Pardon myawful photchopping...



My dodgy red line reflects a fairly typical flow characteristic of a cossie.. As you can see, both the GT35 and the T04b/S-3 compressor is 'too big' for the amount of boost a 2 litre engine needs to flow enough air.. The question is, how does the GT35 deal with the surge? Every turbo behaves differently.

What actually happens in reality is the T34 surges, but you don't hear it, feel it, and it doesn't break anything.. but the GT35's can't run full boost until they get to about 30lb/min of air flow.. otherwise they surge themselves to pieces..

The GT range are great.. but something like a 35 really belongs on an engine with much more flow at lower pressure ratios (like a big v8) where you're nowhere near the deadly surge line..

I'm just talking from experience here..