Twin Scroll Turbo system?
05-04-2011, 08:11 PM
#26
You're not really writing about a twin scroll in the traditional sense but instead a divided turbine/manifold setup. Twin scroll are valve actuated designs that change the angle the exhaust gas flows into the turbine wheel.
Best option would be to do what Mazdatrix is up to as it should also benefit exhaust manifold pressure issues.
Best option would be to do what Mazdatrix is up to as it should also benefit exhaust manifold pressure issues.
I believe that pic is the new BMW design, boost and stump pulling tq right off idle with big power too
Last edited by TeamRX8; 05-04-2011 at 08:14 PM.
05-04-2011, 09:08 PM
#29
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1984-1985 exhaust p-port housings with the Renesis side ports plated off and you're golden, you will also need to modify the rotors for deeper 13B apex seals
friend recently built a divided turbine twin scroll 13B with custom two pipe header to each scroll, equivalent to a Garrett 28xx size, makes boost right off idle with 430 hp peak and extra fat tq curve
friend recently built a divided turbine twin scroll 13B with custom two pipe header to each scroll, equivalent to a Garrett 28xx size, makes boost right off idle with 430 hp peak and extra fat tq curve
Good god, that sounds like perfection. Is he a professional builder? Is this one of those $10,000.00-$20,000.00 engines?
05-04-2011, 10:22 PM
#31
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I was reading the Renesis/rx7 hybrid thread and it isnt much thorough on how this can be achieved. Cant you explain a little bit better? I read that the side seals are different and also the Renesis has the cutoff seal which im sure wouldnt matter since the side ports are plated off. Also too much intake/exhaust overlap.
05-04-2011, 11:40 PM
#33
friend recently built a divided turbine twin scroll 13B with custom two pipe header to each scroll, equivalent to a Garrett 28xx size, makes boost right off idle with 430 hp peak and extra fat tq curve
Last edited by hoss -05; 05-04-2011 at 11:46 PM.
05-04-2011, 11:58 PM
#34
I have always wanted to play with a variable vane set up on a rotary. I think its just a really cool idea and would a good fit for the rotary engine. I have in the past looked for a Shelby CSX-VNT just for this reason. They work very well on the 911.
I sometimes wish I would not have spent the $$ on my SC set up and did some sort of custom VNT set up. There are a few very reputable shops in my area like BEGI that im sure would have been more then happy to give me a hand.
I sometimes wish I would not have spent the $$ on my SC set up and did some sort of custom VNT set up. There are a few very reputable shops in my area like BEGI that im sure would have been more then happy to give me a hand.
05-05-2011, 09:25 AM
#35
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it is a divided turbine and it is a twin scroll, you are just stuck in the dark ages of old technology .... divided exhaust pulses directly to both scrolls is the hot ticket now
I believe that pic is the new BMW design, boost and stump pulling tq right off idle with big power too
I believe that pic is the new BMW design, boost and stump pulling tq right off idle with big power too
05-05-2011, 09:31 AM
#36
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I seriously doubt it is RG.
I have always wanted to play with a variable vane set up on a rotary. I think its just a really cool idea and would a good fit for the rotary engine. I have in the past looked for a Shelby CSX-VNT just for this reason. They work very well on the 911.
I sometimes wish I would not have spent the $$ on my SC set up and did some sort of custom VNT set up. There are a few very reputable shops in my area like BEGI that im sure would have been more then happy to give me a hand.
I sometimes wish I would not have spent the $$ on my SC set up and did some sort of custom VNT set up. There are a few very reputable shops in my area like BEGI that im sure would have been more then happy to give me a hand.
05-05-2011, 11:50 PM
#39
it is a divided turbine and it is a twin scroll, you are just stuck in the dark ages of old technology .... divided exhaust pulses directly to both scrolls is the hot ticket now
I believe that pic is the new BMW design, boost and stump pulling tq right off idle with big power too
I believe that pic is the new BMW design, boost and stump pulling tq right off idle with big power too
05-05-2011, 11:53 PM
#40
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I actually talked to someone offline and he too commented on the heat a rotary produces and said that it couldn't handle it. I was just thinking out loud really and wanted to see what you smart people thought about it since I have not seen any other threads about it here.
05-06-2011, 12:58 AM
#41
1984-1985 exhaust p-port housings with the Renesis side ports plated off and you're golden, you will also need to modify the rotors for deeper 13B apex seals
friend recently built a divided turbine twin scroll 13B with custom two pipe header to each scroll, equivalent to a Garrett 28xx size, makes boost right off idle with 430 hp peak and extra fat tq curve
friend recently built a divided turbine twin scroll 13B with custom two pipe header to each scroll, equivalent to a Garrett 28xx size, makes boost right off idle with 430 hp peak and extra fat tq curve
just sayin.....
regardless ... its been done more than once ... just not here really
05-06-2011, 07:00 AM
#42
To me it seems easier to make those mechanical changes to a Renesis than to integrate the older engine into the RX-8 chassis and electronics, especially if you intend to build an engine anyway (which should be the case on any FI project IMO). The housings are a bolt in, the apex seal change is fairly common now, couple of plates over the Reni exhaust ports is easy, all you are really talking about is a custom exhaust work which is also req'd for a 13 swap. A 2 pipe top mount manifold is about as easy as it gets IMO.
You make a good point though because what you essentially will end up with is the equivalent of a street port 13B fitted with a fancy intake manifold, just depends on the integration involved for the chassis.
You make a good point though because what you essentially will end up with is the equivalent of a street port 13B fitted with a fancy intake manifold, just depends on the integration involved for the chassis.
04-01-2014, 08:50 AM
#45
Lets wake up an old but interesting thread, and theorize a bit.
9k, was this the one you read? Twin Scroll Turbo System Design - Modified Magazine All Pages
My thought was that in stead of PP, you could run center exhaust port to one of the scrolls only, or maybe even put it in after(bypassing) the turbo. This would maybe help in the area between idle and where you get boost, when engine is running as a NA.
Stupid maybe, my knowledge is limited, but obviously this would be a solution for a daily driven RX8, not a top HP setup. One of the drawbacks of turbo is throttle response seen from my point of view, and therefore a twin scroll setup seems attractive to me. I also prefer a flatter torque curve, even if it makes the car slower in the straights.
9k, was this the one you read? Twin Scroll Turbo System Design - Modified Magazine All Pages
My thought was that in stead of PP, you could run center exhaust port to one of the scrolls only, or maybe even put it in after(bypassing) the turbo. This would maybe help in the area between idle and where you get boost, when engine is running as a NA.
Stupid maybe, my knowledge is limited, but obviously this would be a solution for a daily driven RX8, not a top HP setup. One of the drawbacks of turbo is throttle response seen from my point of view, and therefore a twin scroll setup seems attractive to me. I also prefer a flatter torque curve, even if it makes the car slower in the straights.
04-01-2014, 09:04 AM
#46
04-01-2014, 01:16 PM
#50
Last edited by hoss -05; 04-01-2014 at 01:17 PM. Reason: add link