rrkpitt15

iTrader: (1)

I know what the AFR should be for WOT but what should i tune the AFR to be during partial throttle? I usually hit around 10-15 psi and shift around 4.5k rpm. What should i tune the AFR to be? I have been DD my car recently, so i wanna save on some gas.

I was rich before i started to tune it (11.0 by 4.5k rpm). Right now i am at 11.8-12.0, do you think that is safe?

Hiboost

iTrader: (9)

I tend to shoot for 13.0 -> 12.5 AFR for 1-10 psi and 12.5 -> 12.0 AFR from 11-20. Once at 20+ psi you want to be around your target WOT AFR which is typically 11.5 or so. Make sure you setup the Closed Loop Trim control to a lower number so that LTFT's don't constantly kick in at above 10 psi or it will vary quite a bit. Shooting for 12.5 on average is a safe bet, just takes time doing multiple part throttle pulls at 5 psi, 10 psi, 15 psi and 20 psi in different gears to verify. Also check your Open Loop load maps which determine what load percent you leave closed loop. You could change map values all day in the 2000-3500 range at low boost and never see results if it is still in closed loop and shooting for 14.7 AFR's.

xhomm02

If you wanna save gas in DD, set high MIVEC overlap, higher ignition timing and perhaps lower WGDC in cruising areas.

rrkpitt15

iTrader: (1)

My mivec is pretty aggressive i think and my WGA is a Blouch so its around 22 psi. I have been playing with my boost at WOT and it starts to knock around 26 psi. Idk if my mivec is alittle to aggresive or if my 93 oct sucks.

rrkpitt15

iTrader: (1)

I am new at this. I can not push more than 25 psi or my car starts to knock. Could this be the 93 oct or too much timing aroung 4.5k rpms or is my mivec to aggresive? I ran 28 psi on my stock turbo with this gas. I have an FP red now.

Any help or suggestions would be greatly appreciated.

rrkpitt15

iTrader: (1)

Here are two logs, one at 26 psi and one at 25 psi. You can see it starts to knock when it hits 26 psi.

Logs.zip

ImEv0

iTrader: (3)

interesting...

i'm between 10.3-10.7 at wot. is this too rich? my boost holds at 25 lbs from 3.5k-5.5k.

Hiboost

iTrader: (9)

10's AFR at WOT will bring tears to anyone following you on the road, generally low to mid 11's is what people target. 10's are just too conservative and rich and I've actually seen "rich knock" from running like that with more aggressive timing advance.

richardjh

I've been going through the early stages of learning the art/science/voodoo of tuning on my Ralliart. It helped me a lot to put together a table of target AFRs... mostly because I could then chat to people who know way more than me about the subject, and distill their advice down to something measurable and specific.

As an example, here's a target mixture sheet for when I'm fooling around at the track (so on the rich side)...

Noob warning - these aren't EcuFlash fuel map numbers. Sorry, I just felt compelled to say that.



Ignore the actual numbers. I'm showing you my own learning process. With numbers in it, that's all.



So, for part-throttle mixtures... Assuming you're happy with your WOT mixtures, you "simply" have to settle on your target mixture at 10 psi, at each point up the rev range.
For my RA, 10psi is dead on 150-load. So the 140 and 160 load columns of my target table were the key to the whole exercise. I actually used the WGDC map to lock boost so that I tracked 160 load to redline. Once I got that column sorted, it was then a smooth join-the-dots exercise above and below 160 load.


The experts at this will probably look at a "target table" and laugh, because it's not something they need to think about or commit to a spreadsheet. As it's not second nature to me, I still need the noob props. Maybe explaining it like this will be helpful to you, or someone else.


Rich

Beeble

Good to know... i had a disagreement with someone recently with a car running high 9/low 10 AFRS with quite a bit of knock. he refused to believe that leaning his car out would actually help his cause.
Surprise surprise, the knock went away.

Is this something common across many new motors, or a 4B11 thing?
I don't recall seeing this in my IX, but maybe that was just coincidence...

Hiboost

iTrader: (9)

https://www.evolutionm.net/forums/ec...ses-knock.html

Just do a google search of "Rich Knock" and you will read all kinds of stuff, the most importan being that it can induce some knock and you are best keeping the car at high 10's to mid 11's with appropriate timing.

Even having your timing advance TOO LOW is a bad idea as well.

Hiboost

iTrader: (9)

Hahaha...

Actually it is a nice visual way of doing it, and yes setting 10 psi correctly which is around 140-160 load on most cars will allow you to interpolate the rest of the map for the most part for a smooth transition. There will always be some adjustments by the ECU based on current LTFT so you just want to have some room in your numbers plus and minus your target.

richardjh

Heh, that LTFT WOT adjustment stuff is disabled in my ROM... inherited from Bryan's GST Base Map tune.


I've got an interesting example of something that exactly fits that description. It's topical, as it occurred at midrange loads 140-180... a full second of grumbling, low-level knock...



If this is what knock looks like when the engine would prefer a slightly leaner mixture, I'll head in that direction first.

This was throttling on in 4th at 2000rpm, up a hill... so I guess I'm now at the academic end of the tuning phase! I don't go WOT @ 2000rpm in 4th at any time apart from a test pull! So... am I testing a tune, or tuning a test?

Rich