Minimum exhaust size? 1-7/8" okay?

[saturnv7890]

Definitely a different question than usually asked, but the issue is I am doing an m42 swap into my 2002, and the car I bought came with a nice new midpipe:

LINK TO MIDPIPE

And it is 1-7/8" diameter. I will have good headers from the engine, going to a 2.25" "downpipe" which will then be reduced to this pipe you see here.


The reason I am doing this is because of simplicity, budget constraints, and quietness. Will I run in to any issues? Will this backpressure cause a severe loss in power?

[saturnv7890]

Here is the car for curious parties:

[roguetoaster]

If it's a budget concern I'd imagine that a 1 7/8" pipe would work for now. Ideally the M42 is designed for a system somewhere between 2-2.5 inches, yet I have seen many M42s with poorly bent, damaged or hacked up exhaust systems that may restrict flow below 2 inches without seemingly harming the car.

That said, if you are already doing that amount of custom work to make the front fit the mid pipe I'd try to scrape a bit more together and just do a complete system and not allow a new $70 part to dictate design.

Neat '02 in any case, if I weren't addicted to the burbly sound track of the 32/36 Weber equipped lightly cammed M10 with headers in mine I'd put in an M42.

[saturnv7890]

Well I suppose I'll throw a flange on and make it a temporary fix for now, thanks for the reassurance!!

[Old city bimmer]

My next favorite model after my E30


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[saturnv7890]

Gonna be my first 02, really excited to get this thing on the road!