[Tom Hand]

I was thumbing through my new SEMA News, Motor Trend, and Car and Driver magazines and found some interesting ads I wanted to share. I enjoy working with exhaust systems and components for HP Pontiacs and have been excited and impressed with how well X-crossovers work. Many of you know the X-crossover was first used extensively on NASCAR cars because they offered HP and torque increases. Through the 1990s, they found their way to drag cars and are now used on a very wide range of them because of the gains they offer in both sound control and performance. Now the OEMs (Ford Lightning) are adapting them to specialty vehicles, again because of the improvements they offer. Who would have thought that they would have progressed from super speedway to drag racing to this sort of OEM applications?

Our evaluations on Pontiacs, testing in Hot Rod, Ford magazines, MOPAR, and Chevy magazines continue to demonstrate their effectiveness over other crossover systems and even over open exhaust.

For instance, I found this ad from Corsa (www.corsaperf.com). “From a pure performance standpoint, the "H"-pipe has some shortcomings. It is fairly restrictive because it is placed 90-degrees to the path of exhaust flow and any crossover gases must turn a 90-degree corner. For several years performance enthusiasts have been upgrading their dual exhaust systems with a more advanced setup with the crossover, or X-style. “CORSA's X-Style Crossover Pipe Improves Exhaust Flow”. CORSA Performance, makers of the World's best-selling C5 Corvette exhaust system featuring it's patented *Power-Pulse RSC™ technology, has focused its attention on developing the ultimate C5 Crossover Pipe. This design, based on sound engineering principles, provides improved, balanced side-to-side exhaust flow for increased power and eliminates the exhaust "idle burble" and popping on deceleration in most fifth generation Corvettes. CORSA's X-style Crossover Pipe improves exhaust flow, at the same time smoothing out the LS1 engine pulses for better throttle response and a cleaner sound.”

Hedmen (www.hedman.com), a well known supplier of headers and other components says this about their X-crossover system: it “Eliminates Firing order pressure differences, increases H.P. throughout all RPM ranges, and is made from 16 gauge, aluminized construction with smooth, mandrel bent tubes”.

BBK (www.bbkperformance.com) says: “Our expanded line of popular high-flow x-pipe assemblies... With computer mandrel-bent aluminized tubing, die-stamped flanges and precision welds; the quality matches the 12-20 horsepower improvement seen on the rear wheel chassis-dyno”.

Magnaflow (www.magnaflow.com) makes a version from stamped and welded plates formed into the X shape.

Other racing magazines feature ads from Dr. Gas (www.drgas.com) and several other independent manufacturers. All state they add power and reduce noise levels.
For anyone thinking about upgrading exhaust on your Pontiac, please take a look into this technology. We have found that there are not many other things you can do to your high performance Pontiac engines that will let the power increase, lower the exhaust sound level, eliminate resonance from certain mufflers, and change the exhaust tone. If any further information is required or you would like to read the work performed on the X-crossover and other various exhaust components, please visit: http://www.boyleworks.com/ta400/psp/exhaust.html

[This message has been edited by Tom Hand (edited 11-11-2001).]

[Tom Hand]

I was thumbing through my new SEMA News, Motor Trend, and Car and Driver magazines and found some interesting ads I wanted to share. I enjoy working with exhaust systems and components for HP Pontiacs and have been excited and impressed with how well X-crossovers work. Many of you know the X-crossover was first used extensively on NASCAR cars because they offered HP and torque increases. Through the 1990s, they found their way to drag cars and are now used on a very wide range of them because of the gains they offer in both sound control and performance. Now the OEMs (Ford Lightning) are adapting them to specialty vehicles, again because of the improvements they offer. Who would have thought that they would have progressed from super speedway to drag racing to this sort of OEM applications?

Our evaluations on Pontiacs, testing in Hot Rod, Ford magazines, MOPAR, and Chevy magazines continue to demonstrate their effectiveness over other crossover systems and even over open exhaust.

For instance, I found this ad from Corsa (www.corsaperf.com). “From a pure performance standpoint, the "H"-pipe has some shortcomings. It is fairly restrictive because it is placed 90-degrees to the path of exhaust flow and any crossover gases must turn a 90-degree corner. For several years performance enthusiasts have been upgrading their dual exhaust systems with a more advanced setup with the crossover, or X-style. “CORSA's X-Style Crossover Pipe Improves Exhaust Flow”. CORSA Performance, makers of the World's best-selling C5 Corvette exhaust system featuring it's patented *Power-Pulse RSC™ technology, has focused its attention on developing the ultimate C5 Crossover Pipe. This design, based on sound engineering principles, provides improved, balanced side-to-side exhaust flow for increased power and eliminates the exhaust "idle burble" and popping on deceleration in most fifth generation Corvettes. CORSA's X-style Crossover Pipe improves exhaust flow, at the same time smoothing out the LS1 engine pulses for better throttle response and a cleaner sound.”

Hedmen (www.hedman.com), a well known supplier of headers and other components says this about their X-crossover system: it “Eliminates Firing order pressure differences, increases H.P. throughout all RPM ranges, and is made from 16 gauge, aluminized construction with smooth, mandrel bent tubes”.

BBK (www.bbkperformance.com) says: “Our expanded line of popular high-flow x-pipe assemblies... With computer mandrel-bent aluminized tubing, die-stamped flanges and precision welds; the quality matches the 12-20 horsepower improvement seen on the rear wheel chassis-dyno”.

