Tuning Closed loop map to get better fuel

[AuSpec Vr4]

Hi

I have a stock Vr4 with the only modification being a different ebay exhause manifold and a 2 1/4" exhaust all through. 11Psi boost with a newly fitted ECMlink.

I have tuned my open loop timing maps to remove all my knock. Now i need the better fuel economy for town driving. i will setup to open onto open loop around 35-45% throttle.

What do i need to start adjusting my closed loop maps to get the desired km per tank. Atm on 98 octane i'm scraping 300kms till theres about 3l left in the tank. I looked at the fuel trim demo video on ECMlink but i don't know how to get the CombinedFT to work.

450cc injectors
11psi
2 1/4 exhaust
1g MAF
All sensors stock and working with new Knock and O2 sensor and replaced TPS.

Cheers

 

[brisvr4]

What have you tried doing so far? Is combinedft cycling at all?
I could have a look at it for you if you like? You are southside aren't you?

 

[AuSpec Vr4]

I have got it all sorted now, its just the combinedft sits on 0% alot but moves under different throttle. I was going to post my most recent log but when i try to attatch i'm told i dont have permission.

 

[VR-4Squid]

only 300km's to a tank on just 11psi? Do you nail it absolutely everywhere?

I average 400-450km to a tank with 510's, evo afm, 264º cams and a very roughly tuned s-afc (making 200kw on 15psi)

 

[AuSpec Vr4]

only 300km's to a tank on just 11psi? Do you nail it absolutely everywhere?

I average 400-450km to a tank with 510's, evo afm, 264º cams and a very roughly tuned s-afc (making 200kw on 15psi)

Since the new 2.4l has been put in, fresh motor with 450cc injectors and 8 PSI, with new walbro, stock tune with cbFT sitting around 2% mark on idle, I get 400kms to a tank of 98 octane. could be better.

 

[milkandoj]

Are you actually getting in closed loop at cruise, you can log it, 1 you on closed loop, 0 you not. Are your low, mid and high fuel trims on a value other than 0% (not talking about combined) ? If not, your not getting in closed loop at cruise so it reverts back to 0% on all 3. They will constantly correct and change and hopefully be within 5% is its getting in closed loop at cruise.

And 450's on 8psi i on 2.4, i take it you just running it in with some setting that are easier to dial in so you dont get bore wash for run in ect, before you throw larger injectors in?

 

[AuSpec Vr4]

Are you actually getting in closed loop at cruise, you can log it, 1 you on closed loop, 0 you not. Are your low, mid and high fuel trims on a value other than 0% (not talking about combined) ? If not, your not getting in closed loop at cruise so it reverts back to 0% on all 3. They will constantly correct and change and hopefully be within 5% is its getting in closed loop at cruise.

And 450's on 8psi i on 2.4, i take it you just running it in with some setting that are easier to dial in so you dont get bore wash for run in ect, before you throw larger injectors in?

The engine has done 3000kms now and can start to be modified but currently is now on stands because my clutch fork broke in half. I can check all that when it gets back on the road. 850cc injectors, bigger fuel rail and fuel fittings are soon to go on.

 

[omad]

The engine has done 3000kms now and can start to be modified but currently is now on stands because my clutch fork broke in half. I can check all that when it gets back on the road. 850cc injectors, bigger fuel rail and fuel fittings are soon to go on.

Must be something terribly wrong for you to be getting 300km out of a tank while it's still so stock.... not sure how much difference it makes but maybe the 2.4 is keeping the 14b spooled up or bringing it on much faster/more than normal? ... but even then that's shocking economy.

you are judging by a full tank, and not from filling the tank to half and doubling or something ?

 

[milkandoj]

Can a log be attached to a post on here, if so put a log up. Providing you have recorded the right info we can see quickly if you getting into closed loop or its stuck in open loop, wich woudl contribute to running rich and cruise and chewing fuel.

 

[AuSpec Vr4]

Well, i have found a few boost leaks since this, havent put a full tank in the car yet but average before leaks was 400kms on stock injectors, and the turbo is a 16g with a 18g compressor. Spools around 2500 and full about 3800. Not sure how to post a log up, every time i try it wont accept the file type, unless i upload it to another web site host and post a link but i'm sure thats not allowed?

 

[AuSpec Vr4]

Here is a external link

Log file

Im only using this site because i can't upload it into my post so i hope thats ok Moderators.

Cheers

 

[omad]

I'm not too familiar with ECM link and how the logs display etc, but if I'm not wrong, it looks like you've set up your ecu for speed density... if it's stock and you have no map sensor that's your #1 problem right there!

Also doesn't speed density work quite a bit differently to calculating cruise fuel trims etc to stock? I thought SD pretty much ignored stock trims etc and works another way to calculate correct AFR at cruise... I don't know too much about SD though as not running it on my car.

Edit: for anyone else that wants to help out but cbf waiting 5 mins for download: http://users.chariot.com.au/omad/log.2011.05.26-01.elg (right click, save as)

 

[AuSpec Vr4]

SD isnt set up, it tells me to assign a map type but I'm sure its just using all the stock maf sensors because I use maf comp adjust and change those values. Maf is ignored when speed density is connected which I don't have on. I just put my denso 850cc injectors in and changed my fuel settings to -47% by using the calculate function with a base fuel pressure of 37%. So now it's running ok, retuned low idle maf and when I give it a Rev in neutral I get knock about 15 degrees but only for a split second and it's around 3000rpm. I'm confused on what else I should be doing now. I get a little knock about 3-4 degrees during boosting, not to much to worry it but without my wideband and sd on, I don't know what it's doing

Cheers

 

[omad]

SD isnt set up, it tells me to assign a map type but I'm sure its just using all the stock maf sensors because I use maf comp adjust and change those values. Maf is ignored when speed density is connected which I don't have on. I just put my denso 850cc injectors in and changed my fuel settings to -47% by using the calculate function with a base fuel pressure of 37%. So now it's running ok, retuned low idle maf and when I give it a Rev in neutral I get knock about 15 degrees but only for a split second and it's around 3000rpm. I'm confused on what else I should be doing now. I get a little knock about 3-4 degrees during boosting, not to much to worry it but without my wideband and sd on, I don't know what it's doing

Cheers

In standard mode, you should have an AFR and a timing table. All I can see on your log is an SD table, which I'm guessing you shouldn't be using if you haven't set it up... ?

Do you have a wideband hooked up? If not, how are you tuning/checking your AFR's?

The O2 is cycling and computer is registering you're going into closed loop. Something else must be amiss. Don't have the experience with ecm link as others here may have to pinpoint it though....