Silly idea but worth a thought. - D-series.org

Go Back   D-series.org Motor Mayhem & Suspension Satisfaction Naturally Aspirated

D-Series.org is the premier Honda Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
Old 02-11-2011, 01:21 AM   #1 (permalink)
rdc
D-series post SLUT
 
rdc's Avatar
 
iTrader: (7)
Join Date: Jul 2010
Location: Bangalore - India.
Posts: 2,054
Rep Power: 7 rdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow up
Default Silly idea but worth a thought.

As you tune from the honda base map towards the map your engine needs.
Is it not possible to develop a s/w which will take your map as an input and spit out a Dyno curve. ?

Or at least give you info on where your engine is breathing better than stock.
And where its worse.

The idea being we are testing variable length intakes and Exhausts.

The idea is simple. Change the intake length / ex. length then tune.
Your map will now need more fuell in some area's and less in others.

So you can tell where the tuned length is working.

After all what is a map. Its how much gas your throwing at the engine.
We know the AFR says I have tuned 14:1 at all map points.

We know exactly how much gas is going in. We know the AFR.
That will tell us how much air is going in right.
That will tell us the VE of the engine.
If know the ve we can figure the BHP right ?

Anybody care to explain the math to pull this off ?
rdc is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 02-11-2011, 04:44 AM   #2 (permalink)
All powerful D-series member
 
ddd4114's Avatar
 
iTrader: (7)
Join Date: Mar 2006
Location: Columbus, OH
Posts: 3,463
Rep Power: 15 ddd4114 is hot as a volcanoddd4114 is hot as a volcano
ddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcano
Default

It's possible to get a ballpark estimate, yes.

The changes in your fuel map generally reflect VE changes, as you mentioned.

There is already software that will estimate your wheel horsepower while you drive. The right way to do it is first do a bunch of neutral coastdowns on a flat road during a calm day. Do 5-6 in one direction and 5-6 in the other direction. Once you have this, you can calculate your drag force vs. speed. Next, do a pull (ensuring you're in a high enough gear that the tires don't spin). You can then calculate the rate of change of engine speed vs. speed and calculate the car's acceleration vs. speed. Then, multiply that by the car's mass to get the net force, add that to the drag force, and multiply the total by the vehicle speed to get power. It would be good to also do this 5-6 times to get an average.
ddd4114 is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 05:55 AM   #3 (permalink)
rdc
D-series post SLUT
 
rdc's Avatar
 
iTrader: (7)
Join Date: Jul 2010
Location: Bangalore - India.
Posts: 2,054
Rep Power: 7 rdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow up
Default

Na man that shits old.
I was playing with stuff like street Dyno and Road Dyno which did this stuff back in the 90s.
I own a Iphone/ Veypour/ Gtech / Virtual Dyno all which give pretty good Dyno curves.
Which are as repeatable as a real dyno.

This is more to see changes a part has made on the car by looking at the maps. i.e. If we have the map. We have the fuell being injected. We have the VE change.

We dont even have the roads to do a decent 2nd gear pull. Otherwise I would just use Virtual Dyno.

This is why I want to use the maps.
So lets try and get back on subject. The value in a crome map is the injector on time right. ? What is the unit of measure ? usec / msec or dwell ?

Ps: Veypour even calculates your coefficient of Drag.
rdc is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 06:23 AM   #4 (permalink)
D-series G0D
 
K2e2vin's Avatar
 
iTrader: (19)
Join Date: Aug 2005
Location: Raleigh, NC
Posts: 5,538
Rep Power: 13 K2e2vin It's a JDM Star Bitches....
K2e2vin It's a JDM Star Bitches....
Default

You'd use a dyno to figure out VE/fueling, so kind of defeats the purpose.

It's possible to get theoretical HP figures, but you'll run into lots of variables which makes it difficult. Simplest formula I've seen require a HP figure to start from and use BSFC figures.

