3" downpipe?

[llenrub]

Have hks rear exhaust and standard mid pipe. Will 3"downpipe flange fit this?

Standard mid pipe is not 3". I'm hoping that the flanges will be same size though.

[TBDevelopments]

they usually are, its just the hole in the middle thats different.

Tim
xxxx

[algie]

If it's an HKS Turbo exhaust then it fits. I've got one on.

[matt_mr2t]

Not ideal though as it'll create a bad flow of gasses.

[algie]

Not ideal though as it'll create a bad flow of gasses.

Doesn't seem to on mine. I pulled 204rwhp at 1BAR on Rev2 with this setup.

[Mark Edwards]

Not ideal though as it'll create a bad flow of gasses.

Doesn't seem to on mine. I pulled 204rwhp at 1BAR on Rev2 with this setup.

It's natural that it will. if the gasses are coming down a 3"pipe and then forced into a 2.5" pipe then it'll slow the flow down a bit. Not enough to worry about, but enough if you're after every last little bit.

[Al-sw20]

Mates mr2 still traps 110mph at the strip with a 3" aussie downpipe off his ct20b going into a 2.5" custom exhaust.

[Mark Edwards]

Mates mr2 still traps 110mph at the strip with a 3" aussie downpipe off his ct20b going into a 2.5" custom exhaust.

I bet you if the exhaust was changed for a 3" then the turbo would spool quicker.

[Al-sw20]

His actually spools faster than mine, he has a ceramic ct20b and I have the WRC steel wheeler, however my top end walks over his.

[Mark Edwards]

It's basic physics that it'll be creating a bottleneck in the system, as i said above though, not enough to worry about.

[mr2ash]

Hey,

Jumping on this wagon, does a rouge downpipe fit with a HKS spec Nur

[jonb-]

Am I missing something? A replacement exhaust will be designed to work with the stock downpipie and a downpipe replacement will be design to worth with a stock exhaust so no matter what you've got they should mate...

[Ian Geary]

yes, the flanges and the 3 connecting bolts will mate up.

What the question refers to is the hole inside the pipe.

The downpipe tube diameter is 3" across, the exhaust diameter is 2.5" across.

If you were magically shrunk, and trapped inside these 2 pipes when they are bolted together, you'd see a 1/4" lip around the inside of the pipe as you pass from the downpipe into the exhaust system.

This is the bottleneck Mark Edwards is referring to.

It will make a fast car slightly less fast, and can be removed by purchasing a exhaust system that has a 3" diameter where it joins the CAT (e.g. Apex'i GT, HKS Hiper or Blitz Nur Spec).

hth

Ian

[jonb-]

Ah, thanks Ian, i was missing something