Magnaflow (www.magnaflow.com) makes a version from stamped and welded plates formed into the X shape.

Other racing magazines feature ads from Dr. Gas (www.drgas.com) and several other independent manufacturers. All state they add power and reduce noise levels.
For anyone thinking about upgrading exhaust on your Pontiac, please take a look into this technology. We have found that there are not many other things you can do to your high performance Pontiac engines that will let the power increase, lower the exhaust sound level, eliminate resonance from certain mufflers, and change the exhaust tone. If any further information is required or you would like to read the work performed on the X-crossover and other various exhaust components, please visit: http://www.boyleworks.com/ta400/psp/exhaust.html

[This message has been edited by Tom Hand (edited 11-11-2001).]

[Rocky Rotella]

I'm not going to believe any of these claims! Exhaust companies are just promoting their own products for added revenue. NASCAR and dragsters only use these devices for the sponsorship monies they receive. I feel these X-pipe producers all conspired with Ford to use these on the new Lightning for additional business and promotion of the X-pipe in general. Their intentions were to draw attention/interest towards the X-pipe with hopes that individuals might purchase an X-pipe thinking they are beneficial for performance.

If we'd only listen to the "experts" thoughts and not organizations like NASCAR who utilize every edge available. Maybe NASCAR should consult the "other" board for performance enhancements!

[larry davis]

Hey Tom, the link wouldn't connect?

Anyway I am in the middle of a complete frame-off resto & 428 build-up for my 78 T/A. I have a complete Flowmaster system 2 1/2" w/ thier transverse muffler. This has the older H style crossover.
What's your & Jim's opinion as to the best crossover & exhaust system to use?
I may opt to use the Flowmaster on my 79 instead.

Thanks!

[Tom Hand]

Larry, try now.
Tom Hand

[Tom Hand]

Larry, Rocky Rotella has a unique system on his TA. I will contact him to have him post a summary of what he used. He has some information that is applicable to yours.
Tom Hand

[Rocky Rotella]

Larry, my 76 uses the 17104 transverse system. Although, very little, it's still the basic kit. I have headers that were developed/built by Tom and his family. To the 3" collectors, I'm running a 3" Dr Gas X-kit. The 3" pipe extends to a pair of 3"-into-2.5" Flowmaster reducers about at the rear seats. I welded a 2.5" flange at this point for easier removal. From the flange it goes info the Flowmaster kit which includes the 42585 muffler. The supplied tail pipes fit like crap so the muffler shop bent some 2.5" piping and clamped the 1974 Firebird exhaust tips in place.

Initially, when I hadn't planned on using the 3" stuff or headers, I had the original RA manifolds. I planned on using Torque Tech's 2.5" mandrel head pipes and a Dr Gas 2.5" x-kit and then the rest of the Flowmaster system. I'm sure the Flowmaster muffler is somewhat restrictive but it tucks up nice and I really do like the sound. What's great is that the X reduces all that droning that is associated with the Flowmaster series.

[goathead68]

Does the location of the X-pipe affect performance, or do you just put the X-pipe in the most convenient spot?

[Rocky Rotella]

My X-pipe is directly behind my driveshaft loop. I don't think that location affects performance that much to worry about it. You're pretty limited to where it can go.

[sscherin]

Hey Rocky.. It sounds like we are running an almost identical exhaust setup.. Except I have the Hooker Supercomps.. After I aded the X I lost the loud drone I had at idle and highway cruzing noise is a bit lower..
The sound is.. well ya gota hear it.. It's cool tho [img]/infopop/emoticons/icon_smile.gif[/img] http://www.pontiacs.org/firebird/pics/
Go to the bottom and look at the pics starting with X.. I'm still working on the HTML for the X project.. Yeah I'm slow..

Check These 2 pics to see how it fits in the car.
xincar1.jpg
xincar2.jpg


[This message has been edited by sscherin (edited 12-02-2001).]

[This message has been edited by sscherin (edited 12-02-2001).]

[Tom Hand]

I liked all those pictures and that was/is a lot of work! Recognized the other headers too with your new Hookers.
Tom Hand

[sscherin]

Thanks Tom.. If I had to do it over again I would just buy the Dr Gas Kit.. I only saved about $50 doing it my self.. Same story with the Cal-Traks.

[Rocky Rotella]

Looks something like mine!
http://www.geocities.com/rotella31/x1.jpg http://www.geocities.com/rotella31/x2.jpg

[455Dave]

Rocky:

I have to laugh, but right now it hurts to laugh. [img]/infopop/emoticons/icon_smile.gif[/img]

I started with a 70-74 exhaust with stock manifolds and upgraded to the FM transverse setup with RAIII manifolds. Then I installed headers.

I just ordered a Dr Gas 3"/2 1/2" X pipe and am replacing the transverse muffler with a set of Hemi Super Turbos. I remember hearing someone not being happy with a certain brand of tailpipes so I'm going to have a set fabbed locally.

Seems like we went down the same road with exhaust systems. I did make my own set of headpipes for the RAIIIs though. I got a local shop to bend as tight a radius as possible using heavy wall pipe and then installed them on the car. They were way off so I started cutting wedges out of the inside of the radius and tacking them till I got what I wanted. When it was all welded up, it wasn't the prettiest job but the bend was very smooth and not flattened.
I'm going through all of this because my wife says the T/A is too loud to drive. I'm hoping for a quieter exhaust with some gain in performance.

Dave