Stock Boost

[Gonthrax]

Just wondering what the stock boost on a japanese 3s-GTE is.

Also I've been told that the max safe boost on the engine and turbo is 13psi, true or not?

A few people have done some dyno runs and increased their boost 1psi at a time and recorded about 10kw and 15nm increases for each 1psi. Can any one second this?

[94mr2turbo]

Originally posted by Gonthrax
Just wondering what the stock boost on a japanese 3s-GTE is.

Also I've been told that the max safe boost on the engine and turbo is 13psi, true or not?

A few people have done some dyno runs and increased their boost 1psi at a time and recorded about 10kw and 15nm increases for each 1psi. Can any one second this?

I have a Japanese spec 3S-GTE and I think the stock boost is around 9psi. My 3S-GTE is a Gen 3 and from what I've been told, doesn't use a CT26 turbo, so I'm not sure if the previous or later versions run the same amount of boost. I didn't run any extra boost on my stock turbo, but it still blew.

[bluetwo]

i'm not sure about genIII engines, but the genII (91-95 us, and 90-93? japan) has a stock boost between about 7-11.5psi. it's not set at a given value, but a range (this is what is considered "normal" in the BGB). the genII with a steel turbine ct26 can be safely boosted to about 14-15psi (about 1bar, give or take) before heat/thermal efficiency becomes a limiting factor. the ceramic ct26 may be able to boost higher, and the ct20b found in later genIII's (i believe 98+) also higher than 15psi.

and yes, each psi (assuming you're in the thermally efficient range of the turbo and the car is tuned properly) is good for roughly 10psi. dyno proven. ymmv

[Gonthrax]

Originally posted by bluetwo
i'm not sure about genIII engines, but the genII (91-95 us, and 90-93? japan) has a stock boost between about 7-11.5psi. it's not set at a given value, but a range (this is what is considered "normal" in the BGB). the genII with a steel turbine ct26 can be safely boosted to about 14-15psi (about 1bar, give or take) before heat/thermal efficiency becomes a limiting factor. the ceramic ct26 may be able to boost higher, and the ct20b found in later genIII's (i believe 98+) also higher than 15psi.

and yes, each psi (assuming you're in the thermally efficient range of the turbo and the car is tuned properly) is good for roughly 10psi. dyno proven. ymmv

Thats a pretty wide range when it comes to boost, why does it fluctuate like that? I've never heard of a stock car's boost changling like that. Well, accept for the RX-7's 10-8-10 boost pattern.

So whats the accepted amount of boost the stock injectors and fuel pump can handle?