Edit:
Required VE = ( 9411*HP*BSFC ) / (displacement(in^3) * rpm)
BSFC= 5.92*Fuel Flow(gph)/HP
__________________
-Kevin N. E.
2005 Subaru Legacy GT wagon; v9 EJ207 (6spd soon!)
1988 Honda Civic hatchback; in limbo
1992 Honda Accord LX coupe

Sign up for Groupon! Deals on resturaunts, stores, etc:
http://www.groupon.com/r/uu16193153

Last edited by K2e2vin; 02-11-2011 at 06:26 AM.
K2e2vin is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 09:00 AM   #5 (permalink)
rdc
D-series post SLUT
 
rdc's Avatar
 
iTrader: (7)
Join Date: Jul 2010
Location: Bangalore - India.
Posts: 2,054
Rep Power: 7 rdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow uprdc is about to blow up
Default

thanks guys.
Just trying to figure out if we can use the changing fueling requirements of an engine to help us understand whats going on in an engine.
So say change X will give a 30% increase in fueling from 800-2500 RPM. But then it results in a drop off flow from 2500 - 3500 and so on.
I remeber reading a post by a mega squirt user who could figure out his flow rate improvements and how much his head was flowing better or worse post porting just by studying the changes in the fueling map.
rdc is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 09:12 AM   #6 (permalink)
D-series PIMP
 
90dirtydsi's Avatar
 
iTrader: (10)
Join Date: Mar 2009
Location: Frankensteinville
Posts: 1,264
Rep Power: 7 90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness90dirtydsi is approaching greatness
Default

I dont think you could generate power numbers but if you are datalogging with a wbo2, just make the afrs consistent across the pull then make you change and see where the fueling changes. In a speed density car it will lean out when it flows more and get richer when you are going slower as long as the ecu is still running off the same section of the map.
__________________
90 Civic si- dirty turbo Frankenstein racecar wannabe
98 Mazda B2500- soon to be turbo sohc beater truck
90dirtydsi is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 09:21 AM   #7 (permalink)
D-series post SLUT
 
cyanide's Avatar
 
iTrader: (16)
Join Date: Jun 2009
Location: Bombay, India.
Posts: 2,358
Rep Power: 14 cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!
cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!cyanide is the fucking MAN!!!!
Default

Quote:
Originally Posted by rdc View Post
thanks guys.
Just trying to figure out if we can use the changing fueling requirements of an engine to help us understand whats going on in an engine.
So say change X will give a 30% increase in fueling from 800-2500 RPM. But then it results in a drop off flow from 2500 - 3500 and so on.
I remeber reading a post by a mega squirt user who could figure out his flow rate improvements and how much his head was flowing better or worse post porting just by studying the changes in the fueling map.
Can't you do that right now anyways? The only problem is quantifying the increase in power which can "sort-of" be calculated by how much fuel was added to the individual cells post the change in the hardware. Get an approximate percentage of the increase in fuelling and you can make an educated guess about the increase in VE at that load/RPM.
__________________
RIP patprimmer.
cyanide is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 10:14 AM   #8 (permalink)
D-series PIMP
 
dj211855's Avatar
 
iTrader: (3)
Join Date: Jun 2010
Posts: 1,127
Rep Power: 6 dj211855 is a name known to alldj211855 is a name known to alldj211855 is a name known to alldj211855 is a name known to alldj211855 is a name known to alldj211855 is a name known to alldj211855 is a name known to alldj211855 is a name known to alldj211855 is a name known to all
Default

Im staying away from this one rdc..
__________________
MY SHIT STINKS
dj211855 is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 12:50 PM   #9 (permalink)
D-series lover
 
iTrader: (0)
Join Date: Mar 2009
Location: South Africa, Durban
Posts: 112
Rep Power: 6 Shane Ruthnum is learning the way of the DShane Ruthnum is learning the way of the D
Default

Power output of any engine is not just a matter of how much air and fuel is being consumed.
Its a combination of factors, one of them being mechanical efficiency/advantage.
Another is friction of the moving parts.

2 engines having the same afr will not have the same power output.
How will the software calculate for that?

