my friend was just telling me that he is getting his hands on some "teardrop" porting templates, and that porting it on a 13bT that way will make 300-360b.h.p running all stock parts other than porting at 7psi...

i did some searching in these forums and looked on fc3spro.com and didnt come up with any matches....

anyone experimented with this?

or is what he is talking about just like a bridge port turbo?


cheers,Dan.

 

He must be talking about street port templates. And the whole 300bhp on stock parts is complete bullshit.

 

i think that the templates are more like a bridgeport, but the bridge is left higher up or something...

about the 300bhp on stock parts being bullshit: thats exactly what i said...

i couldnt let myself belive that it wouldnt need slightly bigger injectors, front mount, higher pressure oil pump

 

i would guess he stalking about a bridgeport and large turbo. i dont see how the stock turbo could make that.

 

Im not buying the 300 @ 7psi on the stock turbo.. I made 372rwhp @ 12psi on stock ports with T04E

The stock turbo can not flow enough air at 7psi to make 300 hp

 

300bhp at the flywheel...maybe.
No ways the stock turbo can flow to make 300hp to the wheels.
No ways the stock turbo can make 300hp under any conditions at 7psi.
I guess you forgot the part about the NOS...


-Ted

 

yup if that is the case then I must have about 1,000,000 bhp...
I think it is bullshit,
turbo-polak where are you located?

 

close to vancouver...

 

BHP= Break Horse Power which is measured at the flywheel

 

Your not trying to lecture RETed what that means are you...?

 

The stock turbo can flow enough for 300 to the wheels. But only with the correct mods and tuning. definately not 300 at 7 psi though.

 

Sounds like rotary urban legend to me, BUT there is often a kernal of truth in legends.

By teardrop port, perhaps he means an early opening streetport that cuts into the cornereal track. This makes the port very fat and teardrop looking and indeed I believe it has many advantages over the bridgeport when using a turbo and with anything resembling a stock intake manifold.

I am just a rotary novice, but this is my thinking right now.

Intake manifold compatability-
The intake timing is only altered tens of degrees from the early opening and slightly later closing. This means it is MUCH better suited for the stock intake manifold lengths as far as dynamic effect tuning. Maybe you use 1st reversion wave now instead of stock 2nd reversion wave? Regardless, a bridgeport requires such a short manifold for dynamic effect it is shorter than the stock lower intake manifold alone, right?

Flow volume-
Sure you are only adding a couple mm of port area at the opening edge on the "teardrop" streetport, but if you add that up for the full length of the 2ndary ports and primary ports the area is just as much as a small auxillary bridgeport that is so popular for the turbo applications AND the flow path is not as compromised as a bridgeport.

Overlap specifics-
Perhaps on a turbo application it is not all about how MUCH intake to exhaust overlap you have, but how the overlap works.

With the teardrop streetport you have the advantage of less intake charge dillution than the bridgeport and you have the advantage of less intake stroke volume increase prior to port opening during exhaust overlap (stock intake opening allows for 32 deg of intake volume increase sucking exhaust into the chamber).

And here is another possible teardrop streetport dynamic.

If you carefully time your intake opening and exhaust opening you actually get the NEXT exhaust phase opening just before the intake opens.

So what?

Well, if you are already on full boost your exhaust backpressure is very low with an efficient, optimized turbo system- especially if you consider the relationship as exhaust backpressure versus intake pressure and compare it to a naturally aspirated application.

Just after the pressure spike in the exhaust port caused by opening dissapates and as the exhaust pressure is "blowing down" (as the exhaust expands to the lower pressure of the exhaust manifold) the intake port opens up.

So what?

If you look at the edge of the rotor at this point there is the high pressure high volume exhaust port at the bottom with its flow already initiated out of the engine and into the exhaust manifold.

There is the intake just opening to initiate flow at the top with the rotor tip in between- at and angle, forming the conditions for a siphon effect.

Literally "sucking" the full boost pressure intake into the now expanding intake chamber. Think about it in terms of absolute pressures, not "sucking" in the traditional sense.

Add to this, the intake charge lost out the exhaust during the "next" exhaust blowdown hits the exhaust at its hottest stage and so expanding (burning) driving the turbo even more. With a bridgeport, the intake would have already been open for quite a while equalizing the intake to exhaust pressures with the cooler just ending exhaust pulse as the "next" exhaust opening hasn't happened yet.

Anyways, thats what I am thinking at 3:30 in the morning as I type this. I'm going to bed!