Test Pipes

[zraji777]

so i'm thinking about putting resonated TPs in front of my Borla exhaust. however, i have heard from a couple sources that removing the cats will cut down on back pressure and hurt my torque. I know TPs can pick up a couple HP, but idk if its worth losing the torque. Like Carrol Shelby said, "HP sells cars, torque wins races." anybody got any input on the negative effects that TPs might have on torque?

[SmoothZ]

It won't be significant enough to even notice depending on the brand you get.

[NAGA]

If you have the money, you should pick up the new Motordyne Advanced Resonance Tuning Pipes. They're quieter than test pipes, minimize rasp, have bigger gains than test pipes, and are generally amazing. I had big gains across the board when switching from my Stillen HFCs to the ART Pipes. The normal problem of losing low end torque is nonexistent with the ART pipes as well. I actually gained 23wtq at 2800rpm.

I would post my independent review of them, which is on the my350z forums, but the forum format here hates me and won't let my pictures work.

[zamski]

Hey Naga,

Did you get a retune as well, or was this just a straight swap from the HFCs to Motordyne's ART pipes?

[NAGA]

It was just a straight swap. I got an eTune a couple days ago, and I'm actually getting my car re-tuned on Uprev's dyno down in Austin tomorrow afternoon. I imagine I'll see some nice improvements seeing how my last full tune was before both headers and the ART Pipes.

[zamski]

Sweet.

Did you see any significant changes to your AFR after you put on the headers? Or did you make some minor adjustments after you put them on?

Do keep us in the loop how that goes.

[NAGA]

QUOTE (Zamski @ Mar 12 2010, 07:03 PM)

Sweet.

Did you see any significant changes to your AFR after you put on the headers? Or did you make some minor adjustments after you put them on?

Do keep us in the loop how that goes.

Well, this developing story could likely work its way into a full-fledged thread in the very near future. Simply put, the dyno tune session yielded very little gains over the eTune that was sent. As it is, it is looking very much like I lost a significant chunk of power from the Stillen Headers. Until I get to the bottom of it, I highly recommend you stay away from them. The basics are this: I had my car dyno tuned at Uprev and it put down 270.66whp. Since then, I swapped the JWT Popcharger for the K&N Drop-in, swapped my stock headers for Stillen Headers, and swapped out my HFCs for ART Pipes (showed a 9whp gain). After everything today at Uprev, I maxed out at 267whp. Same dyno, basically the same conditions. Knowing that I gained 9whp from one thing, and may have lost some small amount of power from the intake (let's be generous and say -3whp), that means the only thing else that changed (headers) didn't gain me anything - but LOST at least 9whp [(270+9-3) - 267 = 9]. I had them run a compression test to see if there was a problem with the engine, but it showed a nearly perfect bill of health (about the only good thing to come from this). I then had the ragged spark plugs replaced and the car re-dyno'd. Same results. I'm upset, to say the least. Stillen will be receiving a phone call from me very soon.

But to answer your question, the AFR didn't change very much. Leaned out by maybe 0.3 AFR?

[zamski]

Will be subscribing to that thread when you draw it up.

There have been lots of people that say the AFR gets very lean after a headers swap, so I was curious to find out from your experience since you document a lot of this.

[zraji777]

NAGA,
I must say, those ART pipes do look pretty sick. If i had the money, that would undoubtedly be the way i would go. However, i'm pretty much broke right now and at best would be able to do a couple hundred on TPs. Does anyone have a recommendation in the $200-250 range?