i have JDM headers and a 2.5' carsound cat, i connected those 2 with grade 8 bolts that are 3 1/2 inch...i also put the stock springs on there so the tension can be less...but now i hear them squeaking and they are making noises now...what kind of method did u guys use to bolts ur header JDm and CAt...need help fast!!

 

The stock bolts wouldn't seal my test pipe to the donut gasket very well. The "foot" hit the flange on the header before the were adaquately tightened down. I just bought plain old bolts, and compressed the spring quite a bit, but it is coming loose again. I would also like to hear how people have dealt with this.

 

There're some ways that constuction industry use to prevent bolt from getting loose. I dunno if they can be applied to cars tho.
One way is to tag weld the nut after tightening.
Another way is to damage the thread after tightening.

In case you need to remove those bolts in the future, just cut them off.


[Modified by Wai, 12:36 PM 11/1/2001]

 

You could also try high-temp thread lock.

 

Some red loctite maybe? I used them on my swaybar install heheh

 

I believe the spec is 16 lb-ft but you can tighten them snug but just make sure you don't coil bind the springs. Your bolt length is correct. But 2 extra nut and just double nut the bolts. My kit consists of the (2) 90mm bolts with 4 nuts and 2 washers and (3) 10mm x 40mm bolts with nuts for the b pipe. Double nutting is better than a lock nut since they are a lot easier to take off, time wise.

 

I would make sure you know what is making the squeaking sound.

I have the SAME EXACT PROBLEM, however, it turned out my O2 sensor ont he carsound cat. was rubbing the upper metal shield attached to the car. That was causing the squeaking.

So I would look under the car and make sure you know where the squeaking is actually comming from.

 

****, I put anti sieze on the damn things so that they wouldn't be hard to get off. Ha, that's probably why they're loosening.

 

Im sure this is where the squeaking sound is coming from because it happeded to me before and i went under the car and tightened everything...on each nut i have 2 sets of washers, lock nuts and a big washer so the spring can compress against it...it looks exactly like the stock setup.....i also have 2 nuts screwed against every bolt so its tight...but still i hear the damn thing...i asked around by just using a regular nut and but...but i heard that it has to flex...and if it doesnt it make crack off...im gonna go under the car soon as soon as it coold down...i dont wanna get burned.....ANY OTHER ADVICE on what i should use or do?...is this a common problem also??

 

Hmm, I dunno, make sure nothing is rubbing. When you are done there give the pipes a good tug and see if you can replicate the sound.

I am using the same setup as you will all my bolts replaced (no stock bolts being used).

TypeRmsm has some good tips/suggestions on bolt sizes, etc to replace the stock ones. I will toss him an IM and see if he can post reccomendations.

 

Use the 4" (or 4.5", i forgot) ones... they are longer, so u have more thread to play with... they worked fine for mine...

 

did u guys use the stock springs that were attached to the stock bolts?...

 

90mm Length bolt Grade 8 12mm bolt into 2 fender washers then stock springs through cat then through header, followed by flat washer, lock washer and a nut, Tighten down until the spring is compressed to about 1/8-1/16 of an inch between each coil. When finished install another nut which will keep the other from loosening

 

Hey Mike..i bought the Carsound Cat from you...but the nut keeps on popping out...you wouldnt happen to have a picture on how the setup is suppose to look like?...this would be very helpful...also i as going to go buy some kind of lubricant that seals the thread of the bolt...its called something 271???...my setup is grade 8 bolt, then flat washer, then stock spring, then another flat washer so the spring can be compressed against it...then on the header side i have 2 small washers, 1 lock nut, then 2 regular nuts...but damn thing keeps on popping out..post a pic if u got one..thanks..

 

Sorry no pics, just follow the instructions i posted above, The nut wont come loose if you put a 2nd one after it.. You can also try some loctite, but not needed and i doubt it will last with the high temps

 

wow... u got more bolts than i do... i dont have any problems w/ mine tho... i did exactly as mike described... and it works fine...

 

im just plain stupid....this is what im doing...got a 3 1/2 grade 8 bolt...stuck a flat washer threw it..then stock spring....then stuck it in threw the cat side and other end popped out of the header...then on the header side added another flat washer, then lock nut..then 2 nuts....hope this works....what u guys think...am i good to go?

 

How tight did you put it? Should have the spacing in the coils as i explained above

 

Doesn't the spring go between the cat flange and the header flange?

 

i have some space...so should it be fine?...

 

No, my first post describes how it should be

 

the springs are pretty well coiled up and very tite....

 

i think i need help...any shops u may reccommend here in the bay area?...