What turbo manifold to get? There arent many options out there....
#45
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Gosh, I've never seen so many people bash the BEGI cast iron manifold before. What got into everyone all the sudden? It is one of the best available and has the best history of any manifold, ever made for the Miata. 16 years and two unexplained failures. There have been other failures, but those can be attributed to too much ignition retard. Too much ignition retard will kill/crack any manifold. That said, it has to take alot of abuse in order to crack it.
I think the true test of durability - is that all of the 400 hp plus miatas running a cast iron manifolds - are using the BEGI manifold. The first 600 whp Miata was running a BEGI cast iron manifold. Short of dropping it on the floor or retarding too much timing, it is nearly bullet proof.
As for flow, the only one that potentially has us beat is the absurd flow manifold. It is pretty spiffy, but not a cast iron manifold. Time will tell how the welded ones hold up. The FM manifold has more bends and angles to it, therefore it will flow worse. It also does not have the divided pulse feature.
As for reliability, I can just about guarantee you that an FM manifold will break studs. 8mm studs do not last that long even for street use. Been there, done that, and learned that lesson. We have been using 10 mm studs for a few years now. The only people that have problems with the 10 mm studs are the racers. That could very well be because we were shipping grade 5 studs instead of grade 8 studs. That problem is fixed now though. The grade 5 studs got thrown in the garbage and the grade 8 studs are shipping with ALL the turbo kits and manifolds. However, they still seem to have a stud stretching problem. Corky's investigation continues. I, personally, do not track my car and have never had a loose nut or stud problem. I put lots of miles on it, but no track use. If I had to choose between an S4 manifold and the cast iron one, I'd probably choose the cast iron for the reliability factor.
Stephanie
I think the true test of durability - is that all of the 400 hp plus miatas running a cast iron manifolds - are using the BEGI manifold. The first 600 whp Miata was running a BEGI cast iron manifold. Short of dropping it on the floor or retarding too much timing, it is nearly bullet proof.
As for flow, the only one that potentially has us beat is the absurd flow manifold. It is pretty spiffy, but not a cast iron manifold. Time will tell how the welded ones hold up. The FM manifold has more bends and angles to it, therefore it will flow worse. It also does not have the divided pulse feature.
As for reliability, I can just about guarantee you that an FM manifold will break studs. 8mm studs do not last that long even for street use. Been there, done that, and learned that lesson. We have been using 10 mm studs for a few years now. The only people that have problems with the 10 mm studs are the racers. That could very well be because we were shipping grade 5 studs instead of grade 8 studs. That problem is fixed now though. The grade 5 studs got thrown in the garbage and the grade 8 studs are shipping with ALL the turbo kits and manifolds. However, they still seem to have a stud stretching problem. Corky's investigation continues. I, personally, do not track my car and have never had a loose nut or stud problem. I put lots of miles on it, but no track use. If I had to choose between an S4 manifold and the cast iron one, I'd probably choose the cast iron for the reliability factor.
Stephanie
#46
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I'm always the first to say that my BEGi kit was 100% reliable on the street. I never had to put a wrench on it once. Even after track action, the only parts that failed were the studs...and that says a lot considering the demands I've put on it.
Now, for a discussion that hinges upon untested equipment that may, and probably will fail on the track, lets just pretend that v-bands work for a moment:
I don't want to deal with taking the turbo manifold on and off to replace studs 5-hours from home, and sending the manifold to the machine shop each time to get it fixed. Considering that BEGi now makes a V-band kit there is no reason to deal with cast iron any longer in my esteemed opinion. They warp, the studs break/stretch, so why anyone would spend money when there's as absolute solution from one of the big vendors? Of course BEGi should keep selling it, but "I told you so" for every person who experiences this problem when either BEGi or Tim are making manifolds which circumvent this problem. Its 2009, every competitive racing team is using V-bands, so now its time to evolve. The turbo miata world had a revolution this summer, I embraced it.
If I could turn back time, I would have started with V-banding (or stay naturally aspirated like I knew I should have) and never had any of these problems but after the amount of money I've spent trying to make it through 1-session on a cast manifold it would be foolish to go with anything but v-bands. If the V-band kit fails, I've learned a roughly $6k lesson just in turbo parts alone. I'm going to cry and cry over it...but I'm selling everything and buying an Evo-9. Get ready for the fire sale.
