Tech - NA Exhaust Dyno Testing

The 3SX NA Exhaust Comparison
6 Stages of Stock to Full 3SX Exhaust



6/26/13 - Concord, NC

3SX has done a LOT of new product development over the past year releasing a slew of new exhaust products for the non-turbo FWD 3000GT and Stealth! We partnered with Kooks Custom Headers, a leading aftermarket exhaust manufacturer located less than an hour up the highway from 3SX, to design and develop all of these new components. This means everything is MADE IN THE USA - laser-scanned and designed fitment, top quality steel, and top quality craftsmanship! The component pipes are cut and bent with computer controlled mandrel benders, then expertly welded on precision made jigs that look more like works of modern art than exhaust manufacturing tools!

3SX NA Exhaust Dyno Testing

Once we had everything developed and available for sale, we did something that has never before been done for the 3000GT and Stealth - we actually TESTED all the parts on the dyno to see just what gains can be had from upgrading your non-turbo exhaust system.

What did we find? How about FIFTEEN horsepower and TEN pound/feet of torque with a full exhaust upgrade?!?! Well, actually the power increase reached TWENTY horsepower over 6500rpm with the full 3SX setup versus all stock! That's a more than TEN PERCENT increase in power AT THE WHEELS from simply upgrading your exhaust! Talk about freeing up some power - and that's not even making changes to the engine, the tune, ANYthing! Piqued your interest? Read further...

The Test Car: We started with a test-bed car: a 1996 Mitsubishi 3000GT DOHC 24-valve Non-Turbo FWD Cali-Spec car with 145k miles at time of testing. The car is mostly stock, with only an open element intake filter, aftermarket intake pipe between the filter and throttle body, and Accel 8mm spark plug wires (hey, if you gotta replace em, might as well upgrade em!). Everything else on the car is stock factory original parts.

We then took this car and ran it through 6 stages of exhaust upgrades using different mixes of stock and/or the new 3SX exhaust components. This accomplished two things: 1) We KNOW the 3SX parts go on the car without issue! 2) We have dyno-proven results of what different combinations produce as far as power gains.

Dyno Testing: Test results were compiled from conducting 4 to 5 pulls for each stage of component installation over a 2-day period. All tests were done on our in-house in-ground SuperFlow 880 AWD Dynamometer. Obviously, your results may vary depending on your particular modifications, general health of the vehicle, dyno your car is tested on, etc. These numbers are really more to show GAINS of various exhaust options and direct comparisons of the different options available.


The 6 Stages of Testing: Components & Power


These are the various stages of testing we went through, ranging from all stock to all 3SX parts, and select mixes of parts in between. These tests are of course not EVERY possible combination of parts, but combinations that we felt might be "common upgrade" options.

Note that these are PEAK horsepower numbers. If you look at the comparison dyno graphs further down this page, you will see that the ACTUAL power gains are often greater than sinply the difference in peak numbers. When you look at the power bands over 4000 rpm, you will see that the power gains actually INCREASE as you go higher in the rpm range - particulalry when comparing the "all stock" to the "all 3SX" numbers, the gains increase beyond the peak differences to yield and actual gain of 20 hp!

Test        Manifold                    Downpipe               Cat/RP               Catback            HP           TQ

1             Stock+Precats            Stock                       Stock Cat            Stock                 159.6       154.0

2             Stock+Precats            3SX Cali                   3SX Cat              3SX Catback       164.6       155.4

3             Stock+Precats            3SX Cali                   3SX Race Pipe     3SX Catback       167.8       160.5

4             3SX Long Headers      3SX Long Headers     3SX Cat              Stock                 165.8       157.0

5             3SX Long Headers      3SX Long Headers     3SX Cat              3SX Catback       169.6       160.9

6             3SX Long Headers      3SX Long Headers     3SX Race Pipe     3SX Catback       174.3       163.8

NOTE: ** Your results may vary!! ** These tests were conducted over 2 days with no work being done to the car other than swapping the various exhaust components for the above listed tests. 


6 Stages of Testing: Dyno Test Comparisons

We have taken the dyno graphs above and "stacked" some of them to give direct comparisons between the different modification levels. You can click on any of these graphs to load larger versions in a new window. As expected, the power gains are negligible below 4000 rpm, but some combinations result in progressively larger increases from 4000 all the way to redline!


