The double-walled factory manifold is a pretty elegant solution if one is running in the flow characteristics which that manifold supports. It's not made for big horsepower applications, obviously. Just curious if you think otherwise?
Filippo
Technical Turbo design discussion and opinions
- Thread starter MMP
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Filippo
Rob@RBTurbo
Lieutenant
There is absolutely NOTHING wrong with the OE manifold in the form of the primary tubing design or flow limitation. It does neck down at the collector, however, but it is not of any real restriction in comparison to the A/R housings it is being used upon.
All in all the OE manifolds are a very all around ideal component for up to the 550-600whp range while retaining optimum transient response IMO; which is where the vast majority of enthusiasts are looking to be at (or below). Obviously the higher they are pushed, Back Pressure will build, and the better flow units will be more desirable as one decides to chase power more so over response. Trying to minimize this power/response trade-off is always what is key.
Lastly there is nothing wrong with making some improvements for those chasing the bigger power ranges, but doing these improvements tastefully seems to be the question at hand here. IMHO Hydra (who mind you is a would be competitor) is doing things much better than what I'd ever seen done with any setup prior or present. That is for those whom are looking to push the envelope of twins as efficiently as possible into deeper yet realistic power goals... meaning optimized response and best power area under the curve to cater to those chasing the next levels of power with the least possible hit in the transient response department.
Rob
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The stock manifolds are not, in any shape or form, a restriction if you are using a "stock-frame" TT setup. I would have gladly used them on my build had they fit. Once again, a 6" long 32mm ID runner is never going to be the bottleneck if it feeds a turbine housing with a nozzle area of <8cm2. This is going to be my only contribution to this thread, as I prefer to save the good stuff for my upcoming product release thread, but I will leave you with this nugget @MMP , I saw 17.x psi @ 3100rpm in 3rd gear running a 3.46 diff in my sub-3000lb 6MT 135 on a warm afternoon... Over and out 
@MMP , thank you for sharing such detailed info - its stuff like this that makes me enjoy this forum over the FB groups much more still. Regardless of any competition between companies, and even though I can see why @doublespaces made this a seperate thread, I think posts like that are not only interesting but very informative about the platform as a whole to the point of being entertaining imo.
Before I bit the bullet on an expensive turbo upgrade, my anxiety about having the best option available for my goals drove me to do research on all the info offered on the different high-Hp-capable setups in regards to technical info offered with each ones respective product description (and not just on typical things like wheel specs, but so far as reading about the different metallurgical properties and the casting/machining processes etc), before ultimately deciding the 1Ks were the way to go for me - so I personally can see Mauricio *really does* know what he's talking about due to extensive research and uses that knowledge to make an excellent product. I'm pretty excited to see where @hydra takes things still though (and tbh I think even Mauricio would be/is), because like Mauricio and a handful of other vendors he is absolutely still breaking new ground with the N54 and also is clearly putting in a lot of work and research into designing his products.
I wish @Rob@RBTurbo didn't have me blocked at times like this because he clearly does have technical knowledge too, but I think the "argumentative" side of what's "best" is popping up not just due to sales, but because the 3 vendors clearly have very different goals with their turbos. @hydra has stated he wants to design a turbo that offers a consistent and smooth powerband designed for road course work, @MMP made the 1Ks for the higher peak power dragstrip style setups, and @Rob@RBTurbo seems to design things to be "OE+" daily driver style setups as evidenced by a lot of his products and his posts. If the three had a picnic, MMP would be bringing a decadent caramel apple, Rob would be bringing a pre-sliced organic farmers market apple from granny's, and Hydra would show up with a 5lb bag of apples from the grocery store so he wouldn't be stuck with a bad apple - how are you gonna objectively decide one person brought the best apple?
I understand where Rob comes from with the "OE is good enough" thing to an extent, but I think there's several flawed thoughts there too. Yes the OE manifold is good about heat and is probably more than capable in regards to bang:buck for his production costs since he sticks with OE turbo housings exclusively, and of course more isn't always better. But the 1Ks are specifically designed to make more power than stock frame turbos are capable of and obviously pump in more air as such - which would mean a higher flowing exhaust manifold is beneficial in a cyclical way since more would be coming *out* too. Maybe the MMP manifold would be a hindrance to a pair of RB EVOs, but applying the same line of thinking would be akin to discussing how the stock manifold design would perform when piped for a single 6466 - entirely different different applications.
