bigleman

iTrader: (1)

Stock 99 C5 A4
50,804 miles
89*
24% Humidity
SAE: 0.98


It looked like it was doing damn good until the tech said it hit some sort of "spark detonation" (?) He said he stopped the run early, as soon as the drop happened. He doesnt know why the computer kept going but thats why the A/F is crazy at 5100-5400. The guys at the shop said it could be the computer advancing the timing too far or a bad batch of gas.
I was kinda disappointed with 288/292 until i realized it wasn't even testing at the peak rpm range.
Can anyone tell me what is going on here?
What is the problem?
What should I expect when i fix the problem?
Is this as good of a base as everone is saying?

Maybe i was just mad that i didnt see a 3 at the begining...

jessedale98

iTrader: (16)

not bad, sounds like a stock ls1 a4.

s346k

iTrader: (4)

+1

don't sweat it, sounds on par for a stock pre-01 ls1 a4.

i use 1/4 mile timeslips as my dyno. it is foolproof and leaves no questions. so get to the track!

bigleman

iTrader: (1)

any clue on whats going on at 5300 rpm?

prostock_bigblock

iTrader: (11)

what octane r u runnin ?

bigleman

iTrader: (1)

unless the station is screwing me, its only had 93 in it sense the day i bought it

chris93266

iTrader: (5)

you may have carbon build-up causing detonation. when your knock sensors detected the ping, they should have retarded timing, and i bet they would have if you had finished the pull. you should run some sea foam or take your car to a shop and get a carbon treatment done. after that, re-dyno and see how it does.

SideStep

That is KR pulling timing. You can see the differnce in the line-angle climb rate before and after the knock...

MANY A4 C5 owners pull 280-290 (sae) factory. I am a little surprised you got KR at an AFR of 12...

BTW those wheels look bad-azz on a C5... where did you get them???

STRIPSTAR

iTrader: (4)

You could also see if your sucking major oil thru the pcv.

tx77015ls1

my dyno/1/4 mile states in sig

tx77015ls1

Oh BTW, 314 HP on 87 octane dynojet

bigleman

iTrader: (1)

I'll give the sea foam thing a shot and see if i can tell a difference. I'll re-dyno in about 2-3 weeks when i get the intake and exhaust done.

The wheels were on the car when i bought it. I dont know if the old guy who had it in FL before me put them on or if the dealership did. A lot of people are saying the C6s look good on my car. Too bad i cant say the same for the red camaro i saw with them 3 days ago...

bigleman

iTrader: (1)

umm ok.... congradulations?
good luck running 87 dynosaur **** in your car

WS6FirebirdTA00

iTrader: (33)

If you are running too rich, that can also cause knock.

allngn_c5

iTrader: (3)

Check your a/f ratio. the graph looks like you are 12 to 1. You could definately lean out to 12.8 or 12.9 to 1 while strapped on the dyno. You will lean a little bit more when you have fresh air moving while driving on the street.

98Z28MASS

iTrader: (6)

those numbers are pretty good IMO, especially with the new 10% ethanol gas in a stock ls1 a4 vette. I dunno but it kinda looks like valve float around 5300 rpms? Not certain but that could be it.

SideStep

Why are you posting in this thread???

WS6FirebirdTA00

iTrader: (33)

hahaha exactly what I was thinking...

bigleman

iTrader: (1)

How would i test for valve float?

EDIT:
Would valve float happen at the EXACT same spot each time?

98Z28MASS

iTrader: (6)

Im not exactly sure, ill post up my graph, it sorta got cut off when I was uploading it but my dsl is down so im on dial-up right now and it would take forever for me to load again. Here it is:



as you can sorta see I get that little dip around 5700 rpms. I dunno if its the same deal with your setup but after getting my cam installed and tuned it went away. The valve float came on my stock setup.