Log Manifold (SFR/Esmeril) Vs Tubular (turboblown) Turbo Manifolds, and setups
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12-30-2010, 08:50 AM
#36
In a typical commercial situation, they spend as much funding as they think can be recovered in sales profits and call it a day. In the end, RB provides a reasonable quality header that the avg street guy can slap on and be content with.
12-30-2010, 10:14 AM
#37
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Its possible to run the OMP with an inconel heat shield. I've had several guys contact me with other top mount turbo systems who continue to melt the connectors. The turbo system is designed to be as bullet proof as possible, reliability is a key element.
12-30-2010, 10:23 AM
#38
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That's just the results of their limited testing and conditions. It doesn't make them the know-all experts in Renesis manifold design. The details matter. This is well proven in racing. The best funded professional race teams rarely conclude that they have the best. They never say never and have the resources to pursue anything and everything possible. Unless you test every possible design in every possible configuration and condition plus get all the details right you may never discover the ultimate combination. You may never discover it any way if its something so different and bizzare as to have been considered, so simple as to be overlooked, or you just didn't get the right combination of details required to optimize it. It's often as clear as mud, though some people will profess to have the best because in their mind they did it all and they can't possibly be wrong or up-ended by someone else. It happens on this forum all the time.
In a typical commercial situation, they spend as much funding as they think can be recovered in sales profits and call it a day. In the end, RB provides a reasonable quality header that the avg street guy can slap on and be content with.
In a typical commercial situation, they spend as much funding as they think can be recovered in sales profits and call it a day. In the end, RB provides a reasonable quality header that the avg street guy can slap on and be content with.
but everyone that I KNOW OF that has tried more than a couple combinations has ONLY discovered more power collecting back at the mid pipe as RB, Hymee and the Grand Am teams mentioned by Jeff.
The other way is not practical for RB to sell as Team points out. The one they do produce is excellent, does what they say and in conjunction with the rest of the exhaust system pieces they sell makes a marked improvement over stock.
12-30-2010, 10:33 AM
#39
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There isn't an engine on the planet that doesn't benefit from actual bends over brick wall transitions. A turbo manifold is suppose to be as free flowing as possible. Just look at F1 80s turbo motors; large radius gentle bends. The manifold wasn't designed to keep the rotors exhaust pulses from interfering with each other, as said that won't make that big of a difference because of the center port exhaust. It was designed to be free flowing.
I have done back to back testing on a pair of Rx-7s that showed a 1000rpm gain in boost threshold and 20rwhp across the board from a hks style log manifold to tubular design. Its pretty much the same on piston engines, even small 4 cyl which you can somewhat compare the Renesis too( low overlap/ and more exhaust restrction(valves/sideports)). You don't see any performance piston motors running log manifolds.
We looked at the boost curve compared to MM's smaller 3076R, and this bigger 1.06 Gt35R spooled almost as fast at partial throttle. Given the dyno doesn't exactly show real world conditions, ie: transient response. I haven't seen a lot of top mount turbo systems dynos, but they look awfully laggy to me, and these have all been 60~ish mm turbos.
You can't really compare n/a headers to turbo manifolds either, there is no pulse tuning in a turbo manifold. Just look at supercharged top fuel dragsters, the headers aren't even collected. You just want to get the exhaust out as fast and as easy as possible when you are under positive pressure. Even so you sure don't see RB selling log manifolds. Futhermore in an ideal world under 1 bar you are at twice the atmospheric pressure making your engine basically twice its size. If you had a 2.6L Renesis you would see bigger gains in n/a form from the exhaust system.
Outside of all this theory, real world results show VERY fast spool for a big Rensisis turbo, and if you look a the powerband its almost doubled everywhere, not just up top.
12-30-2010, 10:38 AM
#40
If you go to this page, http://www.racingbeat.com/mazda/perf...gurations.html , it shows the prime length for a long tube header system for the RX7. I has such a system on my 85 GSL-SE, thou I don't think I got it from RB. I don't know if the siamese center port would affect the tuning of the exhaust. I do remember the 12A had a shorter distance to the collector than the 13B.
