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Re: 1.8T tuning

Posted: Tue Jan 17, 2017 3:46 pm
by iceman_n
i believe the same...but i have read most of posts here using and prefered the tps main load and map compensations (not even the 20x14 map compensation, just the simple one) ...and i was wondering why they do prefer this...i am a fan of map sensor as load even on n/a exngines...

much smoother engine running, better idle and much less fuel consumption...

Re: 1.8T tuning

Posted: Wed Jan 18, 2017 12:32 am
by ignitionautosport
TPS with MAP correction should be better at all those things you listed in last line. Even TPS for load on VE tune (other ECU, obviously) is agreed a good way to go, and was recommended to me by Haltech many moons ago.

I fail to see how adding another dimension to make your tune more accurate could make it worse. Of course, your engine is only as good as the tuner.

Re: 1.8T tuning

Posted: Wed Jan 18, 2017 8:04 am
by stevieturbo
ignitionautosport wrote:TPS with MAP correction should be better at all those things you listed in last line. Even TPS for load on VE tune (other ECU, obviously) is agreed a good way to go, and was recommended to me by Haltech many moons ago.

I fail to see how adding another dimension to make your tune more accurate could make it worse. Of course, your engine is only as good as the tuner.
But then why add complication tuning multiple tables, when it is well proven MAP vs RPM alone works great for 95%+ of applications

With TPS vs RPM and MAP compensation.....you now have more tables to tune and when on what would be regarded as the main fuel table..the numbers dont actually have a direct relation to what the injector sees because of the other table that then also needs tuned.

Unless you have a specific engine that necessitates TPS vs RPM ( ie huge cams, ITB's etc etc or something that can give a poor MAP signal at some loads )...I can see no sense in going down that route on a boosted application.

Re: 1.8T tuning

Posted: Wed Jan 18, 2017 10:46 am
by rxboxster
Alex DTA wrote:There are two options - open loop boost, and closed loop boost control.

Open loop just uses the PWM map, and ignores the target values. These target values are greyed out if the "Use PID loop?" box isn't ticked.
This is the most common, and works exactly like L.H. says. Simply alter duty cycle on the dyno until target boost is achieved.
Obviously as the wastegate spring gets weaker, so the boost will drop over time.

Closed loop will use the PWM map as a base, and then alter the duty cycle to match the requested boost.


So if you are running two maps, for example I want one for the dirt sections of the rallycross track/wet conditions ... I can leave the PWM to the N75 valve as tuned in map 1, but alter the target pressures to a lower value, limiting the boost for map 2?

Re: 1.8T tuning

Posted: Wed Jan 18, 2017 12:28 pm
by stevieturbo
MAP1 and MAP 2 each have their own boost control tables so yes that can give you two boost levels.

Re: 1.8T tuning

Posted: Wed Jan 18, 2017 2:41 pm
by L.H.
Great and useful discussion here. Thanks for that! Anyway I think that I will go in a TPS/RPM direction. First because I feel more comfortable in this, experienced with previous N/A tunes and second- I think, that it might be more engine friendly. This way, I can for example make a fuel map on low or close to zero boost. As the fuel mapping will need some time, on low boost it means less punnishment to the engine. As soon as the fuel map is ready, I will make couple of pulls on full boost and just fine tune boost corrections. Is this an acceptable way or non sense in your opinion?

Re: 1.8T tuning

Posted: Wed Jan 18, 2017 3:42 pm
by stevieturbo
I can see no reason to tune things twice...when you can do them once MAP vs RPM

Re: 1.8T tuning

Posted: Wed Jan 18, 2017 6:10 pm
by ignitionautosport
Yes that is acceptable. Fuel with TPS and MAP correction is easy, Ignition is the one that messes with your head a bit. Making sure it's set to degrees not % is the way I go. Or for ignition you can zero out the TPS table and just use the MAP table. Many options.

I would do it the way you described. If you read the DTA manual it recommends TPS with MAP correction. I have no reason to think that Allan had no idea what he was doing.

If using MAP only, eg if you have single throttle body and mild cams (therefore good vacuum off-boost) then of course you only need to tune one table, up to the boost you are running, then tune above where you tuned too once you up the boost. Up to you, you're paying for the dyno time... I know what I prefer but as stated by others a lot of setups don't warrant the extra tuning time. It's your money - though it pays to check what the tuner is familiar with also.

Re: 1.8T tuning

Posted: Thu Jan 19, 2017 6:13 am
by stevieturbo
ignitionautosport wrote:Yes that is acceptable. Fuel with TPS and MAP correction is easy, Ignition is the one that messes with your head a bit. Making sure it's set to degrees not % is the way I go. Or for ignition you can zero out the TPS table and just use the MAP table. Many options.

I would do it the way you described. If you read the DTA manual it recommends TPS with MAP correction. I have no reason to think that Allan had no idea what he was doing.

If using MAP only, eg if you have single throttle body and mild cams (therefore good vacuum off-boost) then of course you only need to tune one table, up to the boost you are running, then tune above where you tuned too once you up the boost. Up to you, you're paying for the dyno time... I know what I prefer but as stated by others a lot of setups don't warrant the extra tuning time. It's your money - though it pays to check what the tuner is familiar with also.

Of course Allan did...but he also had his own peculiar way with things too. There's clearly a reason why MAP vs RPM is the most common method across virtually all ecu platforms.

IMO clearly TPS is not the best way...otherwise why start with a 2D MAP compensation table...then later realise this is not sufficient and offer a full 3d MAP compensation table ?

So you now need to tune fuel/spark tables for TPS vs RPM....and then to do the job right tune another full 3d MAP vs RPM table anyway lol.

Or conversely it also seems to offer MAP vs RPM...and then with a full TPS vs RPM compensation table. Or a combination of them

Re: 1.8T tuning

Posted: Thu Jan 19, 2017 1:19 pm
by gnutz2
I would do it MAP vs RPM (speed density), it's just easy and effective.

I've never mapped a TPS vs RPM (alpha N) but can't see any point in complicating things.