barchetta1

I dont like the idea of adding a switch to my car to engage performance mode but wondering; for those of you who play with programming transmission shift points and tc engagement have you tried using the ASR switch to engage?

My thought is the ASR switch is likely momentary but even if I wired it as so that the two could be out of sync, Ie. when ASR is engaged performance mode could be off and visa versa.

Just a thought.

rjacobs

what is this "performance mode" you speak of?

barchetta1

It is a mode available in odb1 and odb2 pcm's essentially a alternative set of tables for various purposes. Its enable by a momentary switch.

drcook

I know about the extra tables that were available in later year vehicles, this has been done in the diesel world for a long time. maybe even up to 4 (maybe 5) different settings, each with a different purpose and tune, such as towing, stock, +x HP, etc.

How are you seeing the tables in the 96 ?

barchetta1

Im not sure what you mean by how are you seeing. If you mean how am I accessing then the answer is I use a Jet DST Tuner. I am succeeding in making my 96 with a damn 2.58 rear end much more performance oriented. But Id like to go to extremes when I want it. For example, I dont shift from 2nd to 3rd right now until 42mph even at very low throttle positions. I dont release the TC unil something like 20mph. I dont shift into 4th until 70mph. I downshift into 3rd at something like 65mph.

With my ridiculous rear end ratio Id like to leave it in 2nd until 50mph when Im driving with spirit as just one example.. but I dont want it like that for just driving around town.

For anyone with a 2:58 or 2:56 or whatever it is this makes a huge difference in how your car feels.. I cant imagine driving it with the stock settings.. I would say its similar to what people say when they install a 3:07 or larger diff. I mean in terms of feel. Im not saying the result is the same but the impact is similar.. At least I believe it is..

Im just kicking around ideas on getting a switch installed without having to drag wire through the firewall and drill a hole in my instrument area somewhere.

I honestly think Id likely have a synchronization problem. Id also like to use the performance engaged light feed.. I could probably use something in the warning display somewhere.

These connections, the performance mode actuator and 12v light feed are in your oem repair manual. I guess trans ams and some other variations of the f body came with a switch.. the tables are all there in our cars just not in use. One simple thing you can do is copy and paste the tables right into your non-performance tables to get you started. Its not enough though on a 2:58.. would probably be close on the 3:07's.

Something else I learned.. the TC (torque converter) is released very quickly if you are in D (drive).. if you put your car in 3rd it is held for a lot longer so you have more of a standard shift feel when you lift the throttle.. On top of this you can force the TC to hold longer using tables. I havent succeeded to make it hold as long as Id like though. As I understand it you can wear out the coast clutch if you arent careful. I dont know enough about this but I guess you can upgrade to a dual coast clutch. Im not using the correct terminology here but hopefully it makes sense.

I HATE coming through a corner and have to wait for the motor to spool up the converter because it was released when I get back on the throttle.

Unfortunately, there is no way possible that I can determine to stop the car from releasing the TC when the brake is applied.. other than disconnecting the brake wire to the transmission.. and I doubt that would be a very good idea.. shame. Would be nice to brake before entering a corner and not release the converter.

Im sure modern cars can do this.. I know my BMW can but thats a whole different breed.

drcook

I know you are using the DST, we have spoke before, so am I. What I meant is how is the DST accessing the alternate tables ? In the diesel world, folks wired a switch into the ECM that allowed you to select which tune you wanted and used EFI Live to do the programming.

Such as this:

https://www.thoroughbreddiesel.com/l...iABEgJGr_D_BwE

As soon as I get the Dana 44 installed, I have a low mileage (18K right now) 3.07 rear that I will be selling. Keep that in mind if you are interested. I changed the diff oil and put in new additive when we bought the car at 12K miles.

Being able to use the additional tables would be a great way to work on a tune, try it and if it doesn't work out, go back to what you had.

barchetta1

Oh Sorry.. well Im not accessing the tables from the car. thats the issue. I need a momentary switch to the PCM connection (I forget the connection point). And right next to it is the light which is lite when its enabled. So I just modify the stock tables to realize the result.

Thanks.. but if Im gonna do the rear end its gonna be a 3:48 or whatever that # is... sorry was in a bad accident and my memory is ****. Such is life and then you go on being punished for what you did in your youth.

This is why I didnt recognize your name too.. sorry.

So I guess what Im asking is probably not something someone can answer.

As soon as I get my life back together I want to do the rear, a cam and spend the rest of my years screwing around with the PCM

I really enjoy messing with the transmission.. and one day probably the fuel and spark once I modify it with the cam. Yeah I know, needs to be on the dyno... but what from I read these tuners are good but not God.. takes some time and patience to really nail it.

Considering this is a freaking 23 yr old car (manufactured in 1995) its quite advanced!

Mr. Peabody

I have to say to you in all honesty that from reading your posts that a 3.07 rear is going to give you much of what you are seeking. Before I bought my 95 I drove several C4s with the 2.58 rear before I ended up with the 3.07.

To me it felt like going from 6 cylinders to 8. Recently I swapped in a Dana 44 from a 96 so it has the 3.45. I don't think there is as much of a difference in SOTP from the 3.07 to the 3.45 as there was from the 2.58 to the 3.07. I don't track my car so I do NOT have empirical data to back up my SOTP.

The main reason that I mention this is that it is a lot less expensive and easier-to-find a take-off 3.07 (Dana 36) pumpkin than it is to find a complete Dana 44 rear-end.