Yea I do believe the 421 milltek cracked
Would go to the 4-1 myself so was possible to hit high BHPs

I thought the 4-1 loses acceleration and power low down speeds?

I think im right in saying it doesn't create as much torque as a 4-2-1 but like adam08 said it generates more bhp which means you need to rev it a bit more to get going.

421 is for low down pulling power but I do believe if your going to take modding further then the 4-1 is the one to have

So if I get a 4-1, I won't lose anything that I currently have in low down power but I won't get any increases either, other than mid range to high range? Is that the revs we're talking here? What do we class as mid, 3k revs or less??

for a standard car here are the power/torque leves. Keep in mind every car is different

Power: 150PS (aprox 148bhp) at 6000rpm
Torque: 190Nm (141 lb/ft) at 4500rpm

(power)If you get a 4-1 you will gain more bhp at peak power(revs) but not gain as much torque low down as a 4-2-1

(torque)a 4-2-1 will give you more torque than a 4-1 at peak power(revs) but not generate as much bhp as the 4-1

Okay but installing the 4-1 will not -lose- me any torque or low down power as the standard?

no you will not loose any torque but you peak bhp power potentially may come in later than 6000rpm. Then again it may come in spot on 6000. Its hard to say. The only true way you will know is have it done and get it on a rolling road. Or try and find a rolling road graph on a ST with the same mods you have/planning

So you get the main lump of your power at 6k instead of the current 4.5k or so? That would make the gears really small usage? You only have a small window to use your power I mean..?

no mate i think you are confusing torque and bhp. maximum torque is 4.5rpm, maximum bhp is 6000rpm. Torque pulls the car, bhp is overall power of the engine.

Okay right damn confusing stuff lol.
So it does acceleration over 30mph pretty much to put it basically?

i dont understand what you mean? sorry.

the basic way of looking at it is when you accelarate to 4,500rpm you have 190Nm (141 lb/ft) pulling you along. When you pass 4,500rpm your torque figure decreases the further up the rev range you go because you have passed torque peak

And that's where the BHP makes a difference?
What I meant as the 4-1 says it's more for mid range and high range, I presume that is more for when you're already going along and you put your foot down, and the 4-2-1 is more for when you're first setting off?

Sorry for al lthese questions, I just want to make sure I purchase the right one to save wasting £

4-1 is for people that like to drive hard up to the limiter
4-2-1 is for people that like to pull away from 30mph in 5th gear
But if your ultimate goal is for all out power then you want 4-1
But for normal driveability for going round town from low revs in each gear then 4-2-1