Contour Enthusiasts Group Archives Forums Modifications Duratec Performance BTR True Duals - long term update

Yessireee, Bob!

Main reason I haven't gone back and done a balance tube is that I don't feel like it. It's a PITA doing this kind of stuff with just ramps and cheap stands. If I could score a deal on a scissorlift, that'd help immensely.

I still gotta get the s-afc to fix WOT, but for now, I get plenty of oomph from part-throttle. I also ended up yanking the superchip and am running the 10k iat mod. Werks grate!

dan

So you got the S-AFC then huh? I missed that post... Probably hit the email list though didn't ya, Da(m)n you Beggs! Be sure to hit us with the fix for WOT...

Is the voltage not reading high enough for WOT or what? Should be 4.7+ IIRC for the TPS... Where your TPS reports? Didn't you get the memo? I'll resend you a copy of that memo...

What what?

I haven't gotten the s-afc yet.

I'm getting WOT signals to the pcm, that ain't the problem. Proper fuel mix at WOT is. :p

dan

O.K. I guess I misread that post... or did I...

Okay then maybe you can explain something to me. The exit off the rear manifold comes straight down, bends, and then starts to head downstream. The exit off the front runs under the oil pan, bends around a few times, and then ends up right next to where the rear one is. That means you already starting with a large difference in temperature between tubes. From here, you can work your way downstream to find the best point, but what about cats? Those have to come first especially when you have headers for emissions. Now you have a choice. Either find the best point after the cats or find the earliest point after the cats. Also, since an x-pipe has to be mounted at the same point on both pipes, you will have to choose the same location on both pipes. Having said that, I'm not sure how you can optimize this set up. Maybe I'm wrong. Maybe I got lucky. Dyno next month will tell my story.

You've got a few things wrong. The exhaust pulses have to match, not the distance from the manifold. Distance from the manifolds might work IF this were an inline engine and IF the manifolds were of the same design. Transverse engine offers only a few possabilities. If you use the crayola method, you will see each pulse will end and begin on each pipe several times before the heat gets to cool for you to see the pulses down the rest of the pipes. Line up one mark on each pipe and you've got yourself a well placed balance tube. The point is, if you put the balance tubes in a place where the pulses don't line up you will allow presure back flow and create more turbulence in the exhaust flow which will hurt, not help, performance. For packaging considerations, yes, you should do it on the first two marks that line up and to keep good heat in the cats.

That's cool with me... Let me know... I sometimes go to the East side of the state... OR show up at our next October Bash over here in K-zoo at the end of October...

Whoever knows the method(s) for determining where to put the crossover pipe, please explain with more detail. I don't know the method and I'd like to.

warmonger

If you already installed the crossover in the system :rolleyes: could you still use the crayon method to check if it is in the right place?