gojo

My car, an 03', C4, A4 was on the dyno today.

Here's the last two runs of six. The best run was the last run at 283.9 hp and 310 tq.
with both at about 5500 rpm's. I was hoping for more. I decided not to try tuning since on the previous run I had 11.3 knock retard as in previous runs. We added octane booster and retard dropped to 6.3. The knock always started at 4000-4500 rpm's. If you note the blue AFR gets richer right in the area of knock after adding booster and power goes up. It looks like I need better gas. I use 93 0ctane, but who knows what kind of winter gas we get. It does look like I could richen it up from 4000-5000. Otherwise it already looks rich. Any opinions? I'll be modding in Jan.so I won't stress too much right now. http://im1.shutterfly.com/procserv/4...acef0000003410

Mean Green

looks like some issues with the AF for starters :)

scool93535

:iagree:

Big time.

Looking at your mods the only thing that jumps out is "LS1 edit". Have you "tried" tuning it yourself?

It goes from way lean ~ 15:1 at the low end to near 11:1 at the top end. My A/F dropped off like that before tuning, now it stays pretty flat around 14:1 across the range. It never went as lean as 15 though, something like about 13 and fell off to 11.

We're limited to 91 octane here in CA, no knock problems here.

LOL
:cheers:


[Modified by scool93535, 8:50 PM 12/20/2002]

SharkbyteLT4

Why do you have that big spike at the start of the dyno. It looks like the tranny shifted down in 2nd gear with too much gas inputted too soon.. But you air fuel ratios do look outta wack. I thought you had LS1 edit performed on this car before by Woodbridge dyno???

gojo

I wish I had tuning then I could blame something. The car is stock with no tuning. The AFR in the chart is not accurate until it hits just over 4000rpms.

gojo

Disregard the spikes. It's only the shifts. If you wait until it shifts before turning on the computer you only get one. The A/F looks lean at 4000 rpms then gets richer. Is this normal for stock?

SharkbyteLT4

I'm just curious. You car shouldn't be shifting on the dyno anyway. Once you ease it up to about 3 grand, then you can really stomp it without downshifting to 2nd. Anway, I wish I could telling you why you are running lean like that. If you are taking the AFR at the tailpipes, then that is not really accurate. The only true measure is to take it before the cats. You could actually be running richer than you dyno graph is showing..

gojo

What you see are the 1-2 and 2-3 shifts. The A/F at the pipe is not good for low rpm tuning because the cats are effective. After 4000 rpms they no longer work and the A/F is correct. That's a fact. Anything else is rumors. I've added fuel in knock areas and the retard has decreased. I'm going to try and get race gas to be sure it's not false knock. I don't think it is. But?


[Modified by jfpilla, 12:10 AM 12/22/2002]

SharkbyteLT4

Could be bad or winter gas like you said before. I know around Raleigh in the winter, they use the crappy gas that is supposed to be lower on emissions,etc... Could be the same thing up there..

Crushinator

If I remember correctly, the drivetrain loss for an A4 is 20% right? That would give you 354 FWHP and 388 FWTQ. That doesn't seem too bad. :confused:

gojo

what a great bunch of guys. Trying to ease my pain. We will get to the bottom of this. :cheers:

MTWallet

Since you have LS1Edit, you should be able to fine tune the A/F and play with the timing a little.:steering: