Chip398193

I have a 95 ls, soon to be boosted via drag 3. i'm going to buy a 3 inch thermal, but i'm not sure what to do about meeting my downpipe with my exhaust. i know i dont want a cat. but i also don't have enough money to buy a flex pipe. I just want to get a cheap test pipe and put it in there until i have money to either buy a flex pipe or buy a bigger dp with a flex already in it (art's maybe?). i was just curious....whats the worst that can happen. could it crack my manifold?

Ri5e

You need a flex pipe. Especially if you have like a really grabby clutch and u like to shift hard. It puts a lot of stress on the downpipe bolts and manifold everytime u shift. My frend stripped the bolt thread holes on his turbo cause he had no flex. He had to get it welded and retapped. Get a flex pipe and u'll be happy

dbman96

You can buy a flex pipe for like $10 at pep boys. It may not be pretty stainless steel braid covered, but it's the same stuff they use underneath the stainless jacketing.

bigTom

http://www.roadraceengineering.com/exhaustparts.htm

if u can afford a turbo kit dont tell me u cant shell out another $60 for a flexpipe

BlueShadow

Sayang,

I think even this kind of pipe would end up causing damage. it'll have plenty of left-right and up-down movement but it doesn't look like it'll have a lot of front-to-back movement, and that's were you want the most "play".




[Modified by BlueShadow, 2:47 PM 4/1/2002]

CovertFI

i have the cheap flex pipe from RRE. it is 20 bucks for a foot. works good. all it takes to install it is two exhaust clamps. really cheap insurance for down the road

CovertFI

that is why your exhaust is on rubber hangers


[Modified by CovertFI, 2:49 PM 4/1/2002]

dbman96

I was going to say... those $60 braided SS flex pipes don't exactly have a lot of give in the front-back direction either.

BlueShadow

That's not what the hangers are for, they might help a little bit, but even with rubber hangers a non-flex piped exhaust system is still gonna be under a lot of stress.

EDIT: in that case why do almost all cars have flex pipes? I don't think its cause they look purty....




[Modified by BlueShadow, 3:11 PM 4/1/2002]

CovertFI

"Sayang,
I think even this kind of pipe would end up causing damage. it'll have plenty of left-right and up-down movement but it doesn't look like it'll have a lot of front-to-back movement, and that's were you want the most "play"."

hey mr smarty pants! did you read the quote?? he was talking about "front to back" movement.

BlueShadow

Hi I'm BlueShadow and the guy you're quoting is me BlueShadow!

I dont know what you're getting at, The hangers are there just for that, to hang the exhaust from. Its rubber cause it has to prevent any vibration from getting to the car body.

By not installing a flex-pipe or by installing a pipe like the one in that pic and relying on just the rubber hangers to counter any movement is asking for trouble.

that piping in the picture can be moved around like a snake-light but It looks like it wont "stretch" from front to back.

CovertFI

o, lol i did not notice that was you. but any way i never said anything contradicting you about adding a flex pipe!!! ****, they are good! you need them! i agree with you, all i was saying is that is one function of the exhaust rubber hangers is so your exhaust can move, because there is nothing to let it move front to back. also you would not have any vibrations if your flex pipe was able to move in all directions!!

also before i had a turbo my exhaust never had a flex pipe and it was stock!!!!!! it had a little joint that was held on by two bolts with springs!!!! this allowed it to move left, right, up, and down, but not front to back. so that is why you have rubber hangers.

BlueShadow

I would get your turbine housing checked for cracks if I was you :D j/k

like I said though It might give a little, but I wouldn't recommend running a non-flexpipe exhaust permanently.

CovertFI

not sure if you understood, i ment when i had all stock exhaust, no turbo, no nothing.

i would at least get the cheap **** from pepboys it is like 10 bucks less than at RRE. the only diffrence between the two is RRE is much thicker, and will last alot longer. i promise you, you will hear squeaking if you don't install some kind of flex joint. that will be the sound of broken exhaust welds and sheared bolts.

