So hi there, after talking about getting a dual resonated midpipe with my friend. He told me becareful because i might loose Back pressure since i have a N/A car. I have no idea what he meant, so i googled it. Some say back pressure is good, other say its just a ricer gimmick. Hence the question will a dual resonated with a borla catback makes me "loose" back pressure?

So hi there, after talking about getting a dual resonated midpipe with my friend. He told me becareful because i might loose Back pressure since i have a N/A car. I have no idea what he meant, so i googled it. Some say back pressure is good, other say its just a ricer gimmick. Hence the question will a dual resonated with a borla catback makes me "loose" back pressure?

he must not know about the Renesis?? well go ahead and get that midpipe because in the world of the 13b-msp we need as much airflow as we can get!!

get the pipe. which one are you looking at?

Im guessing he is looking at the Racing Beat midpipe (which is good) or the crappy Agency power midpipe.

I say go for one resonator from BHR.

racing beat Dual resonated ofcourse =D

Don't worry about backpressure. 3" pipes from headers down to the tips will not slow you down or cause any problems. Careful with the flames though ;)

Don't worry about backpressure. 3" pipes from headers down to the tips will not slow you down or cause any problems. Careful with the flames though ;)

If i am not mistaken our stock headers measure 2.75". No point in going 3" in that case.

to the OP: we have side exhaust ports here and no overlap, back pressure and helmholtz resonances shouldn't play a big role. Just remove any kind of restriciton :)

thanks ya =)
learn new things everyday

the BHR midpipe sounds nice :icon_tup:

If i am not mistaken our stock headers measure 2.75". No point in going 3" in that case.


If you get a custom header there is ;)

Either way, it's minor. I'm going 3" because I'm getting a blower :Eyecrazy:

Getting a 3in header as well is another story :)
Anyway the OP was talking about back pressure but Ross' answer is the one that fits better imho.
On a street driven car it usually ends to be a matter of personal preference!

yea i want to get a bit more kick out of the car. But not a blower yet lol

Why are people in love with BHR so much? Last I checked, their prices on the mid-pipe were astronomical!

You NEVER want backpressure! Show me a race car that utilizes it and I'll show you a car that's never won. Here's what's going on and why people get confused.

As we all know different rpms and loads (which effect VE) will move different amounts of air. As a generalization the higher the rpms, the more air we move in and out of the engine. Any given pipe size can only flow so much air per any given unit time before pressure inside it rises to the point that flow is being severely impeded. When this happens, a larger pipe size is needed. At idle there isn't as much air flowing through the system and there is at 9000 rpm. This is pretty obvious. We want the pipe to be as small as possible while still being able to do it's job without restriction.

At idle, since there is relatively little flow, we really don't need a large pipe. You could have a very small one and have no appreciable "backpressure". However our engines don't stay at only idle speeds. We can see that a pipe size that is small that has good exhaust velocity for idle speeds is going to have problems when we raise the rpms. We need a larger pipe. At 2000 rpm it needs to be larger. Depending on the pipe diameter at this rpm, it too will be too small at some point. The same holds true for higher and higher rpms. We typically size our exhaust based on the absolute max flow through it which means at redline. Everywhere below that is the compromise.

High exhaust gas velocity allows for greater scavenging (Typically. The Renesis is different). Greater scavenging allows for a higher VE which means more power and/or better economy. The generally accepted max gas speed is .6 mach. This is an average speed though as gas flow is not a constant but rather a set of pulses. The above number is a subject of debate though.

If we have a pipe sized for high gas velocity at 9000 rpm, we can see that anywhere below this rpm is going to mean slower and slower velocities. At some point there is no gain whatsoever. When people say to reduce the size of the pipe to give backpressure so you can pick up low end power, what is really happening is that you are raising the velocity of exhaust gasses at lower rpms. The downside is that you choke off the top end. Yes you are increasing exhaust pressure but it's not the pressure that's giving you low end power. It's velocity. Pressure is killing power up high. Now when someone says backpressure is needed for low end power, you can correct them.

Keep in mind I have greatly simplified things. There is so much more to exhaust than just this. I've ignored lots of stuff such as tuned lengths, wave reflections and what kinds there are, temperatures, etc...

