Attention all tuners! Doing some OBD1.5 tuning, any tips?

Want to know how to get more out of your Beretta? Or have a mod you would like to share?
User avatar
whiteretta
Registered User
Posts: 760
Joined: Mon Jan 31, 2011 2:40 pm
Location: New Carlisle, Ohio
Contact:

Attention all tuners! Doing some OBD1.5 tuning, any tips?

Post by whiteretta »

Here is the data list that you can access on TunerCat's OBD 1.5 tuner kit. Any good tips on simple things to start with? If you'd like to see what the calibration is underneath a certain category, I can post a better photo as well for reference purposes.

I have bumped the fuel cut off to 120 mph, along with removing the P/N rev limiter and the lean cruise mode. My current setup is a '99 3400 block, bored .040 over with .480 lift on the cam along with a 65mm throttle body, headers and an underdrive pulley. I'm also EGR delete. The transmission is the 4T60E.

Image

I hope this thread can be used at some point to help others who are just starting tuning to get some good advice and pointers, not just for myself on this one.


1994 Chevy Beretta, mild 3500 swap.
https://youtube.com/@MurphRocks86?si=mpCQc0DnEitPx3Jg
Image
1988GTU
Registered User
Posts: 2744
Joined: Sat Mar 23, 2002 1:06 pm
Location: A town up north

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by 1988GTU »

Screen shots would make reading the data a lot more viewable to the potential readers.


_________
Image
-------------
User avatar
woody90gtz
Registered User
Posts: 4698
Joined: Thu Jul 11, 2002 8:45 pm
Location: Walton, NY
Contact:

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by woody90gtz »

VE will be the main thing you need to tweak.


91 "SS" - WOT 3400/5spd - 13.29@101.6 - World's fastest N/A FWD Beretta
96 "T56" LS/6spd/8.8 RWD swap - 13.45@104.7 lol
GEARHEAD dezign youtube
User avatar
whiteretta
Registered User
Posts: 760
Joined: Mon Jan 31, 2011 2:40 pm
Location: New Carlisle, Ohio
Contact:

Attention all tuners! Doing some OBD1.5 tuning, any tips?

Post by whiteretta »

Here are the VE graphs, where do I even start with these?

Image

Image

Image

Image


1994 Chevy Beretta, mild 3500 swap.
https://youtube.com/@MurphRocks86?si=mpCQc0DnEitPx3Jg
Image
User avatar
Rettax3
Registered User
Posts: 1805
Joined: Mon Oct 22, 2012 3:34 pm

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by Rettax3 »

This is a little above my head overall so far as the actual details of the process. I am just now starting OBD2 tuning with a DHP, and would love to get into OBD1 at some point too, but I have already forgotten most of what I had learned while researching all this in the past (like forgetting a language you never actually get to speak to other people in). I don't think I'll be getting into the 1.5 stuff, even though my Z-26 is a '95 -I will probably just swap in the OBD2 setup if I get that far with the car. I am really curious though, as to why you would want to delete the lean cruise mode? EGR delete I am right there with you on, but then I would also delete the speed governor altogether rather than just pushing it up a tiny bit like that -isn't it normally at around 114 MPH?

I am really interested in this thread though -it is great to see this info on this site, so thank you for sharing. Maybe you will change my mind about tuning the 1.5 on my '95...


1989 SuperCharged 3800 Srs-II (First)Six-Speed GTU
1990 Turbo 3.4 5-Speed T-Type
1990 4.0L 4-Cam 32-Valve V-8 5-Speed Indy GTi (Project)
1990 Stock(!) 3.1 MPFI Auto Indy
1995 LA1/L82 4T60E Z-26
1995 3.4 DOHC Turbo 5-Speed Z-26
User avatar
3X00-Modified
Administrator
Posts: 10912
Joined: Thu Jul 05, 2007 9:18 am
Location: Brooklyn CT

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by 3X00-Modified »

Ok... Here we go....

Now this is directly related to DHP, BUT The process used to perform a VE tune is very similar... Read it over and get an understanding for what's going on. The biggest thing is going to be able to log while your driving to see what the car is doing. That means a good laptop with a good battery, OR a 12v power adapter for your laptop.
Tuning_Notebook.pdf
Read the VE section of this and gain some knowledge on it... You can ignore anything that relates to MAF though since you don't have it.
(3.3 MiB) Downloaded 4068 times
Another DHP guide but still has quite a bit of background
tuner_rev_109h.doc
More General tuning info
(1.39 MiB) Downloaded 3037 times
You will probably have to use excel to make your changes, OR just use the tuning program but here is the table modifier I use to make changes to my individual tables using my scans as reference.
http://theblattners.com/projects/tablem ... fault.html

And seeing how this setup is very OBDI like you can probably find a bunch of info on OBDI tuning over on Moates or 60*v6

Also remember there are some terms floating around like you just stated Retta... like Deleting lean cruise mode... In essence you really only change an enable value to prevent it from happening. Same goes for EGR... the most you can do with that is to set the SES codes for the EGR to no reporting and then change the EGR enable temp to over 250* so the ambient temp is never hot enough to request it to even run.

