Dyno performance- actual readings

You and the Boss have a good time tomorrow - methinks you are Barry-bound...

Really interested to see what the stacks do for the figures, along with any future the changes to exhaust.

You blokes have worked hard on this one and deserve all the success you get!

Yogi
 
have 2 batteries on charge here as well just in case
been through a few today just starting her so we can listen to her roar again, and again, and again  :D

Yogi,
Max and I have already booked a room for the Barry, you should book one as well at least for Friday/Saturday night, save having to drive home pissed
good bar at the Chifley/Alpha hotel and great tucker

also, exhaust is already modified again, that is the main reason we are heading back to the dyno
1st run, standard alloy velocity stacks with new modified exhaust
2nd run, new velocity stacks with same exhaust






 
markQLD said:
ok. exhaust systems?  as always, an interesting topic.  & i really do no nothing!  ???  well,, bugga all.

i can remember reading one of Piet's comments a while back, so went a searching, again.http://www.laverdaforum.com/forum/index.php/topic,89069.msg262677.html#msg262677

yes, i am more than a little interested in this concept.  so went looking for the Triumph mentioned.
triumph800-01.jpg


ok Piet, i can understand that you won't be throwing all of Moto Witt's development work out on the table for us, but can you add anything about this concept?
: was a single exit (3-1) tested?
: do you think it would perform similar with the 180? crank?
& i guess the outer tubes will have to wrap around the triple frame down-tubes.
maybe a bloke better go picking through some Triumph wrecking yards.  :-\

and i made note of this earlier comment, that others may also be interested in today.http://www.laverdaforum.com/forum/index.php/topic,89069.msg262569.html#msg262569

as always. comments are welcome.
but,,  dyno readings are better than any opinions ay?  8)  just saying.
Click to expand...

Hi Mark,

Haven't followed this thread for a while...

Wasn't really development work with the wierd short headers, just mucking around, trying new ideas.  This was in a time when the complete exhaust system was still considered a major motorcycle design element, hence the opinion it was too ugly to be worthy of further investigation (imho, modern bikes are so fugly that a horrid looking exhaust system doesn't really matter any more ::)).  As always, our experiments were centred on steet-legal exhaust emissions because we wanted to try things out on the road if they looked promising.  Didn't want to fuck around with the law back then! :eek:  All testing was done with RGS silencers with enlargened exits.  When we found something promising, we fitted  an open exhaust (completely empty Jota cans) for comparison, usually huge dips and holes in the mid-range and only slight improvements at top rpm resulting.  In real-life road riding, a couple of top-end ponies are worth far less than a dozen more in mid-range. :D  The exhaust experimentation was more or less a follow-up to the fuel-injection testing we did back then.  We thought we might be able to optimize the exhaust in order to take full advantage of the injection, didn't get us much further.

Don't see the system working with a 180? motor.

The comment on the stock RGS system working best was fact, not an opinion.  Sure, it doesn't look very flash, nor is it loud and "in-yer-face" as many would prefer, but as Red states, dynos don't lie.  For a working, everyday street motor it is difficult to better.  Fits in well with the "gentleman" manners of an RGS too. ;)

piet
 
Them titty pump stacks certainly seem to dramatically improve airflow. As an aside I have started fitting a support bar for the carb bank when using the Mikunis without an airbox after discovering the rubbers were feeling the strain and starting to soften.

 
15783614330_9b83140ff9_c.jpg



  Keith
 
laverdakeith said:
Them titty pump stacks certainly seem to dramatically improve airflow. As an aside I have started fitting a support bar for the carb bank when using the Mikunis without an airbox after discovering the rubbers were feeling the strain and starting to soften.
Click to expand...

And some of us use a basket weave of cable ties  ;)
 
sweetas said:
I have to agree with Keith, they do kinda look a bit like a breast pump for that girl in the movie Total Recall! :D
Click to expand...

Bit small for the Russ Meyer babes though... ::)

piet
 
Ian's Monty racer, run #8, July 2015. (red)
run #6 was back in March 2014. (blue)

& recently, the Monty head has spent some quality time in the Redax shed
i understand there's been no change to valve sizes or cams.  just an improved setup.
Monty%20racer-%20runs-%200608%20c_02.jpg

i reckon the Redax work has been a good investment.  (thumbup)

also, Ian went +2 teeth on the rear sprocket, hence the shift in road speed to engine rpm.
& the engine rpm has a lot of interference in the plug lead sensor, so starts to jump around.
ignore the main jet comments as they didn't get updated between runs.  both runs were with a 130 main jet.
yes, it's rear-wheel power.

Fred at work
DSCN1062_02.jpg

 
chrisk said:
:eek: Fark, that's a 24% increase in HP.
Excuse my ignorance; What's a standard Monty push out?
Click to expand...
Around 50 bhp ,over 50 says to me well setup.Less than 45 -problems.Of course its a bit difficult comparing one set of dyno figures with another from different dynos.

Andy
 
chrisk said:
:eek: Fark, that's a 24% increase in HP.
Click to expand...

According to my calculator an increase from 46.71 hp to 51.59 hp (the figures given at the bottom of the dyno graphs) is a change of 10%. So how do you get 24% Chris?

Cheers,

bazzee
 
Maybe in the midrange where the vertical line is through both curves.
The midrange looks fatter than at the top end.
 
Grant said:
Maybe in the midrange where the vertical line is through both curves. 
Click to expand...
hence the reason why i dropped the cursor line down through the mid-range.

i didn't include the torque curve before, because the sensor interference of engine rpm always throws out the calculated crank torque.
but here it is anyway.
Monty%20racer-%20runs-%200608%20v3_01.jpg

just ignore the peaks in the torque curve, as it's due to the drops in engine rpm.  (so the maximum torque listed in the notes is also crap)

however, it does show a meaty 'flat' torque curve from 4,500 - 8,000 rpm ??
considering the y-axis is only scaled between 20 - 40 ft-lbs.
also highlights where the jump in power comes from around 6,000 rpm.
 
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