samson

So your saying it's not worth it and doesn't work? Steve has done it and I'm in the process of doing it. Jon has a .48/.60 ON his car and will tell you how much better it is than a .42/.48. The wheels are the same what is different is the volume or A/R which is Area divided by Radius. That means more volume/air/CFM/power.


JP

MikeJ-2009

Samson, take a picture of the wheels and measure them when you do it. Then swap the housing and tell me it wasn't worth it. :P

Even if the front of the turbine wheel is 0.156 smaller, it works, and it's an improvement over the 42/48. A 42 comp. housing being switched to a 60 is way more applicable than the .156 the turbine wheel may be missing off the front of it.

sixsick6

When did I ever say that? I never said anything about the efficacy of doing such a modification, only that the 60 trim wheel and the 50 trim wheel are different. He said he thought they'ren the same but didn't why the other guy said they weren't, and I told him because I know.

Believe me I don't need a lesson in A/R, CFM, or trim. Be careful in saying that a larger A/R means more volume, it doesn't, potential for more volume, but not more volume by itself. Tests have shown that at nearly all boost levels the performance of the 50 and 60 were nearly identicle and that a majority of the time the smaller 50 wheel averages potential for a couple more hp than the larger 60 wheel. The reasoning behind the madness is that for most power and boost levels being run on smaller engines, all that the larger wheel accomplishes is a reduction in shaft speed. With the shaft spinning slower, exhaust backpressure is more than likely higher which could easily result in a loss of power.

Now, should you be able to test higher boost levels with both the 50 and 60 compressor, you might find a point where the 60 outperforms the 50. All other factors being equal (turbine and exhaust side, compressor housing, boost level) the maximum flow is related to the compressor wheels minor area (pi*r2^2). An example would be an increas of the minor diameter from 50 to 60mm which would roughly be a 20% increase in diamater. But, the increase to the minor area would be 44% which is probable cause to believe in an increase in hp potential, not hp, but hp potential, which doesn't always happen.

samson

I will. My Dad is a hater and is the thought of the wheel being the main cause of HP gains or whatever. So the Volvo wheels is .156 smaller than the stock T-Bird wheel right, but it's the same trim?


SickSix ---> Good stuff, I wasn't being smart. Hard to tell over the internet I was just curious. Good post. So basically on a small D-Series a 60 trim (larger wheel) is worthless? Not enough motor to use it to it's full benefit? So a .63/.60 isn't as good on a D as a .48/.60? 50 trim is the Volvo and my stock wheel and the 60 trim is the T-Bird stock wheel? So my soon to be hybrid (i.e. not t3/t4 of course ) is NOT the same as a stock T-Bird .48/.60? Correct?


JP

samson

Sorry. I know I know. I tend to do that, huh? Okay. Continue and I'll sit back and "learn".


JP

ixlr8ez

well im gonna go ahead and pick up a .60 comp housing and do the swap. thanks for the info guys

samson

Feel free to PM me if you have any troubles or questions as I am doing it shortly. I have all I need, but am doing a little "maintence" work first. I'm sure Stevemode wouldn't mind either, but I can't speak for the Reverand of White Rap Men United.


JP

sixsick6

No, a 60 trim is a 60 trim the same as a 50 trim is a 50 trim. The measurements are different therfor the trim is different.

I never said that. But at the boost levels you guys are running (8-10 psi) you're hardly using either turbo to it's true potential.

Be careful, you're adding A/R into the equation and thinking it's the same thing as trim. The T Bird came in a .60/.63 A/R with a 60 trim wheel or a .60/.48 A/R with a .60 trim wheel depening on whether it was MTX or ATX.

What they're talking about is using the .42/.48 turbo with a 50 trim wheel and swapping the compressor housing for a .60 A/R housing rather than a .42 A/R This would avoid 1) having to buy a 60 trim T3 2) having to swap a 60 trim wheel. Any change in A/R is going to hook the compressor map slightly to the right but the surge lines will still be similar as will the max Pr. On a case of small displacement motors like you guys are using, along with the relatively low boost levels, there isn't much of a difference between a 60 trim and a 50 trim as far as potential. You won't get into what either are worth until you're running 14-18 psi.

As far as the .60 A/R on a 50 trim wheel, it's nothing that hasn't been done before. if you want to maximize the potential of that bastard child, slap a .63 A/R exhaust housing on instead of the .48. Your boost will come on a couple hundred rpm later but will also make use of the larger A/R compressor housing as well. BUT, there is a point of diminishign returns depending on what it's used for. You could very well choke the compressor side if you're too adventageous with boost pressure and have a high rpm which is capable of overspooling the turbine.