^ Excellent Point. Let it breathe

BHR is a great company and Charles has done a lot for the enthusiast rx8 community. Wether it be extensive research and development of better products to helping out the club here with support and wisdom.

I agree his prices are a little on the high end side of things, but the mans gotta make a living some how.

Why are people in love with BHR so much? Last I checked, their prices on the mid-pipe were astronomical!

Have you heard it in person or seen the build quality? It is far superior to any other mid-pipe I've seen/heard.

You can slap whatever pipe you want on your car, but for me, BHR!!!

Why are people in love with BHR so much? Last I checked, their prices on the mid-pipe were astronomical!

You don't get this type of welds with that midpipe: http://i87.photobucket.com/albums/k133/mx5adam/midpipe10.jpg

Why is re amemiya expensive? :)

Build quality is important to some of us, that's why we like even BHR's expensive product.

I am all about quality, so when you say "build quality is important to some of us," please don't think you're excluding me...

I think its great that Charles has done for the rx8 community, really offered specialized product and whatnot, its just the pricing of their mid-pipe that has me wondering why anyone would pick one up. No, I haven't heard it in person, for the record. Personally, a slight tone change in something designed to quiet the exhaust as much as possible, would not be worth an increased price.

How much are BHR's midpipes?

"$425+"
&
"$575+" for the shiny version

Racing Beat offers a dual resonated pipe for $339. Their unresonated pipe is $248. Not only will the quality of product be great and fitment be superior, but you can trust a company who is renowned for excellent products with a history greater than 30 years.

A midpipe is not something that takes a whole lot of development, like many other companies. A simply designed midpipe will net roughly the same amount as a more expensive one. I agree some of the other products are great and prove to be well thought out, it just strikes me that the midpipes seem expensive. Not bashing, I just can't see myself spending $425 (let alone $575) on a pipe that does nearly the same thing as some other products.

and turbo xs' single resonated pipe is.... $150. or free with their exhaust.

and turbo xs' single resonated pipe is.... $150. or free with their exhaust.

Oh it gets even cheaper, some midpipes can be found for even cheaper. I just used RB in my example because there is no doubt in any informed individual on this forum that Racing Beat is synonymous with quality.

You are right. Anyway you need to understand that some midpipes are "sound" tuned while others are not. Raspyness etc must be all kept into account and producing a single resonated midpipe that is as quiet as dual resonated one means some testing.

I personally built with another mate here a single run of 5 midpipes entirely out of 316 steel (instead of the classic 304 one). Guess what? We ended up paying around 400€ per item, meaning that we had to sell them for at least 500€ to ensure any profit.

Add the bells and the whistles such as the gaskets and the new bolts and you get a further idea of why a midpipe is slightly more expensive than another one of about the same quality :)

I'm not defending BHR even if do like their products, it's just that at time the production mechanisms can be tricky and hard to understand. I'm sure that Charles will vouch in if it is worth an extra explanation!

Heh, I know they aren't gouging 8 owners with loads of profit; their margins are probably very humble at that. Just some input considering I see so many people on here bowing down to their products.

Yes sure, is that at times this H4t3rz vs fanbois stuff gets to a point where the main focus is lost :)

We had some users break their agency powerìs welds for instance. Buying 2 pipes is more expensive than buying one! In that case i think that both BHR and RB are on the same quality boat. Also remember that people kept buying Mazsport's dual resonated midpipe, an ugly fitting-poorly assembled ensemble of a midpipe with 2 rb silencers sold at an insanely high price! At least this isn't the case with said products!

the OE exhaust manifold outlet is approx. 2-5/8" OD

It's correct that the Renesis performs best with zero backpressure, but there is no real scavenging in a stock-block Renesis due to the zero overlap intake/exhaust port timing. You can't be too big given this fact, but you can be too small ...

the standard piping choices are 2.5" OD or 3" OD, this is why you rarely see anything inbetween them unless it's an imported metric part

Heh, I know they aren't gouging 8 owners with loads of profit; their margins are probably very humble at that. Just some input considering I see so many people on here bowing down to their products.

