SJTrance

I did a dyno-tune with the mods in my sig. The car has 71,xxx miles, was on the same 93 octane Shell gas I always use, and the plugs are stock and just a few weeks old. I bought the car with 49,xxx miles on it and I don't know the history of the car. The best time with my current mods is 13.092 @ 107.74 mph. I was planning on doing cam and stuff but I wanted to see where the car stood first. All runs were done without the stock converter unlocked.

Well the problem started with the first run. The problem was detonation. The airfuel was rich around 14 or so. It ran 298Hp and around 305 Tq. He tried some different tunes and things were getting worse. He then re-loaded the stock tune and started again at baseline. The wierd thing is that this time, with the pre-existing tune, the airfuel ratio (shown in the picture) was under 12. After fiddling with it for a while, he got the detonation out by backing out a few degrees, fixed the air fuel and got some power out of the car.

My question is this...should my car not be making much more power? I really didn't feel much difference on the drive home. Well, I mean, I might not be able to hear much difference with 15 hp. 15 Hp out of a tune is good, so I'm happy with that. The end result is 312.55 Hp and 317.94 Tq. I'll have to take it to the track to get some hard times.

Basicallly, after seeing all this I'm starting to realize my worst fear...there's something wrong with my car. I can't figure out what it is. Maybe it's the miles on the car. I really feel that with the mods, my car should be running a faster time and showing more power. Or, maybe I'm wrong and it's just fine. Please give me your thoughts on it. Thanks.

Here are a few things I'm going to do:
- Try the TR60 spark plugs
- Run some injector cleaner through the tank
- Run the car at the 1/4 mile track
- Anything else?

oange ss

iTrader: (50)

mods ?

SJTrance

99 C5 Auto (3:15 gears)
FLP Headers, X-Pipe, high flow cats
Z06 Ti Exhaust
MTI Ram Air Intake
Built Tranny to 500 Hp
Transgo Shift Kit

INVISIBLEZ

iTrader: (45)

That does sound weak, I called while Mike was tuning your vette. Something is definatly out of wack, do a compression test. That'll tell you where you're @ down low.

blkZ28spt

107.7 mph in an auto with nothing but exhaust doesn't look bad.

INVISIBLEZ

iTrader: (45)

I hate to dispute that, but I went 106 m.p.h. in my old bone stock WS6 with radials. Also had 83,000 on the ticker.

BOWTIE

That is about right for an A4 car (by the way, 14:1 is lean, 12:1 is rich, 12.5-13:1 is about what you want). What type of dyno was this on? I have always heard that the Vettes dyno a little lower than F-bodies due to the independent rear axle. I had a friend with similar mods with an LS6 intake, and no cats, but a looser converter dyno 325 rwhp and run 12.3 at the track in a 2000 SS.

BOWTIE

If this is the same car in your sig, it's not an auto. There is a 3-4 mph difference in comparable cars between an auto and M6.

SJTrance

This was done on a DynoJet.

The 1/4 mile time I posted was with all the mods in the signature (FLP Headers, MTI Intake, etc.).

compression test is a great idea.

INVISIBLEZ

iTrader: (45)

There is a comparable difference and no it's not the one in my sig. It was a 99 M6 that weighed a considerable amount more than this vert vette. My WS6 was in the high 3800's. An auto vette runs a few more mile an hour than a A4 f-body. Later with 3000 more miles on my old car adding only headers, y-pipe, borla, lid and nittos I went a 12.78 @ 111 with a stock tune.

Krazy98Z28

iTrader: (12)

I dont think those numbers are bad, your looking at 275-285RWHP stock, so your making good power. And your A/F is right on the money at 13.0.. take it to the track, dont stress the dyno number your car is tuned you should run 12's no problem

SJTrance

You're right. That small increase and the tranny tuning SHOULD get me into the 12's. But I fear that the weather being hotter might even things out. We'll see. Hopefully, I can get out there by this Sunday.

SJTrance

Another question...would locking my torque converter have net me much higher numbers? You guys are actually making me feel more at ease.

blkZ28spt

My 98 A4 camaro made 319/337 with CAI, lid, headers and duals. Added a 3500 stall converter and sticky tires, pulled the front sway bar and removed some weight and it ran 12.62 @ 106.5 on 1.72-1.75 60's.

Unstang

iTrader: (26)

Yes, it will raise the numbers, not sure how much though. You numbers aren't terrible. For comparison, my '98 Z A4 made 302 rwhp/325 rwtq with a cut out & lid, the converter was locked.

dubrado

iTrader: (20)

if it's unlocked you'll prolly making ~20 more hp or so

blkZ28spt

It's hard to say how much doesn't show on the dyno due to the unlocked converter.
But, consider this:
I dyno'd 319 rwhp through the unlocked stock converter.
Added 3500 stall and ran 12.6 @ 106.5.
Added cam/tune and dyno'd 343 rwhp. Ran 12.2 @ 111 on bad tranny.
The difference in dyno output was 24 rwhp, but I ran 0.4 quicker and 4.5 mph faster.
That would point towards the 3500 stall converter eating about 20 rwhp more on the dyno than the unlocked stock converter.

BOWTIE

I disagree 100% with this statement. Granted, I never ran my car totally stock, but my fully loaded and fully optioned (- disc changer) 00 WS6 T/A with a lid, free mods, and catback went a 13.12 at 108 with a stock junk clutch. My roomates bone stock (except for a Blackwing filter) 99 A4 Vette went 13.4x at just over 104 mph. Granted we were both having some traction issues, but that should not effect mph much. I was 4 mph faster in a much heavier M6 TA with only free mods and catback difference between us.

SJTrance

I just called my service manager and according to him, the spark plugs have not been changed out. So, the plugs are the TR55 with the MSD wires. Should I bother changing them out to the TR60 plugs?

v8maro

iTrader: (4)

no stick with the 55's