JohnnyWadd Posted July 28, 2013 Report Share Posted July 28, 2013 I am rethinking the flex pipe install location. Downpipe or past the downpipe? Last time I did downpipe, here my logic was get it close to the engine so to stop vibration from moving back right away. Also for the reason that the flex gets chewed up easily downstream and because of that sharp bend where the downpipe heads back can sometimes catch, so have the flex up stream of it lets it move without stressing the s*** out of the exhaust manifold. But as far as vibrations I am thinking now that downstream is better because the flew section does not really compress but bends side to side (right??) and in the downpipe it is being forced to compress which would send engine vibrations down the pipe. What do you guys think? Link to comment Share on other sites More sharing options...
Convette Posted July 28, 2013 Report Share Posted July 28, 2013 (edited) buy a funk lock, no need for flex pipe. If your motor cant move, neither can your exhaust. Edited July 28, 2013 by Convette 1 Link to comment Share on other sites More sharing options...
JohnnyWadd Posted July 28, 2013 Author Report Share Posted July 28, 2013 buy a funk lock, no need for flex pipe. If your motor cant move, neither can your exhaust. Been there done that with the hard Stedebani trans mount. I just want it optimal for overall. I mean if I want to run a OEM engine mount. Also having it flex if it hits something and not stress the manifold. Link to comment Share on other sites More sharing options...
RonnieJ Posted July 28, 2013 Report Share Posted July 28, 2013 I haz a funk lock and my catback still moved and shakes like hell. Its the OEM donut hangers. They allow fro way too much movement. Link to comment Share on other sites More sharing options...
importwarrior Posted July 28, 2013 Report Share Posted July 28, 2013 mine is in the down pipe. not the B pipe.i feel if it is in the B pipe the flex twists due to engine movement if it is in the down pipe it is more of a side to side movement. does it matter. probably not. Link to comment Share on other sites More sharing options...
Skullzaflare Posted July 28, 2013 Report Share Posted July 28, 2013 mine is in the down pipe. not the B pipe.i feel if it is in the B pipe the flex twists due to engine movementif it is in the down pipe it is more of a side to side movement. does it matter. probably not.i feel the same, however i do not believe the flex units allow twist, only flex Link to comment Share on other sites More sharing options...
89PalermoSHP Posted July 28, 2013 Report Share Posted July 28, 2013 I always felt having one regardless of where is better than not having one at all. Link to comment Share on other sites More sharing options...
Shelby Posted July 28, 2013 Report Share Posted July 28, 2013 they will flex and twist some you won't have enought twist to damage the flex coupling unless you have a bad driver side engine mount ,most logical location would be just after the turn back on the down pipe ,idealy they should be in the point of turn back but that is very hard to do unless you have a very aand and flexable connectorin the mid if the turn is where the oem pipe joint was and if you recall it was a ball and socket with springs so it could twist and movewith engine movement if you had a joint just like that it'd work with out a flex connector but but makeing a 2.5 or 3"spring loaded ball and socket is not easy Link to comment Share on other sites More sharing options...
RonnieJ Posted July 28, 2013 Report Share Posted July 28, 2013 Im telling you its the hangers. Go to your exh tip and give you system a shake to feel the amount of movement. Do the same to a newer car with modern hanger. Way less movement. With updated hangers and a good flex you shouldn't have any more stress issues Link to comment Share on other sites More sharing options...
importwarrior Posted July 28, 2013 Report Share Posted July 28, 2013 i feel the same, however i do not believe the flex units allow twist, only flex exactly my point. Link to comment Share on other sites More sharing options...
JohnnyWadd Posted July 29, 2013 Author Report Share Posted July 29, 2013 (edited) Im telling you its the hangers. Go to your exh tip and give you system a shake to feel the amount of movement. Do the same to a newer car with modern hanger. Way less movement. With updated hangers and a good flex you shouldn't have any more stress issues I can see that. Still want to have the flex located optimally. I always felt having one regardless of where is better than not having one at all. Well yeah hello lol mine is in the down pipe. not the B pipe.i feel if it is in the B pipe the flex twists due to engine movement if it is in the down pipe it is more of a side to side movement. does it matter. probably not. How does it twist in the b pipe? I am visualizing the engine as it moves and it mostly moves the downpipe up and down which would flex the b pipe not twist it? i feel the same, however i do not believe the flex units allow twist, only flex Well it twists a little my 2.5x6 inch one would twist enough to let me move the b pipe back and forth. I think the real question here is "Which direction does the engine shake the exhaust" Edited July 29, 2013 by JohnnyWadd Link to comment Share on other sites More sharing options...
Shelby Posted July 30, 2013 Report Share Posted July 30, 2013 under load all engine tourqe oposite their normal rotation direction , only mentioning this cause some frt wheel drv car engines turn back wards ,,honda for example Link to comment Share on other sites More sharing options...
JohnnyWadd Posted July 30, 2013 Author Report Share Posted July 30, 2013 under load all engine tourqe oposite their normal rotation direction , only mentioning this cause some frt wheel drv car engines turn back wards ,,honda for example Yes I noticed this. Link to comment Share on other sites More sharing options...
