I have been watching E-bay for TO4's, and I have seen alot of them with 1.15 AR on the hot side. And I am wondering would this be good for a car with a big port? And on one turbo it said it would suport 450 HP and 30 PSI of boost is this true?

And for the hell of it, what would be the best hot side size?

 

For a street turbo, 1.15 would probably be the largest I'd go with and even that would give you slightly more lag. Most popular is .96 and either P trim or O trim, O trim being a larger wheel. I had a .70 a/r and changed to a 1.15 due to the .70 being too small for a rotary.
Larger the wheel the better , less back pressure, but larger you go, more lag you'll get. A street turbo doesn't need a larger than 1.15 a/r . But, there are alot of opinions out there and I'm sure a lot of people will give their opinion.

 

OK I am seriously considering to buy a TO4 that I found, but there is one thing that I don't like about it, and that is that it has no coolant running threw it. The only fluid that does run threw it is oil. And I am wondering how much of a binifit is the coolant running threw the turbo?

 

The only thing about non-water cooled turbos is that youhave to let them sit longer at idle to let them cool down.

 

I'd say for a mainly street-driven car a Wet CHRA is very benefical compared to a dry in terms of long term durability.

There was a post once in the single turbo forum about the difference in heat soak after shutdown and wear on the bearings between the two.

Try to find one that is both oil/water cooled.

 

I just read all of those threads that I could take, and it looks like I'll be looking for a water cooled turbo rather than a dry one.