i didn't receive ANY hardware with my downpipe, do i just need to use the existing hardware?

it's the HKS mildsteel 3", for a '94 auto.

 

Unless you strip them, I dont see why you wouldn't be able to use the existing studs on the exhaust manifold.

Just make sure you drench them with WD-40 for a few hours before taking them off.

 

You'll need a gasket from the downpipe to your catalytic. It costs 8 bucks at any mazda dealership.

From the manifold to the downpipe. I re-used the one that was on my precat. If you want to get one, it's around forty or so bucks.

As far as for bolts, I had a hard time with mine because the two bolts hooking up on the manifold, the upper left and lower left (if you are looking at it dead on from the passenger side of the engine bay) side was too long and it was hitting the downpipe. I also had problems bolting them in because of the limited space. I had to cut mine down to make them bolt in. The bolts for the downpipe to cat, I reused

I thought this was easy. It was a pain in the *** but all worth it.

Laters,
Jason

 

I would not use the stock studs when putting it back on. I would back those studs out and buy some high dollar bolts. If you have a 93 just keep in mind that they are 8 years old. Plus the way the nuts are shaped, it's verry easy to round the hell out of them

 

thanks for the tip, i just wondered if you new what the dimensions are on the bolts i need to replace the studs with.

THANKS!!!

 

just pull the studs out and bring it with you when you get new ones. I think it's either 2" or 1.5". Not exactly sure. I had some that I took off but I threw them away, sorry

 

i am currently in the process of installing my HKS DP. i had one stud come out on me when removing the pre-cat, so i ordered another $13 Mazduh!! stud, along with 4 of the $5 nuts. i put my $13 stud on by screwing a nut onto it (not one of my $5 ones) then screwing it into the turbo, but then it kept coming back out whenever i would try to back the nut off. then i ended up screwing up the $13 stud when i took the nut off!!!

so then i went to Pep Boys and got 3 (a few extras ) M10 x 1.5 x 42mm studs for $1.90 each, which looked exactly like my $13 Mazduh!!! one. even the length was the same. although the $13 Mazduh!!! stud was a mm or 2 shorter than the original one that screwed out of the turbo. but it's close enough in the length. so to recap:

the size of the stud is an M10 (10mm) x 1.5 (thread pitch) x 42mm (length).

if you're gonna remove the studs & go with straight bolts, you'll probably want one that is no longer than 42mm. i was considering going this route, but i was scared that one of the studs might break off on me instead of just backing out

 

i really appreciate all the advice. hopefully, everything will go as smoothly as most of your all's have. thanks again, AND GOD BLESS THIS FORUM!!!

 

Definetely go with the bolts. I also have an HKS DP and it was no trouble putting it in. With the bolts if you have to remove it later for some other mod it will be easier than with the studs. I was lucky that when I removed mine (I drenched then in liquid wrench the night before) the studs came out with the bolts. Use some type of lubricant the night before and it will make it a lot easier. Also use it on the ones going to the cat, those were harder to take out.