Datalogs taken from the OBDII port on the same day/evening. It was a bit cooler outside during the "after" runs, but not much. It seem that I gained a little spoolup but didn't gain that much more flow once boost was established.

The second graph was "calculated" with (MAF/RPM)*constant. I kept changing the constant until it gave some reasonable results. It's basically a scaled derivitive of the first graph.

Comments... Ideas????

Buschur 3" catback /w magnaflow muffler... nothing more.

 

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Is this vs stock? If so then I'll give up that hump in torque for smoother power delivery (stock) and much quieter exhaust. Probably based on stock engine management?

 

Yep, Buschur vs stock. The Magnaflow muffler makes this system comprable to stock sound wise. My wife couldn't even tell a difference. I'm also using the stock engine management.

 

If you didn't replace the POS stock down pipe you are not going to see that much of a gain. It doesn’t matter what cat back system you got.
The stock down pipe is such a restrictive piece of junk replace it, and you will notice a big difference.

 

Maybe you're talking about running a complete system? The stock downpipe, from what I read here gives about 7whp? Do you have some before and after numbers or 1/4 mile times with and without the stock downpipe? When you replaced yours did you only do the downpipe? Or did you do other things at the same time? thx

 

I guess I don't understand what you are measuring in the first graph (lb/min). What is lb/min showing you?

 

Look at the stock down pipe and compare it to any aftermarket pipe, that thing is very restrictive. I wish I had a pic I could post up of it. I did my whole system at once so I don’t have before and after numbers on the down pipe. After I did the entire system I gained almost a second on my ¼ mile time. The entire stock system is pretty restrictive, but my money is on the down pipe being the most restrictive part.

 

Mass Air Flow in pounds per minute.

 

Does anyone have any results from a stock Evo vs one with a Buschur 3" catback & 2.5" downpipe?

I wanna upgrade the DP, but I'm not sure which one to get.