500 BHP Turbine Housing?

[carthik]

Hello Bimmerforums. I have a few questions regarding choosing a turbine housing for 500hp at the crank on a M50B25NV with ARP head studs and a Cometic MLS.

First off, should I go with a T4 housing or T3 turbine housing and why?

Second, I want to make power all the way to 7500 or maybe even 8000. What size AR turbine housing should I go for? My options for T3 housing are .65, .82 and .85. For T4 my options are .81, .84 and .96. For both housings the AR options do go higher and lower than I have listed but I think the ones I posted are in the range I'm going for.

Thanks.

[Captain Bondo]

Delends a lot on what turbo (turbine wheel) you plan on running.

[lucky hare]

I was wondering similar things regarding t-3 vs t-4 exhaust housings.
I've been told that the t-4 housing is a better/proper fit of the turbine wheel.. not sure what that means, but it was a legit turbo supplier.

[Shuasha]

What cams are you running to make spinning the engine to 8k worth it? You'll find that it falls off quickly after 7k.

[carthik]

I am actually now going with an M50 Vanos Motor. I'm not sure if they are safe to rev that high but I basically want the setup to pull to the maximum "somewhat safe" RPM and was hoping the turbo would keep feeding the motor after the cams reach their peak.

I guess will a T3 turbine be able to flow a 2.5 litre M50 to 500bhp? If so I'm assuming I would get less lag with a T3 turbine vs a T4. Any disadvantages in going with a T3 housing when I only want to make 500bhp?

The next decision is the turbine wheel, if I stick with a T3 according to Turbonetics my options are:

F1-49
F1-54
F1-57
F1-62

I'm not sure if those numbers refer to sized in mm or not. Can anyone elaborate?

[gstuning]

a T3 sized right can.

Your assumptions on the T4 vs T3 for lag is not going to make a big difference if the T4 and T3 turbine + wheel flow about the same

No disadvantage at all running a T3 for 500 crank.

turbine wheel of about 57mm will do 500hp crank.

[uk525td]

7k + on an m50tu safe? is it really? ive got my NA M50TU rev cut set at 7k hard....