It's always cheaper when you mass produce something in large numbers and build them yourself. Ray isn't in the garage welding these things up personally. Racing Beat does though. They buy very large amounts of raw material and throw it all along with some food and water to the fabricator sitting in a corner of the shop. That's how they keep their costs down. Other companies may contract out to places overseas where material prices are very cheap and so is labor. China would be a good example.

In the end a simple midpipe is nothing more than a pipe with 2 flanges. If the welds are good on all of them and the flanges are thick enough not to warp then there shouldn't be an advantage of one over the other. However are the welds from each company comparable to the others? Are the flange thicknesses acceptable on all of them?

When it comes to the presilenced (resonated) midpipes, the above apply but of course we add in the silencer itself. This can get tricky. Is it a proper perforated core style or is it louvered? Is it stainless packing or fiberglass? Then you just have to realize that depending on what the packing is, how tight it is packed, and total silencer length and area will all play a role in the sound. Just because there is a silencer doesn't mean it will sound good. Some may sound great while others may not and may be raspy. Ask around to those who have each kind.

As far as why to buy BHR, it's really a simple decision for some. Ray is a great guy with great service. He has literally travelled across the country on his own dime to help others out and his support is great. He also doesn't sell crap. If it sounded bad or didn't perform as it should, you can be sure he wouldn't sell it. Does he cost more on some things than other places? Maybe. Some people are content to shop at Walmart for everything while others would rather go to specialty stores for better products. It really depends on the individual. Walmart sells lots of clothes. None of mine came from there. I prefer to support the small hard working individual. That keeps the money domestic. It's funny to mention that when talking about a Japanese car!

In the end it's up to you. Do your homework and make an educated choice. If it's Racing Beat then cool. I support them. They're a great shop with a good history. If it's for BHR then cool. Just know that there are many people out there that chose them who are very satisfied and glad they did. If Ray ever started bottling water, it would probably sell!

Why are people in love with BHR so much? Last I checked, their prices on the mid-pipe were astronomical!

I am all about quality, so when you say "build quality is important to some of us," please don't think you're excluding me...

A midpipe is not something that takes a whole lot of development, like many other companies. A simply designed midpipe will net roughly the same amount as a more expensive one. I agree some of the other products are great and prove to be well thought out, it just strikes me that the midpipes seem expensive. Not bashing, I just can't see myself spending $425 (let alone $575) on a pipe that does nearly the same thing as some other products.

Oh it gets even cheaper, some midpipes can be found for even cheaper. I just used RB in my example because there is no doubt in any informed individual on this forum that Racing Beat is synonymous with quality.

Heh, I know they aren't gouging 8 owners with loads of profit; their margins are probably very humble at that. Just some input considering I see so many people on here bowing down to their products.

Tilt,

If you honestly think you can design a better product for a smaller price then I encourage you to open your own business and do so.

Otherwise I am more than willing to put our products up against any other vendor that produces similar products.

The one aspect BHR did with the mid-pipe design is test various resonators until we found one which not only produced the sound we wanted and a near stock loudness but also did so without having to resort to using two resonators. We are not bandwagon jumpers and we didn't buy into the notion that the RX8 could only be quieted with two resonators. That fact has been proven with our mid-pipe.

Quality and performance without compromise is our design strategy. There are dozens upon dozens of midpipes out there for the RX8 and 99% of them all sound the same. The 1% that does sound different people were paying much more money than what we are charging and they had to deal with parts that could not withstand the high exhaust gas temperatures of the RX8 as well as fitment problems.

We were not going to waste time designing a midpipe unless it was the best out there. We are working with a local fabrication company that produces headers for pretty much every major funny car team you can name. Like with other products we find the best of the best and bring that quality into our own products.

We also make sure you don't have to source all your own hardware for the installation. We include all the bolts and gaskets necessary for the install. We have thought out every possible detail to ensure the installation and use of our products is as painless as possible.

I'll have this mid-pipe on my own RX8 at Sevenstock so I encourage everyone there to come by and have a listen/look for yourself.



As far as why to buy BHR, it's really a simple decision for some. Ray is a great guy with great service. He has literally travelled across the country on his own dime to help others out and his support is great. He also doesn't sell crap.

