With just a lid and cutout, it dynoed 310/322

I installed Longtube headers, Catted Y, Magnaflow, LS6 Intake, and various free mods.

Two weeks after I installed them I got it dynoed, and it put down 319/323.

So, I gained a whopping 9 HP and 1 TQ.

What do you guys think the problem is? The only thing I could think of is that the pedal may have been hindered by a thick rubber mat I have on top of the stock one.

The A/F at WOT is 13.5 all the way through.

 

has it been tuned? were the dyno runs made on teh same dyno?

 

id say tune also. you an a4 or m6? i had problems with the same dyno where they would put the car in a 1:1 drive situation but would still shift so they ran a pull in second and got a better curve but lower numbers.

 

Did you run with the cut out open the second time? Or were you dynoing the magnaflow?

Also giving the car time to cool down helps a bit, I dynoed over 10hp more after waiting 15-20 minutes with a fan on the engine before the last pull.

 

The cutout was removed with the addition of the new I-pipe.

Look at the dyno graph:

Here is the dyno chart...

http://img72.echo.cx/img72/5498/dyno67044ok.jpg

What is with the dips in-between 3000-4500RPM? I think that is my problem. It drops about 10-15 HP each time it dips, and never seems to recover...

 

tune prob help alot.... hmmm wierd

 

Do you think it may be pulling the timing?

 

Do they really like to run that lean? 13.5 sounds a bit lean...

 

Dyno sheet looks like you pulled 331 in one of the pulls. I could be reading it wrong, numbers are kind of hard to make out.

 

Yeah, it was due to some dyno tricks. I tried changing up some subtle things in a failed attempt to get the dip to go away. (Iced the intake, removed filter...etc..) For all intents and purposes, the 331 doesn't count.

It honestly looks like it pulled the timing...but the A/F doesn't show it. Very strange...

 

what kind of fuel were you running?

 

I'd say get it tuned then dyno her again

But then again, dyno numbers don't mean a whole lot on automatics. See what it does at the track

 

I really don't think it has anything to do with the tuning.

Someone suggested that it may not be getting enough fuel, which could actually make sense. I'm going to change out the fuel filter, change plug wires, and run some seafoam through it.

 

honestly i think your setup would still benifit from a tune.. honestly it wouldnt surprise me if you picked up 20+ rwhp from a good tune we have similar mods and i know my car could use a good tune.. also with the tune they would fix the fuel/spark problem is there is one.. just a thought

 

I'm going to change out the plug wires and fuel filter and will dyno again on a different dyno.

Yes, a tune would help overall, but it's not what's causing the problem. I don't care to be a dyno queen and just get a high peak number either. I'm more concerned about the fact that the dip affects the entire powerband while there aren't any lean spots present to indicate that it is a A/F problem.

If you guys look at the A/F. The dips have nothing to do with the tune.

I'm thinking:

Ignition/Fuel related