I am in the process of installing miniram 383 into 80 corvette.
I installed a vss adapter on the th350c and verified functionality.

I will be using a modified aujp bin to start tuning but will i have issues being the ecm has no idea what gear i am in? Also my lockup is controlled by the original vacuum switch, do i need to disable any flags in the bin ? Should i be using the bin for a manual transmission instead ? I have read about IAC surge issues with that.

Thanks for your time!

 

I think that as long as you have four-pulse 4007 pulse per mile sine-wave signal going to the ECM I believe you are OK. I would not advise using any manual Bin. If you are using tunerpro 5 then think about using the S_AUJP_V4_1026 Bin. You can find it on Moates.net under the Custom Modified Binaries. It has all of the definition files and bin. It provides expanded mapping and many more customizable items than AUJP.

 

I was thinking of using S_AUJP_V4 but I thought it would be easier to do initial tuning with aujp. I think the timing in v4 is way too much, my dcr is around 8.5:1. I didn't want to start out with too many changes. Yes I am using tunerpro 5. Thanks for your insight!

 

Yes the timing maps are a little aggressive (for aluminum head Corvette) but really only takes a few minutes to copy from AUJP using the compare funtion. If you are going with aluminum heads that is what you need already. At the very least use the S_AUJP xdf and adx files so you can see the full list of configurable parameters.

 

Ok, I transferred my existing tables to S Aujp 4, Ill post the results when i have a chance to try it out.

 

i forgot the the VE tables are the same.

 

cool!

 

I dont think the ecm ever knows what gear your in.

 

I agree that It doesn't know what gear your in but looking at the ANHT hac, it looks like theres a term at location L82FC for first gear determination, not sure what its for though, AUJP has it set at 255.

 

255 means it is not used

 

Utilityguy thank you, yes I know 255 means not used, I just dont know what the scalar is used for.

 

I personally think that programming engineers used same routines for lots of different things and just left everything in there and put in unreachable numbers if not needed.

 

Looks like I was wrong, taking a better look at the hac, it looks like its a look up term for the E segment loop, so it does look like the code tries to determine what gear your in.

 

does your th350 have lockup? i guess i mean to say is it a TH350c?

 

I dont think TH350 have a lockup.

 

no,they did make a th350c trans around 1980,it had a lockup conv

 

Looks like your right, I just did a little of the google, had no idea that they made one, I think its called TH350C.

 

The only thing I see (not hac) is TCC based on speed and tps and temp ect. and 4th gear ratio. there is other stuff that is disabled but nowhere do I see or think the ECM can know which gear you are in at least for AUJP.

 

Yes thats correct its TCC based, what I meant was ( and I'm most likly wrong here) that the code tries to determine what gear its in to enable/disable TCC.

 

What I see is:
Coast release 32 mph
hi gear lock 38 mph
minimum temp to lock 50c
hi gear minimum speed to lock 36 mph
lo gear min mph 38 mph
unlock hi gear minimum speed 38 mph
unlock lo gear minimum speed 36 mph
unlock prevention mph 75 mph
Then there are 22 other items mostly disabled relating to TCC that refer to hi gear and lo gear but they are configured by speed or tps position. so there really is nothing that tells it what gear the transmission is in and of course there is no sensor input that tells it that either.

 

With a stick trans there is a determination of 1st and 4th gear. This is for the CAGs set up (skip shift from 1st to 3rd or 4th, can't quite remember).

For an automatic there is the P/N input to the ECM from the shifter position. Plus there is a high-gear (4th/OD) pressure switch input to the ECM. The high gear switch is used for several purposes, but mostly for the selection of which set of TCC parameters to use.

The TCC functionality can be used for a TH350C, just set the 4th gear input, which is left open, to the correct polarity for the lo gears. Then use those TCC tables for lockup control.

RBob.

 

Aggh, yes it is a th350C, I forgot the C. Anyway, Initially I was thinking about using the ecm to control the lockup. Just one wire to control lockup on the tranny. I don't think I am going to mess with it right now because the original vacuum lockup system seems to be functioning.
As far as gear selection, I was thinking back to my TECH 1 showing PRND Indication. I also remember gear selector switch input to ecm.
Eventually I plan to change the car over to a 6 speed anyway!

 

Once you see how easy it is to make the lockup turn on/off at different points that YOU specify, you would never go back to a simple vacuum operated system.
The engagement at speeds are not always what you want, just like using a speed based controller like the B&M as well. Once you are up and running, give it a try using the ECM tables.

 

Ok, you have me convinced. Once I get basic tune going , Ill do lockup through ecm. Ill post some results. Thanks everyone for your time and knowledge.