Low RPM tuning. What do you all do?

[phunny]

I'm curious to see what you all do with timing and fuel at low RPM(IE. under 3500k)

 

[1992awdlaser]

Depends on if your in boost or not. This is what I do for no or starting to boost.

I will do all my regular tuning first.
Then I find a rpm where I am sarting to create a good amount of boost. I do this by logging my map sensor.
I take the timing sliders below that rpm and start to retard them.
I retard the closest slider by 1* a first. The reason for this is the turbo is going to start creating boost sooner once I am done.
The slider farthest away gets retarded the most.
I make sure to not have any sliders that are more than 3* different from the next.
Then I do basically the same thing with fuel. But, I will be adding fuel to it.

 

[turboglenn]

Well, when I'm doing my first basic dial in (not worried about spool yet), i put the car in 4Th or 5th gear at each RPM range. 1000, 1500, 2000, 2500 etc.. I will hold the car wide open where it typically makes about 1/2 a psi until about 3-3.5k RPM. At all those points i dial the AFR to be right at 14:1 when WOT at low RPM and no boost. Timing i start off with about 10* at idle (1kRPM range) Then by 2k i work up to about 18* timing (peak) By 2500 I ramp it up a bit steeper to 28* in high vacuum and keep it around 20 - 24 at 0 vacuum and the first few psi. I raise 3k a little more to where by 3500 i have a peak advance of 38-40 degrees at no load and have about 24-26 at 0 vac/boost and then dial it off in a linear manner as boost sets in. I continue this all the way up the RPM band, but i know you're only interested in the LOW RPM stuff

After i get the main curve dialed in I'll do what 1991awdlaser said and log a WOT pull and see where boost seems to come on but not really climb (especially in 1st) Then just as he said, i will start retarding timing a couple degrees at a time under the areas where there's that beginning boost to try and help spool... What this method does is gives me a nice economical tune for cruising, but when i lay into WOT and the map is in a cell above cruising load the timing will be dialed back to gain spool, then by about 4-4500 where full boost first hits I've got the under boost timing dialed back up to my peak (mine is high because i run E85) But i run about 20* total advance at 30 psi and about 24* total advance at 5 psi..between those two spots i linearize the curve.

Now my ECU allows me to set timing and fuel at every individual inch of mercury and every single psi in increments of every 500 RPM. If you're running DSMlink or something like that the tune will be much easier, and you can just follow what 1992awdlaser wrote, or maybe use a few pointers of mine in there as well. I just wrote this out for your basic stand alone since i didn't check your profile to see what you were running

 

[1992awdlaser]

He is running dsmlink as I am. If/when I get a stand alone I think I will have some questions for you turboglenn. I'm good with dsmlink but not sure how I will be with a stand alone.

 

[phunny]

Well, when I'm doing my first basic dial in (not worried about spool yet), i put the car in 4Th or 5th gear at each RPM range. 1000, 1500, 2000, 2500 etc.. I will hold the car wide open where it typically makes about 1/2 a psi until about 3-3.5k RPM. At all those points i dial the AFR to be right at 14:1 when WOT at low RPM and no boost. Timing i start off with about 10* at idle (1kRPM range) Then by 2k i work up to about 18* timing (peak) By 2500 I ramp it up a bit steeper to 28* in high vacuum and keep it around 20 - 24 at 0 vacuum and the first few psi. I raise 3k a little more to where by 3500 i have a peak advance of 38-40 degrees at no load and have about 24-26 at 0 vac/boost and then dial it off in a linear manner as boost sets in. I continue this all the way up the RPM band, but i know you're only interested in the LOW RPM stuff

After i get the main curve dialed in I'll do what 1991awdlaser said and log a WOT pull and see where boost seems to come on but not really climb (especially in 1st) Then just as he said, i will start retarding timing a couple degrees at a time under the areas where there's that beginning boost to try and help spool... What this method does is gives me a nice economical tune for cruising, but when i lay into WOT and the map is in a cell above cruising load the timing will be dialed back to gain spool, then by about 4-4500 where full boost first hits I've got the under boost timing dialed back up to my peak (mine is high because i run E85) But i run about 20* total advance at 30 psi and about 24* total advance at 5 psi..between those two spots i linearize the curve.

