I couldn't wait for the evo-9 20G so i purchased the evo 8 TME version. Upon close inspection the turbin side looks like it has been clipped severly to accomodate the bigger compressor wheel. From what I understand, they clipped the turbin wheel to increase exhaust flow to match the intake side - which will decrease surging.

Was I right about the clipping theory? What's bad and good about clipping the turbin?

I will post some more later.

 

If you read busher's one of the first thead about the testing on his first evo, he expains why. I think he clipped to give more flow and dismissed the early spool up to gain more horse power up top if I remember correctly.

 

Not sure how to tell a 20-G TME from the 6.5 TME (which I'm assuming is a 16-G), but you're numbers stamped into the compressor housing (in the third photo) are identical to mine, and I have the 6.5 TME w/ 10.5 hotside. The last number stamped towards the bottom is different, but that looks more like a serial number, and not a model number like the upper numbers do.

Are you sure it's a 20-G?

 

well these turbos are modified stockers so it makes sense that they have the same numbers, i dont see why david would file those off and Thats just one of the reasons they are so cool( they look stock).

 

If I remember correctly he was clipping the wheels to try and dismiss some of the surge problems.

 

Your right, it is a 6.5 TME but modified with a 20g compressor wheel. Did your turbo work the way you wanted? Did you get any surging?

 

My turbo works exactly like I wanted it to, spoolup is quick as a ****. But it has a 16G wheel, and not a 20G. No surging either. It's a true 6.5 TME though.

 

The compressor wheel itself does look slightly different, but its not easy to tell that way, the easiest way to tell is by looking at the turbine, the 20G is clipped to match the exhaust and intake flow, because it spools so fast, you have to spend alot of time adjusting your wastegate actuator, Diverter Valve, and use an Electronic Boost Controller (closed loop) to prevent the surging that some people complain about.

Physically they *ARE* either standard or TME turbos with upgraded compressor wheels, so their outside appearance should be identical to the stockers.

 

The clipping was not done to help surging. The clipping is done to increase exhaust flow. The clipping slows down the spool up slightly.........which could also help to get rid of some of the surging, but that wasn't the idea behind it originally.

Enjoy.

David Buschur
www.buschurracing.com