My mods are listed below for my 99. I just added a Vararam and removed TQ management. Now it seems that I touch the rev limiter on the 1-2 shift. It may seem odd, but I could sware it doesn't actually go all the way up to my 6400 limit, but I get the feeling you get when you do in fact hit the limiter... Anybody have any suggestions......Please

 

Are you sure you are hitting the rev limiter and it is not Traction Control kicking in and removing timing? I had this happening on me ever since adding more power to the car and it always "appeared as if it was rigth at the 1-2 shift. Was running autotap at the track a few weeks ago and was able to determine it was TC causing this and not actually me hitting the rev limiter as you could determine by vehicle speed that as the car approached 49 mph of the line, the computer went to -10 degrees of timing to let the wheels catch up.. This appeared to be the 1-2 shift when in actuality i was still in 1st and still had to shift into 2. which at the time I was thinking I was shifting into 3.

Once I figured this out, turned off TC and added a good set of tires to the car. My ETs dropped by about 4/10ths.. However on the street.. I would recommend leaving AH/TC on as it WILL save your butt on regular street tires as many times you are spinning the tires and do not even realize it.

 

I did have traction control off, BUT can traction control still kick in if you push the botton off?? Can you use LS1Edit to remove the timing retard in regards to traction control?

 

ttt.....need help here guys....

 

If you have TC off, then it will not affect your timing in any way. You can spin your tires until they come apart and it will not affect timing. Log it and see what is happening. That's the only way to see what's going on in the PCM.

 

I agree.. you will probably need to hook up something like Autotap's EFI Live to diagnose exactly what is happening here.

 

I do have autotap logs, but not for anytime that my problem occurs. I will try to catch it this week....

 

Yes, but if you register knock retard while spinning-which I do even with TC off the timing is decreased.....

 

That's precisely why I'm thinking logging is in order. As you well know, logged data can be the difference between knowing what's the cause and guessing.

 

Tony...

Remember what that guy emailed to me...

Change the values in the spark retard limit table to 15 across the board.. This allows you to maintain 15 degrees of timing advance thru the shifts instead of 0.

Mine was set at stock -10, now its on 15.

Maybe try that... :confused: :crazy:

 

Also.... I have heard that:

Sometimes if you get a good launch the PCM just can’t react quick enough to make the shift happen.

Anyone else hear of that?

 

Hi I'm not an expert by any means but have logged many 1/4 mile runs
and with my C5 there is about a 300 rpm overrun from where I have the
shift points set (set for 6200-43mph ,6200 -82mph) shifts at 6500.

This is ok for me as my rev limit is 6700.

Converter is yank st3500, Rossler built A4

I have abuse mode off and torque limit at 500,

Hope this is of some help as to how an A4 shifts (at least mine)

Dick

) :flag :flag :flag

 

Thanks Dick...I have heard that sometimes it shifts 200-300 over where you set the shift point, but my friend has the exact same problem I have and has had it for two years now. He has his 1-2 shift at 6000 with a 6600 rev limit and it still occurs. The thing is that you can feel what seems to be the "rev limiter bounce" BUT the tach isn't up to the rev limit rpm yet..... Strange! Somebody must know what is happening here........

 

If you have a chance to get EFI live set up on the car to log a couple of runs.. you should be able to see within the graph everything that is happening at once and then determine what is actually happening. As for setting the shift points..

And yes you will need to set the shift points about 300-400 rpm below your rev limiter on a stock tranny. However I am not sure about on a built tranny such as your Rosler as I would think that the shift engagement from 1-2 would be more precise (but i could bve wrong). I know that when I put in the FLP later this winter I will be looking to reduce the gap between shift point and rev limiter to test this.

Currently I have my rev limiter set at 6800 and we moved the shift points down to 6200 thinking I was hitting the rev limiter onone of my last runs at the southern shootout. Turns out that while sitting in the staging lanes I had turned the ignition off while they were cleaning up one of the lanes and forgot to turn TC back off and was thinking I was bouncing the rev limiter. All in all I am still happy with the times as I still managed a 1.59 60' and 11.386 run with only 3.42 gears and a 3600 stall converter.

Hopefully I will be able to get back down to my car over the Thanksgiving holidays and even make a trip up to Hallsville to reduce my times some more. At that time I hope to get a few more diagnostic runs now that the car seems to be running well through the 1/8th. However I will be needing to do a few changes on the top end to adjust the fuel maps for the flow of the vararam as I am about 2-3 mph off where I should be. i think that I can also adjust the shift parameters a bit more to pick up another .1 as well as they are set pretty conservatively now.

Bottom line is get something to do some diagnostics. We can all sit here every day and come up with different possibilities for you to look at and all be wrong at that. However with some hard data to look at, we should be able to give a better idea of where to start. Heck that is the beauty of the forum.. everyone (most anyway) is here to help.

Also, I will try to get one of my logs from the runs where i was having this problem to post so that you can see what I am talking about. on the "apparent" 1-2 shift.


[Modified by brialex42, 4:38 AM 11/18/2003]

 

Thanks Brialex42, I wish it was as simple as leaving TC on. I know my TC was off. In fact my problem happened twice in a row with two different drivers. My friend has been experiencing this for two years. The funny thing is that it ONLY happens at the track and not on the street. I have autotap and plan to log my 1/4 runs this weekend(weather providing). I'm on a mission to solve this damn issue.....Any opinions are welcome....

 

Once you get the logs.. feel free to email them. Would love to try and help you get this resolved. I know how frustrating it was when something similar was happening to me.