Ok, so looking for someone more experienced then me for a little insight before install day(next sunday)

I have :
skunk 2 Tri-y Alpha b-series, came w/ :
extra flange, donut gasket, bracket, 2 bolts nuts and washers

Test pipe w/ flanges and bungs to weld highflow cat. (no gaskets or hardware)

apexi ws2-
3 gaskets (2 2 hole 1 3 hole) 4 bolts nuts and washers.

So, with all that said, I beleive I need 5 bolts, with nuts and washers to connect the custom cat to the header / cat-back.

Do I need to get a new gasket for my exhaustmanifold to head? and what size bolts do i get?

first time Im doing a full exhaust system replacement at once, and not looking to have to run out to the store

before anyone says anything, I have an engineer to do my welding and fitting the tri-y to cat + test pipe.

 

new exhaust manifold gasket to the head would be recommended. i'm surprised it didn't come with one(unless you bought it used).

i usually replace the fasteners when I work with exhaust. if it has a donut gasket, i would highly recommend using the factory type bolts with springs so that you have that little bit of flex if necessary.

If the mating surfaces are flat flanges and they are threaded, just find a bolt long enough to go through and thread in as far as possible. If they aren't threaded then figure out what size the hole is and get the closest bolts to the diameter of the hole that will fit and the appropriate washers and nuts.

 

its 2.5" collecter, and 60mm on the cat back side, can i just go to honda and pick up some hardware?

 

just go to a hardware store it's 80% cheaper lol I did that once just for lols(buy bolts at the dealer) got laughed at when I spent 35$ for 2 bolts

 

what size should i get (length wise) id imagine 13mm since everything normally is on these?

also would it be smarter to go to a napa / advanced to get the exhaust mani gasket ?

 

length wise I'd say 3-5'' the flanges are thicker on aftermarket exhausts header's. usually an M10 bolt fits good/won't brake just grab some springs to allow for flex. yah don't know where else you'd find one.

 

where can i find the springs? pick them up from honda/autostore w/ the mani gasket?

and is it just the mani to cat that needs them?

 

OEM style, did your header not come with a doughnut gasket tho ? yah just make sure they're thick.

 

My header came with the donut, i just want to make sure i do it right and have everything i need the first time. I have plenty of experience driving built cars, (built h22a, ej25, ej20) but this is the first one I will actually be getting hands on and doing myself rather then allowing a performance shop do it. (thankfully i have very good engineer/ welder /mech to help i just want to have everything we need to do it right first)

 

I guess the only thing left to answer (and thank you for the help) is will i need the spring bolts on just the front of the cat? or on front and back, I do still use them even with the donut gasket provided right?

 

Is it a stock cat? well anyways I think it doesn't matter what kind of screws you use to bolt on the cat.

 

just the front and yes you need the donut gasket it makes it all seal up.

 

Ya, thanks for the help will be doing the work tomorrow after work.

 

Due to scheduling conflicts we weren't able to do the install I till after work today. Including the time to cut and weld it took about 5 hours. 35 minutes of it was fabricating stock hanger to fit.... Only to find the provided skunk 2 hanger after fab was done(cut and welding to fit- 2&3/8" over 1" up)

The other time sink was welding the cat to test pipe-
After getting all the old off, and getting the alpha tri-y mounted. We welded a flange directly on one side of the cat, use 3" and a scounch (less then 1/4") of the block test pipe outlet to the outlet of the cat and drilled in an o2 bunch.

The cat back was a sinch, had bang down the hangers on the a pipe so it would line up w header/cat.

Sounds extremely close to stock w the stock intake, next week putting on CT eng. icebox (it was finally shipped after a back order on the cold air pickup)and maybe chipped ecu for a street tune.

 

i usually replace the fasteners when I work with exhaust.

 

Get a little bit of a Ping from underneath. Can't pin point where yet, any ideas?

 

MAKE SURE YOU GET THE EXHAUST BOLTS WITH SPRINGS ON THEM WHERE THE HEADER CONNECTS TO THE CAT CONVERTER...NOT JUST REGULAR BOLTS AND NUTS. I DID MINE LIKE THAT AND THE MUFFLER SHOP SAID IT HAD TO HAVE THE SPRINGS SO IT COULD "FLEX"

 

Ya replaced all bolts but exhaust mani bolts. Used sprigs at the collector, can't quite figure out why I'm getting a ping, it's not very loud, and I imagine it's from the movement of the exhaust under load. It just doesn't settle w me completely.

 

Rear o2 sensor was smacking the under body heat shield. #fixed