I tried a search but nothing came up so here goes. Do the pro tuners alter the ve table or adjust fueling via the INJ pw? I'm new to tuning with HPTuners and it takes me quite a bit of time to go out and try to hit a majority of the histo, make changes, and then go back out and see where my trims are. Not to mention timing, MAF (if your using it) and trans settings. I was just wondering how they do it since I've never witnessed a live dyno tune.
Thanks for your insight.

 

the handful of tunes ive seen have alterd either ifr, maf or pe or a combination of the three...i have seen one tune that used the maf for all the fueling & used the stock pe table. Saw one the other day that used ifr & pe. My intial tune was done via ifr & maf if i recall. If they touched the ve tables it wasnt noticable enough for me to tell.

 

Thanks man. I wouldn't think they would have time to jack with the ve table. Seems like it's better to do it yourself if you have the means and some help from LS1Tech.

 

the thing is up until 2 years ago doing a full ve remap wouldve been a painstaking process...with programs like hptuners & efilive they have made things so much more user friendly...but when you've already invested $25 grand in ls1 edit many would rather just stick with that and do it the old fashioned way. I think in the next few years you might find more tuners out there doing VE tuning because of programs like those and having load bearing dynos. It honestly doesnt take much longer in the end.

 

It doesnt take much longer and it seems your car or truck would be much more responsive in the end and have a fuller tune.

Chris

 

trying to tell some of them that is like talking to a brick wall...they will fight you tooth & nail that ls1 edit, ifr & maf tweaking is the end all be all to tuning.

 

Thanks again guys for your responses.

 

Professional doesn't mean "right". It means "get paid".
The thinking on what's "right" has evolved a whole lot
in the years I've been watching the scene, as more of
the tuner tools' wizards cough up explanations of how
the airflow and fuel delivery calculations really work.
What was dogma two years ago is now comedy. How
tragic.

The best idea is, fix what you know is broke and don't
mess with what you don't understand. That means, you
don't jack around the injector table when all you did was
hang airflow mods on the motor; you don't change the
MAF table to fix low speed, idle airflow problems (unless
you are dead sure the MAF is being fooled somehow).
You don't change the PE table to overcome bogus airflow
measurements. At least, not until you have exhausted
the more relevant tables' fitting ability and they're as
proper as they can be. Sometimes you do have to cheat.
But not from the get-go, and not as your main strategy.

Understand the source of the error and you can find the
closest model table to adjust. Fake it once and the next
time you have to not only fake the second thing, you have
to unfake the other fake with yet more fakery and pretty
soon it's a yarn ball full of snot.

All you want is a truthful model that stays tight with the
air & fuel reality of the motor, so that your commanded
operation is received as-said. That's why you fix the boring
basics first (fuel trims, being the symptom of good/bad
airflow metering and fuel delivery) before you try and bed
in WOT fueling (a commanded thing).

 

Up until about a week ago, if it was posted here that a Pro Tuner drilled a throttle body hole larger, they would have been flamed off the board. And because of one post, it is now OK to do. Hmmmmmmmmmmmmm........

 

You'll see the same stuff come back time and time again.I've been into tuning for 5 years now on these cars.There is always a new fad that everybody say's is the best,then a few months later they say that sucks and off to something else.This is probly the reason you don't see tuner's from the past post up here anymore.They just use what works and they have used on 100's of cars

 

probably because the admittedly ignorant masses here dont know WHY.. and view it as a hackjob...

meanwhile thoes of us who do understand it, have known why for so long that we just do it and dont bother arguing with people online.


if you really want to hear something funny, consider this.
everyone has been drilling them on heavily modded LS1 motors since '96.
a year or so back, someone said "STOP DRILLING THOES THROTTLEBODIES, and went on with a moving the blade/dicking with the TPS scheme"
up till then, there wasnt even a choice.

realistically, the two are doing an identical thing... allowing more air into the motor, so the IAC counts stay within a specified range. the only diff is one involves resetting the TPS, and realistically, requires elongating the TPS holes, so you can move the blade enough to get enough air.

the other, involved either enlarging the existing hole GM put there, or drilling a second small hole.

its only a problem when people drill a friggen huge hole thats too big.. or when you de-mod and no longer need that hole.

otherwise, there isnt anything to argue about.




im sure someone will halfass, halfway read what i said, and want to argue about it...

