Looking to replace my dual exhaust for better performance gains. The new Rapid looks interesting but I've heard couple complainants of failures with little hours put on them. Not sure how accurate that is. Anybody hear that?
From what I've read/heard, the theory behind the Rapid has to do with the longer piping providing more of an asist to scavenging the exhaust and help with the performance. Of course maybe that's BS. If that longer pipe theory is accurate then it seems like the shorter pipes on the MAC (and even my duals) don't offer the performance of the longer Rapid exhaust. Just curious as to how the shorter pipes on the MAC and my current duals compare to the longer pipes on the Rapid exhaust? Sorry for the long ramble- just trying to make a good decision before i shell out for a new exhaust. Thanks

The rapid's are definitely having qc issues. Saw a few with the ends blown out of em at caddo this year.

Saw another last week.

The longer primaries do help proper exhaust things happen to make more power.

Sent from my SAMSUNG-SM-G891A using Tapatalk

I sure like longtubes on a 2/1 header

^ Get that guy to make you one.

Of the two, I'd get the Mac... but if I had my choice, it would be D, none of the above....

If I were buying something off the shelf, it would be the latest version of the Q from BPS.

I've got the updated Rapid on my motor right now. Haven't had a chance to put it through the ringer, yet. It is a baffled exhaust that has a really great tone. I've ran the new one on the trailer....but, still trying to dial in my carb right now....and just don't have the time!

Get a Stainless works, similar gains as the rapid but much better craftsmanship. You could get a voodoo which will probably provide the most gains but you might blow an ER drum!

damm, too many choices. Marshmellow, Q, Mac, Rapid, VooDoo, ...... I figured the exhaust "world" had advanced in performance over my older dual exhaust system and I was looking for more performance but, so many choices. Maybe all 4 offer better performance over my duals and maybe i should just close my eyes and pull the trigger on any of the 4? I don't guess anybody on here has done extensive testing on all 4? maybe some dyno numbers on all 4? Forgot to add previously: I did reach out to BPS re: the issues i was hearing they had. I was told it was due to a clip inside that wasn't up to par and that all new rapid's are shipping with the new clip or new screws that correct the issue. So that was their response for what its worth.

For a hunting motor I'd choose the mac, that's just my opinion.

I've put quite a few hard hours on my mac with no issues, they are low profile and seem to be stout

Did everyone turn away from marshmellow due to the cracking or bc the performance is that much better with the newer exhaust? I personally still like the sound of a baffled marshmellow

If you are running heads, cam programmed ecu, prop etc, is one of the new latest greatest exhausts gonna give you that much more performance over a stock that's been opened up the breath a little better? Gotta believe it's negligible.

One of my buddies has been through 2 Rapids in a week. Blew the end cap off both. Tried the baffle with one. Still same result. He's getting a mac now

Is there anything to the longer pipe vs. shorter pipe? Maybe the length doesn't matter if the builder can place the correct backpressue into his pipe for it to scavenge engine exhaust efficiently? I'm curious since the majority of "performance" pipes over the years are relatively short pipes and then along comes the Rapid which is much longer and supposedly had better dyno results. Seems there may be something to the longer pipe concept? of course if Rapid doesn't get their s**t together we may remain with the world of short "performance" pipes. (I was told by BPS that the issue with the Rapid is being addressed and new shipments will be coming out soon that supposedly correct their problems) Who knows....... What's the deal with the longer vs. shorter pipes? better dyno results? actual real world performance?

I've never put two motors on a dyno to test them so this is just speculation, but I'd be willing to bet there is no more than a 5% difference between two performance exhausts.

On a 400 hp motor, 5% increase is 20 hp, definitely a noticeable difference.
On a 40 hp motor, you are talking about ~1-2 hp

If you are trying to build the baddest motor around I won't argue a well designed exhaust is part of the puzzle, but on a hunting motor the average person will probably never notice the difference.

A dyno is a tuning tool. Nothing more. Don't get bent on dyno numbers... they can be made to read basically whatever the dyno Operator says. I'm not saying that's the case every time but i wouldn't put much stock in them. Long vs short makes a difference. But how much exactly is still up for debate, and packaging is still a concern with these exhaust systems because of vibration and heat stress.

