[Scott B]

I conducted some dyno testing recently which I thought may be of interest to the community. (Here is the chart of my car bone stock.)

- Boost was sampled from the BOVs.

- AFR was sampled from the tail pipe (right side, of course) with an Innovate LM-1

This first graph is comparing The JB2 to the JB2H. While the JB2H does produce more boost and peak torque, it actually produced less horsepower on my car -- 6AT 335xi coupe on Cali 91 -- when compared to the JB2. I suspect that the extra boost, when coupled with my heavier car and crappy Cali gas, caused some ignition timing to be pulled in the higher RPMs. It's important to note that I never experienced a limp mode with either configuration. Both of these runs were done after full adaptation (note the acquisition dates).



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The next test is comparing the stock coupe exhaust to the stock exhaust without the secondary catalysts. Both of these runs were done on the same day, with the only change being the exhaust modification. I ran each configuration for 6 pulls to encourage accurate results. As for the change in sound without the cats, it's quite subtle and entirely bearable. The biggest change is the sound upon cold startup - noticeably more aggressive. Other than that, it is a tiny bit more aggressive sounding at WOT, but undetectable during cruise conditions. In my opinion, this is a worthwhile mod for those wanting a little power and aggressive tone without spending a fortune or turning your 335 into a ricer.



(For those that may be unaware, Mustang Dyno numbers are somewhat conservative when compared to the DynoJet numbers that are often posted.)

[stillclaimndp]

Cool, looks like that awd version doesnt lose much power to the wheels...

[TheBreak]

they make AWD - COUPES?
i thought AWD was only available in Sedan?

[forza1976]

Originally Posted by TheBreak

they make AWD - COUPES?
i thought AWD was only available in Sedan?

yup, that's what I have

[Scott B]

Originally Posted by TheBreak

they make AWD - COUPES?
i thought AWD was only available in Sedan?

Yes. Starting in 2008.

[turboawdfanatic]

Originally Posted by stillclaimndp

Cool, looks like that awd version doesnt lose much power to the wheels...

here is one comparison where an xi and i were dyno'd back to back on same dyno.

http://www.e90post.com/forums/showth...ght=335xi+dyno

[forza1976]

Originally Posted by turboawdfanatic

here is one comparison where an xi and i were dyno'd back to back on same dyno.

http://www.e90post.com/forums/showth...ght=335xi+dyno

That would be mine and jt's.

Definitely some driveline loss between the i and xi version.

[Nikolas]

Originally Posted by turboawdfanatic

here is one comparison where an xi and i were dyno'd back to back on same dyno.

http://www.e90post.com/forums/showth...ght=335xi+dyno

That dyno still surprises me that the drivetrain loss is not as high as I would have expected.

[leftcoastman]

Hey man, when you removed the secondary cats, did you just remove the cat or did you replace the crushed piping that is adjacent to the secondary cat, also?

[Scott B]

Originally Posted by leftcoastman

Hey man, when you removed the secondary cats, did you just remove the cat or did you replace the crushed piping that is adjacent to the secondary cat, also?

Just the cats. I wanted to isolate the test to show only the gains from the seconardy cat removal. Any other changes would have clouded the results.

[vanillarice19]

Isn't the JB2H supposed to be used with 93 or higher octane only?

[leftcoastman]

That's great. I'm curious, did power on the 2nd cat removal DECREASE after each successive adaptation run?

The reason I ask is that it appears that it runs a bit leaner without the 2nd cat than with it. I wonder whether the ECU slowly "adapts" that leanness out.

[Scott B]

Originally Posted by vanillarice19

Isn't the JB2H supposed to be used with 93 or higher octane only?

Yes, but I told Terry that I would do some testing for him. The question now is whether or not the "H" pill would show gains on a heavier car like this if it were on 93 octane...

[Scott B]

Originally Posted by leftcoastman

That's great. I'm curious, did power on the 2nd cat removal DECREASE after each successive adaptation run?

The reason I ask is that it appears that it runs a bit leaner without the 2nd cat than with it. I wonder whether the ECU slowly "adapts" that leanness out.

I'd have to go back and look, but I don't recall much adapting at all after the cats were removed. The runs produced consistent results before and after.

The O2s are UEGO widebands, which measure O2 using a method involving pressure. Since the pressures changed when I removed the rear cats, the sensors now function with less pressure, changing their reading. So, to answer your question, I don't think that the AFR will go back to where it was.

This test, and others, underscore the need for tunes that account for each mod on these cars.