Will a Perrin DownPipe connect to an STi catback ? Does a Perrin DP need special gaskets for the turbo and the catback ends ? thanks guys
all of them from my experience are pretty much standard so it should just get new gaskets if you can. But they all pretty much line up.
Well, that's not entirely correct. Yeah, they should line up, but there might be issues with the flange. The stock (and probably STi) catback does not have a regular flat flange like aftermarket exhausts tend to do, and if the downpipe is made to mate up with one you may need to stack some gaskets and slosh some copper gasket maker on there to seal it up ok. I used the stock 'donut' gasket reversed, the gasket that came with the Helix downpipe, and some liberal amounts of gasket maker before mine stopped leaking.
It's really not a big deal... just something to keep in mind so you're not lying under the car wondering why the hell things aren't fitting right.
is there an adapter i can get and for the turbo side do i have to get a gasket specific for the turbo or for the dp
There is, though I can't remember who makes it. Turbo/DP gasket, doesn't matter. If your DP requires a different gasket than your turbo you have some serious problems. http://www.daddysscp.com/dcart4/cat...et-Flange-Adapter-For-Borla-Exhauts-p-47.html
i ran the perrin dp on my car with the stock catback and it seals pretty good. the one problem you will run into is the offset of the 3" dp to the 2.5" catback. you WILL have a rattle under the car. the problem is fixed by changing the catback to any 3" exhaust.
where is the rattle from and how to resolve it (without changing to 3" exhaust) Im about to get a Perrin DP How do i deal with the CEL prob when i have it installed ? I have AP - will that remove the CEL ? or do i have to do something more
The AP will fix the CEL. Not sure about the rattle; never had that problem and my intermediate pipe is still stock.
I suppose moose is correct it's just that i have done three wexhausts now one on an o4 sti and one on an 04 wrx and 06 wrx and ihad no issues, All I did was mate the flanges up with a gasket and put the bolts in before we hung the cat back and had no leaks but it;s posible of a slight varience in angle on the two flanges.
moose can you tell me what parts you use for the gasket between the DP and the stock int.med pipe (resonator pipe) you mentioned using a combo gasket
This worked for me on the Helix pipe. I took the stock gasket which is almost like a donut shape. Reversed it and pressed it into the Helix downpipe flange (it'll squeeze partway into the pipe). Then took the gasket that came with the downpipe and used as intended between the flanges, and coated it very liberally with high temp gasket maker (the copper stuff) on both sides. Bolted together tightly and let sit for a while.
i retract my statement. thinking about it, the rattle came from doing vice versa. with the 3" dp you will have penty of clearance. I remembered that i put the 3" catback on before the dp, that created the rattle. sorry for the bad info before.
moose provided me a great solution and illrpobably go that route. Like to ask one more q / option I have all the parts either in the garage and waiting for my PPC exh manifold (crucial). So its easy to mod the DP to Int pipe. I was thinking maybe cut the doughnut flange and weld a flat flange - that way i can use the stock catback with no difficulty. What do you think ? Is the flat flange fairly easy to find for the int pipe (sti)? Is it 2.5" ?
Can someone let me know if i can get a 3" flange gasket locally from auto parts store ? Someone said to look for truck/bus exhaust gaskets