Did a w0t pull tonight to about 125 mph on a deserted back road with no intersections or houses. When I shift into 4th I see flashes of light behind me, look back and there are sparks flying.

I go back and make another pull and at 6600rpm in 3rd gear it coughs hard and I let off. No sparks though. AFR was around 11.3 last I looked, which is what I tuned it for. W0T timing was at 18*. Unfortunately I was not data logging at the time or I would post the HPL files.

I'm thinking the 3" pulley is a bit too much. Probly should go back to the original 3.15 TVS pulley. Signature mods are otherwise accurate.

Car still pulls strong though. No WRX mod yet.

Opinions on the source of the sparks?

 

Flames

 

Sparks are material from the cat igniting and coming out the exhaust. Gut the cat or go catless = no more sparks.

 

This. My car did it on a catless setup though, but it was metal pieces from the flex pipe that I melted down during nitrous runs. They would eventually work their way loose and result in a cool shower of sparks as they oxidize when they pop out of the exhaust.

 

I figured the cat was coming apart, but what explains the misfire? KR? Too much timing? I know I'm not lean by any means...

 

Normal LSJ problem? I used to get that sometimes, random, felt like rev limiter for one pop, lots of LSJ's do it. I got it from very close to stock all the way through heavily modded.

 

Yeah, I was going to say I used to get it somewhat consistently at the track on the front stretch during the 3-4 shift. That seems to be the one that does it the most.

 

Feels like KR hesitation though. Need to do some data logging. Probably need to lose the converter also, but I have been avoiding that due to loudness and raspiness.

 

i would say loose the converter then the 3in pully will love you longtime

 

I won't lie it is loud, raspy, and annoying without a cat. But meh.

 

I like the way my exhaust sounds now :-(

 

Throw a resonator in

 

Yeah. I miss my normal exhaust, but I don't even think I could run a high flow cat and be OK on my setup, you MIGHT be able to, but I doubt it. If you don't already have one, that is.

 

i have the zzp 3in catless it isent loud and it sounds awsome

 

I have a resonator. Let me reiterate my exhaust. Shorty header with 3" collector, 3" ZZP downpipe with converter into 2.5" flange, stock resonator, 2.5" mandrel axleback with straight through muffler.

My restriction point diameter-wise is the stock resonator. I believe it measures in at a hair under 2.25" but I'm not sure if that is any worse flowing than the converter

 

i would ditch both of them and get a good res

 

I'd rather ditch the TVS at this point.

 

Blasphemy! Unless you're going turbo, then we coo.

BTW, was your title MEANT to be a Taylor Swift reference or is that just a ghey coincidence?

 

makin power son!!!!!!!!

 

Taylor Swift reference. I even saw her in concert in 2008 when she toured with Rascal Flatts
What? You haz problem?

I don't know what I'm doing with the car. It's a love/hate thing. I don't want to spend the $ to finish the necessary supporting mods, and sometimes I want to sell it for something more "grown up"

I did some data logging last night in about 60* weather and everything was perfect. 0 kr under w0t. 2* for a second between the 3-4 shift when I was off the throttle. I assume engine movement. No more misfires. IAT2 never topped 122*

Anyone want a ZZP cat'd dp? lol

 

Exhaust turbulence and loss of power?

Also, I shut it off for about 15 minutes right after running the **** out of it, went to restart it, and it did not want to start. Cycled the ignition twice, nothing. 3rd time pumped the gas and it sputtered to life. Ran fine and no problems since.

 

I think I saw this on a movie...did you make sure your passenger floor was still in tact, sometimes those things shoot off, but the power gain is incredible

 

Put the stock muffler back on and go catless

 

Well he didn't mention his laptop saying anything about danger to the manifold. So I think his diamond plate floor panel is safe.

 

^ Yes. HPT did not say "Danger To Manifold!!!" so the 2nd stage of NAWZ did not rip off my bolt-in floorpan.