Dyno Tests


CHART #1:Comparison shows the value of an aftermarket catback system. OEM mufflers were not available at the time of the testing. We feel that the Merit aftermarket replacement muffler flows better and therefore should be closer to a 10-15 hp difference when going from an OEM exhaust system to Pypes or Flowmaster catback systems. A Dynomax SuperTurbo was also tested with the following results: Pypes 2.5" Catback w/ SuperTurbo Mufflers Max hp = 212.6 Torque = 276.0 @ 3300 rpm


CHART #2:Comparison shows the difference that a complete header back system can make. Also note that our Mustang did not benefit from the 498 cfm flow of the UltraFlow "straight through" mufflers vs. the Pypes V-Force 304 cfm flow mufflers. Thus re-igniting the ongoing arguement that the better the flow, the higher the horsepower. We will continue to gather data on this subject but feel that in the final analysis, the cam will dictate whether a car needs the additional flow. Most stock lower-horsepower cars will be less likely to benefit from the additional flow. At this time, we recommend full-flow mufflers when engine horsepower exceeds 400-425 hp.


CHART #3:In this chart, the difference between running high flow catalytic converters and NO converters is minimal.

EMISSIONS TEST FOR 1994 FORD MUSTANGClick to enlarge! >This emmissions test was performed in January of 2004 on the same Mustang that was used for the dyno tests. Every emmissions category was exactly where a completely stock 94 Mustang GT should be. In other words, there was no recognizable difference when the X pipe and mini cats were substituted in place of the factory dual catted H pipe.

Tested combination: Factory short tube headers, Pypes 2½" X pipe with mini Cats, Pypes 2½" V-Force Mufflers, Pypes 2½" tailpipes.


CHART #4:Pypes Catback only yielded 5 extra horsepower over stock because of very restictive OEM catalytic converters. But it sure sounded great!! Note the big jump when adding our mandrel bent downpipes into the Pypes X-pipe system.


CHART #5:A moderately rebuilt Pontiac motor gets completely choked by restrictive compression bent system with stock turbo style mufflers. Additionally the test car lost about 10 HP when Flowmaster type deflector mufflers were used. Lower HP cars tested did not show the same loss, adding credibility to the fact that more flow doesn’t always mean more HP. Our tests show the need for full flow mufflers around 300 net rear wheel horsepower.


CHART #6:Pypes newest product is two products in one. Our X-Change is an X-pipe and dumps all rolled into one. Un-capping the dumps gave our 300 HP motor an extra 10+ HP at the wheels.


CHART #7:Upgrading from HO manifolds to ceramic coated headers made by Doug’s. Since this motor has a good high performance cam, We expected these results. Stock HP motors may see less of an increase.


CHART #8:Notice that the full Pypes mandrel bent system almost performed as well as the open headers car!


CHART #9:Yes! It’s true. Our test car with open X-change Crossover dumps out-performed open headers by a noticable amount.


We had one of our dealers do some independent Dyno Testing and here is what his results showed:

Stock system 294.1 hp & 430 torque @ 5500 rpms

Pypes system 322.1 hp & 469 torque @ 5500 rpms Pypes Street Pro mufflers

Pypes system 322.8 hp & 468 torque @ 5500 rpms Magnaflow XL mufflers

One of our customers was nice enough to give us an update on his Pypes Exhaust install with Dyno results. Here is what he had to say: Hi Chris.. just thought you might want to know my results after the 2.5 inch xpipe/splitter installation. This was on my 65 GTO convertible that I brought down to you in early February. Remember, it was the car with the standard log manifolds.

RWHP RW Torque
Before 251 351
After 313.45 401.5
Cutouts 320.55 407.27
Now, before you get too excited, I did rejet the tripower because they were running too rich, but nevertheless I believe you can attribute at least half the gain from the new exhaust. I’ll be running the car in F.A.S.T. class at Musclepalooza/Lebanon on May 27th but the true performance test will be at Englishtown on June 11th to compare with my last run there (14.01 @ 99mph). Will let you know the results.


We had this Camaro dyno tested with it's stock exhaust and then with the Pypes 2.5" Manifold-back X-pipe System. Here are the results: Low end torque numbers were down because the customer wanted Violator mufflers installed for a radical sound. These mufflers flow to high for a low horsepower motor such as this. Notice the huge increase on the high end horsepower numbers.




We've been working on the design of our C5 Axle-back system. We got a change to run this 1999 Corvette on a dyno.

1999 C5 Corvette Max HP Max Torque
Stock Exhaust 295.2 HP 300.3 ft-lbs
Pypes Axle-back System 304.2 HP 310.0 ft-lbs
We also had a chance to take a video clip of the Pypes C5 System with our mildest muffler, Racepro. Video Clip with Racepro Mufflers Here is a sound clip of the same Pypes C5 System with more aggressive Violator mufflers. Video Clip with Violator Mufflers


A few months ago, Marlin Spotts was nice enough to allow us to test fit one of our Pypes Crossflow systems on his beautiful '70 Yenko. You can see the pictures of the install here. He recently had a chance to take the '70 Yenko Nova with his new Pypes system to the track. Here are the results he reported back:

I have pulled my previous slips with my best ET and MPH. As you will see, my previous best was in 2005, but if you would like a comparison versus 2006 let me know because the improvement is even more dramatic. The attached pic is all three slips together. I was not sure what to expect from the new Pypes, but after 4 years of wittling it down from mid 17's to 14.2x's, I was hoping to get into the 13.9x's. I was completely shocked with my first (and best) run, right off the trailer of a 13.505 @ 104.11mph!!! That is an ET improvement of <.747> and an MPH improvement of 5.19!! This run ruined the rest of my day as I couldn't focus on duplicating, and was trying to figure out how. The air and traction were steadily deteriorating as the day wore on, but I was able to pull a 13.83 @ 103.68 a little later. My car was the one to beat in the Yenko Deuce shootout as I had the field covered by 3 tenths. Some of the Deuces showed up with drag radials, J-hook traction bars and open headers - to no avail :)) I'm not sure what your expectations were, but I hope you are as pleased as I am. My first thought after looking at the slip was 'there's a 13.20 in this car' - typical racer eh?!
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