A dyno graph that I don't get. - MVAgusta.net
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old 08-02-2006, 11:04 PM Thread Starter
Senior Member
 
quacker998's Avatar
 
Join Date: Jul 2006
Location: Manhattan
Posts: 395
A dyno graph that I don't get.

Below is a picture of a dyno run [pirates lair] that makes me say wtf? The red line is a brutale with the stock pipe - the blue line without the mid pipe - yes I know that the blue line makes more peak power 110hp against 104hp but look at the middle where you would want driveability - how is making 60hp at 70mph better than making 60hp at 60mph?
It would seem from this graph that you would loose a lot of the driveability of the Brutale by sticking on a straight through midpipe - maybe the stock collector box thing actually adds exhaust 'length' therefore making more torque bit like an exhaust valve?
Has anybody cut one of the collector boxes in half and really looked inside?
I don't get it - perhaps someone [airfuel?] could enlighten me - I have been known to get things assbackward before so please be gentle with your replies......
Attached Images
 
quacker998 is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 08-03-2006, 06:08 AM
Senior Member
 
hb88xx's Avatar
 
Join Date: Jul 2005
Location: A'dam, NL
Posts: 3,399
New Site Garage
Too me it looks that they have not used the same gear as it is in speed and not in RPM's.
The cut of at the right should be the rev limiter. So if you place these lines together it is not so bad at all.
Therefor you shift back to over take, having more power/torque at lower speeds.

4,5Mg~3Al~2Ti~Fe

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
hb88xx is offline  
post #3 of 12 (permalink) Old 08-03-2006, 07:21 AM
 
Join Date: Jul 2006
Posts: 29
That looks like the 750 graph.

The restrictive stock mid pipe is probably providing some back pressure in the mid RPM range that is helping boost power. That back pressure is exactly what the EXUP and other mid pipe valves accomplishes for the Jap manufacturers. The idea is to have some restriction at mid RPMs and then have the valve open and allow freer flow at higher RPMs.

Very often aftermarket pipes (slip ons) will diminish the mid range of a motor. The buyer feels more push as the motor comes on the cam so he thinks he is going faster. Sells millions.

It is probably necessary to re-map and perhaps even adjust the cam timing a bit to get the most out of the exhaust changes. It may not be possible to regain all the mid RPM HP but there could be more gain up high.

It comes down to "how do you want to use it?" Mid power for the street 0r high RPM power for the track.
sailor22 is offline  
Sponsored Links
Advertisement
 
post #4 of 12 (permalink) Old 08-03-2006, 08:39 AM
Senior Member
 
airfuel's Avatar
 
Join Date: Feb 2006
Location: Connecticut
Posts: 1,292
This graph puzzles me also.

The speed difference means he probably did the last pull in 5th vs 4th gear. BUT, usually doing a pull in a higher gear shows more power everywhere.

STD horsepower also gives higher readings than corrected HP.

I would also like to see the graph in rpm and why no torque curve?

I just think the dyno operator screwed up somewhere.
airfuel is offline  
post #5 of 12 (permalink) Old 08-03-2006, 09:15 AM Thread Starter
Senior Member
 
quacker998's Avatar
 
Join Date: Jul 2006
Location: Manhattan
Posts: 395
Yes I see different gear - funny way of doing things, If you did overlay the two traces the outcome would be superb - my photoshop image below - now that's a graph I could get my head around!
I am waiting with bated breath for airfuel to post his dyno pulls so I can see first hand, from someone I trust, what real world gains will be made by changing the mid pipe. For now I will get a pc111 and get airfuel to map it for street rideability. Straight after the 600m service that is.
Attached Images
 
quacker998 is offline  
post #6 of 12 (permalink) Old 08-03-2006, 09:23 AM
Senior Member
 
airfuel's Avatar
 
Join Date: Feb 2006
Location: Connecticut
Posts: 1,292
Now that graph looks like a real graph!!!! Good work.

I've posted graphs before on a 910 with header and midpipe. (Anucci) I saw about 5hp gain with that setup. 121 RWHP. I'm hoping high 120's with the full system.

Don't worry, when I get the full system, you will be flooded with graphs!
airfuel is offline  
post #7 of 12 (permalink) Old 08-03-2006, 11:20 AM
Dyno printout glitch

You guys are pretty sharp! This is the dyno I had done on Christmas 2004 right after my wife gave me the mid-pipe as a present so I ran over to a friend's house. He owns a mobile dyno set up. Being Christmas I didn't bother him with torque wiring since I was going to re-dyno when I got the PC installed anyway.

Both runs were taken to 4th gear. The run starts at 20 and drops off at 120 so the photoshop overlay is correct. Dyno operator was having a party right next door at this house while I installed the pipes and had the re-run. Anyway being one of the first mid-pipes brought in by pirates lair he asked me to provide the graph.

I have one showing the airfuel mixture for both these runs and if you thought the 750 ran rich before this canisterectomy, you'll be shocked at how much richer it made the bike.
brutal2dmax is offline  
post #8 of 12 (permalink) Old 08-03-2006, 11:59 AM
 
Join Date: Jul 2006
Posts: 29
Oh, i get it now. I'm looking forward to seeing the data on the full system.

Regarding running rich - seen this?

http://www.moto-one.com.au/performan...e750eprom.html

The curves look very much like the one you posted - with a slightly more optimistic dyno.
sailor22 is offline  
post #9 of 12 (permalink) Old 08-03-2006, 12:25 PM
116 hp on a 750 with just a mid-pipe does sound optimistic.
brutal2dmax is offline  
post #10 of 12 (permalink) Old 08-03-2006, 12:26 PM Thread Starter
Senior Member
 
quacker998's Avatar
 
Join Date: Jul 2006
Location: Manhattan
Posts: 395
Ah yes good stuff from the Aussies - interesting to note [my ego bloating] that:

'This bike had a Casoli midpipe fitted to the exhaust. This eliminates the central box – which has pipe work inside it to lengthen the system (I assume that’s the reason anyway) - it’s not a catalytic convertor.'

Ho Ho! 'it’s not a catalytic convertor' he said - I still want someone to cut it inhalf so we can see inside. The other thing to note I think is that the first critical area - as with Ducatis - is to properly dial in the tps settings and set up your base lines before using the dyno. Or will the new fuel map optimise the system irradicating any imperfections? Any thoughts friends?

'The report “Weber Marelli Throttle Position Sensor Setting Notes and Procedures – with photos for MV” is a detailed TPS setting procedure with lots of general information and some specific to the Brutale. Fitting our eprom requires this basic setup to be carried out correctly to get the most from it.'
quacker998 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to use all of the features of the MVAgusta.net site, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome