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Series I Aftermarket Performance Modifications Discussion of power adding modifications

Any word from YAW lately?

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Old Sep 20, 2003 | 04:40 PM
  #26  
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I would be interesting if somebody tried dynoing the RX-8 with the front jacked up so the front wheels could spin. Then dyno the car with the front wheels still, and then hand spin the front tires as fast as they will go by hand and dyno again. If the computer is looking at the front wheel speed, it would probably show some difference.
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Old Sep 20, 2003 | 06:34 PM
  #27  
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Originally posted by yawpower


To keep inertial losses to a reasonably low level, the run is normally done in high gear. (That's why I mentioned the speeding tickets.)

in 6th you have no chance of reaching redline, in 5th there is a slim chance if conditions are perfect. Considering drag is proportional the square of the speed, I doubt you would want to do a pull in anything higher then 3rd gear.
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Old Sep 20, 2003 | 06:39 PM
  #28  
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From: PA
Originally posted by BRealistic
I would be interesting if somebody tried dynoing the RX-8 with the front jacked up so the front wheels could spin. Then dyno the car with the front wheels still, and then hand spin the front tires as fast as they will go by hand and dyno again. If the computer is looking at the front wheel speed, it would probably show some difference.
I think it would be better to try to use a variable speed electric motor...

or better yet find the speed sensor, determine the electric output (usually 4-20milliamps DC), and use a signal generator to fake the speed.

However, there may be even more complicated programming which would compare intake pressure (which is related loosely to speed) to wheel speed. Cars are getting more complicated all the time.
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Old Sep 21, 2003 | 12:19 AM
  #29  
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Why not just send the signal from the rear tires to ecu input that normaly wouls be from the fronts? That way the computer thinks all 4 tires are spinning at the same rate. Shouldn't be too much harder than diconnecting the front sensor wire and running 2 wires from the rear sensor ecu input to the front speed sensor ecu input. That should work and you could undo it in about 10 mins and shouldn't have any ill effects on the car. Could be wrong but what do you think?
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Old Sep 21, 2003 | 06:26 PM
  #30  
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Originally posted by pr0ber


in 6th you have no chance of reaching redline, in 5th there is a slim chance if conditions are perfect. Considering drag is proportional the square of the speed, I doubt you would want to do a pull in anything higher then 3rd gear.
im with ya there, i've never hit redline in anything higher than 3rd...9500 in 4th, how fast is that anyway? ...way too fast for me =p
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Old Sep 23, 2003 | 07:15 AM
  #31  
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Originally posted by yawpower
The service manual details the way that the ECU monitors the engine, and other sensors, and how those inputs are processed. In the case of running on a chassis dyno, the computer will "investigate" the situation. And try to determine what is wrong. In other words, why is the driver asking for full throttle while I am sitting still?

For instance, DTC number P0500 States that under the following conditions, there is a vehicle speed sensor problem:

Car in gear
Engine speed more than 2,500 rpm
Load (Throttle Opening) more than 40%
In put signal reads less than 2.3 miles per hour.

It does not explain what actions will be taken once it thinks this problem exists.

In the ignition timing control section, it mentions one of the modes called Acceleration correction. It states: "Performs retard correction of ignition timing to prevent knocking at acceleration from a standstill."
If we assume that the car is performing poorly on the dyno due to this kind of intervention by the ECU, that still doesn't explain the poor performance and G-Tech results that at least some people have seen. Or the anecdotal reports of a lack of power at high revs.

I have one theory that might explain this: what if the cars are generating all sorts of ECU errors in normal operation, due to software bugs or problems with sensors? Lots of people seem to be seeing spurious Check Engine Lights so it looks like there are some problems in this area, and not all error codes would generate a CEL anyway (but they may still affect engine operation). This would also explain why some cars can actually achieve the stated performance - perhaps not all cars are affected and not all the time.
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Old Sep 27, 2003 | 07:56 AM
  #32  
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Originally posted by ChrisW

If we assume that the car is performing poorly on the dyno due to this kind of intervention by the ECU, that still doesn't explain the poor performance and G-Tech results
Yea, that IS the rub in all these arguments. Others, and my own GTECH Pro Competition simply show the WRHP just isn't there, save extrodinary power train losses. The other "MOST HOPEFUL" answer is we need to wait for SP1, or SP2, or SP? on the ECU at least! It's apparently one complicated piece of software that!

It seems highly likely the ECU WILL need further development, esp. if someone QUICKLY came up with a last minute ECU redo at port (who knows?) that has been done supposed to meet emmisions. If that is true is is highly likey that was not a well developed ECU effort, more like a FAIL-SAFE effort to get the cars out of port. Did someone say BUGS?

