Originally Posted by scoobwr1
I'm at around 380 but I'm wanting a genuine 400/400. So I was thinking about a 9 turbo,how safe am I without forging or is it a must at 400bhp.carl
Ask some of the more experienced tuners/modifiers/mappers on here, but from what I've read it's debateable whether the IX turbo gives you much over the VIII MR turbo to justify the cost of fitting one - an FP white may be a better option if you want to replace the turbo for increased performance without losing spool.
I know grayw fitted an IX turbo to his VIII MR and wasn't overly impressed with the difference.
As for how safe a "genuine" 400/400 (whatever that might be!) is on a stock engine, that's also open to debate - I think a lot of tuners would advise upgrading at least the rods at around that level. Other owners are happy to run significantly more and "risk it".