View Full Version : URGENT: Flex Pipe or no Flex !!!
i got a BC III exhaust on atm, and im running no flex. going to the exhaust shop tomorrow to install one.
however the guy said there today that i might not need one cos the BC III designed using the spring joints rather than clamp and that has enough flex as the flex pipe??
tomorrow i am going in to get my pipe shortend to fit the flex and the spring joints will be welded together (spring vibrate and its annoying me)
what you guys recommend? i will be tracking this car so it will be going pretty hard when i do. dont want a crack header or anything a long the way
EDIT: also i have no room between my header and cat so my flex pipe will be installed between my car and my b pipe. would that be as effective or usless?
EKVTIR-T
10-12-2007, 04:59 PM
Ive seen a few Ek and Em1's with cracked header welds because of no flex joint but the donut flanges come from Honda like that so it's hard to say.
The donut flanges are supposed to serve a similiar purpose to flex joints.
ek4-guy
10-12-2007, 05:03 PM
i'm just using the honda donut with my toda's
flex joints are also known to leak
Kiz_EG6
10-12-2007, 05:22 PM
Definately go the flex, my cat broke clean off the header in my B16 EG coz i didn't have any!!
hmm ok . well then my qns goes
"i have no room between my header and cat so my flex pipe will be installed between my car and my b pipe. would that be as effective or usless?"
ACTI0NMAN-1
10-12-2007, 10:47 PM
hmm ok . well then my qns goes
"i have no room between my header and cat so my flex pipe will be installed between my car and my b pipe. would that be as effective or usless?"
will still be effectiive.
i got a BC III exhaust on atm, and im running no flex. going to the exhaust shop tomorrow to install one.
however the guy said there today that i might not need one cos the BC III designed using the spring joints rather than clamp and that has enough flex as the flex pipe??
tomorrow i am going in to get my pipe shortend to fit the flex and the spring joints will be welded together (spring vibrate and its annoying me)
what you guys recommend? i will be tracking this car so it will be going pretty hard when i do. dont want a crack header or anything a long the way
You don't need a flex as long as the Headers and Exhaust system are hooked on correctly. The Donut+spring joints are designed to provide movement and flex.
The headers themselves should be correctly bolted in place and move with the engine. Alot of exhaust shops get lazy and don't secure the headers properly.
The Exhaust system should be free hanging on rubber.
Example, at the Ozhonda track day, my system came off the rubber hangers and dragged, swaying on the ground for 2 whole laps...So that means it was only holding onto the headers, but because my headers were correctly mounted (Thanks Toda :angel:), nothing was harmed except my exhaust wrap.
hmm yea thats wat that dude today told me. my exhaust is hanging on the rubber handers and when i push it it does move a bit and the exhaust joints do bend.
what do you guys mean by the donut+spring joints?
like a smaller pipe fits into a bigger pipe and bolted on freely by 2 springs on each side?
Kiz_EG6
11-12-2007, 07:28 AM
You don't need a flex as long as the Headers and Exhaust system are hooked on correctly. The Donut+spring joints are designed to provide movement and flex.
The headers themselves should be correctly bolted in place and move with the engine. Alot of exhaust shops get lazy and don't secure the headers properly.
The Exhaust system should be free hanging on rubber.
Example, at the Ozhonda track day, my system came off the rubber hangers and dragged, swaying on the ground for 2 whole laps...So that means it was only holding onto the headers, but because my headers were correctly mounted (Thanks Toda :angel:), nothing was harmed except my exhaust wrap.
...so from what you are saying, a small inexspensive piece of flex pipe could have saved ur potentially expesive exhaust system and possible damage to your engine/mounts??
Remind me again why it is not important?
In case you didn't understand, the donut and spring flange is already a flex joint.
dsp26
11-12-2007, 07:40 AM
depends on the quality of the donut joint that the spring bolts function.