Now my ECU allows me to set timing and fuel at every individual inch of mercury and every single psi in increments of every 500 RPM. If you're running DSMlink or something like that the tune will be much easier, and you can just follow what 1992awdlaser wrote, or maybe use a few pointers of mine in there as well. I just wrote this out for your basic stand alone since i didn't check your profile to see what you were running

I understand the basics of WOT tuning after i reach full boost. But the idle to boost is what I don't understand. In your top paragraph when you say u put it in 4th or 5th in all the rpm ranges at WOT??? I'm totally lost, could you explain it out a little more to me.

 

[turboglenn]

No no, i'm in 4th or 5th in all the LOW RPM ranges. meaning put it in 5th and lug around wide open at 1500 RPM, then tune that area since it won't make boost that low you can still run lean to the point of being near 14:1. I wouldn't date try and tune the upper RPM's in 4th or 5th on the street.

1992awdlaser, that sounds good to me, ill pick your brina for dsmlink stuff and you can pick mine for stand alone tuning/setup/issues. I'm always glad to help, mainly because no one would share their "secrets" with me when i started so i learned it all through trial and error and a LOT of reading and you really aren't giving anything away by telling some one how to do it, half the time thye don't remember of understand half of it anyway, so i make it a point to explain things in the best manner possible, but i know i still confuse the hell out of people sometimes because i have my own descripions or words for things you or some one might have another name for..

DOn't get me wrong i have some "secrets" too, but i'll always help the next guy out when i can.

 

[1992awdlaser]

I understand the basics of WOT tuning after i reach full boost. But the idle to boost is what I don't understand.

Just do a 3rd gear pull from 2,000rpm till redline. Tune for the same air/fuel ratio across the entire rev range. Start raising timing from the point where you start to create a few psi. Then do what I mentioned in my first post.

1992awdlaser, that sounds good to me, ill pick your brina for dsmlink stuff and you can pick mine for stand alone tuning/setup/issues.

Sounds good to me. I will answer any question I can, if I can't answer it I will get the anwer from somebody else.

 

[phunny]

Okay, but when you say, "a good amount of boost", what exactly is that?

 

[1992awdlaser]

I use 5psi. Not really a good amount when I am running 28psi. That is why in my last post I said few instead of good amount.

 

[Kevin Jewer]

The factory has that part of the map pretty well tuned, spending more than a few minutes on it is over tuning. I usually just add a couple to a few extra degrees of timing for maximum fuel economy, which is really all you're worried about there.

I know this is a matter of constant debate, but reducing timing to increase spool is usually shooting yourself in the foot. You get more boost, but less power. You're always better off tuning every cell for max torque, IMO. It also improves fuel economy. YMMV.

As far as fuel goes, I roughly tune for 15:1 in the low vac areas coming up to ~13:1 at or just above atmo, richening up to the typical WOT AFR around 10 psi. A lot of the minor tweaks to this methodology depend on the compression ratio of the motor, the amount of timing you're trying to run, and how long you're in those mid-boost cells. I also runa richer idle to get big cams to idle well, tapering it off somewhere around my max cold idle speed.

 

[phunny]

Okay, I'm really starting to get this, my question is though; when you tune say 1,000RPM, you'd just put it in 5th gear and cruise at 1k? Then tune A/F's from there? Or should I do it in 3rd? I'm guessing it wouldn't make a difference from what TurboGlenn said.

 

[1992awdlaser]

1,000 rpm won't matter. The only tuning you will be doing for that rpm is idle tuning.

 

[phunny]

Well what about 1500,2k, up to 3k

 

[selmerguy]

I have only messed with link a few times. But I know with DSMAP you can set the car up to run off the o2 sensor and switch to the ve map via tps% per rpm. Meaning you can be crusing at 2500 rpms and 18% tps and set it up to run 14.7:1 AFR. And then turn around and mash on the pedel switching to the VE map which is tuned to max power. I have set my car up like this for the purposes of lean burn and got great gas milage around town.

So for me I tune the low rpms(crusing) via the o2 sensor and what AFR I want. Mind you that my ve table is close enough to this that the o2 sensor only has to make fine adjustments to make the correct AFR.
I tune the low rpms (wot) by adjusting my ve table to get the correct AFR under whatever load with a timing curve that starts about 11 degrees and goes to about 28 degrees by redline.