Thanks RG and everyone else for your comments! I don't mind people challanging our stuff because none of us at BHR believe that "trust us" is enough when it comes to justifying why what we make is the best. You all as customers are the best judge of our product quality and our customer service quality. If we sucked at both we wouldn't be here...period.

Yeesh, I got myself in here deep now didn't I! For the record, as I've already stated, I think what Charles has done is great, beyond so in fact. I was just playing a bit of devil's advocate.

Tilt,

If you honestly think you can design a better product for a smaller price then I encourage you to open your own business and do so.

Otherwise I am more than willing to put our products up against any other vendor that produces similar products.

The one aspect BHR did with the mid-pipe design is test various resonators until we found one which not only produced the sound we wanted and a near stock loudness but also did so without having to resort to using two resonators. We are not bandwagon jumpers and we didn't buy into the notion that the RX8 could only be quieted with two resonators. That fact has been proven with our mid-pipe.

Quality and performance without compromise is our design strategy. There are dozens upon dozens of midpipes out there for the RX8 and 99% of them all sound the same. The 1% that does sound different people were paying much more money than what we are charging and they had to deal with parts that could not withstand the high exhaust gas temperatures of the RX8 as well as fitment problems.

We were not going to waste time designing a midpipe unless it was the best out there. We are working with a local fabrication company that produces headers for pretty much every major funny car team you can name. Like with other products we find the best of the best and bring that quality into our own products.

We also make sure you don't have to source all your own hardware for the installation. We include all the bolts and gaskets necessary for the install. We have thought out every possible detail to ensure the installation and use of our products is as painless as possible.

I'll have this mid-pipe on my own RX8 at Sevenstock so I encourage everyone there to come by and have a listen/look for yourself.



Thanks RG and everyone else for your comments! I don't mind people challanging our stuff because none of us at BHR believe that "trust us" is enough when it comes to justifying why what we make is the best. You all as customers are the best judge of our product quality and our customer service quality. If we sucked at both we wouldn't be here...period.

Hopefully my posts weren't taken the wrong way. I wasn't exactly challenging your product, just a bit of critical comparison. I never said I could create a better product, let alone for the same price. My idea of a budget resonated midpipe would be hacking out the OE cat, welding in a pipe, and leaving the resonator :lol: It just struck me, as I was reading the other thread, that a midpipe could reach nearly 6 bills. Seemed a bit steep but I suppose those who are anal enough to want a stock sounding car will enjoy.

I guess BHR crew has had its hair up on the back from the stupid attacks from other forum members. I wasn't attacking, just making valid questions and comparisons. I think that's fair enough, didn't mean anything aggressive by any means!

Lastly - RG, did you just compare Racing Beat to Walmart? Hopefully RB doesn't have sweat shops in 3rd world countries! :lol:

Yeesh, I got myself in here deep now didn't I! For the record, as I've already stated, I think what Charles has done is great, beyond so in fact. I was just playing a bit of devil's advocate.

Hopefully my posts weren't taken the wrong way. I wasn't exactly challenging your product, just a bit of critical comparison. I never said I could create a better product, let alone for the same price. My idea of a budget resonated midpipe would be hacking out the OE cat, welding in a pipe, and leaving the resonator :lol: It just struck me, as I was reading the other thread, that a midpipe could reach nearly 6 bills. Seemed a bit steep but I suppose those who are anal enough to want a stock sounding car will enjoy.

I guess BHR crew has had its hair up on the back from the stupid attacks from other forum members. I wasn't attacking, just making valid questions and comparisons. I think that's fair enough, didn't mean anything aggressive by any means!


I appreciate the comments and the clairification.

There is always going to be a more inexpensive way to complete any project. I simply wanted to comment that our pipe isn't the same as every other mid-pipe out there.

We don't use dual resonators and our single resonator actually quiets down the exhaust while producing a tone that allows the unique properties of your cat-back exhaust to be heard. These elements as well as the excellent build quality are all elements that carry the price we have.

