PSI Twin Pipes for the SX

[racerrob6m]

Hey Tony & others!
Here is a question for you SX knowledgable guys. I acquired a set of PSI twin pipes for the SX & am curious about a few things.

A) Both pipes have holes where I presume a EGT probe would have been used. Were these holes "stock" or
"standard" when new?
The pipes need a good bead blasting but otherwise are in really good shape. I will be getting them ceramic coated when I get my PSI Vmax 4 quad pipes coated next month & was wondering if I should just weld the egt probe holes shut as I do not plan on running a egt setup, if that is what those holes are for.

B) What was the HP gain when using the PSI twins on the SX motor?

C) What type of jetting & carb settings were used when working with the PSI twins?
I do not want to melt this engine or even come close!! LOL

I have a nice complete SX motor I pulled from a rough chassis last winter & found these PSI pipes on another SX that was "toast" & am considering putting this motor & pipe setup in a 87 Exciter I also acquired last winter that is a 1 owner, 2200 mile chassis. I am thinking that this motor package would be a cool "sleeper" in the old 87 chassis.

Thanks for any info & looking forward to watching this site grow...its way

Rob

[speednutt]

Here are some twin pipe comparisons as well as some setup recommendations by RPC. I hope they help out. I am sure that Tony and others will be of more help as well. If your not using the pyrometers (egt) then you can weld the holes shut.

DynoTech Shootout Results

RPC SX Setup info.

You can get the adobe reader here if you dont have it. Get Adobe here.

[YAMMIEGOD 3:16]

THOSE DYNO TESTS FROM DYNO TECH ARE THE BEST TUNEING INFO. JIM LOVED THESE SLEDS AND TESTED THIS MOTOR ALOT. ROB , SHURE JUST WELD THOSE HOLES, YOU WILL HAVE NO ISSUES. I JUST FOUND A BENDER SINGLE PIPE FOR MINE. I LOVE IT, WHAT SOUND AND WEIGHT SAVOR. AND THEY DO ADD POWER. 3:16 (yammie tony)

[racerrob6m]

Hey thanks for the info guys.
Looks like the PSI pipes had both the highest HP curve & db's on the noise side huh?
I have never heard how these pipes sound. Hope they are not real "obnoxious"..LOL

I am out there a bit before I attack this project so we will see how it works out

And the carb tuning should be fun as I have to set it up for 4500-7500' elevations.
Will cross that bridge when I get there.
I am not even sure if the pipes will fit under the hood of a 87 chassis. I know the engine will bolt right
in & all that stuff but clearence for the twin pipes may be a challange!!
I have a really nice SX hood, but...I really like the looks of the older 87-90 hood. Will see.

Thanks again.

Rob

[speednutt]

HEllo rob, just curious how your project is coming along?

As far as everything fitting, it should be a breeze as the chassis are virtually the same. When you change the engine, make sure you change the wire harness as well, as the CDI box for the SX will not plug into the 87' harness and you dont want to use the 87' cdi as that is where a large part of the HP increase comes from.

Also, if you ever decide to part ways with those PSI twins, let me know.

Speed