Hypothetical situation: two modded 20VT's are running the same power - one on a smaller turbo, the other on a bigger one. Both have been custom mapped to the same standard and have identical specs other than the turbo - they produce the same power, but the smaller turbo has to be run at 1.4 bar, whereas the bigger turbo can run 1.0 bar to get the same figure. Both turbos are operating well within thier efficiency, and charge temperatures are not to be considered (assume both cars cool the charge to the same level).

Obvioulsy one car will spool better than the other - but which is going to be more reliable in general when pushed hard for say 20-30 mins....

the one on the large turbo, less pressure obviously

Would both cars generate the same heat for the Rad to deal with?

Not got a clue, that would be down to the in cylinder temps and how hot it is and transferring the heat from the block etc...

hmmmm - a bigger turbo is looking more and more tempting....

Bigger turbo will be more reliable all things equal. However If you rev the engine higher it will generate more heat. More RPM = more heat.

Also remember you are substituting the spool up and the kick in the back aswell.

Ross

Yep, even though my Coop is provably faster with a GT2871R, it feels much slower because the boost feeds in more progressively and higher up the rev range.

On the old turbo it was running about 260Bhp, on this one it's running about 280Bhp, but feels slower.

Oh btw, I found the new .64 housing has made a considerable difference to my exhaust note. Louder and more... dunno, metallic somehow. It seems to resonate noticably better. Also with being able to use full throttle at higher revs, but not having the fast acceleration by being on boost, I find I can cruise down a high street with a longer growl than a short growl then long rip. Very Scooby. Even followed one down Newport high street once and the Coop seemed to get more looks than the Scoob because of the noise (or is that because the Newport populace isn't into making bricks go fast?).