What does this phrase mean? haha

My buddy in his S4 took his two stock turbos and clipped the wheels. What does he mean by that?

 

No one?

 

A qualified person can clip the turbine wheel blades and somewhat effect how it spools. We have had it done a couple of times and you can feel the difference. You can also lighten the turbine wheel too. I have heard mixed results on that though.

 

So it just helps it spool quicker... not make more power?

What's actually happening to the wheel though?

 

Jose and Jason do clippings for alot of our diesel units. Clipping drops efficiency of the turbine down and slows the spool up, but does relieve backpressure. That is the main purpose for backcuts.

 

What is changed?

 

The turbine wheel is machined on a CNC down by back cutting the fins 10 to 30 degrees. Then precision balancing is needed..and then that is it. The problem is knowing how much and where to cut the material out.....its a black art for sure. I have no idea how to do it, but I know the process...hehe

 

Excuse my ignorance... why would you want this again?

Why would a car like the S4 want it?

 

Cause ricers like spending big $ on stuff they can brag about even though it doesnt make them any faster???

 

To funny, only cause its so true.

 

 

An S4 uses fairly small turbos that become inefficienct and backpressure starts to rise fast with boost. So to counter the back pressure you have it clipped.

 

wouldnt the clipped wheel make it spool faster since it would be lighter?

 

You would think, but no. The way Jose and Jason explained it to me was when the turbine is clipped you are now bypassing more air around the turbine blade face, so less actual push on the blade, which effects it greater then weight loss does, which is very minimal anyhow.

 

To much backpressure is bad why?

Not enough back pressure is bad why?

 

too much is bad cos it chokes the engine. you normally want back presure to be below 2-1 (ie twice you boost presure). if you could run 100% effient then you would be at 1-1, but you cant! lol i think after 2-1 you start to loose power.

why is to little bad?? well cos you need some back presure to turn the turbo! if you had none then why would the turbo spin? this is what the weastgate is for, to keep the backpresure at the levels that give you the boost you want!

i dont like clipped wheels. you should have to run them if you have the right combination of hot and cold side.

is there not a company that will do a hybrid turbo for them?? maybe a bit bigger on the exhaust side???

thanks Chris.

 

What would be the downfall on a poorly clipped wheel?

 

I mentioned this tread to a friend of mine and he said that this stuff it for real. Although the one car he seen it done on was a Vortech Supercharged car. He said the guy put in new lighter ball bearings and clipped the wheel. Said the car was way quicker after that and a tranny rebuild. The MPH was their to suggest it was pulling more power as well. I want to say a half second and maybe 5mph. Just what i heard though.

 

a clipped turbine wheel and ball bearings with a vortec sc?

 

cuz his friend told him, thats why

This one is over