VandykeT/A

I haven't had hptuners long and I bought the greg banish DVD and he mentions the spark tables but doesn't really give any info on how to tune these. What's the best method for tuning the timing tables on the street? What do I need to log in the scanner etc. thanks.

mrvedit

First you want to log total advance so that some of the timing adjustment tables don't surprise you.
Next your want to log Knock-retard so that you know when/where you have too much advance.
The stock advance tables are very conservative, partly to compensate for very low octane gas. You will likely find you can add 4+ degrees especially if you run premium gas.
Greg Banish has has two tuning books which you may want to buy. They cover much of the material in the DVD in more detail.

Tally TransAm

iTrader: (17)

turn it up til it rattles then back it off a hair

soundengineer

iTrader: (16)

you need a dyno that can apply a load to the vehicle
using a loaded dyno you can lock the vehicle at various RPM's speeds and push into the cells you want to change....

using a HP tuners Custom Real Time OS you can push around spark tables and see where it makes the most power/torque

it will peak and then fall off... where it peaks is where you want your timing...
its a slow and tedious process...and you need to allow your engine some cool down time every few miniutes
you work on it in steps.....

once you have a good base, you can go back in and hand smooth the tables to make nice smooth spark transitions and it will accelerate smoother




they are not really all that much conservative....
yes, they are built so that you dont get knock on low octane gas....but they usually arent a long ways off...

the thing people dont usually realize is just how much power and torque you can see from just a 2* change with a vehicle that is pushing the ragged edge
the timing tables in the stock ECU were designed for longevity....not for all our race power.




^^^VERY BAD ADVICE^^^

sometimes it wont rattle till Long after where it makes peak power/torque....
we've seen vehicles that make best power at 25* and dont rattle till 32*.....where its already lost a bunch of power from being too far past peak MBT

almost forgot to mention....it only needs to rattle once to put a hole in a piston.....some people get away with a lot of rattle for a long time... others make an ashtray the first time it rattles..

dreww

iTrader: (1)

if you don't have access to a real dyno tune...I would generally avoid touching timing.

Ive messed with it once on a street tune, but that was only to get rid of the last tiny bit of knock that MAF/VE/Fueling could not fix. I would never add any timing without a dyno tune to see if it was actually making more power or just leaning me out.

VandykeT/A

What if no dyno is available.

joecar

This:

And this:

mrvedit

I tune my spark tables at the track, based on maximizing trap speed.
Every setup is different, but on my LS2 27* and 28* gave me max trap speed with 29* showing a loss of power. I never logged any knock below my converter's stall speed. I occasionally did log knock at the very start below my stall speed and then simply reduced the advance table there.

Obviously I cannot fine-tune every cell of the spark table at the track and therefore simply set big blocks, e.g. from 4000 to 7000 rpm at the same value.

As soundengineer and Joecar state, tuning the spark tables without a dyno is risky at best. If you are willing to take (and can afford) the risk, at least read the two Greg Banish tuning books first.

soundengineer

iTrader: (16)

we often do the same thing with a customer...
we go to the track, and try the timing curve out...

sometimes making best power on the dyno does not always equate to the best timing when real world loads are applied

if we know for certain that we are going to the track with a customer
we will leave a few degrees out of it, and then go to the track and slowly add timing back in until it stops picking up MPH....
we also read the plugs... reading the plugs can tell you a lot about a car...
if thetiming mark is in the bend of the strap... its all good... if its gotten past the bend...its probably too much, of its just barely on the tip...its not enough...
and if you have no timing mark at all... you might just have too cold of a plug
if it turns a bunch of thread a different color, you probably have too hot of a plug...(much like stainless headers turn a different color after they get heat on them)
you should only see a thread or two change color...and the timing mark should be clearly visible.
you also have to shut the car down and coast to a safe spot with little to no idle time on the plugs to get a good reading... even 15 seconds of idle can wash away the plug reading marks in some cases.
we often send one guy up to the end of the track to be ready to check a plug or to get the timeslip so the guy can check the plug himself.


you can tune without a dyno....it just takes a lot more than hoping your knock sensors are close.

rpturbo

iTrader: (47)

soundengineer,
I was wondering, when you guys add timing at the track, do you only pick specific cells that you add 1* at a time to just those cells? I have always been curious with the newer tuning software, what the best way is to go about that.

I like that you broke down how to read a plug. That is just older knowledge us old carb guys remember. I was always capable of tuning a distributor, but all of the cells confuse me a bit.

LSX Power Tuning

iTrader: (4)

I just add timing in the tune where its running WOT at the track when tuning off mph and plugs.

soundengineer

iTrader: (16)

Yup... pretty much no way to do plugs part throttle, so no way to do those cells..
So you concentrate on wot cells only when reading plugs.


We don't dyno a car without also reading the plugs..

Plugs never lie....and sometimes the dyno does lie.

mrvedit

Perhaps I am the only car guy that cannot read plugs, but could you please explain what the "timing mark" is and what the "bend of the strap" is. I have no idea what you are talking about. I know that the color of the insulator is related to the AFR, that is about it. Sorry to be so ignorant about plugs.

Thanks!

ctd

iTrader: (1)

Two questions please.

Have you gone back to the dyno & compared the best track findings vs the best dyno numbers?

Does the type of dyno make a difference, Inertia vs eddy brake for finding best timing vs the track?

Tx's

01ssreda4

iTrader: (96)

Where are yall making these changes? The high octane table? Do you copy and paste to the low table to lock them in and keep the computer from moving over?

mrvedit

Just FYI:
When running or tuning in open loop (MAF disabled, SD mode), the PCM uses the Low-octane table.
When running in closed loop, the PCM will typically use the the High-Octane table; I don't know if/when the PCM might use the Low-octane table in closed loop.

It is therefore a good idea to keep both tables the same, especially if you are switching between open loop and closed loop while tuning.

Pulse_GTO

iTrader: (2)

I thought it only did that when in Speed Density without a custom OS.

mrvedit

Thanks you for the correction - I edited my thread to make that clear.
I was thinking of people disabling the MAF for tuning and not realizing that the PCM then uses the low-octane table.

HeavyMetl

iTrader: (2)

At the Holley EFI tuning class, they talked briefly about tuning the timing tables.

One recommendation for street tuning:

1) Log Injector Duty Cycle
2) Drive at a steady state on flat ground
3) Using "real time" tuning, adjust ignition for the lowest duty cycle for a given cell

Obviously you couldn't possibly hit every cell on the table, but hit enough and smooth and this could be promising. Like everyone else here, I've been using a plain' ol LS6 table then tweaking the total timing for my WOT track runs. Hope the weather breaks soon and I can fool around with this technique a little.

JimMueller

iTrader: (9)

Greg Banish says to use the spark hook method with a load bearing dyno. You basically hold the vehicle at steady state in a cell and while watching the real-time torque output from the dyno, you slowly add/remove timing until it reports the best torque. I had a tuner do this last year on a Mustang dyno; I thought it was pretty hard to locate that desired point because even though it was being held steady the torque reading was still jumping around a fair bit, making it hard to decide which exact amount of timing is best.

That's the first I've heard of using min IDC to find optimum advance. I'm curious what others have to offer on this method?