Stillien Downpipe problem

[Knight2040]

alright, i'v been trying to install this frickin thing for the past week. i have all the bolts lined up except one on the rear bank. It'd be easyer to show pictures rather then explain it.

Okay first off, is the pre cat suppose to be like this? it looks like its been hit and bent off.

And second of all this is my prob, the bolt comes down in BETWEEN the two mounting holes, i'm not sure if this is becuase of the bent precat or not. has anyone experenced this? i was thinking about getting a DNP Rear precat eliminator from 3SX. the DNP bolts directly to the Stillen right? do yall think this will solve the problem? how difficult is it to remove the rear precat? getting the pre cat eliminator would be wise (performance wise) anyway right? (no emmison testing here) Please HELP!!!!!!!!!!!!!!!!

Yes, i did paint my downpipe blue

[Hotshot8792]

mine bolted up fine, if your precat is bent wrong, i'm sure that could have something to do with it

[Knight2040]

has anyone bought the DNP Rear Precat eliminator? if so, how hard was it to remove the precat and install the DNP?

[Knight2040]

bump, comon, has ANYONE ever removed their rear precat before? can it be removed with the engine still mounted? anyone have a digram, ahhhhhhhhhhhhh, lol sorry i need to kno so i figure out if i can do this myself

[Gateway]

i would help if I could, but I haven't bought my stillen downpipe yet.

fyi, is the pipe easy to install (set aside your alignment problems) ?

[Igovert500]

http://www.team3s.com/~egross/3S/Mod...tDP/index.html

This site mentions a similar problem with fitment of the stillen downpipe:
"Remember to use new gaskets, and put anti-seize compound on the nuts/bolts when you install the Stillen pipe. If you have a 1991-1993 model, it should be really easy. If you have a 1994+ model, you may need a BFH (Big Frickin Hammer) to coax the front connection on - put the rear bank connection on first. I even had to drill out the holes in the rear bank connection a little to make mine fit well. Drilling stainless steel sucks... use a titanium bit and lots of cutting oil to keep it cool."


http://www.monninengineering.com/Downpipe.html

This site also mentions that alot of people have fitment issues with the Stillen Downpipe...so I'm thinking that it isn't that your precat is bent, but that the downpipe is the problem:
"I recently had a Stillen Downpipe fitted to my 1999 (GCC specs) VR4 and after reading
about the slight misalignment many on the list had mentioned, I would like to confirm
the following. The Stillen Downpipe does not match the position of the original
downpipe. Using a plum-line and felt pen to mark the chassis, the position of the
Original downpipe was marked and we proceeded to fit the Stillen (no extra drilling
etc. was required), sure enough it did not line up with the HKS exhaust. Using the
plum-line again on the Stillen, I can confirm that the Stillen is 2cm to the left of
the original. As we could not bend the Stillen, we had to move the HKS to match, the
result is (especially on start up) the HKS system now hits an exhaust mounting bolt.
With just the HKS matched to the original downpipe, I have never had any knocking
sounds. The misalignment is visible by looking at the mounting rubbers on the first
part of the HKS system, instead of coming straight down, they are at an angle of about
45 degrees. I therefore agree with many on the list, "Stillen" Downpipes require
modifying before they fit our cars properly."

As far as getting the other precat eliminator, I think it would be a good idea to at least gut it, if not eliminate it, so that air is flowing out of the 2 at similar speeds, and not being significantly more restricted on one over the other.

Most of the things I've read regarding gutting the rear precat say to leave it on, as it is harder to remove than the front, because the rear is actually part of the exhaust manifold.

I personally havn't gutted my cats yet, so I really can't help you much with personal insight...sorry, but I hope this at least helps some.

[Knight2040]

yes it did help some, at least i kno that i'm not the only one who has to modify the pipe to fit, but they seem to refer the offset on the rear of the downpipe to the exaust. well i guess i'll try some more grinding....but it would still be nice to have a rear precat eliminator, they are larger in diamiter then the stock o2 sensors right? i just need to know if i can remove the stock rear precat while still mounted on the engine. if i have to pull the engine, then i'll just gut it. thanks Igovert500 for the info.