Hey guys,
I'm am very new to this and have read a ton and searched a ton and I think I got the basic grasp on this stuff. I recently bought te AutoProm along with the LC-1 wideband controller and gauge. I am building a 383 stroker for my 89 Camaro, and while the engine is in the machine shop I thought I'd start playing with TunerProRT and getting acquainted with it. I no longer have EGR, since I am using the LT1 intake and I have disabled it. I also installed all new Autometer gauges, including a cable driven speedometer. The problem is that the stock gauge ran the VSS. I did some searching and it is my understanding that the VSS is only needed for cruise control and torque converter lockup, neither of which I have. I want to disable VSS diagnostics but there are no flags for it, anyone know how I would go about doing it? Should I change anything else having to do with TCC?

Also, from what I've been able to understand, the ARAP bin is a pretty good starting point (with some slight changes). My stock chip is a AUJL (Original L98, A4, 2.77), should I still start with the ARAP?

Thanks for any advice.

Andy

 

Metalli, you finally decided to join us! Welcome to our world.

I don't have TunerPro, but TunerCat. But there is most definitely a "bit switch" flag for the VSS (Err 24). By "bit switch", there is a "single bit" in a particular byte (1DE from the start at C000) using "bit mask x'80".

x'80 would be the left-most bit in the byte "1xxx xxxx"

The VSS also affects the IAC as it is engaged until a certain vehicle speed before it stops. As well as these features:

1) Fuel Speed Cut-off
2) DFCO disable speed
3) Highway Mode minimum speed
4) Various TCC locking parameters and "unlock prevention"

This is only from what I can see is controlled in TunerCat. Of course, there may be other constants & tables that also maybe affected but are not currently defined.

If you don't have an auto, then really the DFCO disable speed, IAC control and Highway Mode (if you would like to invoke it) are the most important factors that the VSS would affect for you.

As for the ARAP vs your AJUL; you need to do a number of "house-keeping" for the ARAP such as changing the Fans Switch to Normally Open, adjust the crank pulses (ARAP is a bit tough to start) and greatly cut-back in the spark tables. There are other 'minor things' - I suggest doing a search on ARAP first.

What I think I like the BEST of the ARAP is its MAF Scalar Tables. I have found it requires the least "adjusting". Conversely, you could just copy all the ARAP MAF Scalar Tables to your AJUL and start from there.

 

Yeah, I've always wanted to get into this but when I started on these boards, I was 16 and didn't exactly have the money to be tossing into my car. But now I do

So are you saying I have to view the text file of the bin in order to find the byte for VSS diagnostics? If so, what do I do then?

As for VSS, did I screw myself by sticking with the cable driven speedometer? I have an automatic and the converter I bought does not have lockup.

And in regards to the ARAP vs. AJUL, you are saying it would be better for me to keep the AUJL and change the MAF Scalar Tables to the ARAP ones?

Sorry if these are "newb" questions, I appreciate the guidance.

 

I believe the VSS for the late 80s 700R4 supports both cable AND electronic - so you can have BOTH worlds. That is if you are using a 700R4.

As for the VSS through out the code - that was a "bit of a warning", though I think I have addressed the main items the VSS affects as the 700R4 in the late 80s was used in cars both with electronic and manual speedos. Maybe a quick post on this on the Tech/General Board or a few searches on VSS on this question will confirm

Personally, I would prefer a locking convertor though. But, it may be because you are not using a 700R4 or that was what was available. Somehow, I recall someone toasted their 700R4 when they went to a non-locking TCC. I recommend you do some research on that topic if you are using a 700R4.

 

Id keep the VSS if possible. IIRC, there should also be a connector down by the transmission for the electronic VSS. Youll need to get an electronic VSS, applicable gearset if needed, as well as the buffer box from a later car if you decide to stick with having a VSS.

As for the non-lockup converter, I believe there are some mods needed as well as teh use of a large external trans cooler to keep the trans cool without lockup.

 

http://www.jagsthatrun.com/Pages/Spe...eedometer.html

For $80 you can put VSS back on the car. It really needs to be there.

 

Andy, why not try BOTH and see which you prefer. When I was tuning my buddy's car we found the modified ARAP seemed faster and had more power BUT the stock bin (I don't think it was the AJUL though) ran smoother and started better DESPITE copying virtually every setting over.

I tried to do a bin compare but the code itself is also different so it was impossible to why the difference despite the nearly identical tables.

While his setup isn't too radical, he is running a solid roller of 248/256 duration @ .050 with a 110 LSA.

 

Perfect, thank you very much.


Glenn, I will start with the AJUL with ARAP scalar tables then go from there. I'm sure I'll be back around with more questions