However, people have clearly paid much more for much less.

the OE exhaust manifold outlet is approx. 2-5/8" OD

It's correct that the Renesis performs best with zero backpressure, but there is no real scavenging in a stock-block Renesis due to the zero overlap intake/exhaust port timing. You can't be too big given this fact, but you can be too small ...

the standard piping choices are 2.5" OD or 3" OD, this is why you rarely see anything inbetween them unless it's an imported metric part

are you talking about the size of the outlet, or the nuva ring? hey at least we are safe..

beers :beer:

I didn't compare Racing Beat to Walmart at all. I know those guys over there and I think everyone should support them when possible. My Walmart comment was really aimed at the cheap China made mass produced crap that is all over ebay.

mind my ignorance please, for I am about to question--what might rather be a mundane term to some--what N.A. means. I looked up in a dictionary, but nothing relates to the context of how the abbreviation is being used here.

Naturally Aspirated FI = Forced induction

thanks for clarifying that.

are you talking about the size of the outlet, or the nuva ring? hey at least we are safe..

beers :beer:

The OD of the outlet is approx. the ID of the ring.

Is my memory off? Been several years since I actually measured it.

1) I wasn't exactly challenging your product, just a bit of critical comparison. 2) It just struck me, as I was reading the other thread, that a midpipe could reach nearly 6 bills. 3) Seemed a bit steep but I suppose those who are anal enough to want a stock sounding car will enjoy. 4) I guess BHR crew has had its hair up on the back from the stupid attacks from other forum members. 5) I wasn't attacking, just making valid questions and comparisons. I think that's fair enough, didn't mean anything aggressive by any means!

6) Lastly - RG, did you just compare Racing Beat to Walmart?

1) PLEASE challenge ALL of our products. We welcome the opportunity to explain our motivations and design perspectives, especially when we are given the chance to compare them to those offered by other companies.

2) Yes, midpipes that have features such as ours are not cheap, especially when ordered with the literal "show-car" polish on it. BTW, that additional $150 is EXACTLY what BHR is charged for the polishing so we make no extra margin on it. I tend to do this much of the time when it comes to available options. Maybe that is why every month is a scramble to pay my rent around here. :dunno:

3) "Anal enough....."? Some people simply don't want another buzzy-sounding, cookie-cutter, midpipe and prefer one that offers a sound one can immediately identify. Once we get the rest of our pre-order list shipped and these pipes are on their respective cars, people will start to call it the "BHR sound". Especially when we also begin to roll-out our cat-back system.

4) We don't get upset with even "stupid" attacks as each one of them is an opportunity for the BHR team to learn something. We just like BHR product to be fully understood and those who "attack" our product are typically those whom have never bought it, heard/seen it, or even asked us about it. Simple as that.

5) No aggression taken, Tilt. :)

BTW, it might be interesting for people to know that 4 guys had to ambush me in my garage and harangue me for a good TWO HOURS before we could all agree to the terms under which a BHR Midpipe would be pursued and for me at assent to even bothering with our own offering. Flashwing was begging me, Easy was thinking I was foolish for waiting, Hund was scorning me, and Rotaryman25 was shaking his head at me. MazdaManiac was the only one who never harrassed me about it.

Every new idea that one of the BHR team members presents to the rest of the team suffers scrutiny like you wouldn't believe, even my own ideas, and we don't build stuff just for the sake of selling it.

There are enough companies building product you don't need, to solve problems that don't exist, for prices that are TRULY "astronomical". BHR refuses to be one of them.

If people want to know the difference between the BHR Midpipe and each of the others available I would be happy to discuss it. Rotarygod already touched on certain concerns we had when seeking a resonator to use.

Charles would ya enlighten me the difference between yours and racing beat mid pipe?
I rather spend the money for quality

Sure.

Since prices are always a consideration, I'll point out that RB's pipe is $339 before shipping. BHR's is $425 with shipping in the 48 States included.

They both use 304 Stainless, have nice-fitting flanges, and mid-hangers.

I am impressed that RB is using the factory spring/stud kits because they are not cheap. BHR uses a Vibrant spring/stud kit that is of equal quality and a bit cheaper. We both probably also include all the hardware/gaskets, too.

From what I can see the welds are of comparable quality.

I would say that both pipes are equal along all lines except for what matters most; the chosen resonator/silencer.

