sizing a turbo

[cdd]

I am wanting to upgrade the turbo in my R/T but need help in sizing. I found a website that has a progam that plots points on a compressor map based on the info you put in.
http://www.turbofast.com.au/turbomap.html
How do you get Volumetric Efficiency of a T3 engine? I have a stock engine w/ 3" exhaust from end of downpipe back.(downpipe 2.5") It seem that Volumetric Efficiency maks a big difference on plotting the points. At 85% it looks like a 46 trim is a good choice. At 100% a 50 trim?

[MachineHead]

A 50 trim is a good choice. There is no easy way to walk out to the car and measure the volumetric efficiency. People have had good experience with the 50 trim T04E though.

[4sfed4]

Heres my take----

The TO4E Super 50 trim compressor is a good choice for most people. I paired it to a Stage 3 / 0.63 exhaust side and it spool quite nicely gace gave a healthy power bump over the stock turbo. Some guys have gone with the Stage 2 / 0.63 exhaust side as well. In any case, you definitely want a 0.63 exhaust housing. The 0.48 is just too small no matter what wheel you put in it.

This basic turbo (TO4E Super 50 / Stage 3 / 0.63) was good to just about 400 dyno whp on my car when tested with drag radials. It just couldnt make more power than that as boost pressure dropped with rpm and exhaust backpressure was quite high. The power curve just flattens out as the turbo struggles to move its maximum mass flow rate of air. (I posted a week or so ago about the effects of drag radials on dyno numbers......my tests showed a 10% loss across the board due to rolling resistance when tested on the same dyno.) So, in order to paint an accurate picture of that turbo (accounting for the tire losses over "normal" tires and driveline losses), that spec turbo was capable of something around 500 crank hp which is just about what most turbo shops will tell you it can move if you really max it out.

So, my thoughts are that if you are going to be happy with power levels in the 375-400 hp range, that spec turbo will probably do what you want and be a nice quick spooler.

If you want more power, or the ability to make the same power at lower boost, youll probably need to go to a larger compressor wheel and an 0.82 exhaust side. Ill be testing this out shortly.

Youll probably also want a new intake manifold

[dmopar]

what would you buy if the price wasn't a factor ?

[4sfed4]

Quote:

Originally posted by dmopar what would you buy if the price wasn't a factor ?

Probably one of the new Garrett GT turbos, maybe a GT35R ,GT40, or some sort of hybrid using the GT stuff. But, you have to really mean price doesnt matter as they can approach $2000 smackeroos!

[dmopar]

ok i get it they need to know everthing thats been done to the engine.has anyone on here used the gt series?