The PDF he posted also not only talks about how the manifolds were designed for the whole "reduced emissions, increased MPG, increasing engine bay space" type of turbocharging (surely not MMP or Hydra's goal, right?) but also shows a manifold that increases ID similar to MMP's, although less aggressively (fig 12? I think). That's not even to mention that if we all stuck to the "OE is best" line of thought, everyone spending $3k+ on turbos would still be dealing with shitty wastegate rattle and never have the option of coated or ball bearing turbos. I also believe his opinion on upgraded outlets being a complete waste is evidence of his preference for using an N54 as nothing more than a cozy-but-capable daily driver - if that's his preferred use more power to him but the dyno proven gains even on stock turbos are there no matter how minimal - and those of us chasing bigger numbers certainly don't view high quality outlets as a waste. Basically, this is my long winded way of saying Rob doesnt seem interested in pushing things like many N54 owners now are, and as such his opinions are unfortunately often solidified by his bathroom mirror imo.
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FWIW and for anyone considering the 1Ks but concerned about spool or Mauricio's results possibly being "overly optimistic", here's a log from my second revision from Jake a few weeks back. I've specified to him that I don't want crazy low end anyway until I get my crank hub fix installed just to be safe, but the turbos certainly still have plenty of oomph down low and slow spooling is never a thought that crosses my mind with my setup - here's hitting 15.9PSI @ 329x RPM.
Before I bit the bullet on an expensive turbo upgrade, my anxiety about having the best option available for my goals drove me to do research on all the info offered on the different high-Hp-capable setups in regards to technical info offered with each ones respective product description (and not just on typical things like wheel specs, but so far as reading about the different metallurgical properties and the casting/machining processes etc), before ultimately deciding the 1Ks were the way to go for me - so I personally can see Mauricio *really does* know what he's talking about due to extensive research and uses that knowledge to make an excellent product. I'm pretty excited to see where @hydra takes things still though (and tbh I think even Mauricio would be/is), because like Mauricio and a handful of other vendors he is absolutely still breaking new ground with the N54 and also is clearly putting in a lot of work and research into designing his products.
I wish @Rob@RBTurbo didn't have me blocked at times like this because he clearly does have technical knowledge too, but I think the "argumentative" side of what's "best" is popping up not just due to sales, but because the 3 vendors clearly have very different goals with their turbos. @hydra has stated he wants to design a turbo that offers a consistent and smooth powerband designed for road course work, @MMP made the 1Ks for the higher peak power dragstrip style setups, and @Rob@RBTurbo seems to design things to be "OE+" daily driver style setups as evidenced by a lot of his products and his posts. If the three had a picnic, MMP would be bringing a decadent caramel apple, Rob would be bringing a pre-sliced organic farmers market apple from granny's, and Hydra would show up with a 5lb bag of apples from the grocery store so he wouldn't be stuck with a bad apple - how are you gonna objectively decide one person brought the best apple?
I understand where Rob comes from with the "OE is good enough" thing to an extent, but I think there's several flawed thoughts there too. Yes the OE manifold is good about heat and is probably more than capable in regards to bang:buck for his production costs since he sticks with OE turbo housings exclusively, and of course more isn't always better. But the 1Ks are specifically designed to make more power than stock frame turbos are capable of and obviously pump in more air as such - which would mean a higher flowing exhaust manifold is beneficial in a cyclical way since more would be coming *out* too. Maybe the MMP manifold would be a hindrance to a pair of RB EVOs, but applying the same line of thinking would be akin to discussing how the stock manifold design would perform when piped for a single 6466 - entirely different different applications.
