Im about to get a new motor buit and am was going to get a large street port done and the exhuast ports done also.
I have a hybrid S5 turbo with a To4b S trim wheel and .6 ar compressor housing.

How much air is this turbo going to be able to flow?
Is a port job ever to big for a turbo? I dont want my port to be to big for my turbo as i dont plan on upgrading again
I have the requied fuel set up to cope with upto 300whp (660cc primarys and 850cc secondarys)

Am i going to be able to maximise the use of this turbo?

 

I would say you could make the ports too big for that turbo. The problem you could encounter is that the hotside is too small and the exhuast gasses cant escape through the wastegate so you get boost creep. My current set up has a GT35/40 on a T4 flange with a 0.96 and the turbo is too small on the hot side for my porting which nothing huge although i make 380 rwhp. What is your hotside ar?

If you make the exhaust ports about 1 mm higher and lower than stock, basically port out the stock bevel and then put a new one back, you can get away with making the primaries a reasonable size, not quite as big as the stock 2ndaries, then just clean up the secondaries a tiny bit you should be fine but make sure you have a decent sized wastegate on your turbo as you dont want boost spike/creep.

If you are not trying to squeeze every last hp out of her you could run her on stock ports but you will only wish you had it ported while the engine was out. At least that way you can always modify the turbo at a later stage.

Goodluck with it

 

thanks. its a stock S5 hot side with a ported wastegate.
I know what you mean. Ive building this new motor ( my old one is only 3000km old ( apparntly, i dont know the full history ) and on selling the block ive got in the car now ( which goes fine, but i want new motor security.

thanks for the input. I really dont know what this compressor is capable off.

 

If its a stock hotside i would consider not touching the exhausts ports unless you can get the wastegate hole a lot larger than stock.

How about selling your existing set up with the turbo and buying a slightly larger turbo, you can never have too much power.