IIRC my limiter is still set at a reasonable value because let's be honest here, these cars really weren't built to go those speeds... Rev limiter on mine is changed from a fuel cut to a timing reduction... It's very catastrophic if you cut fuel to limit the rev's especially when your spraying nitrous. Results in a very lean condition and will burn a piston. The timing removal is a safer way to limit the rev's.

Your biggest mods to the file will probably come from trans tuning. Changing the way that trans shifts wakes up the car a ton.


Mr.Pink
Supreme Unit
Sleepy Goodness
"Beretta Guy"
User avatar
whiteretta
Registered User
Posts: 760
Joined: Mon Jan 31, 2011 2:40 pm
Location: New Carlisle, Ohio
Contact:

Attention all tuners! Doing some OBD1.5 tuning, any tips?

Post by whiteretta »

Thanks John! I'll take a look at these when I get back from my work tonight!

Retta I just didn't want lean cruise mode because I want my car as close to stoichiometric as possible at all times. I don't really need lean cruise, I don't take it on trips anyways. The enable conditions are set to engage the mode at 255 mph, so needless to say, it won't be engaging at any time while I'm driving it now!

I really appreciate all the feedback so far, keep it coming guys! I know this will also help our community as a whole!


1994 Chevy Beretta, mild 3500 swap.
https://youtube.com/@MurphRocks86?si=mpCQc0DnEitPx3Jg
Image
RobertISaar
Registered User
Posts: 98
Joined: Tue Nov 27, 2012 7:14 pm

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by RobertISaar »

jesus christ, WTF am i looking at?

those tables are just all kinds of wrong. determining VE from RPM and airflow? no, just..... no.


User avatar
3X00-Modified
Administrator
Posts: 10912
Joined: Thu Jul 05, 2007 9:18 am
Location: Brooklyn CT

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by 3X00-Modified »

LOL I guess that's how Tuner Cat does it. Mine is RPM vs engine load IIRC... maybe that's what they meant to put.

yeah verified, Mine is RPM vs kPa


Mr.Pink
Supreme Unit
Sleepy Goodness
"Beretta Guy"
RobertISaar
Registered User
Posts: 98
Joined: Tue Nov 27, 2012 7:14 pm

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by RobertISaar »

i took some time to look at my XDF..... that isn't VE... it's used for calculating the temperature of the cat.

Engine Speed Reaction Temp vs RPM and Airflow

the RPM scaling is off as well.... i just double-checked my math in the assembly and mine are slightly off as well.... i have 0-3200 in 400 RPM increments, it's actually 0-2800 in 400RPM increments, then 3600RPM as the last row, not 3200. the RPM scalar used is a goofy one, luckily it is only used 5 places throughout the entire calibration, guess i'll have to re-verify those table intervals as well.



actually all of those tables claiming to be VE related are the cat temp calculation tables.....


User avatar
3X00-Modified
Administrator
Posts: 10912
Joined: Thu Jul 05, 2007 9:18 am
Location: Brooklyn CT

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by 3X00-Modified »

That's scarry... LOL since well VE is the most important thing you can tune with OBDI...


Mr.Pink
Supreme Unit
Sleepy Goodness
"Beretta Guy"
RobertISaar
Registered User
Posts: 98
Joined: Tue Nov 27, 2012 7:14 pm

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by RobertISaar »

pretty much..... i can guarantee zero'ing all of those tables will have absolutely no effect on engine running characteristics..... it will only disable the cat temp calculations.


also, i just went through the entire RPM calculation subroutine, turns out i made one error along the way that cascaded into other errors..... i'm correcting it now, not a lot of tables/scalars effected, but a couple of important ones. i should probably keep changelog notes as to which tables are effected for when i upload.....


User avatar
3X00-Modified
Administrator
Posts: 10912
Joined: Thu Jul 05, 2007 9:18 am
Location: Brooklyn CT

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by 3X00-Modified »

Will your XDF work for him and replace this piece of garbage he was given?


Mr.Pink
Supreme Unit
Sleepy Goodness
"Beretta Guy"
RobertISaar
Registered User
Posts: 98
Joined: Tue Nov 27, 2012 7:14 pm

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by RobertISaar »

inside of tunercat, no. requires TDFs.

would have to use it with tunerpro(not that i see any downsides to it).


RobertISaar
Registered User
Posts: 98
Joined: Tue Nov 27, 2012 7:14 pm

Re: Attention all tuners! Doing some OBD1.5 tuning, any tips

Post by RobertISaar »

checked all 18 RPM values in the RAM that i know of, corrected tables that used them, most were small changes, others were quite radical.

PE Sub'd SA vs RPM Multiplier
Knock Attack Rate
Knock Attack Rate in PE
Maximum Knock Retard
Maximum Knock Retard in PE
Knock Retard Recovery Rate
Knock Retard Recovery Rate in PE
Dwell Offset vs RPM
Dwell Time vs RPM
TPS% Threshold to Enter PE vs RPM
Power Enrichment Target AFR
Engine Speed Reaction Temp vs RPM and Airflow
Offset to MAP for Barometric Update vs RPM vs TPS Table (F59)



also discovered what i have labeled as dwell tables may not be dwell tables, rather signal latency offsets? i'll have to do a little more investigation on those and then i'll upload the updated XDF to 60V6.


Post Reply