A/F with RPM - Graphs
#1
I like cheese!
Thread Starter
Join Date: Sep 2003
Location: Little Rock, AR (was vegas)
Posts: 957
Likes: 0
Received 2 Likes
on
1 Post
A/F with RPM - Graphs
Ok, got my "beta test" rpm converter back with the update from http://www.innovatemotorsports.com
Here's some more graphs as promised:
![](http://rx8.swankmonkey.com/images/af/afrpm1.jpg)
![](http://rx8.swankmonkey.com/images/af/afrpm2.jpg)
![](http://rx8.swankmonkey.com/images/af/afrpm3.jpg)
Next will be to start tapping in other sensors and graphing those with wideband A/F and RPM![Wink](https://www.rx8club.com/images/smilies/wink.gif)
If the images are loading slow, I might just limit the bandwidth on the server using mod_bandwidth.... just be patient for them to load.
Here's some more graphs as promised:
![](http://rx8.swankmonkey.com/images/af/afrpm1.jpg)
![](http://rx8.swankmonkey.com/images/af/afrpm2.jpg)
![](http://rx8.swankmonkey.com/images/af/afrpm3.jpg)
Next will be to start tapping in other sensors and graphing those with wideband A/F and RPM
![Wink](https://www.rx8club.com/images/smilies/wink.gif)
If the images are loading slow, I might just limit the bandwidth on the server using mod_bandwidth.... just be patient for them to load.
#3
I like cheese!
Thread Starter
Join Date: Sep 2003
Location: Little Rock, AR (was vegas)
Posts: 957
Likes: 0
Received 2 Likes
on
1 Post
That's one thing I'm going to request with the software. For the first two, there is a veritcal line that I tried to position on the peak of the rpm curve, and it shows the value at the bottom.
You can select one axis with the software right now, it's a radio button in the pic.
It does log to a file and I can import to excel and do some charts there at a later date.
You can select one axis with the software right now, it's a radio button in the pic.
It does log to a file and I can import to excel and do some charts there at a later date.
#5
Registered
iTrader: (1)
Join Date: May 2003
Location: PA
Posts: 3,754
Likes: 0
Received 0 Likes
on
0 Posts
For ***** and giggles, I'm thinking you can take the RPM curve of the 2nd graph with the 1st gear WOT, take the derivative of it to find acceleration, monkey with the gearing, tire diameter, and vehicle weight and produce a Torque and Hp graph to see what the Rx8 is really producing under real world conditions
... be much better then relying on accelerometers like the G-Tech uses (providing there was no tire spin) and since its 1st gear there is little drag.
... be much better then relying on accelerometers like the G-Tech uses (providing there was no tire spin) and since its 1st gear there is little drag.
#6
I like cheese!
Thread Starter
Join Date: Sep 2003
Location: Little Rock, AR (was vegas)
Posts: 957
Likes: 0
Received 2 Likes
on
1 Post
There are OBDII specialy tools that do this.
One that I can think of that goes beyond obdii is http://www.ross-tech.com
You can actually calc HP from the sensors.
You are missing a few variables from this equation. You would need a speed reference logged with it all. You could monkey with tire diameter, but it's not gonna be even close to accurate! You also need the mass of the car to calc it all!
Good thoughts though, but once there's a cheap CAN Bus reader AND it can tap into sensors, then it's all downhill from there.
These are some of the questions that I'm asking at SEMA.
One that I can think of that goes beyond obdii is http://www.ross-tech.com
You can actually calc HP from the sensors.
You are missing a few variables from this equation. You would need a speed reference logged with it all. You could monkey with tire diameter, but it's not gonna be even close to accurate! You also need the mass of the car to calc it all!
Good thoughts though, but once there's a cheap CAN Bus reader AND it can tap into sensors, then it's all downhill from there.
These are some of the questions that I'm asking at SEMA.
#7
Thanks again for all of the great graphs Syntrix. Did you say that the RX-8 idle ratio is right at stoichiometric? Was that when the car was cold, hot or does it matter?
Brian
Brian
#8
Registered
iTrader: (1)
Join Date: May 2003
Location: PA
Posts: 3,754
Likes: 0
Received 0 Likes
on
0 Posts
Originally posted by syntrix
There are OBDII specialy tools that do this.
One that I can think of that goes beyond obdii is http://www.ross-tech.com
You can actually calc HP from the sensors.
You are missing a few variables from this equation. You would need a speed reference logged with it all. You could monkey with tire diameter, but it's not gonna be even close to accurate! You also need the mass of the car to calc it all!
Good thoughts though, but once there's a cheap CAN Bus reader AND it can tap into sensors, then it's all downhill from there.
These are some of the questions that I'm asking at SEMA.
There are OBDII specialy tools that do this.
One that I can think of that goes beyond obdii is http://www.ross-tech.com
You can actually calc HP from the sensors.
You are missing a few variables from this equation. You would need a speed reference logged with it all. You could monkey with tire diameter, but it's not gonna be even close to accurate! You also need the mass of the car to calc it all!
Good thoughts though, but once there's a cheap CAN Bus reader AND it can tap into sensors, then it's all downhill from there.
These are some of the questions that I'm asking at SEMA.
well for the speed you just have to take your car out and record the speedo reading and rpm and probably factor in what the speed should be according to the gearing/tires to eliminate the error.
yea, you do need the vehicle weight... you need the vehicle weight for any hp measurement thats not done on a dyno stand though.
Thread
Thread Starter
Forum
Replies
Last Post
Shankapotamus3
Series I Trouble Shooting
28
03-14-2021 03:53 PM
jasonrxeight
RX-8's For Sale/Wanted
2
09-30-2015 01:53 PM
tommy26Germany
Series I Trouble Shooting
11
09-29-2015 10:33 AM