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While fixing a couple weld leaks on my hot side I found out my flex coupler is leaking where the stainless mesh goes into the collar. I removed and pressurized the y pipe and sprayed soapy water on it to find the leak. Its not leaking real bad, but its making some bubbles . Are they suppose to be 100% leak free and who makes a quality replacement ?
I dont think its that rare of an occurrence but the more seasoned vets here can chime in on that. I personally have always used Bellows instead of Flex Couplers as they are less likely to leak. Vibrant has a nice selection should you choose to go that route.
I always run the 3-layer flex couplings without issue. They have a mesh on the outside, then a bellows in the middle, and then a smoother metal liner on the inside.
I don't know what mine has for a middle layer, or even if it has one, but its got the metal sectioned inner . I went ahead and ordered a vibrant T-flex for it. Should be here tomorrow. I might have tried the bellows like 2much suggested , but it was too late, I had already ordered it by the time he responded. Patience is still hard for me, even as an old fart .
patience is for people that don't have **** to get done!
I built my up pipes with an ebay tri layer mesh. seems to be holding up well, even with 30-40psi drive pressures.
I will say going upmarket makes fabrication much easier. the flanges were oversize and I had to do some fuckery to make it fit my 2.25 pipes...hella gappy nasty stuff that I had to grind flush a tig a fake weave over to look decent.
none of that with my vibrant bellows i used on my gate dump. minimal fitting, just zap it on and start brappin
How many here have actually checked their flex coupler for leaks? I swapped out the CXracing flex coupler on my merge pipes because it had a slight leak when checked with a pressurized pipe and soapy water. I bought a Vibrant t-flex coupler to replace it, welded it on yesterday and it leaks too, from the same place ! I just wonder if there is a slight leak on all of them where the stainless mesh goes under the collar. So, anyone REALLY checked their flex couplers and what did you find?
That part is not made for a pressurized application. That's all there is to it really. Little leaks won't hurt you too much. Exh Flex bellows are the correct part. I've used the flex braided stuff too. Comes down to time/budget like everything else. Summit sells some vibrant bellows relatively cheap. Leak free and seem to hold up well so far for me.
That part is not made for a pressurized application. That's all there is to it really. Little leaks won't hurt you too much. Exh Flex bellows are the correct part. I've used the flex braided stuff too. Comes down to time/budget like everything else. Summit sells some vibrant bellows relatively cheap. Leak free and seem to hold up well so far for me.
That is exactly what I have ordered now. Im gonna just redo my Y-pipe from headers to turbo. I am going from a "2.5in.Y to 3in. pipe to T4 turbine "to a "2.25 in.Y to 2.75in. pipe to T4 turbine".
Just gonna start over since my welding has improved and my low boost 6.2 doesnt need the big pipes for my power level anyway. Hopefully spool a little quicker too.
Or dual 2" piping merged into a cheaper 2.5" t4 flange.
Your 2" setup actually scared me away from it. I will never hit 1000 wheel like you, but I dont want to be close to choke on the Y pipe size either. I read the whole "why does everyone run 2.5" crossover" sticky, and I dont know that it will help me that much to push past the 2.25 to 2.75 setup. My concern centers around reversion . Usually you would think of reversion coming from a turbine thats too small, but doesnt it make sense that it could just as easily come from a Y pipe thats smallish ? Im just getting my feet wet at this forced induction thing so dont blow me out too bad if I missed the boat on that theory completely, LOL.
You're back pressure will be the same with the smaller piping as it is with the larger. The turbos the bottle neck setting the back pressure. You could run 6" pipe to the turbo and the back pressure would be the same. Reversion will depend mainly on cam overlap, but it will basically be the same regardless of the pipe size you choose. For 900ish hp and under on an ls3 2" or 2.25" merged to 2.5" is fine IMO. But what ever is easier for you.
I don't think my issues were caused by the 2" pipe. I know I had too short of a push rod in the motor now.
Last edited by Forcefed86; 05-19-2017 at 10:33 PM.
Are you still running the 2" setup ? and if so did the PRs fix it ? I made my decision based on the 2" system limiting you rpms. If that were the case, and the rpms werent limited before with the larger pipes, wouldnt the cross over have been the worse of the 2 possible causes of back pressure (turbine AR size vrs crossover pipe diameter) ?
Are you still running the 2" setup ? and if so did the PRs fix it ? I made my decision based on the 2" system limiting you rpms. If that were the case, and the rpms werent limited before with the larger pipes, wouldnt the cross over have been the worse of the 2 possible causes of back pressure (turbine AR size vrs crossover pipe diameter) ?
Sold that engine. But running the same hotside on a 4.8. plan to rev it out quite a bit this year if I can ever get to the track. Havent made it yet. I wouldnt bother with merging. just run 2 " to each side of the scroll. Or squish the 2 pipes into a t4 flange and be done. 2.25 is fine too, but if you have moderate power goals no need for it.
05-15-2017, 09:43 AM
Flex couplers 
LOL.