The PDF he posted also not only talks about how the manifolds were designed for the whole "reduced emissions, increased MPG, increasing engine bay space" type of turbocharging (surely not MMP or Hydra's goal, right?) but also shows a manifold that increases ID similar to MMP's, although less aggressively (fig 12? I think). That's not even to mention that if we all stuck to the "OE is best" line of thought, everyone spending $3k+ on turbos would still be dealing with shitty wastegate rattle and never have the option of coated or ball bearing turbos. I also believe his opinion on upgraded outlets being a complete waste is evidence of his preference for using an N54 as nothing more than a cozy-but-capable daily driver - if that's his preferred use more power to him but the dyno proven gains even on stock turbos are there no matter how minimal - and those of us chasing bigger numbers certainly don't view high quality outlets as a waste. Basically, this is my long winded way of saying Rob doesnt seem interested in pushing things like many N54 owners now are, and as such his opinions are unfortunately often solidified by his bathroom mirror imo.
---------------
FWIW and for anyone considering the 1Ks but concerned about spool or Mauricio's results possibly being "overly optimistic", here's a log from my second revision from Jake a few weeks back. I've specified to him that I don't want crazy low end anyway until I get my crank hub fix installed just to be safe, but the turbos certainly still have plenty of oomph down low and slow spooling is never a thought that crosses my mind with my setup - here's hitting 15.9PSI @ 329x RPM.
Attachments
Thanks for comments and posting results. We aim to make the highest power twin turbos out there at the best prices, nothing from the stock frame re-used, purpose built designed for max power and still awesome drive ability. The mission is the same, make parts I love and enjoy on a daily basis and if I love it as an enthusiasts and would buy it for the price there is a market I think and others will love it. That’s how the company started just as an enthusiast hobby and grew from there.
Not a problem - I'm very happy with the product and the choice I made. There's still plenty of work to be done on the tune at this point, and I think once I get my cams in + a few other things I should really be able to push these things how they're designed to be. As of right now Jake has me peaking around 25-26psi with hardly any taper - these things really do pull and pull, and I have no doubts that with the right supporting mods and tuning they're capable of the advertised numbers.
Well different manifolds are most likely superior in different segments. VTT has said the OE manifold becomes restrictive over 600whp. Rob is saying he is targeting the segment below 600whp. So they seem to be in alignment somehow.
But I am also curious how anyone would optimize the OE manifold in a cost-effective way for the "spool" segment below 600whp (where I definitely am). Now, I have obviously chosen the GC lites, but I do not have any proof that transient response is any better with these manifolds over OE.
Rob@RBTurbo
Lieutenant
The OE manifold poses no restrictions for any turbine housing less than around 5cm2 A/R, maybe a bit more, but I'd say even 6cm2 would be a push. Hydra said above it is no restriction up to around 8cm2, but IMO this is a large stretch as this would allow for virtually no funneling effects in the turbine housing inlet and surely be a restriction along the way. Fortunately the OE turbine housing is 4.9cm2, the china frames are about 4.8cm2, the Zage/GC ~5.0cm2, so either could be supplied very well with the OE manifold. We've used it as have some other very well respected vendors, for many years now with great results.
Meanwhile Hydra is going to be 6.6cm2 and the MMP 1K is now claimed to be 7.0cm2. IMO once you get to these levels in A/R, a new manifold with proper merger ID is going to be warranted. But keep in mind once you go too large on A/R you better have a large displacement, a ton of RPM, or both. No matter how you skin it overly large A/R's are just not going to be but for a very small N54 demographic, and making these extreme power levels is going to be beyond just a large turbine housing as other turbo design attributes most also be in perfect alignment as well. Likewise and as for the manifold design you should never design any turbo manifold with overly large primaries, there is no good to come from that. Ask VTT how their initial Garrett Stage 3 went when they built it initially with 1.5" weld EL's if you want some platform specific experience on the matter (quick recap: low power and slug response, even with BB turbos). I believe this setup was claimed to have recently made 900+whp, on the current 1.25" weld Els, to also illustrate that large manifold primaries just not needed for even that level of power. While this should be common sense, the cylinder head exhaust port and primary runner should be held very close to each other in area.
