Tuning sequence, - is there one?

General Tuning Questions And Discussions
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Tuning sequence, - is there one?

Postby JohnDee68 » Thu Sep 09, 2021 11:17 pm

I am having to get in to tuning my car a bit more seriously (for a newbie to ecu tuning that is).

On old carby, points and distributor vehicle tunes, there were a sequence to the tuning process. Is there similar to the ecu tunes today? As all I can seem to find is you need to test drive, make selected changes, test again and keep cycling till it works. Which can be very long in time when you can't live tune and need to refer back to log files constantly.

If there is a sequence of steps, is there any where I can find that step by step list ?

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Re: Tuning sequence, - is there one?

Postby In-Tech » Fri Sep 10, 2021 3:08 am

I have been around a long time so my first attack is generally what I would do if it had a carb and points, then adjust accordingly. I am a lazy fack, as well as the next guy, so I try to save time where I can :) Carb and distributor can both be adjusted but they just take more time than efi is all. With efi it allows you to hit all of the parts you WANT to fix.

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Re: Tuning sequence, - is there one?

Postby Charlescrown » Fri Sep 10, 2021 8:20 am

I start off with a timing map similar to a carbie and then work on warm idle and go from there. Driving and logging can be a pain but it's a lot of fun.

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Re: Tuning sequence, - is there one?

Postby JohnDee68 » Fri Sep 10, 2021 10:53 am

Thanks In-Tech & Charlescrown,
So I guess there really isn't a step procedure, just log and try, adjust, log and try...:)

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Re: Tuning sequence, - is there one?

Postby Charlescrown » Fri Sep 10, 2021 12:18 pm

Yea. You must have a wideband though.

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Re: Tuning sequence, - is there one?

Postby NSFW » Sun Sep 12, 2021 1:39 pm

The "inner loop" is something like:
- drive, make data logs
- study the logs
- make changes to the tune
- repeat

The bigger picture starts with getting fuel metering and air metering dialed in. The big ones are injector settings, MAF scaling, and VE table.

Get idle and cruise right. Maybe deal with some random driveability issues like transitioning to and from idle, hot starts, cold starts, etc.

Then there's transients like tip-in and tau/wall-wetting, and temperature compensations, but I have had pretty good luck leaving those stock or close to it.

Then there's tuning for power. For naturally aspirated engines, I don't know of a way to do this without a dyno. With setups that are knock limited (which is the case for most turbo engines) you can just set minimum boost, advance timing bit by bit until you get knock, then back it down a couple degrees, then add a little boost and repeat the process.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!

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Re: Tuning sequence, - is there one?

Postby JohnDee68 » Sun Sep 12, 2021 4:07 pm

NSFW wrote:The "inner loop" is something like:
- drive, make data logs
- study the logs
- make changes to the tune
- repeat



Thanks NSFW, I am glad in a way then that is it a matter of trial, log, adjust, log, trial.. Otherwise i would be concerned if I was going about it the long way round..
Thanks.

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Re: Tuning sequence, - is there one?

Postby Holden202T » Tue Sep 14, 2021 1:48 pm

i guess it kinda depends on the car in question, generally i try to find the best base map, either off the forum or from previous tunes i've done, then set what you know for the engine before you get to it, ie. if its got a big cam you want higher desired idle etc ... but yeah generally i try to get the idle areas fuel and spark right so it will idle ok, also means its less likely to stall when you pull up .... then as the others have said, get into some logging and change from there, but also if you have someone who can drive while you look at the laptop you can get them to hold steady states and tweak as you go ....

also two a thing to note, particularly if its a dizzy engine, make sure the diagnostic mode timing is right, you'll regret it later if you dont, and if its got an adjustable reg, try and set it where you want it before you start fucking with the VE table.

at the end of the day alot of it will come down to the specific requirements of the combo and also as you learn you'll work out more work works or doesnt work best for you.

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Re: Tuning sequence, - is there one?

Postby JohnDee68 » Wed Sep 15, 2021 8:41 pm

Thanks Holden202T, You and all have made good points and advice, appreciate it.
I think I am on the right track, hopefully.

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