Test 1 vs Test 6

WANT A DYNO PROVEN 20 HORSEPOWER? This is essentially the maximum upgrade - comparing all stock exhaust components to the all 3SX components: Long Headers, Race Pipe, Catback. The result was an impressive 15 hp and 10 tq gain over stock peak power! Again, this is not engine modifications, this is ONLY exhaust! Nearly a 10 percent increase in power AT THE WHEELS from only exhaust components.

Something noteworthy to consider is that the differences are in PEAK power and torque of the two graphs. You can look at the graphs and clearly see that there are actually INCREASING gains as the RPMs increase, with actual power gains reaching 20 hp (!!!) over 6500 rpm, and power falling off at a lesser rate than the stock components! Actual peak gains range from 20.1 at 6752 rpm to 20.4 at 6855 rpm, proving maximum power and maximum flow in the upper RPM range where you would want it for racing.

Having this much more power in the mid and upper RPM range is VERY beneficial to racers - you can run your car longer in a gear becuase you are still in your power band, which means after you shift, you will be starting the next gear at a higher RPM and further up the power curve (up the INCREASED power curve!) which nets quicker/faster drag times, a more responsive car for auto-cross, and more power on the road course. On the street? Heh... It's just MORE POWER, period, over 4000 rpm!


Test 1 vs Test 4

This test pits all stock against the Long Tube Headers with a high flow cat and STOCK catback. This combination resulted in 7 hp and 3 tq at the wheels comparing peak nubmers. As you can see from the graphs, the gains, as expected, start about 4000 rpm and carry through to redline, with the gains actually increasing beyond 6000 rpm to be over a 10 hp gain at the wheels.


Test 2 vs Test 3
Test 5 vs Test 6

These comparisons show the difference in running the 3SX High Flow Cat and the 3SX Race Pipe.

Test 2vs3 has the stock manifolds/pre-cats and 3SX Downpipe with the 3SX Catback.
Test 5vs6 is running the 3SX Long Tube Headers and 3SX Catback.

Comparing the two, you can plainly see that the Race Pipe offers gains over running the Cat in both circumstances. But comparing the two graphs against each other (comparing the stock manifolds to the long headers), you can see that the stock manifolds do inhibit flow regardless of the cat/racepipe as the power difference tends to dissipate in the upper RPM range in the 2vs3 graph. Conversely, the power gains actually tend to increase over the upper RPM range with the long headers and race pipe versus cat.


Test 2 vs Test 3 Graph

Stock manifolds + precats with 3SX Downpipe and 3SX Catback. Comparing the high flow cat to the race pipe. While the Race Pipe clearly offers gains over the cat, those gains are diminishing returns in the upper RPM range as the manifolds are restricting flow.



Test 5 vs Test 6 Graph

The same comparison as above but swapping the 3SX Long Tube Headers in place of the stock manifolds/precats/3SXdownpipe. Now you can see the gains the Race Pipe offer over the Cat are carried throughout the upper RPM range and the gains progressively INCREASE until just before redline.



Test 4 vs Test 5

This test looks at gains of the 3SX Catback Exhaust over the stock catback exhaust. The front half of the exhaust is constant in these tests running the 3SX Long Tube Headers and 3SX High Flow Cat. As is consistent across these exhaust upgrades, they are effective over 4000 rpm. The change from the stock catback to the 3SX Catback netted a consistent 4 hp gain all the way through to redline.


Test 3 vs Test 6

Our final test compares the 3SX Downpipe (with stock manifolds and precats) to the 3SX Long Tube Headers - both are running the 3SX Race Pipe and 3SX Catback to standardize/maximize flow/power in the back half of the exhaust system. The gains are significant with over 7 hp gained at the peak measurements, and about 10 hp total gain over 6000 rpm.


Additional Upgrades

The above power numbers were a result of exhaust upgrades ONLY. As mentioned, the car had an open air intake and 8mm plug wires and no other modifications from stock. While your specific horsepower gains may vary, additional upgrades will only ADD to the power to the wheels of your car. Such items as light weight pulley, light weight flywheel, cams and cam gears, high compression pistons, and other modifications can ALL benefit from an engine with a much less restrictive exhaust. In fact you could potentially see greater gains from other mods due to the restriction of the stock exhaust components (e.g., cams with stock exhaust versus cams with 3SX exhaust).

Enjoy driving your 3000GT/Stealth/GTO!!!