Now, for a discussion that hinges upon untested equipment that may, and probably will fail on the track, lets just pretend that v-bands work for a moment:
I don't want to deal with taking the turbo manifold on and off to replace studs 5-hours from home, and sending the manifold to the machine shop each time to get it fixed. Considering that BEGi now makes a V-band kit there is no reason to deal with cast iron any longer in my esteemed opinion. They warp, the studs break/stretch, so why anyone would spend money when there's as absolute solution from one of the big vendors? Of course BEGi should keep selling it, but "I told you so" for every person who experiences this problem when either BEGi or Tim are making manifolds which circumvent this problem. Its 2009, every competitive racing team is using V-bands, so now its time to evolve. The turbo miata world had a revolution this summer, I embraced it.
If I could turn back time, I would have started with V-banding (or stay naturally aspirated like I knew I should have) and never had any of these problems but after the amount of money I've spent trying to make it through 1-session on a cast manifold it would be foolish to go with anything but v-bands. If the V-band kit fails, I've learned a roughly $6k lesson just in turbo parts alone. I'm going to cry and cry over it...but I'm selling everything and buying an Evo-9. Get ready for the fire sale.
#48
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Nope. It has more to do with a turbine housing that is possibly the wrong size. Or a turbo inlet of 2.5" instead of 3", etc.. The turbo has the smaller a/r turbine. The car makes 267 ft/lbs torque at 4200 rpm (fun to drive!!!), but starts to fall off.
I did ask Corky about that too, just to be sure.![](https://www.miataturbo.net/images/smilies/smile.gif)
Stephanie
I did ask Corky about that too, just to be sure.
![](https://www.miataturbo.net/images/smilies/smile.gif)
Stephanie
#51
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Nope. It has more to do with a turbine housing that is possibly the wrong size. Or a turbo inlet of 2.5" instead of 3", etc.. The turbo has the smaller a/r turbine. The car makes 267 ft/lbs torque at 4200 rpm (fun to drive!!!), but starts to fall off.
I did ask Corky about that too, just to be sure.![](https://www.miataturbo.net/images/smilies/smile.gif)
Stephanie
I did ask Corky about that too, just to be sure.
![](https://www.miataturbo.net/images/smilies/smile.gif)
Stephanie
it sounds kind of like the car gets up to full boost and then the WG starts opening and screwing up the flow behind the turbine and flow/power starts to drop off... I really don't like to contradict Corky, but it just seems like a relatively valid theory.
what a/r turbine do the s4 kits usually have?
#52
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We made this pipe strictly off the jig from the standard SG DP. Since Tim did not know how it would fit, he built the vent tube shorter. But seeing as how be built it off the jig, and no car to test fit it on, he did a damn fine job. It fit perfectly. Went straight down the middle of the tranny tunnel.
.86 A/R. This one has a .64.
Also, we do not think it is the downpipe, because the pipe is already larger than the normal pipe. It is 2.75" pipe right off the turbo. Most are 2.25" off the turbo.
Stephanie
what a/r turbine do the s4 kits usually have?
Also, we do not think it is the downpipe, because the pipe is already larger than the normal pipe. It is 2.75" pipe right off the turbo. Most are 2.25" off the turbo.
Stephanie
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I like that synapse design.
I've spent a significant period of my life under the super-miata with the Boost-Logic manifold and although it looks like ****, its made crazy #'s and the connecting hardware never loosens on race-day. But yeah, it looks like ****.
Tim...going to change the v-band design any? I like the location of the Synapse manifold better (dear god intercooler pipes will be easier and I won't have to change my water inlet neck), but at this point you could give me a hunk of **** with v-bands on it, and as long as it stays together, I don't care.
I've spent a significant period of my life under the super-miata with the Boost-Logic manifold and although it looks like ****, its made crazy #'s and the connecting hardware never loosens on race-day. But yeah, it looks like ****.
Tim...going to change the v-band design any? I like the location of the Synapse manifold better (dear god intercooler pipes will be easier and I won't have to change my water inlet neck), but at this point you could give me a hunk of **** with v-bands on it, and as long as it stays together, I don't care.