While RB is using a pair of custom-designed silencers we are using a single off-the-shelf unit that, apparently, nobody else considered or wanted to use and we are having it custom-tweaked to our specs, too. It is my understanding that the RB silencers are a straight-through design with packing in it that is said to be able to withstand the high heat content. Ours has no packing in it and it is not a straight-through design.

I also believe that there is a 6 lb. (or more) difference in weight between the two pipes. The BHR midpipe weighs 10.9 lbs.

I am also guessing that whichever midpipe one chooses they will not be disappointed and THAT may be the toughest decision of all for people!

Sure.

Since prices are always a consideration, I'll point out that RB's pipe is $339 before shipping. BHR's is $425 with shipping in the 48 States included.

They both use 304 Stainless, have nice-fitting flanges, and mid-hangers.

I am impressed that RB is using the factory spring/stud kits because they are not cheap. BHR uses a Vibrant spring/stud kit that is of equal quality and a bit cheaper. We both probably also include all the hardware/gaskets, too.

From what I can see the welds are of comparable quality.

I would say that both pipes are equal along all lines except for what matters most; the chosen resonator/silencer.

While RB is using a pair of custom-designed silencers we are using a single off-the-shelf unit that, apparently, nobody else considered or wanted to use and we are having it custom-tweaked to our specs, too. It is my understanding that the RB silencers are a straight-through design with packing in it that is said to be able to withstand the high heat content. Ours has no packing in it and it is not a straight-through design.

I also believe that there is a 6 lb. (or more) difference in weight between the two pipes. The BHR midpipe weighs 10.9 lbs.

I am also guessing that whichever midpipe one chooses they will not be disappointed and THAT may be the toughest decision of all for people!

Ok now im in limbo :scratchhe

Ok now im in limbo :scratchhe

Did I fail at my explanation or is it still a tough choice? Or both? :lol2:

Did I fail at my explanation or is it still a tough choice? Or both? :lol2:
its a tough choice haha. Either that or my comprehension went down the drain today :Drooling_

I didn't know those BHR prices included shipping, awesome.

I didn't know those BHR prices included shipping, awesome.

I tried to get Charles to throw in a Russian bride to order but I guess there's not only some major paperwork but the shipping costs are pretty high.

It's bad enough we have to pay the models to answer the phone at MazdaManiac's place these days!

The OD of the outlet is approx. the ID of the ring.

Is my memory off? Been several years since I actually measured it.

the crush ring between the exhaust manifold and the cat section is 2.5 "

hum.

btw, you have had warped front rotors???? ;)

beers :beer:

I didn't know those BHR prices included shipping, awesome.

BHR's stated prices always include shipping in the 48 States and we do not add further handling charges for shipments outside that area, just whatever it costs us to ship it to Timbuktu, Transylvania, BFE, or whatever.

cool. Well this thread made me learn a couple of things.

I love reading Charles' posts.

BHR's stated prices always include shipping in the 48 States and we do not add further handling charges for shipments outside that area, just whatever it costs us to ship it to Timbuktu, Transylvania, BFE, or whatever.

Charles,

I was in the same boat as Tiltmode. I was literally about to order the RB Dual Resonated Pipe simply because of their price and also because I live in Anaheim. However, when I figured in the 9.75% Sales Tax that us Californians have to pay:

- BHR is $425 shipped to me and I don't have to do any driving around town.

- Racing Beat is $372.05 picked up.

I like the idea of having no fiberglass packing (as you had mentioned for their resonators). Why? I have had NUMEROUS cars in the past that would generate enough heat to break down the packing. Would I want that from a rotary-engined car that generates even more exhaust heat? No.

You got my attention. As soon as production goes back in, I'm ordering!

Thanks for understanding BHR's perspective on this one, Eddie.

The midpipes with the two new prototype resonators are probably already built but we are making some tweaks to the front mounting flange for better sealing/fitment. Once the flanges are done we will test the new resonators out as best we can and see what happens re: durability. Once we have verified the new resonators to be up to the task we will set about updating all those who have the old version and then start making our way down the "pre-order" list.

I have to say .... I have the AP Dual res mid pipe and it is a bit to raspy for my tastes ... AP mid pipe and greddy sp2 combo is really loud and a bit raspy ... While I love the flow, EG temps, and weight reduction from the stock system -- I really wish I had all that with a quieter system!