Good evening folks, the saga continues.....
ijames wrote
If you go through all the changes he made, you wind up at about 18 degrees of advance at wot over 3600 rpm, along with some other changes at lower rpms to enhance spooling.
Being that this thread is about the thrasher 92 chip, Here is the data for what is called a 'Thrasher 93.5'. I'm not familiar with all of the different nomenclature describing these chips or any of the features, but this is the closest one to 92. I had to take the data over again because someone mentioned something about the timing being different for each gear. Well, there is a difference in timing, but not for each gear. There are basically two 'zones' where the timing is different and it is based on the mph of the car. The first 'zone' is from 0 mph to about 20-21 mph. During this low mph, the timing is advanced by 5* accross the board from the second 'zone' which is from about 21 mph on up. As I previously stated, I'm not that familiar with all the different features of the Thrasher chips, so basically I'm doing some 'blind' testing. Some things I noticed when taking the data.....there is a 'rev limiter' at 6000 rpm. This 'rev limiter' is not a complete shutoff of fuel like a stock chip, but looks to be a 'stutter' kind of limiter. The MAT sensor has an effect on the timing. There is an 8* change from -37f to about 100F. After 100F there is no more change. Also, the change seems backwards, that is, there is more timing at 100F then the is at -37F. So if you read 20* at 100F , you will have 12* at -37F. This trim also looks linear. The data I took was at a MAT of 80*. It's obvious that engine temperature also has an effect on timing. I chose 190* because the previous data I took on a stock chip was at 190*. At this temp, these is nothing added or subtracted to the timing. There is also a 3* retard whenever there is a change in the 3rd or 4th gear switches. This retard lasts for about 2 seconds. Under some certain conditions, there seems to be a random 4* retard. I don't know what this is, but a stock chip does not do this (rules out my setup). So here's the data.....
Thrasher timing data 07-15-02
rrthr935.bin timing MAT=80F Engine Temp=190F
MAF=254 LV8=255
RPM <20mph timing >20mph timing Prom timing
1400 22.2 17.4 31.3
1600 22.3 17.4 31.3
1800 23.0 18.1 31.3
2000 26.7 21.8 35.1
2200 26.8 22.0 35.1
2400 29.1 24.3 37.2
2800 29.5 24.5 37.2
3200 27.6 22.8 35.1
3600 27.0 22.0 34.1
4000 26.3 21.3 33.0
4400 26.8 21.8 33.0
4800 26.9 21.9 33.0
5500 28.2 23.3
6000 30.8 25.6
The two columns with the 20mph tag is the actual measured timing on the est signal.
ijames wrote
As for measuring the est signal directly, that's a neat idea but I have to wonder if the mag4 chip is really giving 38 degrees of advance at wot.
Yes, the mag4 does actually have that much timing and I can prove it
ijames wrote
About the most I've heard of anyone using even with a stock turbo is 30 degrees, with C16.
How was this 30 degrees measured? Just think, that person was probably running running close to an actual 49*! I just plugged 30* in at the LV8=255,4800 rpm address and I read 49* at 5000! This is assuming that a stock type chip was used and 30* entered into that address location.
ijames wrote
Also, what were the coolant and mat timing trims under your conditions with the stock chip? Do they add up to the difference you saw between the 22.1 deg in the main table and the measured 25 or so degrees?
I like to use 190F for the engine temp because there is no correction to the timing. I also use this as my 'standard', so I can do a direct comparison to other chips. The MAT has no effect on the timing (stock chip). This is at least under the conditions that it was tested at. If I remember right, the table is zeroed out. To reiterate, the difference in the timing table and the actual timing is due to the 'time domain correction to spark' data. I hope my data has proven this. Oh, and one more thing I bet most people may not know, is that the timing on the est is not rock solid. Given steady state conditions, there is about +- .5 degree jitter.
All the data I have taken, I take the max timing I see. So if I measure 25*, the timing can be as low 24*.
bruce wrote
I'm not convinced you can read the EST line, and be more accurate the reading the RAM location like DS does.
If you have been following this thread, you now know that DS does not read the timing very accurately. And why are you not convinced that I can'tead the est line? Ya know, I've done design work for NASA in the past. I think I can handle a couple of counters
And that project I did for NASA even made it on CNN's Science and Technology Week program. That was a real feather in my cap. And my cap is not shaped like a cone
bruce wrote
Judging from how linear the timing error is, it looks like there is a constant timing error, ie fixed timing error, and since the GN code doesn't use any spark latency corrections, I doubt the error is in the code or ecm.
If you're playing with address 164 hex, and not seeing any timing changes with DS, then it's just more proof that DS does not read correctly. You really need to look at the est signal and make some correlation. Without correlation you are assuming something. And this can lead to errors.
bruce wrote
the magic of actually seeing what's going on, LOL....
I thought I was the only one, bothering with one.
A bench ecm is really great. I've had mine for almost 13 years. That's even before you bought your car! And by sliding the bench around on the floor, I can induce wheelspin knock
bruce wrote
Next you'll be telling me you've gone to the trouble of making a ROMless conversion......
Why yes I have. I've been running an emulator for quite a few years now. That's probably the second best thing I've made. Of coarse, *the* best thing I made was my High Speed Synchronous Datalogger. It has a top speed of 500 frames/second, with 62 parameters/frame. It can read pressure and temperature and a bunch of othe stuff. Now, I wonder what would happen If I read the temperature across the turbo compressor and measure the pressure across it too. Hmmmmm.....
Danster wrote
Being that you obviously know much about other chips and apparently don't like them much as you do your own chips, why would you not offer a chip that would be perfect for other TR owners?
I think you're giving me too much credit. No two cars are alike, so one chip fits all is not for me. You need adjustability. I hear the Max Effort is adjustable. I also hear it is an excellent chip. I don't own a ME or really know that much about it. I also have adjustability with my emulator and my datalogger. With these two items I have, I get correlation. Have I mentioned correlation? It's *very* important.
Danster wrote
Great way to make mucho $$$ unless of course you already have it Do you share any of this info to other chip burners?
Nope, not many of those $$$$ here
I did share a little info here about address 164 hex and how it affects timing. Use it to the best of your ability. And to any doubters, to enter the fray, you must have some data. Thankyou!
Danster wrote
Curious though, you mention of a flaw in the ECM, can you tell us if this can be easily fixed? Does this flaw hurt the car's performance?
Ok, I found what I said about the flaw. I didn't convey what I really meant. I was refering to that random 4* drop when using the thrasher chip. It's definately there. That's the flaw I was refering to.
tim87tr wrote
I just ran for the first time a Thrasher 97 with 100 octane Xylene mix and just traded a RA 93 for a Thrasher 100, so I am curious to know any differences in timing of the Thrashers. I have some basic knowledge of timing from my Trans + adjustments. Tim
I've got data on a thrasher 100 and a 108. Now these are interesting to say the least! I'll post these in a day or two. This will be worth the wait
Time again to say goodnight.
Dave
) because I was waiting and hoping that you would post again.