A lot of aftermarket headers don't have a proper one, but rather just a 1-2cm extension of the collector past the flange as a makeshift donut joint. If yours is like that then get a flex
^^ .my header is custom and it has no spring bolt its one piece.
the only spring joint i have is on my exhuast and thats on the b pipe just before it starts to bend. then they is another one where the axel starts. so total of 2. but its no way near the header. more at the rear of the car
my frnd said that should work fine also, nothin to worry about even for track
dsp26
11-12-2007, 08:12 AM
if you don't have any spring joins between the cat and header then get at least a small flex.
it's because your headers will be bearing the weight of your entire exhaust system when the rubber hangers fail.
GENERALLY, if you have solid engine mounts or torque damper also you don't flex, since the rocking backwards/forwards of the engine is negated and the exhaust system isn't forced into angles. this engine rocking while the system is soft n hot is the primary cause of breakages
^^^
if thats the case, then you should get a flexi joint just after the headers.
hmm alright will look into it. prob is i have no more space after my header and the guy there said its no good cutting it cos the previous guy didnt do a good weld job.
so a flex pipe can only got between the b pipe and cat. would that still be effective ?
Should be alright as long as its closer to the headers.
BlitZ
11-12-2007, 08:38 AM
u dont need one... just make sure u dont have a broken engine mount.
just make sure u have the spring joins
Blitz u think i dont?? i have no flex in my header atm and i dont have an engine torque damper or anything stock mounts.
only flex is at the rear of the b pipe
BlitZ
11-12-2007, 09:40 AM
Blitz u think i dont?? i have no flex in my header atm and i dont have an engine torque damper or anything stock mounts.
only flex is at the rear of the b pipe
u have no spring joint dounut thingo before cat? most aftermarket honda headers have the donut join there... u need one there...
you dont need a flex at the end of the b pipe... end of bpipe is above/near rear control arm?
u dont need a torque damper... just make sure your rear mount isnt mashed up and is in good condition.. better yet.. sikaflex it...
have you seen JDM ITR headers crack on the DC2R... stainless with no flex pipe.. only spring joins
dsp26
11-12-2007, 09:54 AM
have you seen JDM ITR headers crack on the DC2R... stainless with no flex pipe.. only spring joins
but thats why he needs the flex... coz he said he doesn't have the donut or spring joint in the correct location which is header to cat flanges.
it's hard to fill the rear mount without taking it off and it is a pain in the arse to remove.
BlitZ
11-12-2007, 10:46 AM
but thats why he needs the flex... coz he said he doesn't have the donut or spring joint in the correct location which is header to cat flanges.
it's hard to fill the rear mount without taking it off and it is a pain in the arse to remove.
opps.. didnt read everything.. if u got nuthing either between header-cat or cat to bpipe... then u need one..
And fark.. the exhaust man who made it should be shot:thumbdwn:
how did he not cut the headers and not have a dounut?
lol
previous exhaust had a flex, it was cut off to make way for my new exhaust.
all good
went in yesterday to get a flex in between my b pipe { }==[ ]==( )==
kinda like that drive lol the [ ] is my flex and the { } is my cat abd tge ( ) is my resonator
so should b ok now right?
dsp26
12-12-2007, 07:45 AM
so your headers are to the left of the cat? is your cat permanently welded to the headers?
flex is optimally located between header collector and cat... either way one is better than none.
What size length and diameter? And How much?
Limbo
12-12-2007, 01:06 PM
you should get one there is alot of movement in the engine bay especially when launching. You'll regret it if you don't and you can even get a short flex
so your headers are to the left of the cat? is your cat permanently welded to the headers?
flex is optimally located between header collector and cat... either way one is better than none.
What size length and diameter? And How much?
yeah its on the left.
and yes my cat is welded on my header.
i got a 6inch 2.5" flex to fit my 61mm piping.
should be ok i guess? i mean its probably not the best position but like i said i had no space left in between my cat/header
dsp26
12-12-2007, 07:26 PM
fair enough. better to have one than not... though my headers came with a 2inch flex (the mesh part measures 2inches) so i thought they were commonly available... all good though... you may have just saved yourself spending double on exhaust system :thumbsup:
blk_shadow
13-12-2007, 10:02 AM
damn, mine's also welded onto the header with no flex pipe
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