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ST165 Turbo Downpipe

PostPosted: Mon Aug 25, 2008 2:52 am
by chkpnt
Has anyone ever considered using the stock cast manifold that bolts to the exhaust side of the CT26, unbolting the cat, and making a new pipe with a reducer to replace the cat? I took mine apart today and this seems like it would be a very easy/cheap/logical way to remove the first cat from the exhaust equation... I'm really thinking about trying it...

PostPosted: Mon Aug 25, 2008 5:24 am
by Dracov
There's some examples of that on the exhaust tuning page here:

http://www.alltrac.net/tuning/downpipe.html

PostPosted: Mon Aug 25, 2008 5:51 am
by chkpnt
Very cool. Thanks for the link!

Here is basically what I am thinking about doing except I'll retain the stock cast piece and bolt my creation to it in place of the cat...

Image

PostPosted: Mon Aug 25, 2008 11:36 am
by Jason88AllTrac
You're not the only one who thought that was a good idea. You get around the issues with the aftermarket downpipes like KO (and others) hitting the alternator fresh air duct and it might be cheaper to make. In exchange you don't have a very ideal bend coming off the turbine and also a chamber that enlarges right after the turbo decreasing exhaust gas velocity and again possibly hurting airflow slightly.

Image

PostPosted: Mon Aug 25, 2008 12:36 pm
by Dracov
Personally I would kill to have a well-made rerouted divorced downpipe

PostPosted: Mon Aug 25, 2008 3:30 pm
by chkpnt
I think I'm going to try it... A friend of mine owns an exhaust shop and can easily make all the parts I need except the flange. I designed a CNC water jet / laser cut file for that last night so it should be good to go. I'll make the first one and figure out how it works and how much it costs. If everything works out I might consider making a few more for anyone interested. I have a feeling the flange may not be cheap though.

Re: ST165 Turbo Downpipe

PostPosted: Sun Feb 09, 2020 4:36 pm
by Rick89GTS
12-yr post revival! Lol
Did you ever get this made?!
Edit: his last visit was 2012. Prob not in the AllTrac scene now :(

Re: ST165 Turbo Downpipe

PostPosted: Mon Feb 10, 2020 1:49 pm
by hoys
Necromancy!

Well if it helps I have a ST165 specific catless downpipe if you are searching for one!

Re: ST165 Turbo Downpipe

PostPosted: Tue Feb 11, 2020 8:51 pm
by Rick89GTS
Haha, back from the dead!
You have an ST165 DP with the 4-bolt flange? Sure, what make is it and can you send me a pic please?