting) and the air temp is lower with the higher power readings, Veg, you should get more than 60HP with TZ700 cylinders as even a 350A made 60HP and by the time the 350 finished they were nearer 70HP and from what I am told the lads running 350TZ,s in classic races now are at 80HP (chinese whispers though) yep your right, atmospheric pressure/temps etc does affect it, the 2 dyno's concerned are both the same make (Dynostar D70) which have built in weather stations so all of that is taken into account, but it is a point most people miss and different bikes in different climates and different altitude all play into this, its far from a straight forward my bike does this power etc, etc Thankfully John who owns the other dyno I use to use has been gracious enough to help me not only set mine up, calibrate, etc, etc but also in best practices and how to read the many various factors and variables concerned, I've always said that the readings from a dyno are only as good as the operator and the equipment being used and that can vary a huge amount |
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Post by ozzysbikes on Dec 24, 2016 18:31:44 GMT 1
"Of course the final proof of the pudding is to ride it"
couldn't agree more with your comment, if it feels good screw the arse off of it ! what it feels like to ride is the important thing unless you are racing and then it is just what gets you the fastest lap(s)
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Post by yazza54 on Dec 26, 2016 23:46:06 GMT 1
Nice work mate
To be fair these graphs always make the mid range look worse than it is. For a start you wouldn't whack open the throttle in a high gear and wait for the magic to happen. Rolling on as you would normally makes a big difference.
Looking forward to having another go on the dyno now I've got the carbs a bit better I'm sure you'll be able to get a bit more from it.
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Post by muttsnuts on Dec 27, 2016 22:33:07 GMT 1
Nice work mate To be fair these graphs always make the mid range look worse than it is. For a start you wouldn't whack open the throttle in a high gear and wait for the magic to happen. Rolling on as you would normally makes a big difference. Looking forward to having another go on the dyno now I've got the carbs a bit better I'm sure you'll be able to get a bit more from it. Hi Ryan, for sure you are right and when I did a roll on test it felt mint and went through the gears and rev range really cleanly, when you come across if the weather is ok you can take it for a blast and let me know whet you think |
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Post by alexx on Dec 27, 2016 22:59:21 GMT 1
huh .. indeed impressive.
pity for this lost in the midrange. how typical is this hole unfortunately for PV.
what is your set-up for this lovely beast: 421 (make + tuning), ignitech, ... ?
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Post by muttsnuts on Dec 28, 2016 10:55:04 GMT 1
Hi, the mid-range looks worse than it is, its still making half the horse power of a normal YPVS, so beleive me, you don't feel it, you still make good progress, it just looks worse on a graph, if I overlay that graph on top of a normal YPVS engine, its making around the same/slightly more than a normal PV, so it doesn't feel flat !
The spec is pretty long !
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Post by davecroucher57v on Dec 28, 2016 19:28:05 GMT 1
its got more midrange than std.and twice the top end.whats not to like.
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, not a great start, but nonetheless not a bad start, after some tweaking and approx 20 runs I got the bike up to 95bhp 
, happy days, at this point I decided to print the graphs out and have a closer look at each section in 1000 rpm chunks, after a lot of small but progressive changes, I not only managed to up the power, but I lifted the whole curve and also took 3 secs off the time it takes to reach peak power, which is now 101 bhp, the best run giving up 101.4bhp and a whopping 56ft-lbs of torque (up 6 ft-lbs)
