EFR Internal Waste-Gate Discussion

[Mitchocalypse]

Originally Posted by RICE RACING

Without wanting to read like HC!

Flow priority is far more important than shortness of pipes. The BIG problem you have with short manifolds is heat, fitment, durability.......... nothing dies faster than a short manifold and its allot more stressed than a longer one I find.

The turbine entry flanges do not last very long, especially on a divided unit, they warp and the center section gets eaten away and good luck keeping a gasket alive long term there too.

On turbo rotaries for a while now I have not bothered with divided entry turbine housings 1) they are not durable 2) they are a nightmare to keep a gasket up too 3) they are not really needed much for turbine response 4) they are way too heavy!

For rotaries the single entry Tial turbine housing is the only thing that is durable and will last I have found.

What's your definition of durable? Like holds up well for people beating the shit out of their cars every weekend at the track? Outlasts the engine? Lives through a few oil changes?

[RICE RACING]

Originally Posted by Mitchocalypse

What's your definition of durable? Like holds up well for people beating the shit out of their cars every weekend at the track? Outlasts the engine? Lives through a few oil changes?

People's definitions are very different especially on the internet.

The problem with turbo rotaries used in road cars is if it is set up to be efficient then it will run a high exhaust gas temperature. When you run it at 0.9 Lambda say and at a constant 100kmh you will see a high temperature and as a result the exhaust parts start to eat them selves (as you see on any turbo rotary)... ever seen what a FD3S turbo manifold looks like? Basically after 50,000km road use only these parts are scrap.

On a single turbo I have never seen any manifold last more than 30,000km (or 15+ BDC and HC engine rebuilds!). These effects get compounded if you do any sort of real power utilization (say 2% duty) at full load and power.

If you add power to the equation then its even worse as the effects are worse, high temperature combined with high pressure and cycling of temperature from high to low, pre load on the metal gasket diminishes over time then they get eaten along with the mating flange surfaces = in the end a fucking nightmare. The only things that work are gasket less, while they are not perfect they are 'durable'.

I got sick and tired of resurfacing all types of manifolds (machining is my profession among many!) and seeing all of this shit over the years. This is why rotaries are fucked! the same problem occurs in piston cars but the time is about triple to the time of failure!

p.s. most people never talk about this cause they NEVER have owned them long enough or had an engine last that long LOL....... it is an issue, I'm sure I am not the only one to experience it