I know high compression boosting needs a good tune air/fuel. But what can be done to strengthen the block to be able to take the higher pressures?
I'm talking 15+ psi.

I guess a better question would be: How much boost can a t2 block handle before it cracks or blows an o-ring? Like wise with a 6-port block.

 

Boost level is not nearly as important as HP level, and you're really talking about two different things here.

HP levels is what's going to crack a block.

Most turbo engines are lower compression as a safe measure against detonation. High compression, high boost, or a poor tune are all good ways to detonate, and we all know how much a rotary likes detonation.

Search, all these questions have been answered before.

 

just tell us what you want to do...

 

I've heard of Stock Turbo II motors with upgraded turbos run 15psi with no problem....
are you increasing your compression on the turbo II motor? if so, why?

 

strengthen the block?

you can use a later block (S5 -T, -RE, or -REW) because of the thicker dowel lands or you can add dowels OR both. those are methods that i know of. i'd imagine the rotary gurus may have other secrets, but they remain secrets (at least to me). obviously not detonating would be the best solution for preservation - but i know, easier said ...

 

get the front and rear plate of a late S5 turbo block(better casting)and build the motor with solid corner seals and a good brand of apex seals and springs(upgrade all the internal and clearence everything acording to the aplication)and it should work,i had a S5 Turbo block running 9.7.1 rotors but i never went above 12 psi

 

With 9.7 rotors, I would keep blowing my Apex seals at 15PSI. Perhaps with a GOOD tune, it could of have gone higher in boost.

PS. Avoid low octane gasoline.

 

Right now I have a S4 6-port motor with a s5 turbo on it. I've been running 10psi for a year now and it loves it. A couple times my wastegate has gotten stuck and I've hit 15psi. I just loved that feeling in addition to the performance. I know the efficiency of a stock turbo isn't much good at that much. This winter I've got some stuf planned for the car mostly fixing things broke and wornout from this year(clutch, rear end, etc). If I have some cash left over I was thinking of getting some kind of aftermarket turbo and was wanting to run higher boost, about 15 psi.

Just wondering what kind of limits I would be having. I'm wanting 275-300hp that's still streetable. Ideally i'd get a 4-port block and put the higher compression rotors in it but I'm curious what can be done with the 6-port block. If I tear apart the motor definately doing a port job, and if I can scrounge up supplies a custom intake to full use the aux ports. Also, with that range of hp my SAFC probably wouldn't be able to handle it, right?

Just writing it out to see what it looks like then decide from there.

 

Detonation cracks blocks, not boost.

If you want to make those power levels, you'll want to upgrade to a better turbo. You'll never put down 275HP on the stock turbo. It's out of breath around 250HP, which comes on right around 12 PSI.

I wouldn't suggest using an S-AFC for those power levels on a high compression block. You really need to start pulling timing around 10 PSI to be reliable.

Why switch to the 4 port block? The ports are tiny compared to the 6 port.

 

I'd rather stick with the 6-port as well. Because of the flow and save me some cash from tearing a part and rebuilding a t2 motor with n/a rotors. My block has less than 100,xxx miles on it right now so it's not even close to NEEDING a rebuild.

Honestly, I'm scared to go stand alone, because it's something I'm not familiar with! But I know it's something I'd have to do to make this work reliably. I've been talking to some of my local "tuner" guys and I think they've convinced me that I could do it.