Funky Phil Posted July 30, 2013 Report Share Posted July 30, 2013 mines under the car Link to comment Share on other sites More sharing options...
mistapickles Posted July 31, 2013 Report Share Posted July 31, 2013 I have two, one in the down pipe and one right before where the torque tube mounts but my exhaust is solid mounted in the back. When I was in experimentation mode with my exhaust I found that the motor rotates on the pivot of the crank shaft, so if you drew a straight line from the crank to the back of the turbo you can see the radius that the that the turbo rotates. It moves up and down but also moves between an 1/8th to a 1/4" from right to left. So in my thinking I needed to have something that let it move from right to left, the one in the down pipe but also one that let it move up and down, the one by the torque tube mount. My exhaust system is different because my exhaust is solid mounted in the back but the movement is the same. I think for the most part, if your motor mounts are good and you don't have a really rough idle you shouldn't need a flex, the really loose hangers should allow your exhaust to float however it needs to prevent a cracked manifold. That's my opinion, I would love to hear other view points on this. Link to comment Share on other sites More sharing options...
Trouble_07 Posted August 1, 2013 Report Share Posted August 1, 2013 A flex pipe on a car that didn't come with one from the factory is pretty dumb in my opinion. If you have quality rubber hangers that soak up vibration and allow for movement you don't need one. I've done dozens of exausts and never have I put a flex pipe on a vehicle that didn't come with one. Link to comment Share on other sites More sharing options...
RonnieJ Posted August 1, 2013 Report Share Posted August 1, 2013 Its got a donut gasket with spring bolts...same result. Im guessing he no longer runs that setup Link to comment Share on other sites More sharing options...
JohnnyWadd Posted August 1, 2013 Author Report Share Posted August 1, 2013 (edited) A flex pipe on a car that didn't come with one from the factory is pretty dumb in my opinion. If you have quality rubber hangers that soak up vibration and allow for movement you don't need one. I've done dozens of exausts and never have I put a flex pipe on a vehicle that didn't come with one. It did have a flew section...as stated here... Its got a donut gasket with spring bolts...same result. Im guessing he no longer runs that setup And yes I don't have that anymore. I don't have manufacturer specs in front of me, but every car I have worked on has some sort of flex section or spring bolts. Edited August 1, 2013 by JohnnyWadd Link to comment Share on other sites More sharing options...
Trouble_07 Posted August 2, 2013 Report Share Posted August 2, 2013 Both the 86 and two 87's I picked up didn't have either style joint. I asked the 2 exhaust shops that sponsor our outlaw karts about their thoughts on adding a flex pipe on the starquests and they both said not to do it unless its a last resort. The flex pipe is designed more or less for front wheel drives where the engine rocks back and forth and need that movement in the exhaust. They both did recommend the other joint that was mentioned if you had a spendy exhaust and were worried about it being damaged. Another valid point one of them made was that if your engine is moving enough to the point where you need to install a flex pipe you have some serious issues like bad motor mounts, trams mounts, and other possible parts. I think I'll be picking up one of the funk lock engine mounts like someone else mentioned so I don't have to ever worry about that problem. Link to comment Share on other sites More sharing options...
JohnnyWadd Posted August 3, 2013 Author Report Share Posted August 3, 2013 The flex pipe is designed more or less for front wheel drives where the engine rocks back and forth and need that movement in the exhaust. Interesting , I guess all the all wheel drive and rear wheel drive car manufacturers didn't get that memo. Link to comment Share on other sites More sharing options...
mistapickles Posted August 3, 2013 Report Share Posted August 3, 2013 Interesting , I guess all the all wheel drive and rear wheel drive car manufacturers didn't get that memo.dude, come on...EVOs and Eclipses are setup up as front wheel drive cars first. Link to comment Share on other sites More sharing options...
RonnieJ Posted August 3, 2013 Report Share Posted August 3, 2013 (edited) Donut gasket with spring bolts serves the same purpose and the flex. Edited August 3, 2013 by RonnieJ Link to comment Share on other sites More sharing options...
Shelby Posted August 3, 2013 Report Share Posted August 3, 2013 Donut gasket with spring bolts serves the same purpose and the flex. exactly ,, ( as the flex ) Link to comment Share on other sites More sharing options...
JohnnyWadd Posted August 3, 2013 Author Report Share Posted August 3, 2013 dude, come on...EVOs and Eclipses are setup up as front wheel drive cars first. I don not understand what that means. Let me clarify what I meant. Working at Les Schwab for three years nearly every car I have been under has a flex section. I am constantly under cars at the college and under my friends cars.All drive configurations. So I see a lot of cars happen to have a flex. My response was aimed the guy you said an exhaust shop told him they are not needed except for front wheel drive cars. Are you saying they just happen to have a flew in there because they (evos and eclipses) where "set up as front wheel drive first?" Really, this is not a debate on whether cars came with a flex OEM or not. My car is getting a flex for many good reasons. So this is about where it would best serve the car to be installed. Sure I am running a funkloc and good mounts but I still want it to flex upward a bit when it bottoms out on a Oregon pot hole or a speed bump (D2 coilovers=low car) Nothing to do what OEM. Did my car come OEM with D2 Coilovers? Nope so I better not run then. Did my car have a cd player OEM? Nope so I guess that's not needed either. See where i'm going with this? The whole argument is moot anyway because the car did come OEM with a flex. And these cart racing sponsoring exhaust shops that say its not needed on a starquest, I wonder how many starquests they have worked on? Link to comment Share on other sites More sharing options...
Shelby Posted August 7, 2013 Report Share Posted August 7, 2013 evey muffler shop i was ever in , had one to sell ya but some times the guy working there is not the owner nor the sharpest nail in the pail , so take his advice with a grain of salt Link to comment Share on other sites More sharing options...
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