jlee's (now mine) Forester finally gets a dyno tune

[Viper GTS]

Now that I'm reasonably settled here on the east coast I took the time to get the FXT on a dyno for a proper tune.

First, it needed a boost controller so while a WRX occupied the dyno the Forester got some upgrades.

All strapped in ready to go.

One of a few pulls (audio was a little overwhelming for my poor phone).

http://www.youtube.com/watch?v=Zx8Xe_OaW7I

Results are...

...not enough to be happy with. No worries, we can fix that.

More to come in this story.

Viper GTS

 

[phucheneh]

Let me be retarded here:

Is 'dyno tuning' actually a specific thing? As in, are they using the dyno sheet to optimize specific mappings on an AEM or other highly-tweakable ECU?

Or are we talking more generic terms; i.e. 'well, the A/F isn't quite right, and I think we can make a little more power...so we'll richen it up a bit...bring some timing advance in a little sooner...'

Is that a dumb question? Basically, I just hear so much about 'dyno tuning' that I wonder if there is some standard practice, or if it's just taking the car to a specialist with a dyno to have your tune modded based on his personal recommendations (or your own). Sometimes it seems like all someone means is 'I dyno'd the car.'

edit: anyhow, what was modded on the Forester to begin with? What's EBCS?

I'm guessing your plans are to boost the piss out of this thing. Four 850cc injectors? That's gotta be capable of supporting over 400hp. Maybe closer to 500?

 

[AMCRambler]

Let me be retarded here:

Is 'dyno tuning' actually a specific thing? As in, are they using the dyno sheet to optimize specific mappings on an AEM or other highly-tweakable ECU?

Or are we talking more generic terms; i.e. 'well, the A/F isn't quite right, and I think we can make a little more power...so we'll richen it up a bit...bring some timing advance in a little sooner...'

Is that a dumb question? Basically, I just hear so much about 'dyno tuning' that I wonder if there is some standard practice, or if it's just taking the car to a specialist with a dyno to have your tune modded based on his personal recommendations (or your own). Sometimes it seems like all someone means is 'I dyno'd the car.'

edit: anyhow, what was modded on the Forester to begin with? What's EBCS?

I'm guessing your plans are to boost the piss out of this thing. Four 850cc injectors? That's gotta be capable of supporting over 400hp. Maybe closer to 500?

Dyno is the only way to measure horsepower and torque. It lets you quantitatively measure gains or losses due to changes to timing, spark advance, mods, etc. Generally requires a flashable ECM or something more advanced. Let's you dial in the most efficient settings.

Is that what you've asking?

 

[Viper GTS]

In this case it was a Cobb ProTune, done with an AccessPort.

Viper GTS

 

[JulesMaximus]

I know that car! It spent a couple hours in my driveway not too long ago.

 

[exdeath]

Let me be retarded here:

Is 'dyno tuning' actually a specific thing? As in, are they using the dyno sheet to optimize specific mappings on an AEM or other highly-tweakable ECU?

Or are we talking more generic terms; i.e. 'well, the A/F isn't quite right, and I think we can make a little more power...so we'll richen it up a bit...bring some timing advance in a little sooner...'

Is that a dumb question? Basically, I just hear so much about 'dyno tuning' that I wonder if there is some standard practice, or if it's just taking the car to a specialist with a dyno to have your tune modded based on his personal recommendations (or your own). Sometimes it seems like all someone means is 'I dyno'd the car.'

edit: anyhow, what was modded on the Forester to begin with? What's EBCS?

I'm guessing your plans are to boost the piss out of this thing. Four 850cc injectors? That's gotta be capable of supporting over 400hp. Maybe closer to 500?

Dyno tuning specifically means fine tuning a SPECIFIC vehicle (no 2 are alike, like CPU overclocking) in a SPECIFIC environment under actual load conditions and tweaking it for all it's worth on the razors edge while being able to monitor knock, AFR, temps, etc. and of course power output. Does the car make more power with more boost less timing or the other way around? etc.

vs a one size fits all "canned tune" or "generic tune" which leaves alot on the table.

 

[Black2na]

love it! the sleeper wagon gets fast!

 

[Viper GTS]

Let me be retarded here:
edit: anyhow, what was modded on the Forester to begin with? What's EBCS?

I'm guessing your plans are to boost the piss out of this thing. Four 850cc injectors? That's gotta be capable of supporting over 400hp. Maybe closer to 500?

A fair amount at this point.