X2BOARD

You don't want to even think about using the rubber hangers as anything beyond the limiting vibration reaching the chassis... some people may tell you that the hangers will do it justice, but, from logic and real world situations... it's not a viable alternative.
No flex pipe (to also answer the post) will result in the motor (I will asssume you have stock mounts all around) will be twisting upon acceleration and deceleration, which will eventually looseen the bolts on the DP, manifold and maybe even the turbo housing itself (I've seen it)
You should really get a flex pipe., you can use it to ditch the cat and weld on, basically, a staight pipe from DP to exhaust.

dbman96

I repeat - how much does that $60 braided SS flex pipe "stretch" front to back? If it didn't cost $60 I'd tell you to go slice thru that SS braid so you can see the EXACT SAME PIPING beneath the SS cover as you see in the picture above. There is no such thing as "stretchy" exhaust pipe. If you find some, let me know.

CovertFI

WTF who said anything about the rubber hangers being good enough? read this whole thread over again

RGAZ

Underneath the braid is an accordian like structure which can compress but not stretch. So it does limit the "front-back" movement you need by compressing.

That is why eveyone uses it. that flex pipe you see in the picture is only to make bends easily. It does not compress easily.

So, to recap: there is no such thing as "stretchy" exhaust pipe, but there is "compressable" exhaust pipe which has an accordian shape. You can buy them for about $60 from JC Whitney.

Randy


[Modified by RGAZ, 1:18 PM 4/1/2002]

CovertFI

either way it can't move much back and forth (much), SO that is why we have rubber hangers!!!!! if it could move you would not need hangers becuse there would be no vibrations transimited to the rest of the exhaust!!! ok


[Modified by CovertFI, 6:30 PM 4/1/2002]

Finest

I believe the rubber hangers and the flex pipe BOTH help support the exhaust system when the engine moves under acceleration and decelerarion. The flexpipe seems to be designed for compression and vertical movement. (Engine rocking forward and tilting the DP downwards, and when it tilts back and brings the DP up) The flexpipe accounts for that vertical angle movement. The rubber hangers seem to control the horizontal movement.

Any more arguments?

X2BOARD

1) I said that
2) I read and re-read the post just to amuse you... read on 'smarty pants'


I don't quite see your logic as to how you expect the rubber hangars to absorb this 'back and forth' movement ?! A flex pipe is capable of bending in all deirections as related to it's position, this is what it is designed for.
The small springs on the bolts of your stock exhaust are called a flex joint and are designed to work WITH the exhaust hangers to counter engine movement being transmitted to the rest of the exhaust system. Hangers offer a counter and a cushion to the pressure being absorbed by the flex joint as well as absorb excess vibration and sway (stock exhaust). They (hangers) are not meant to absorb the movement of the motor even near the degree OR direction that you say.
I believe you can all see that a flex pipe does not only absorb left and right movement but more so the back and forth motions (motor tilts toward you or away from you, use your imagination) ... the FP esentially redirects the movement to lessen the degree of movement transferred to the rest of the exhaust system and ultimately, back to the motor. The reason turbo motors should always have a FP is
1) They create more torque
2) They enhance the pivot point of the system,
as there are more weak points in the exhaust system (manifold to turbo to DP to FP to B to muffler) turbo housing and DP being the parts that would absorb the most torque..
Stock Honda motors do not come w/ flex pipes because they do not create so much low end torque to warrant the use of one... thus a flex joint is acceptable.


Cliffs notes... if you don't have time to read, get a real flex pipe and think of rubber hangers as hangers and nothing more...

The be all and end all is that you should use a FP if you care about your turbo, manifold, motor mounts... ah, whole setup's lonjevity... otherwise you will be classified as an *** Clown, so just Fedex your turbo and manifold to me to save you this hassle


[Modified by X2BOARD, 2:45 PM 4/1/2002]

BlueShadow

I had a dog, his name was Fred...He was a good dog.

Malachi

Is Fred dead?

JMinSi2000

So where do you want to put a flex pipe if you dont want it where it is pictured in that pic?

BlueShadow

**sniff** **sniff** yah Fred is dead...I like donuts.

derherher...

I musta been delirious or something last night, either that or someone is having fun with my password. yah thats it... :D

BTW Malachi I got your e-mail yesterday, but I couldn't open it on microsoft works spreadsheet or microsoft Excel. what was it supposed to be?