Mods...

Gutted stock uppipe
Stromung DWG downpipe
stock 3rd cat
Stromung 3" catback
Cobb AP Stage 2 CA 91 Octane

220.59whp
216.70wtq

http://www.cs.ucr.edu/~eito/run3.JPG

looks like a nice curve. You are running pretty rich. Most Cobb off the shelf tunes that I have seen run lean...

What version stage 2 map is that? 1.3+?

Jorge (RiftsWRX)
www.ProjectWRX.com

Most Cobb off the shelf tunes I have seen run very rich 10.0:1 and under.

t

Time for a tune.

Notice his torque curve...At 3.5k where the fuel is richened to provide 10:1 AFR he has some massive torque down low. I just know this for a fact and always wondered because i'm too lazy to research it..but why is it that when you go to the richer side of an AFR you see the most torque versus a leaner AFR for best horsepower?

Notice his torque curve...At 3.5k where the fuel is richened to provide 10:1 AFR he has some massive torque down low. I just know this for a fact and always wondered because i'm too lazy to research it..but why is it that when you go to the richer side of an AFR you see the most torque versus a leaner AFR for best horsepower?

He would make even more torque with a good afr. It looks massive because the pull doesn't start at 2k like most dyno charts. You generally want to run a little richer at torque peak, because that is where you are most prone to detonation. Then lean it out some for more power up top.

Notice his torque curve...At 3.5k where the fuel is richened to provide 10:1 AFR he has some massive torque down low. I just know this for a fact and always wondered because i'm too lazy to research it..but why is it that when you go to the richer side of an AFR you see the most torque versus a leaner AFR for best horsepower?


You always have to richen up at the torque peak b/c that is the time it is easiest to det.

Ahh, why then is it easiest to detonate at the tq peak area? Sorry if it sounds like i'm an idiot here but I'm just wanting to learn why hehe.

Something along the lines of piston rate of change of speed being the greatest at that point or something...i cant really recall.

Sorry if it sounds like i'm an idiot here but I'm just wanting to learn why hehe.

No problem man. We were all there once too. :)

I have the same set-up as you and I am getting tuned today at harman so I will post up my chart as well
My Mods:
Gutted uppipe
Stromung DW DP
Stock 3rd cat
Stock mid pipe
Stromung 2.5" axle back
IC hoses
Grounding kit

I have the same setup as you guys as well. Looking for more power though.. and i'm looking at buying a VF series turbo probably. My goal is to reach around 300whp.

mbiker97:
I know quite a bit..but I'm a BIT new to the world of turbo'd engines! As this is my first turbo'd vehicle ever..and quite frankly I doubt I'll ever go back to NA again hehe!

well N/A has its pluses like instant response, and low end torqe. But thats with a V8 to get that power, but with that you get the crappy gas milage. If cost and everything were not an issue I would buy a big V8.

well I made 213whp with 223 tq. Dan at harman said its the 3rd cat it needs to go. But overall I am happy the AFR is very stable and clean. The first run made 223 whp but it was too lean.

well I made 213whp with 223 tq. Dan at harman said its the 3rd cat it needs to go. But overall I am happy the AFR is very stable and clean. The first run made 223 whp but it was too lean.
Was this a custom tune?

I believe so, he mentioned on an earlier post that he was going to the tuned at Harman.

well I made 213whp with 223 tq. Dan at harman said its the 3rd cat it needs to go. But overall I am happy the AFR is very stable and clean. The first run made 223 whp but it was too lean.
nice...i want to leave the stock 3rd cat though...

PS ....v1.30 map

Time for a tune.


:huh:

nice...i want to leave the stock 3rd cat though...

PS ....v1.30 map

Loma Linda? Enjoying the cool June weather here? You wouldn't happen to know a guy who drives around a silver Saab Viggen would you? :lol:

yes it was an ecutek tune on there dyno, I will post the graph soon.

how many miles on the engine? zinc?

I hope your AFR curve is indicative of all of the new Cobb 1.3 maps. Maybe they finally changed their mapping when they saw everybody was running incredibly lean.

That looks rich enough to wash out a cylinder.

~v6

way too friggin rich all over the place. Yes i'd prefer to be a tad rich at peak torque but not off the charts rich. Definately need to retune. I bet your mileage sucks ass.

:huh:

I wasn't kidding. The tune looks like it sucks.

way too friggin rich all over the place. Yes i'd prefer to be a tad rich at peak torque but not off the charts rich. Definately need to retune. I bet your mileage sucks ass.
thats the weird thing...my mileage has stayed consistent...so im wondering if the readings were not accurate?

what could cause a/f readings to be rich...other than the obvious of course...

can someone host my dyno graph?

Ahh, why then is it easiest to detonate at the tq peak area? Sorry if it sounds like i'm an idiot here but I'm just wanting to learn why hehe.

torque peak is indicative of highest cylinder pressure.

the pressure is highest because the volumetric efficiency is highest. the resonances set up by the cylinders sucking in air and pumping it out, along with the physical geometry of the intake and exhaust manifolds, cause a more complete evacuation of spent charge and filling of clean charge.

the peak in cylinder pressure is both good (highest torque) and bad (highest propensity for detonation).

hth
ken