Well, I finally got the money together to get my burning equipment . I ordered the Pocket Programmer and I am planning on getting Tunercat shortly (I downloaded Winbin for now)..... I have a few questions about what chips to use though...

What is the difference between these two chips (from Digikey's site) and which one is better for our useage?

AT27C256R-70RC-ND

and

AT27C256R-70PC-ND


Also, is this EEPROM (from JDR's site):

AT29C256-90PC

the right Flash EPROM to use and will I need anything extra besides the regular Pocket Programmer to be able to just flash a new bin onto the chip (software or hardware)?

Thanks in advance,

Matt



------------------
1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, Edelbrock TES, gutted Cat, Flowmaster, K+N cone, AFPR, TB bypass, AirFoil, !AIR, !A/C, !EVAP, ARAP, 2300 stall, Hotchkis STB.

 

Get the AT29C256. The others (27s) are UV (EPROM) the 29 is a Flash Prom. UV type require an UV Eraser, take 15 minutes (and generally increasing) erasing time, and can only be erased so many times.

Flash Proms (the 29) don't need a UV Eraser, takes seconds to program and have a virtually unlimited amount of re-programming.

 

Thanks Glenn. I know I had asked you that stuff before but now that I am actually getting all of my stuff together, I want to make sure I get all of the right stuff - the first time...... lol.

I am thinking that the EEPROM way is the better plan of action for ease of burning and cost factor in the long run.

Also, as far as that knock sensor sensitivity issue I had emailed you about; I talked to a few of my mechanic buddies that I used to work with and they agree that the A/C signal producing crystal in a knock sensor most likely will deteriorate over time and become increasingly sensitive to occurances of knock. Kind of like an Oxygen sensor deteriorating over time except getting more sensitive instead of going dead like O2 sensors do. This would explain a lot of the most likely 'false' knock that I am seeing in these other two cars of my friends' that I am playing with. Both cars have over 100,000 miles on them so I told them that it really can't hurt to get a new sensor just as a maintenance item at this point. They both are going to replace their knock sensors and bring them back to me so I can see what kind of a difference a new knock sensor makes.

------------------
1987 GTA L98 MD8 GH3
355 '97 Vortec 4-bolt block, TRW(suck) forged pistons 10:1 CR, TFS 23*, LT4 Hot Cam, Ported plenum and intake, SLP Siam Runners, Edelbrock TES, gutted Cat, Flowmaster, K+N cone, AFPR, TB bypass, AirFoil, !AIR, !A/C, !EVAP, ARAP, 2300 stall, Hotchkis STB.

 

Knock sensor's DO become over sensitive with age as I have said before. I have changed about 20 of them that did this and it happens. This can get rid of a lot of false knock counts that cant be explained.

 

The logic just doesn't follow in my book. How can a rock fail?. It's a bit like quartz, and shaken or squeezed it developes a slight voltage. There is nothing to wear out. What screws then up is not being tightened correctly.

Most likely your false knock with a 100K mile engine is from some oil useage ( ie maybe just drops per 3K miles, can be enough to do it). The closer the tune is to optimume, the less oil it takes to actually trigger some detonation.

 

Bruce, I have been doing some tests of my knock sensor and I have noticed that if I initially start my engine, that the knock sensor is extremely sensitive and will remain that way as long as the engine is running.

However, if I stop my engine and restart it, the knock sensor is less sensitive. Further, if the engine is "hot" (ie been operating for a period of time and then stopped for about 30 minutes), the knock sensor seems to loose sensitivity and would not register any knocks while I actually can have "ping" occur.

I just replaced my knock sensor and I plan to do some testing on it. My engine/knock sensor had over 175,000 miles on it, so I figure mine would be an excellent candidate to test if there is anything to an "old knock sensor" behaving erratically. I will do a variety of tests over the next few weeks and let you all know what I see.

I have a ton of Diacom GDFs to compare the two. If it behaves exactly like it did before, then we know that knock sensors don't change in sensitivity. I am hoping to see that the sensor behaves more "consistent".

I do believe that many of these "false knocks" people are talking about are in fact very real and what they are seeing is the knock sensor is just doing its job on an old engine. I think the scenerio that I am talking about (changing sensitivity) is different and may indicate a "less than optimal" knock sensor. I'll keep you all posted as I do more testing.

 

Well I normally would agree that an older engine cannot be counted on and assuming that the knock it is logging is false is a bad idea. But the two cars that I am talking about have things done to them (1.6 rockers on intake, lowered, etc..) that can create incidences of false knock. I also have ridden in them many times and they do not seem to be knocking (audibly).

One of the cars is an 89 IROC LB9 M5, lowered, stock EPROM, stock engine, intake, and exhaust. It will start logging knock counts as soon as he gets over about 70% throttle and keep logging them steadily as long as he is on the throttle. His car pulls about 5* out of timing when it starts logging knock as well.

The other car is an 88 GTA with a rebuilt L98, A4, stock intake, 1.6 rockers on intake, SFCs, STB, and full exhaust system with headers. His car logs knock as soon as he gets his throttle past 70% as well and keeps logging it until he lets off. His car has an ADS EPROM in it. I worked with him a little bit more than the other guy and his car gets up to 39* of total timing even when it is being retarded 5.4* because of knock. I don't hear knock in his car either.

I know that knock is hard to hear when the engine is at full song, but if these cars are logging that much knock, you would think that I would hear it. They both have their base timing set at or under the factory setting (6*) and they both run 92 octane or better at all times. BTW - I have been using Craig Moates software.

Well if you guys have any ideas I, and they, would appreciate it a lot. Glenn has been a great help to me in the past (Thanks a ton Glenn ) and I was mainly posting to see what he had to say but the more minds the better .

Thanks..... Laterzzzzzzz

 

ttt

 

Right now I am analyzing information on my new Knock Sensor. I think I have some information that some people may find interesting in the next few days. I have definitely noticed some things, but I want to do more testing to get a good "sample" of the results. I also like to build up suspense.

 

Well, WELL..!!????

 

The suspension indused *knock* from what I've heard was in the 17" tired vettes with ultra short sidewalls. I'm running 40 series 16s on my GN and no false knock.
There are sounds of the right frequency, and harmonics also.
The above is just FWIW.
There still in nothing *good* about acoustic *knock* sensors.

At the point of detonation there is an excess of ionization that takes place. I just had some modes done to the GN for hopefully being able to measure that, and if it works out there might me a real easy answer to when knock is actually ocurring