anyone intalled NHP full exhaust???

[Jake Raby]

The NHP is one of the better choices, heck one of our test cars (Charles' 2.9) runs the system and it was compared to several other systems.

That said, if you want a real comparo of the stock Vs the aftermarket system you'll dyno the car before with the stock system then drive it 150 miles and allow the adaptive to compensate for the changes, then re-test. when doing this test work I do 12 runs before and 12 runs after, I start the test with a coolant temp of 160F then test to just about 210F, generally run 5 is the best run all around. Make sure the tire pressures are the same, the straps are tightened the same (measure between the top of the tire and the bottom of the fender) and try your best to use the same regimen for all the tests. I prefer to test from 2,000 RPM clear to redline on all 12 tests back to back for the best data collection.

Also, post the results all across the board, the power through the midrange is where I see the most changes with systems.. Looking only at the peak number is virtually worthless for true comparison.

And measure AFR and include that on your graphs, please.

Remember, the dyno is just one tool I have been using for evaluation. Performance on the dyno is just one element of the "big picture" that I do my best to look at when comparing these systems as well as other components scientifically.

Do a 0-60 and 40-80 MPH evaluation and you'll see much more than the dyno has to offer. Look at the ECU files and see which tables the engine is operating under with different exhausts as well, then it all starts to make sense.

And remember that your stock system and the catalytic converters you'll be comparing against are XXX years old and have XXX miles on them. Over time fuel and lubricant deposits start to clog the cats.. To complete an absolute comparison with only one variable for an OFAT analysis you'd need brand new stock cats... Otherwise you are testing old Vs new and thats a rather large variable.

I look forward to your data, please post it once you receive it and take as manynotes as you can from the before and after.