Before it was mine:

VF39 turbo (from an STi)
STi intercooler
Full turboback MadDad exhaust
AccessPort VF39 canned tune

After it was mine (but before I got it, all installed by jlee):

Catless up-pipe
Killer B oil pickup
Perrin inlet

As of today:

Cobb Electronic Boost Control Solenoid (EBCS)

Soon:

DeatschWerks 850cc Injectors
Walbro 255lph fuel pump

The goal is to provide plenty of safety margin to take the VF39 as far as it will go. I don't really have plans to go any further, this is just my daily driver.

Oh and for comparison's sake with my last daily driver:

This car is putting down more peak torque at the wheels than my 02 Mustang GT was rated at the crank (and at a lower RPM no less).

Viper GTS

 

[phucheneh]

AMC, I do know what a dyno is, heh. I know a lot of people dyno just to check performance- either just for 'bragging rights' or personal satisfaction, or to simply test the car under load and make sure it's performing acceptably.

But-

Dyno tuning specifically means fine tuning a SPECIFIC vehicle (no 2 are alike, like CPU overclocking) in a SPECIFIC environment under actual load conditions and tweaking it for all it's worth on the razors edge while being able to monitor knock, AFR, temps, etc. and of course power output. Does the car make more power with more boost less timing or the other way around? etc.

vs a one size fits all "canned tune" or "generic tune" which leaves alot on the table.

That's more specifically what I was asking about. So basically, the answer is that it varies. I was just wondering if there was a specific intent other than 'make it run as good as possible.'

Some people make it sound like they did a couple pulls, someone hit a magic button, and BAM! Tuned. I suspect those are the ones that just dyno to get a peak horsepower number for posting on the internet.

I mean, if you're not running an AEM box, or some other aftermarket computer, there's not a whole hell of a lot you can do, is there? Are you guys just flashing the software on stock PCM's?

 

[exdeath]

AMC, I do know what a dyno is, heh. I know a lot of people dyno just to check performance- either just for 'bragging rights' or personal satisfaction, or to simply test the car under load and make sure it's performing acceptably.

But-



That's more specifically what I was asking about. So basically, the answer is that it varies. I was just wondering if there was a specific intent other than 'make it run as good as possible.'

Some people make it sound like they did a couple pulls, someone hit a magic button, and BAM! Tuned. I suspect those are the ones that just dyno to get a peak horsepower number for posting on the internet.

I mean, if you're not running an AEM box, or some other aftermarket computer, there's not a whole hell of a lot you can do, is there? Are you guys just flashing the software on stock PCM's?

The EEC-V in my 03 Cobra is a fully modern fully flash programmable ECU from the factory, you can change anything you want from the OBD-II port.

Non programmable stock ECUs can have the ROM chip, even the whole CPU if it's embedded ROM, swapped out with daughter cards that inserts it's own address decoder to break out the ROM into a separate Flash/EEPROM module that can be burned and changed.

The tune itself is just fuel and spark tables and a few other things like MAF curve/VE tables and accelerator pump tables and things like that.

So you don't need a complete aftermarket stand alone ECU to tune.

The tuning process is setting target AFRs in your fuel table and leaving them fixed, and then modifying the VE/MAF tables using wideband feedback until your actual equal your targets. Then you go on to pushing spark as borderline as it will go typically 2 degrees before knock. After that, you an go in and add/subtract fuel and timing as needed for boost "quenching", cat protection, drive-ability, throttle tip in, fuel economy, emissions, etc.

Without the aid of a dyno and a wideband telling you exactly what you are doing, you have no idea where you are and it gets dangerous to push things too much. Depending on the car, there is as much as 50 WHP to be gained from a 1 on 1 dyno tune vs a ballpark canned 1 size fits everything tune.

Oh, and the actual "software" doesn't change unless its a dealer/manufacture update performed at the same time the tune is installed. Tuning isn't programming, it's just providing data tables with fuel/spark maps. The actual program code that the ECU CPU runs doesn't change in tuning.

 

[sontakke]

That implies multiple runs were done on the dyno. How many? Or is the car being tuned while it is on the dyno and thus a "run" is not complete until the tune is done?s

Suppose none of the tunable parameters were changed between the run. How consistent are runs? What is the variation between runs?

 

[jlee]

Runs should be as consistent as the engine's power. Dynos have some margin of error, but only a couple percent (iirc). Different brand dynos will read differently though, so its important to only compare numbers from the same one (Dynojet, etc).

Typically there's a baseline pull and then another pull after each adjustment (or series of adjustments). I think my mr2 made 8ish pulls when it was tuned by ATS.