cat bolts & high flow cat
 

Hey everyone,

I brought a thermal stealth catback from landspeedracing.com and it should be arriving in the next couple of days. I'm wondering what are the size and length of the bolts that are on the cat. Mine are pretty rusted and i will probably break them when i take the old catback off. I want to have the bolts before hand so i don't have to drive to the store while i'm trying to install the catback.

Another question is should i get a high flow cat or is it a waste? I plan on getting a header, but should i get the high flow cat too? I've read that it makes the thermal sound horrible but doesnt it depend on the company?

yea i'm kinda wondering the same question as well because i would like to do the same.

Well...
The bolts on the 'out' end of the cat are part of the flange--welded on, and you just remove the nut on the exhaust pipe side
(theyre 10x1.25 thread) 3 of them

The bolts on the 'in' end are specialized (8x1.25) Once you get under there you will see what I mean...they have this thingy on them that acts as a stop between the cat and the header. 2 of those.

What you can do, if its too rusted, is cut through the end-of-cat/exhaust flange and then cut the bolts ends off and just replace those w/ stainless grade 8+ nuts and bolts

Dont forget to replace the spings on the header side and dont lose the gaskets (1 per end)

Oh, and high flow cats are optional. W/ just i/h/e on a d16 you wont need it...won't gain anything from it but more noise.

3 bolts between the cat and exhaust is easy enough, is there a gasket between the cat and exhaust flange? or is it only on the header side. you might have said it but i probably misunderstood.

yeah, theres a gasket on both ends of the cat

the exhaust pipe side is a thin ring, dont misplace it or you'll have a leak (trust me)

ok thx pdigg. ill save my money instead of buying the h.f.c. hey, a friend of mine has obx header on his 97 prelude with no complaints. have u heard anything bout them? Its either those or probably dc sports. (i don't want to start another header war in this post thats for sure!!!)

anything and everything obx is crap
dc sports are very nice items for the money (i have a stainless steel dc 4-2-1 unit, myself)

do you think those would be a good investment on a d series engine? i rode in a teg that had them and it sounded awesome and seemed really quick (although i know that's a b18 and it's totally different). Anyone here have good reviews on them?

alright, whats the difference between the stainless and ceremic? besides the look and the price?

ceramic will probably yield a bit more power (its a thermo thing), but wont hold up as long
Ceramic is known to crack, chip, etc and then the metal will rust and get holes in it as a result
a stainless header wont give as much power but...it lasts and lasts
(plus it changes bronze after awhile and just looks pimp- just wear rubber gloves when installing or it'll get purple spots on it from the oil)

ok, ill go with the stainless. speaking of which when i install the exhaust should i wear gloves as well, will the exhaust change color from the oil in my hands?
thx for all your help

gloves are not needed

fyi, i've had a ceramic header for about 3 years now and havent had a single problem.

also if you want something to complement your header get a test pipe and an o2 simulator(for you obdII guys). i noticed a decent difference between it and the stock cat.

I noticed a difference between my stock cat and aftermarket cat...

As did my buddy... we test drove it down the same road 2 days apart... same temperature/time.

Also I got a chikara torkstep header... it was cheap as hell and did wonders for the car.

Nothing but good marks from me... only thing bad would be how ugly it gets... but if you take it off and paint it it would be fine... I'm just lazy.

good choice on the exhaust. i got the classic one for mine. Ya those bolts on the cat are a pain. I ended up havin someone torch them off cause my exhaust came with new ones. Well a high flow cat is nice to have i havent ever heard of it making the thermals sound bad. I think it would help them sound even better than they are now.

u don't need to get a hi-flo cat or a test pipe if you aren't going forced induction

yeah sure, have you ever used one?

um?? no u only need a test pipe for trubo and stuff. A high flow cat u can use it for anything. Why not use a high flow cat on natural asperated? IT doesnt hurt nothin and it acutally helps. Talk to the guys from Hytech. They make very nice cats and they put out some nice gains and they got dynos to prove it

I used to think it was dumb not to have one...but now I think its based on preference. I personally dont think I need one...but since I wrecked mine going over a big speed...HILL...I will probably purchase a carsound highflow to replace it (eventually.....)

ohh only experienced ppl poasting here. yeah a high flow cat will help, even more than the whole I.E setup.

well, the exhaust finally came today. I thought everything would go smooth but i could not get those crazy nuts off. looks like ill cut them on saturday.
btw, for a warning, if any of u buys something from landspeedracing.com, make "SURE" that the product is in stock. They pissed me off saying the exhaust was in stock but after calling them 3 times about it they said that thermal was just making it. They said they give me a discount on my next order but anyways just a heads up!
:mad:

See thats where you went wrong. You thought it would go smoothly. Once you realize that NOTHING goes the way it should, then you'll have a better chance at it going better than worse. Get what Im sayin?
I kinda knew you'd have that problem.....most do. (both things)

(Dont forget to lube the hangers...it really helps)

well the problem is that thermal always makes limited quantities of them, not enough to supply all deman, that's why they runs so huge backorders. i had a customer wait like 4 weeks for a damn thermal