Johncy2000

Here's the dyno graph. There are two AF ratio lines. Jeremy tuned my car according to the bottom AF line. Could it possibly be that the first line is the true AF ratio. If so, then I would be running rich. I put down 467whp and 506ft-lbs of tq to the wheels but I thought it would be higher. Do you guys think I'm running rich still?

http://img195.imageshack.us/i/img0156ru.jpg/
http://img141.imageshack.us/i/img0157ku.jpg/

skratch77

Those are fine.I think you got it mixed up higher numbers mean leaner and lower numbers are richer.it looks like you got 11s up top and is exactly what you want.

Johncy2000

What if it was tuned with the other line? The higher one.

320 dreamer

the only true way to know what afr you are running in real world conditions is to datalogg. very expensive engines! if your gonna play and mod a mercedes engine you need to datalogg the wideband afr . only way to do that is to install a 02 sensor before the primary cat and use a zeitronix zt-2 or somilar setup and logg. to lean and you will have a huge paperweight!

GT-ER

I've always tuned engines to high 11's/low 12's A/F ratios...but those engines have always been cheap engines and I was willing to risk them ( I've only had one failure in dozens of engines tuned...and the failure seemed like it was because the engine couldn't handle the power, not the tune ). On an engine like ours however I'd honestly stick to low 11's.

IMO, rich you are not.

blackbenzz

I would target 11.8 on our cars but low 11's is safer. Low 12's afr is definitely not rich at WOT

930chas

That bottom line looks to be just fine. Get your new pulley installed, stop stressing dyno #s, and get out there and enjoy your car!

Jakpro1

A/f seems fine now. We are learning more about ole #8 as the years go buy. Piston 8 runs leaner than the others and seems to almost always pop first. Better rich than lean for sure!!

What dyno did you use? Numbers do seem a touch low for your mods.

Gotta get her to the track. I am learning that is the real dyno.

Johncy2000

How much does a datalogger go for?
I know I just can't wait till Tuesday for the new pulley to be installed.My mind is going crazy. lol
I used a dynamite dyno which happens to read even lower than Mustang dynos so maybe I'm good. I did tell jeremy to leave 5% fuel because I told him I was gonna install high flow cats so maybe that could be factor of my numbers.

320 dreamer

are you tuning at wot with a wobbley pulley? not smart if you are.

dataloggers run 250 or so for a zt-2 or 800 for a full dashdaq setup

skratch77

Don't forget that with your full headers to muflers open exh is losing about 2psi boost so your 180 is really like a 172mm

chawkins2001

It is really interesting to see how different tuners tune in relation to a/f curve. What I am used to seeing is an initial drop from say 14:1 where the pull starts to below 12 on blown motors and the a/f as straight as a ruler to where the pull ends. I will insert a graph when I get home to show you guys what I mean.

Johncy2000

You think I should switch to a 190mm? That sounds awesome.

chawkins2001

Here is a pic of a graph that is perfect in my opinion. There is no squiggly lines representing smooth power and see how flat the A/F is at the bottom tuned to 11:1

skratch77

No

GHAZAN

What would be the upper & lower ranges for 'safe' AFR on 63s at WOT? what would be a serious lean AFR?

Johncy2000

maybe a 185 would make more sense since I am losing boost with my open exhaust system.

AgSilver

Just remember that gas is way cheaper than pistons and valves . . . oh, and I really did like the paper weight analogy a few posts back.