When it comes to the MMP's all we have seen thus far is a very lazy turbo setup that even at high boost they seem to make very little power, even 600+whp seems to even be a struggle for them- and it comes on very late too. Perhaps they will make 700+whp someday, but there has been nothing even remotely close to the 1k potential claims thus far AFAIK and if this persists there must just be some other limitations that were not addressed in the overall design. All said unless something changes there seems to be some very grave design issues with them and all there is a very lazy and low powered setup.
As for optimized transient response and spool it is simple, a smaller A/R is going to respond the best and as you go larger you will lose response (all else equal); but it is good to tailor the housing A/R along with wheel sizing and engine application setups as you go too as long as it is in good design taste.
Rob
Meanwhile Hydra is going to be 6.6cm2 and the MMP 1K is now claimed to be 7.0cm2. IMO once you get to these levels in A/R, a new manifold with proper merger ID is going to be warranted. But keep in mind once you go too large on A/R you better have a large displacement, a ton of RPM, or both. No matter how you skin it overly large A/R's are just not going to be but for a very small N54 demographic, and making these extreme power levels is going to be beyond just a large turbine housing as other turbo design attributes most also be in perfect alignment as well. Likewise and as for the manifold design you should never design any turbo manifold with overly large primaries, there is no good to come from that. Ask VTT how their initial Garrett Stage 3 went when they built it initially with 1.5" weld EL's if you want some platform specific experience on the matter (quick recap: low power and slug response, even with BB turbos). I believe this setup was claimed to have recently made 900+whp, on the current 1.25" weld Els, to also illustrate that large manifold primaries just not needed for even that level of power. While this should be common sense, the cylinder head exhaust port and primary runner should be held very close to each other in area.
When it comes to the MMP's all we have seen thus far is a very lazy turbo setup that even at high boost they seem to make very little power, even 600+whp seems to even be a struggle for them- and it comes on very late too. Perhaps they will make 700+whp someday, but there has been nothing even remotely close to the 1k potential claims thus far AFAIK and if this persists there must just be some other limitations that were not addressed in the overall design. All said unless something changes there seems to be some very grave design issues with them and all there is a very lazy and low powered setup.
As for optimized transient response and spool it is simple, a smaller A/R is going to respond the best and as you go larger you will lose response (all else equal); but it is good to tailor the housing A/R along with wheel sizing and engine application setups as you go too as long as it is in good design taste.
Rob
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I saw 17.x psi @ 3100rpm in 3rd gear running a 3.46 diff in my sub-3000lb 6MT 135 on a warm afternoon... Over and out
Damn, that's pretty good. I know the pain of the slower spool after I switched to 3.46 myself. 3.08 on your car would be in the 2800rpm range for that spool easy
Customer just posted on our page with the 1K turbos 724whp/726wtq on a stock motor stock head at 26.x psi 65% WGDC so plenty left in the turbos. That’s really pushing it for a stock block and a poor flowing stock head.
Rob@RBTurbo
Lieutenant
That is actually very good, rather excellent, news. The only other results out there up until this point have the appearance of pegged turbos in the 590-620whp range, you may want to get this out there on the forums as not everyone follows FB. Also great as customer/3rd party results are always more favorable as they are typically more trustworthy, etc.
However from a dyno perspective we have still seen the 700+whp range on 4.9cm2 stock frames as well (not RB, but others have); and there are plenty making up to 800whp and some over even on the ~5.0cm2 Zage/GC housings. Now we are not saying that <5cm2 housings are ideal to make the bigger numbers, just saying that they are still able to make the same power as your latest results. What this tells you is backing off the A/R to some degree would likely yield much better area under the curve, very similar peak power, and a better responding turbo setup all around. It would be interesting to overlay these results with some of the VTT GC data.
Rob
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Don't the hydra turbos seem to be pretty spot on for what everyone has said would be best. Would seem to me the 650s should have slightly better response and slightly higher potential than gc lites and the 800s do the same to gc and mmp stage 3s unless im misunderstanding? I don't think they are competing with the rb setups but for the higher range they seem to be very solid
I totally believe it, I've seen some similar results from them on FB too. I think the "issue" is moreso people are not pushing them as much as people have with the stage 3s and GCs because they're newer, and I think a lot of people who buy them don't plan on making the higher end power for longevity, but Rob does have a point about not many 1K customers being on the forums.