I can say for a fact, that I noticed a difference in exhausts.
I had a gutted exhaust, then went with straight duals on my Prodrive, and went back to gutted stock because there was noticeably better low end torque with the gutted stocker.
Also, this was on a modded motor

know of 5 including mine that has failed !! blew caps and baffle right out !! they sent me a new one but haven't had a chance to put it on or run it ! not sure I really wanna keep it !!

Yeah I jumped on the exhaust wagon. But went with the BPS Q, yes it was cracked at brackets and flanges after 100+ hrs. Took it off, had it welded back up, put it back on in a different manner.

1. tighten flanges to head(using those graphite gaskets for air cooled VW motors)
2. tightened "mounting" brackets to motor
3. holes on brackets and muffler did not line up, so drilled and wallowed out holes to fit bolts without putting "torque" or twist to mounting.

Approx 30 hrs - good so far.

I will say that while BPS Q was being worked on, I used the factory exhaust. there was a big difference in low end performance and a loss of probably close to 300 rpms on top end.

As far as the Mac vs. Rapid thing, ?????? Both are louder than the BPS Q.

I correct myself. I incorrectly placed the VooDoo in the "shorter" pipe category. VooDoo looks to have a good length of pipe to it. Maybe it's no coincidence that the two pipes that show good dyno results are the two with longer pipes- Rapid & VooDoo. Appears that the builder/designer of those two pipes can "tune" the pipe for performance gains by adjusting the length of the pipe. I know dyno results don't tell the whole story and are only one aspect of performance but, maybe it shows an effort by the builder/designer to try and accomplish real gains vs. any shadetree lawnmower mechanic thinking he can weld some piping together to make a loud sounding mud motor?
Maybe with the designer/builder using some tool (dyno) to measure the effects of longer piping vs. shorter piping the designer can see his results in real time? I just gotta believe that these guys use some kind of tool to measure the performance gains as they are designing their pipe to bring to market. Or- maybe I'm totally wrong and there ain't no science in this crap and they're just welding pipes together, look tough, sounding loud and charging big $$? Haha, sure hope not. I'm sure there is some method to this madness.

Woodie, i agree that 20 hp is a better number than 2, but that 2 will be more noticeable in application of a gain because of the low hp we're dealing with on these motors. Is it worth the cost? To each their own.

Sent from my SAMSUNG-SM-G891A using Tapatalk

Looks like I'm narrowing it down to the VooDoo or MAC since Rapid is out due to current quality control issues. From what I'm hearing it seems the VooDoo and MAC perform better than the Q or marshmellow as far has HP and performance gains.
For the ones running the VooDoo and/or MAC- how do you like yours? Any preference? things I need to be aware of with either one? or just close eyes and pick one?

Noise. Get a box of earplugs for the boat.

Sent from my SAMSUNG-SM-G891A using Tapatalk

35 GTR Stage 3-It adds 15hp. My voodoo adds 3 of it. It is loud. But this combo sounds like a harley running down the water

Well being stealthy is still part of my scouting strategy using binoculars... loud mufflers don't help the cause.

I've ordered cam, heads and programmed ecu. Want to see how that runs with my stock exhaust which I plan to open up the outlet to 2". That is unless someone else has a better way to mod the stock exhaust for better gain and be able to keep the db's down a bit.

The bps q really isnt much louder than stock, if it is at all. It has a different tone, but want to say someone posted the db numbers a while back and there was hardly any difference.

I had a voodoo. Hated it. Too loud for myself or anyone else who road in the boat.


Sent from my iPhone using Tapatalk

Or anyone who rode anywhere near your boat.

damm- if the VooDoo is too loud how's the Mac compare? Does Mac show any performance gains over the "Q" ? Is the Mac as loud as the VooDoo? or does the Mac's rear facing pipe help with the noise unlike the VooDoo's side facing pipe?

Could get a Stainless Works. They are supposed to be more quiet.


Sent from my iPhone using Tapatalk

Ive been around a few mac's that were pretty loud but i cant comment on power. I will add that the newer q's with the flex joint have a rough looking restriction where the flex joint gets bigger then necks back down at the second weld. I would bet money it makes less power than a q without the flex additive