a friends nice words to me..about tuning

[ZL1Killa]

well i got home yesterday and saw an old friend that has a C3 denali in the 10's; a 00 corvette, and a turbo diesel. and has done other car work on other friends cars. Well i told him that I started doing my own tuning and I told him that I was currently dialing in my VE table and that I was in SD mode.

He then proceeds to tell me that all of that is a waste of time and that i don't even need to tune my car unless i do a cam and/or a head swap. He said that the car doesn't even use the VE table unless it can't normally operate in normal mode (not SD mode--stock mode..i think thats closed loop?) and that tuning the car in SD mode will have it surging after one track run and that it won't run right and that the car will want to return to closed loop (normal non-sd mode)

he put in a set of LPE heads and a .619 something cam in a ws6 and he said he at first over compensated and changed several tables and then the car ran like shit...then he paid for a professional tune and the comparison from stock to the pro tune was that one table was changed completely and the car ran fine ( i can't remember the exact table he said now) he said that I was wasting my time with Sd mode and dialing in the VE table.


And so i ask you from all that people have done....is this guy even close to being right b/c i have never trusted him??


Other than doing this SD tune and changing AFR I don't see what else you can do to tune a car...maybe change spark tables...but how much of a difference can that make....?? I think he is just nuts...so i walked away and said nice to see you..bye.....

someone please enlighten me on this.....cuz i think he is wrong

[Tordne]

All I can say is that with tuning alone (no modifications other than tuning in this time frame) my car feels entirely different (in a good way) to what it did at the beginning of the year. The previous tune was also done by a professional, but currently it feels a whole lot better!!!

My tune has been changed in several different areas, two of which have been the correction of the VE table to run in SD mode, and the other has been a major overhaul of the spark tables.

From what I understand you get your AFR's in line by tuning with a WB02, and then you go to the spark tables, and release the power of the car. That s how it has worked out for me anyway.

Cheers,

[TAQuickness]

why not just take him for a ride in your waste-of-time horibly-tuned car? Better yet, let him drive it and half way there, pull over and put the stock tune back in, the half way back put your tune back in.

[Black02SS]

Just because a professional tune has only one table changed, does that make it right???

Continue on tuning the way you are as I have tried about EVERY combination in tuning and re-working the ve table in SD has yielded me the best results. I don't know the exact numbers, but do know my car is faster with my tune compared to the "professional" tune that was on it a few years ago.

There are several things you can change IF you need to. Idle characteristics, sprak tables, AFR, VE table. The options are almost endless.

[joecar]

What else can you tune on a car...? :?
How about Idle characteristics, shift points, shift firmness, shift timing, torque management, fan temps....
wait, are you kidding...? :lol: there are almost 600 parameters that can be tuned.

The stock factory tune covers conditions found across this great land
(110 degree dry/humid heat, 30 degree dry/wet cold... etc and everything in between),
so you can see that it's not optmized for your neighbourhood.

If thru tuning alone you can make a few extra HP, ftlb, MPH, MPG,
or shift better (improves trans. life), or run cooler (improve engine and trans. lives),
or prevent knock destroying pistons... etc, then it was worth going thru it, even if you don't have any mods.

And I might add that we can do it "scientifically": alter, log, analyze, and repeat;
so you can verify that the change is working correctly and doing what is expected,
and not just change parameters willy-nilly on whim.

Cheers
Joe

[ZL1Killa]

exactly...my stock tune was getting me KR BAD!! and now there is none and the car feels better than it did...of course i'm not done with the VE table so thats probably why; but if feels way better and there is no knock...so lets just say that my thoughts were right and that he is an ass..like I always thought..b/c he was always mean to me acting like i didn't know shit. Thanks for responding guys...thought for a while i was wrong just because he has had several successful cars/trucks BUT then again the truck was nitrous only.

anyways thanks, I had my spark tables adjusted and everything runs great now even before I started dialing in my VE table my car ran better with the spark tables.

Also Closed loop is out of SD mode right? and the car DOES use the VE table during normal operation not only SD mode right?

[joecar]

... C3 denali in the 10's...

A Denali is a SUV/truck, right...? Weighs about 5000/6000 lbs, right...?

This must have some beast of an engine (need power:weight ratio to get into 10's).

[ZL1Killa]

I need my question answered about the closed loop above^^^ I'm confused right now...


Yeh the C3 was a 5500lb truck no weight reduce on it and it was turned into a 408 stroker that was nothing but nitrous...he then started shit talking and got himself into a race on the track with a F-150 harley davidson truck; well lets just say the supercharged truck handed him his daddy and nitrous is for babies...at least for this guy. I mean the harley just WALKED him.

The C3 ran a best of 10.91 @ something around 120-130 (yeh..it was topped out )

and the Harley truck ran like a 10.4~.6

[joecar]

Open/Closed loop is irrespective of SD/MAF (i.e. there are 4 combinations of these).

My understanding of the VE table usage:

If you run MAF:
above 4000 RPM: PCM uses VE table.
below 4000 RPM with transient conditions: PCM uses VE table.
below 4000 RPM with steady state conditions: PCM uses MAF.
PCM also uses VE table to sanity check MAF.

If you run SD, then PCM uses VE table.

You can run either of these in either closed loop or open loop;
close loop uses O2S feedback.

Cheers,
Joe

Edit: Ugh, I must have "below" and "above" swapped around...

[wait4me]

What makes a professional a professional that is correct?