The most accurate will be to measure the actual output at the flywheel, not even at the wheels.
Shane Ruthnum is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 01:11 PM   #10 (permalink)
D-series G0D
 
K2e2vin's Avatar
 
iTrader: (19)
Join Date: Aug 2005
Location: Raleigh, NC
Posts: 5,538
Rep Power: 13 K2e2vin It's a JDM Star Bitches....
K2e2vin It's a JDM Star Bitches....
Default

When I took engineering in High School someone actually obtained a torque formula that took many things into account(related to NASCAR engines IIRC). I'm not sure how accurate it was, but it was pretty long(a couple of lines on a two side-by-side whiteboards).
__________________
-Kevin N. E.
2005 Subaru Legacy GT wagon; v9 EJ207 (6spd soon!)
1988 Honda Civic hatchback; in limbo
1992 Honda Accord LX coupe

Sign up for Groupon! Deals on resturaunts, stores, etc:
http://www.groupon.com/r/uu16193153
K2e2vin is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 03:59 PM   #11 (permalink)
All powerful D-series member
 
ddd4114's Avatar
 
iTrader: (7)
Join Date: Mar 2006
Location: Columbus, OH
Posts: 3,463
Rep Power: 15 ddd4114 is hot as a volcanoddd4114 is hot as a volcano
ddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcano
Default

Whenever you change something, you can't get both VE and BSFC from your fuel map. You have to assume one or the other. You'll need to dyno test to really see what's going on.
ddd4114 is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 04:13 PM   #12 (permalink)
All powerful D-series member
 
ddd4114's Avatar
 
iTrader: (7)
Join Date: Mar 2006
Location: Columbus, OH
Posts: 3,463
Rep Power: 15 ddd4114 is hot as a volcanoddd4114 is hot as a volcano
ddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcanoddd4114 is hot as a volcano
Default

Quote:
Originally Posted by rdc View Post
Ps: Veypour even calculates your coefficient of Drag.
Haha, well yeah, but you need to give it vehicle weight, tire coefficient of rolling resistance, atmospheric pressure, ambient air temperature, relative humidity, frontal area, and drivetrain friction torque vs. speed for it to be accurate. That's why I just lump all drag forces into a second-order relationship based on a polynomial fit. It's a lot easier.

EDIT: Well, if you're only using data from when you're driving at a pretty high speed, then rolling resistance and drivetrain friction will be pretty small. Atmospheric conditions are significant though.

Last edited by ddd4114; 02-11-2011 at 04:16 PM.
ddd4114 is offline   Reply With Quote Quick reply to this message
Old 02-11-2011, 05:18 PM   #13 (permalink)
wise in the ways of the D
 
schardbody's Avatar
 
iTrader: (2)
Join Date: Apr 2006
Location: Charleston SC
Posts: 1,624
Rep Power: 9 schardbody is a name known to allschardbody is a name known to allschardbody is a name known to allschardbody is a name known to allschardbody is a name known to allschardbody is a name known to allschardbody is a name known to allschardbody is a name known to allschardbody is a name known to all
Default

most tuning software has an AFR % difference map. as you drive it populates the difference in your "desired" AFR tables to those in the "live" map. if you get your AFR all dialed in, make a change and you look at the % difference map and you need more fuel in XXX cells you know you improved flow there.

no need to know before or after hp or tq numbers. if you increase flow you'll increase the ability to make power.

the key is making sure your tune is PERFECT before any changes.

also, you can do the same using the injector duty cycle. just graph duty cycle vs rpm. in a N/A car load isnt important because you'll be doing it at WOT. this is helpful if you dont have an AFR % difference table.

you can also get a descent idea of where you're at hp wise using duty cycle numbers if you know your injectors true flow rate.
__________________
Lee
schardbody is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the D-series.org forums, 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:

Log-in

Image Verification


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may post new threads
You may 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


iconAll times are GMT -8. The time now is 01:13 AM. | Welcome to Forum, please register to access all of our features.