First time dynoing my car today, I made 254 RWHP/294 RWTQ with cutout closed, 263 RWHP/302 RWTQ with open with an AF of a VERY lean nearly 15:1.

After new fuel filter and tightening air intake, which was loose, AF shot up about 3000 RPM and was closer to 16:1 this time. with HP curve leveling off at the same point on the chart. It looks as though the fuel pump isnt keeping up with the engine demands at WOT. Looks like a new fuel pump may be in order soon. What's best? Walbro?

Oh well, I'm thinking I should be able to pull 270 RWHP with that issue corrected though.

 

Stock tune?

 

Yup. Only thing done to the car, powerwise, is catback, CAI, free mods, 160* stat, cutout.

 

the pump shouldnt have any trouble with your combo, unless it is infact bad, before you go replacing it though get a FP tester and see where its at. If its not that, check maybe the vacuum hose going to the FPR, make sure its not cracked. Other than that not really sure except maybe injectors dirty.

 

I plan on checking the fuel pressure sometime this week, hopefully tomorrow, but not sure if I'll be able to. I'll check the vacuum line from the FPR tomorrow, hopefully it is something that simple, I really dont feel like paying for or doing a fuel pump right now. I will post the dyno charts as soon as they email the dyno file to me, should be tomorrow or Mon.

 

With a stock tune and a fairly stock car you shouldn't have such a lean condition. I would check out the MAF and see if it needs a good cleaning. Cleaning mine did a world of good in straightening out the lean condition that the wideband was showing at the dyno.

 

Well, I got the dyno files in.

Dyno Run 1
Dyno Run 2
Dyno Run 3 (cutout opened)
Dyno Run 4 (with new fuel filter & cold engine)
DynoJet RunViewer (700k zip file)

First 2 runs are with the cutout closed.

Mods are CAI, airfoil, TB bypass, 160* stat, Mac catback, cutout.
I definitely need to have my fuel pressure checked, HPand TQ graphs really start breaking up at about 90 mph or about 4200 RPM, and A/F has a pretty steady climb after 3000 RPM.

Note: Bring the smoothing to 0 on the charts and it will really show the breaking up over 4200 RPM/90 mph

 

Links fixed. Remember to download the DynoJet RunViewer if you don't already have it to view the files, only 700k file.

 

Could you post a link for a .jpg image? I'm at work and dont want to install any programs here. Thanks.

 

Not sure how to make them .jpg images.

 

For the few mods you have done I think those numbers are within the "normal range". Get that AFR down to 13:1 and you will probably see your 270.

 

Its not the numbers that are really disappointing, its the AF ratio that's disappointing. I'm going to have to check my fuel pressure and possibly get another fuel pump, that is what is disappointing.

 

Could also be the fuel filter restricting flow. They are a cheap and easy replacement.

 

The note next to the link for Dyno Run 4 shows where I replaced the fuel filter for the 4th run.

 

I see. Hm, could be the pump then, unless you have a kink in one of the lines.