12-30-2010, 11:12 AM
#41
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^^^^^
12-30-2010, 01:47 PM
#43
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There isn't an engine on the planet that doesn't benefit from actual bends over brick wall transitions. A turbo manifold is suppose to be as free flowing as possible. Just look at F1 80s turbo motors; large radius gentle bends. The manifold wasn't designed to keep the rotors exhaust pulses from interfering with each other, as said that won't make that big of a difference because of the center port exhaust. It was designed to be free flowing.
I have done back to back testing on a pair of Rx-7s that showed a 1000rpm gain in boost threshold and 20rwhp across the board from a hks style log manifold to tubular design. Its pretty much the same on piston engines, even small 4 cyl which you can somewhat compare the Renesis too( low overlap/ and more exhaust restrction(valves/sideports)). You don't see any performance piston motors running log manifolds.
We looked at the boost curve compared to MM's smaller 3076R, and this bigger 1.06 Gt35R spooled almost as fast at partial throttle. Given the dyno doesn't exactly show real world conditions, ie: transient response. I haven't seen a lot of top mount turbo systems dynos, but they look awfully laggy to me, and these have all been 60~ish mm turbos.
You can't really compare n/a headers to turbo manifolds either, there is no pulse tuning in a turbo manifold. Just look at supercharged top fuel dragsters, the headers aren't even collected. You just want to get the exhaust out as fast and as easy as possible when you are under positive pressure. Even so you sure don't see RB selling log manifolds. Futhermore in an ideal world under 1 bar you are at twice the atmospheric pressure making your engine basically twice its size. If you had a 2.6L Renesis you would see bigger gains in n/a form from the exhaust system.
Outside of all this theory, real world results show VERY fast spool for a big Rensisis turbo, and if you look a the powerband its almost doubled everywhere, not just up top.
I have done back to back testing on a pair of Rx-7s that showed a 1000rpm gain in boost threshold and 20rwhp across the board from a hks style log manifold to tubular design. Its pretty much the same on piston engines, even small 4 cyl which you can somewhat compare the Renesis too( low overlap/ and more exhaust restrction(valves/sideports)). You don't see any performance piston motors running log manifolds.
We looked at the boost curve compared to MM's smaller 3076R, and this bigger 1.06 Gt35R spooled almost as fast at partial throttle. Given the dyno doesn't exactly show real world conditions, ie: transient response. I haven't seen a lot of top mount turbo systems dynos, but they look awfully laggy to me, and these have all been 60~ish mm turbos.
You can't really compare n/a headers to turbo manifolds either, there is no pulse tuning in a turbo manifold. Just look at supercharged top fuel dragsters, the headers aren't even collected. You just want to get the exhaust out as fast and as easy as possible when you are under positive pressure. Even so you sure don't see RB selling log manifolds. Futhermore in an ideal world under 1 bar you are at twice the atmospheric pressure making your engine basically twice its size. If you had a 2.6L Renesis you would see bigger gains in n/a form from the exhaust system.
Outside of all this theory, real world results show VERY fast spool for a big Rensisis turbo, and if you look a the powerband its almost doubled everywhere, not just up top.
Anyhow, dont take my word for it...i took notes from Corky Bell....he seemed to know what he was talking about...
Last edited by Jamaalsmith; 12-30-2010 at 02:13 PM.
12-30-2010, 02:49 PM
#44
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The reason it doesn't make as much difference on the Renesis is the air is already doing two 90* bends to start with anyway, where it's energy is the highest, but every bit helps.
12-30-2010, 03:50 PM
#46
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However, I do think pulse tuning in the exhaust shows some benefits even in the zero overlap renny
/gets popcorn for another arguement...
Last edited by PhillipM; 12-30-2010 at 04:04 PM.
01-15-2011, 01:56 AM
#50
Ultimately, I think the turbo choice and MAF housing design are going to play a more significant role in the output of the kit.
Good manifold design is mostly about kit durability and heat extraction from the motor, both of which can't really be determined so soon.
Good manifold design is mostly about kit durability and heat extraction from the motor, both of which can't really be determined so soon.