S90 throttle bodies

[evo-gsr]

I think the below sums it up perfectly..which made my decision when I was looking into this as an option a while back...

Actually its quite the contrary and people fall into the trap of the belief that bigger is better. Its not the case at all for a street car as GSRWRC mentioned above. Large TB's like the Q45 90mm with the accelerator depressed 20% will flow as much as the stock TB at 50% for examples sake. It will give the impression that it's either off or on and you really dont want that on a street car where throttle control is important. On a drag car where the throttle is constantly held open then yeah, a big TB is good to allow maximum flow But the balance between throttle response and control is preferred on a street car.

To be honest you dont even need to upgrade form the stock 60mm TB unless you're making over 300kw atw or so. There's plenty 4G63's running this sort of power with the stock TB's still in place. The change to a larger TB need only be by 10mm to a 70mm unit to allow enough flow to cater for a big increase in hp over stock. The larger the TB, the less throttle control you get.

 

[brisvr4]

Just to clarify on the throttle control section, mine drives like stock at low throttle inputs. It's mainly 80mm and above that you have issues with. On the power side, I agree totally about not needing one till you hit decent power.
But that said, no one has the right to tell someone else what they can or cannot put on their car. All we can do is give advice, if it is or isn't taken is not up to us!

 

[Cranked]

Yeah I'm rocking a 70mm TB and yeah my throttle response is still incredible, I think if your shooting for numbers over 300kw it's not a bad idea, and also considering that aftermaket intakes and TB's can also be used to change Torque application as your personal driving style requires. I do also agree with Tim in that it's personal choice in how an individual chooses to mod their car. I went an inlet mani and TB becuase I was always shooting for over 300kw atw, and in the end the less restriction all round is better, it's like ppl upgrading I/C piping and dump pipes even though the stock units can make decent power.

Cram as much air as possible into the motor for the biggest boom and get it out as quickly as possible.