Bottom line, with:

1) a VERY HIGHLY complicated ECU-ENGINE dynamic
2) cutting edge protocol used in the ECU
3) few new-gen protocol readers
4) the tight-lipped philosophy of Mazda and its engineers
5) unknown DYNO testing possibilities

there is going to be an extended development effort required to get PROVEN results. Paul Yaw has said it best, and most dispassionately, and I'll be waiting to see what he comes up with, IF he comes up with something!
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Old Sep 28, 2003 | 02:14 PM
  #33  
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couldnt you do something rolling-road style, like the wind tunnels?
________
Pissing Panties

Last edited by P00Man; Apr 16, 2011 at 08:20 PM.
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Old Sep 30, 2003 | 08:17 AM
  #34  
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Fooling speed sensor to get proper dyno

Originally posted by Mazda Family
Why not just send the signal from the rear tires to ecu input that normaly wouls be from the fronts? That way the computer thinks all 4 tires are spinning at the same rate. Shouldn't be too much harder than diconnecting the front sensor wire and running 2 wires from the rear sensor ecu input to the front speed sensor ecu input. That should work and you could undo it in about 10 mins and shouldn't have any ill effects on the car. Could be wrong but what do you think?
Exactly what I was going to propose. Must be a breeze, no?
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Old Sep 30, 2003 | 10:36 AM
  #35  
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Originally posted by Spin9k


Yea, that IS the rub in all these arguments. Others, and my own GTECH Pro Competition simply show the WRHP just isn't there, save extrodinary power train losses. The other "MOST HOPEFUL" answer is we need to wait for SP1, or SP2, or SP? on the ECU at least! It's apparently one complicated piece of software that!

It seems highly likely the ECU WILL need further development, esp. if someone QUICKLY came up with a last minute ECU redo at port (who knows?) that has been done supposed to meet emmisions. If that is true is is highly likey that was not a well developed ECU effort, more like a FAIL-SAFE effort to get the cars out of port. Did someone say BUGS?

Bottom line, with:

1) a VERY HIGHLY complicated ECU-ENGINE dynamic
2) cutting edge protocol used in the ECU
3) few new-gen protocol readers
4) the tight-lipped philosophy of Mazda and its engineers
5) unknown DYNO testing possibilities

there is going to be an extended development effort required to get PROVEN results. Paul Yaw has said it best, and most dispassionately, and I'll be waiting to see what he comes up with, IF he comes up with something!
Boy, did I buy a car from Microsoft??...what am I going to do when the next Blaster Worm spreads? I had enough trouble cleaning up mail servers with th original!!:D

On a different note:
Spin9K, let's do a quantitative comparisson. Can you install your Gtech on another car with known Dyno figures? Don't change any parameters on the GTech from your run on the RX8. And compare the results. We don't care about drivetrain losses here. We would simply be comparing 2 different data sources and we could come up with a scaling model for it.

For example, if you have a car X that is Dynoing at 150RWHP; you then plug in the GTech to it and do a couple runs, and results in 170HP (assuming the GTech is not 100% accurate). Verify that the results are consistent. Then you move the GTech to the 8, run it a couple times with the exact same parameters. Let's say you get 180HP on the 8.

Then we can scale this as follows:

CarX
Dyno: 150RWHP
Gtech: 170HP

RX8
Gtech: 180HP
Dyno: 150*180/170 = 158RWHP

or even bettet, you will get the following coefficient: 180/170 = 1.058 which could be applied to the RX8's GTech HP curve to correct it and compare against the original dyno'd X car.

Alright, I made it complicated. Sorry.
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Old Oct 15, 2004 | 09:32 PM
  #36  
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bump. Anybody know what Mr. Yaw is up to these days?

If you're reading this yawpower, can you tell us things you've learned about the RENESIS in the past year?

Are there new products in the pipeline?
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Old Oct 16, 2004 | 09:37 AM
  #37  
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Check out his webpage. He updated it not too long ago.
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Old Oct 16, 2004 | 11:21 AM
  #38  
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i noticed that too, however it doesnt really have updates on the RENESIS, on supercharger plans, or about new products
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Old Oct 16, 2004 | 11:47 AM
  #39  
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Heck, he hasn't even really updated the RX-8 wheel page either!
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Old Oct 16, 2004 | 10:37 PM
  #40  
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He must be really busy, as I should be and my schoolwork. :o
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Old Oct 17, 2004 | 12:35 PM
  #41  
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well y'know, he IS trying to build a competitive race car for the Speed GT thinger.
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Old Oct 17, 2004 | 04:46 PM
  #42  
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true, but he started that last year.
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Old Apr 27, 2006 | 12:39 PM
  #43  
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Any word? The latest posting on this thread seems to be a year, six months, and ten days old as I type this.
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Old Apr 27, 2006 | 01:36 PM
  #44  
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I used to check his site periodically, but after a while gave up. I haven't heard anything about them in regards to the RX-8 in a long time.
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Old Apr 27, 2006 | 01:51 PM
  #45  
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He mostly works on different types of rotary projects such as SCCA cars, rotary airplanes, boats, custom built motors for special applications, etc. He never really did get into the retail side of things like he intended to. As a result of this and the fact he stays so busy, he doesn't really update the website anymore. You might see an update from him every year or 2 but that's about it and even then it will only be on what project he has worked on lately.
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Old Apr 27, 2006 | 02:30 PM
  #46  
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what happeng to the renesis turbo race engine he was working on?
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Old Apr 27, 2006 | 02:33 PM
  #47  
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He was originally working on a Vortec supercharged Renesis for a Speedworld GT cup car but I think the project fell through. I don't think the car owner ended up going ahead with it.
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