Some of you might have seen knockoffs of Brettspeed's manifold floating around social media. Here is why they are absolute garbage, the one pictured and any other that doesn't have as little as 10% of the originals R&D.



For full disclosure I have no business promoting one and shaming the other. I am not paid by anyone nor looking to be. I have had my fair share of boosted renesis journey stops, most of which could be avoided had I been wiser to learn first then try stuff after. For this you can read my build thread and draw your own conclusions.

1) Absolutely terrible flow ! Both rotors have to do 2 very tight bends before reaching the turbo. In the original there is NO BEND ! Rear port drives the turbo directly and the front wastegates out almost directly, with a smooth 90 deg bend and out of a 44mm wastegate.

2) Internal wastegate turbo - all flow has to pass through the turbine housing and that Vband. The original has a T3 flange of similar area AND a 44mm wastegate to flow stuff in and out.

3} 1 + 2 = massive back pressure = very poor flow = poor spoolup = lots of stress on the engine for very poor net power output. While the manifold pictured is advertised as a "400hp plug and play kit" the reality is that you'd need 15psi of boost to even reach 310whp(seller provided info - at least this bit sounds reasonable)
THIS IS PATHETIC PERFORMACE. But performance outside you're going to need lots of expensive internal engine mods to be able to sustain this boost level(which obvs. is not mentioned by sellers).
At 15 psi a proper kit would be in the 400whp area, not barely touching 310whp at redline for 100rpm. The purpose is not to run a lot of boost, it's to keep boost to a minimum and flow to a maximum.

4) Turbo placement is extremely poor - creating a massive bottleneck(hotspot) just in front of the Siamese port which, as those that have been at this game for a while might know, likes to shatter under prolonged heat and pressure. Did I mention already that this kit will have plenty of poor design induced heat and pressure overhead ? If you ask me, I give this setup no more than a few fuel tanks driven with reasonable boost usage before it tears itself apart. I might have been there and done that, a few times even.

That's as much as I can confidently say from what was posted online. I say this from my own experience of trying out various setups over 5 years, ranging from 250whp to 380whp, now shooting for above 400whp with the next build.

 

1/Agreed
2/Agreed
3/Their 400 FWHP at 15psi was for a 4 port which actually sounds about right . (approx. 340whp at 15psi)
4/Agreed. The original design prioritises the outer ports and restricts the Siamese port to a degree. Which I believe is exactly what the Renesis needs to allow that port sleeve to live. Prioritising the siamese like they have is a sure fire recipe for disaster IMO.

Also, according to the manufacturer the design/turbo is for a 4 port engine. This plus the inability to use it on a RHD car make it only suitable for a small % of RX8s.
They say the APV motor needs to be removed and valves locked open or closed on a 6 port. This is a major compromise on engine power at low rpm if left open and high rpm power if left closed.

 

Isn't it a bit like a greddy manifold also?

 

But worse even, as that kit ran low boost and most people left it as is with good results.

 

This is now in production and they are making lots of them.
Lotta Siamese sleeves off to meet their maker!

 

To add insult to... another insult the same (?) blokes that made that atrocity has doubled down and made an intake manifold aimed at boosted engines.


The major gripes I have with that intake are:
1) fuel rail now dangles on the outside, straight into the path of the heat rising from the exhaust/turbo. Heated injectors, wiring harness, fuel rail, gasoline itself, they all behave differently when heated up and even worse when heat soaked. But hey, bling bling points galore!
If you don't believe me, here is how the primary injectors which sit deep inside the middle iron are scaled with temperature and load:




2) unclear if the APV is still there and if it is operational like the OEM one. Probably not. No APV is a major downside unless it's for a racing setup.
3) no SSV. Unless this piece of kit is aimed at racing setups where it literally matters not how the engine behaves below 6000 RPM, deleting the SSV will impact whatever little drivability the engine has under 3000 RPM. It is the kind of mod I despise most: lose 50% somewhere to gain 5% somewhere else; the kind that shows lack of effort.

The major wins I see with that intake:
1) the auxiliary intake ports now get their own injector. The stock setup sadly does not have any fuel going in the aux ports... only the secondary and primary ports get their fuel; leaving the air that comes in through the aux to be mixed with extra fuel that comes in from the secondary port. This alone shall bring a few hp; better air fuel mixing is always a positive.
2) the matching UIM will surely not be made of plastic like the OEM one, which might literally blow up under boost if it feels like so. Not common at all, but it can happen. On the upside, plastic is a good thermal insulator; aluminium is a conductor, so expect some terrible heatsoak and higher charge air temps with an aluminium UIM. Replacement plastic UIMs are also plenty and dirt cheap.
3) no VDI; this isn't much of a win as the stock VDI can be very easily locked in place. I do agree that it looks better not having parts that do nothing.
4) can't really tell but it looks like it: air passages are wider and shorter, better suited to high RPM high flow needs.

Overal: an expensive move that is a sidestep at best. The overall is no, I would not buy it, not even if it was given to me for free.

 

I joined today after reading this post because I was shopping for turbo kits to go into a S1 rx8 along with a bridge ported renesis. Good info and opinions here to take in. Nobody on here buying this kit?

 

Welcome. I’m not sure why anyone would want to buy that kit when everything you need for the ultimate RX8 can be found in Brett's info thread. Brett spent years perfecting it, and I've experienced it first-hand with my build.

 

BP too; 2x jump first, look & learn later …