When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Both are excellent designs, just some difference in design philosophy. FM has a bit of a plenum right past the merge, and Vibrant seems to keep the diameters more constant.
How much do you hope to gain by switching?
I dont expect too much of a difference. I was just curious if sending the FM back and spending the extra cash was worth it. Doesn't sound like it. Sounds like both are solid designs. I'm not familiar with Vibrant.
Every test I have ever seen proved Flowmaster was the worst HP/noise level you can buy. I would cobble together some junkyard parts before ever buying their crap. Their only real claim to fame was making a early 1990's Mustang 5.0 have a pleasant rumbly sound. At less than 300rwhp they did a good job of that.
You're extremely mistaken. We are talking about a merge pipe here and their merge is one of the best on the market. Several notable builds have been made using it.
Last edited by Tyler Dietzenbach; Jan 8, 2022 at 10:37 PM.
Every test I have ever seen proved Flowmaster was the worst HP/noise level you can buy. I would cobble together some junkyard parts before ever buying their crap. Their only real claim to fame was making a early 1990's Mustang 5.0 have a pleasant rumbly sound. At less than 300rwhp they did a good job of that.
I think you are thinking of their mufflers. WE are discussing their merges/Y-pipes, which are generally regarded as very decent examples of the type.
And sometimes I don't bother to read everything before responding. Sometimes it is just a "character flaw", and sometimes I sound like an *******. Sorry guys.
I think was Martin Smallwood that said a good dual 3 inch to 4 inch merge was ~15 to 20 wtq at some midrange rpms.
My old Mufflex Y set up is beat up but one can see how the dual 3 inch to 4 inch merge rocks. It would be easy to do a 4 inch cut out and use a reduce for the 3 inch catback.
Vibrant looks similar to Kooks to me so it's probably pretty good.
Vibrant 3inch Kook's Y pipe for LS1
But that Flowmaster style dual 3 inch to 4 inch merge looks better still in my opinion. Used to run one before going true duals.
Mufflex Y My old Mufflex Y came with the dual Flowmaster 3 inch to 4 inch collector. Had a reducer for the 3inch catback. Would have been easy to do 4 inch cut out then do the reducer.
BTW - the Mufflex fat merge Flowmaster definitely sounds better than the Kook's Y in my subjective opinion all else equal.
Last edited by 99 Black Bird T/A; Jan 14, 2022 at 08:30 AM.
Thank you! I ended up going with the Vibrant over the Flowmaster. My thought process was that the difference would be negligible in performance, but would look a lot better as I prefer to have all stainless exhaust. I will be running a 4" E-cutout and also 4" back to my Magnaflow catback. I'm excited to see how this build all works out. Should be finished up before spring.
I had read on here somewhere that ARH uses a vibrant merge, I haven't confirmed that yet.
What do you recommend running after the cutout? a 45 degree angled piece of pipe?
After the reducer + cut out, we chopped a few inches off of the 3 inch SLP Dual/Dual's I pipe to fit it all together. The cut out ended up roughly under the rear passenger floor board. Then typical I pipe over the axle etc.
FWIW - while I really like the Mufflex set up it was very prone to scrape on speed bumps with ~3/4inch to 1 inch of lowering on my T/A. The Kook's Y didn't scrape on the same speed bumps on the same T/A etc
I am wanting to do the same thing, just try to find a place I trust with the car to do it.
Has anyone done the 3-4" merge, bullet muffler/resonator, cutout, then 3" reducer to go over the axle? Not sure if there is even enough real-estate there to accomplish it. Just figured the bullet/resonator would help even more for a deep sound and further reduce any rasp.
I am wanting to do the same thing, just try to find a place I trust with the car to do it.
Has anyone done the 3-4" merge, bullet muffler/resonator, cutout, then 3" reducer to go over the axle? Not sure if there is even enough real-estate there to accomplish it. Just figured the bullet/resonator would help even more for a deep sound and further reduce any rasp.
I believe I have seen it done but I'll do some looking. Hopefully someone with more knowledge can answer that or come up with an idea
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
Flowmaster vs Vibrant merge 
