What needs to happen when you go beyond 450 hp?
Wrong forum perhaps... what about the transmission at 450+ hp?
When I say 450 I'm talking at the crank. There are several mustang guys making that or better at the wheels on stock or near stock motors. I think the weakest link in the stock 5.0 motor is the block and those don't usually last long at power levels higher than 500 at the crank.
Better heads, cam, intake, rods, pistons and crank may raise that number a little, but the block will still be on borrowed time. Most of the budget minded guys will use a 351 block if they plan on making more power. I think they are considered reliable to around 750 hp when using a turbo. People seeking real big power from a 8.2" deck small block, will use a ford racing block or one of the other aftermarket blocks. I'm using a Dart block, with forged internals.
Depending on what power level your after, there are numerous upgrades required. For 450 hp I wouldn't be real concerned about the stock transmission, but it might not last very long. When it goes south it can be rebuilt to handle more power. My 91 SC has an AOD that doesn't have very much extra stuff and it's been holding up to more power than that for several years. All I have is a hardened inner shaft, non locking converter, deeper pan, Lentech VB
, big oil cooler, some extra steels and frictions and a Kevlar OD band.
My turbo car uses a much stronger version (Lentech Strip Terminator) that's rated for a 1000 HP. Everything in the entire drivetrain except the halfshafts has been upgraded on that car.
My point was..... that if your only looking for 400-450 HP with a turbo system, it can be done with a stock motor, upgraded fuel system and probably an upgraded ignition sysem. You will also need some means of tuning the car.
Beyond that power level it starts getting expensive.