Leon Speed

Thought it is for a wide band sensor.

https://rennlist.com/forums/showthre...ight=O2+sensor

bigs

Ryan -

looking at my dyno graph, the increase in torque is significant right from the get-go. There is about 30 ft lbs difference immediately.

The difference is greatest at about 4500 rpm - where the X-pipe torque peaks.

Interestingly, the stock exhaust peaks at about 3300 rpm (prior to the flappy opening.) There is a "mini" X-pipe peak there as well, but with the X-pipe, the torque continues to go up until 4500 rpm.

So, the stock exhaust torque peak occurs much earlier than the X-pipe peak. In fact, if you compare the torque curves at 4500 rpm (when the stock exhaust torque has already peaked as has begun to decline) the difference is more like 40 ft lbs.

As for horsepower...

Horsepower gains are more modest at first - about 15 ponies - and both curves are pretty parallel until about 4,000 rpm, when the X-pipe curve starts to run away from the stock curve. And then the difference is maintained throughout the remainder of the power band.

Ketchmi

I wonder if Paul Anderson is the same bloke that wanted to "borrow" my design and have them made over there. I refused and never heard from him again.

funkyboogalooo

Maybe, who knows?

bigs

Ryan - and any others who might be interested...

Here's my dyno chart comparing stock vs. X-pipe. (I finally figured out how to scan stuff from my older printer/scanner onto my Vista PC. ) You can see how things compare throughout the rpm range.

Edit: This is the Lomas (Motorsport) X-pipe.

RyanPerrella

Nice graph bigs, very impressive!

Mongo

I have yet to dyno mine to see what I made.

RED SHARK 1990

Hello Andy where did you get your installation of the x-pipe in SAN DIEGO? and how much?thanks LUAN

PorKen

After refreshing the intake and sensors, the X-pipe is the 'first step into a larger world'.

It's a great place for the O2 sensor, not only because it samples both banks, but it stays nice and toasty warm, too.

The (PK) balance pipe may also make more power, but I haven't tested w/w/o back to back, yet. It doesn't hurt power. My new '86 made ~15 rwhp sae more with the balance pipe than my old '86 with the same Ott-X and clone chips. Now I'm likely making close to 320 rwhp sae with the setup in my sig.

(My new '86, SAE)

(My old '86, STP, -10 for SAE)

(GT w/ headers, etc.)

dprantl

I wonder if you just made an isoceles trapezoid from that connecting pipe to the center of the X, would it make even more power?

Dan
'91 928GT S/C

LeRox

Porken,

Have you consider locating the PK balance tube downstream of the x-pipe? My fluid mechanics background is kicking in.

regards..

ROG100

Dave,
I have seen the Paul Anderson X pipe and the design is pretty agricultural and will not achieve the gains your X pipe has been proved to achieve. If I bought it I would want to see some dyno results first. Paul claims an increase of 15 HP for about $750.
Paul is a well respected 928 guy in the UK.
Roger

The_Remora

This is probably a dumb question but... Are there different types of RMB's readily available from different manufactures & distributors? And if so, is there a difference in performance and sound? Thnx

RyanPerrella

yes there are different ones, not sure they perform any different but some look better than others. I have one where the pipes are straight which looks OK, i saw others that are curved down and then out like the factory muffler which look much better and tighter on the car. Much better looking finished piece when installed then the one i have.

Mongo

I got mine installed at Thunderbird Muffler in National City. I bought a universal X and had them do partial pipe bends, cuts, and welds to get the pipe to turn without any kinks in it.