I however do plan on pushing them once I get a shotgun setup and metal IM. I'm very excited to see what they'll do for me considering I'll have cams to help take advantage of the extra flow areas
I'm glad rob can recognize impressive results and applaud a competitor, but I don't think any results showing the 600-650 range for 1Ks show any "pegged" turbos, they're usually limited by fueling. I'd be interested in seeing the comparison to GCs also just out of curiosity, but I still have no doubt the 1Ks are the way to go if you want to be competitive with single turbo cars at the strip, and not have maxed WGDC. That's actually my end goal more than crazy peak HP - I hope to be one of the people in the low 10s but doing it on twins, and from my discussions with Jake he agrees I should definitely be able to with my build plans. Once I wrap up the power adder stuff in the next few months I'll be moving onto suspension and hopefully thatll get me where I wanna be.
Our Wastegates are set to 6inhg vac to close as factory specified. As WGDC goes above 65% on our turbos boost increases quite a bit. The GTX 11blade wheel we chose for our design performs best and most efficiently at higher pressure ratios(higher boost) so at the higher WGDC is where they perform the best which is why they can build quite a bit of boost above 65% WGDC. This Has been shown also on our stage 3 turbos many times that use the same compressor wheel design.
Rob@RBTurbo
Lieutenant
You are correct in that WGDC is only a mild indicator of what is going on especially once you get into the 60+% ranges as Wastegate adjustment/design/etc can play some large variables there.
And while we would not put much stock in ever using it as a "still a lot left" when they are at 65%; it is reasonable to give it more time and see what actually happens with the power with that part out of the equation (ie. when they are just literally pegged) this way there is just nothing else to debate on that front.
Rob
I honestly am at the point where I would take what rob is saying at face value without a grain of salt. Reason being for years he stated what his designs were intended for and that he would have no problem praising a proper setup. Now we finally have someone making something that complies with most of the recommendations made by rob and he has alot of people eating crow cause he has been pretty mature about it, I think anyway
Rob@RBTurbo
Lieutenant
Unfortunately when the masses get conflicting viewpoints from multiple vendors, it just gets very difficult for truth to prevail. We've certainly no issues with telling it how it is, and well agree that most of what we see thus far with the Hydra setup is looking great.
As anyone who can technically follow along with this discussion can understand, what we've always been saying (and are often scoffed at for doing as such) is that the Zage/GC 1.0 (and subsequently cheaper copied GC 2.0's) have essentially the same meaningful A/R as the OE turbos. Unfortunately when one looks at a picture of the turbine housing inlet and manifold outlet mating connection, they however say "WOW look at how much more flow this setup has!" and then all promise of understanding goes out the window. They are not considering that the A/R (the actual A at Radius intersect) inside the turbine housing is basically the same size as OE; and this is the main restriction of any turbo setup from a power production perspective. Hydra seems to have a firm grasp on this and likewise surely would agree as well.
Anyway long story short we could've been selling those GC ~5.0cm2 housings for well over a year now, but have opted out of them as there was no point unless we too want to join in the business of bullshitting customers. So yes when we see an OE housing at 4.9cm2, a Zage/GC1.0/GC2.0 at ~5.0cm2, you are going to hear "not really much of an improvement" from us as that is the truth. Now if we see an aftermarket cast housing with an actual A/R improvement, then we of course will say "there's certainly potential for more power at some trade off of transient response" and the positive thoughts for bigger powered options will begin to flow.
A REAL game changer will come in the form of a perfectly matched setup, meaning all components from inlets to outlets, wheel designs with matching A/R potentials, etc.; and this is the closest thing that has been put out there to date IMO. The MMP 1K setup went off in the right direction by addressing the actual A/R but seems to have really went overboard IMO... but more will have to come with that as more information is shared.
Rob
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Until someone solves the rattling waste gates, you are pissing in the wind. How about this Rob. I'll buy your turbos at 50% of asking price, and I will send $200 dollars a year until they start rattling?
No offense, btw. I'm still deciding between a small bottom mount and what you guys have going on.
No offense, btw. I'm still deciding between a small bottom mount and what you guys have going on.