 

I wish I could remember the author of this tip I saved years ago. I'm pretty sure it was a VERY respected Pro Tuner, but I just can not find the original post I copied it from. I'm positive it wasn't from this board. I'm only posting the whole tip so maybe someone will recognize where it came from. Pay close attention to #3.

1) To add timing you are going to want to use the High Octane Ignition Advance Table located under the engine - ignition tab. Wide open throttle (hopefully all that you are using at the track ) is located in the lower right hand corner of this table. To add or decrease timing simply select all cells for 0.60 g/cyl and 3200 rpm and greater. You will be highlighting the lower right portion of the table. Select the 'Selected Cells Only' box. Put your desired timing change (positive to increase, negative to decrease) in the text box in the lower right. Click on the "Add" button. Select "Apply Changes" to make your changes permenant. Save your file and upload it into your car.

2) To lean out your car you are going to use the PE vs RPM table located under the engine - fuel tab. To lean out your car simply type the desired percentage shift in the lower right text box and pressy "Mult %". Press the "Apply" button to make your changes permenat. Save your file and upload it into your car.
To add fuel (enrichen your car) you will want to multiply the PE table by values greater than 100 (ie 101 to 110). To reduce fueling (lean your car) you will want to multiply the PE table by values less than 100. (ie 90 to 99). Any changes to this table should be between 90 and 110. Never multiply this table by a value less than 90 or greater than 110.

3) LTerms are for emmissions, not performance (despite the general concensus). If they are less than 15% ignore these at the track.

 

i think everyone would agree with that... the orignal intent of LTFTs was to keep the average AFR in the 14.6 range for emissions reasons...
we just like to look at it because the LTFTs are working towards the avg AFR we want under part throttle, and the farther off they are, the farther off our tune is from where it should be. within reason. you cant use them as a exact science, and thats where the only debate is. i view them as a tool to help the mild cars i usually work with.... now the wideband fueling and enhanced IOs availible now, thoes are alot more accurate... lol

anyway, at the track, its not something you're looking at as much because you're usually working with WOT and PE openloop stuffs, not part throttle or cruise...

 

Having been tuning FI systems for 20 yrs, 15 professionally, here are some things I've learned. Never go on a forum to discuss your tuning proceedures. Besides the obvious competitive reason, you will be challenged on every word you state by someone who usually has much less knowledge and experiance, there are so many ways to skin a cat. Never invest $25K in a professional tuning package if you have the option of pay as you go. What looks good one day can be obsolete overnight. There are so many ways of achieving the same results in any engine management system, the more you work with different systems, such as GM and Ford, the more you realize this. Such experiance really helps in tailoring each tuner's proceedure when tuning any system such as LS1 Edit. You eventually learn tricks that transfer back and forth. A professional tuner has to accomplish the most in a period of chargable time that is marketable. The more knowledge and experiance your tuner has the better this tune. I would rather have a dam good tuner with weak software then the other way around, or worse yet, a weak tuner, tuning dyno and software.

 

Thanks for the info guys. Nice to see a couple of the heavyweights checking in (Jimmy, Slowhawk). I can definatley see the logic in not trying to BS the PCM if posible, for fear of getting caught up in it somehwhere down the line.

 

I'm going to have to say that #1 and #3 are incorrect.
The lower right hand corner is not where you're going to be running NA for spark advance. From 60 down is too much area to cover and leaves you no room to put in any retard for a dry nitrous system.

15% fuel trim is enough at WOT to let you add almost a 100-shot of nitrous going in at the TB. Positive Ltrims will affect WOT, and 15% is WAY too much to ignore.

How a 'pro' would go about handling a tune always depends on what has been done modification-wise to the car, and what state of tune the car is in at the start.

If you haven't done anything to change the VE of the car, and you aren't getting any significant Ltrims, then there is little reason to change the shape of the VE.
If you've put in a large cam and a sheet-metal intake, then there is every reason to change the shape of the VE.

If everything else is good and you want to make an adjustment for WOT, then the PE is the place to do it.

If it needs adjustment for a ported MAF, then the MAF table is the place.