initial D is REAL!

hey guys, I was wondering how balancing the turbo is done? Do the intake and exhaust have to be together to be balance, or can they balance each part seperatley?

How much benefit is there in clipping the turbo anyways?

kenn_chan

1 its better if they are balanced together (dynamically balanced) also called VSR ballancing I think

2 yes they can be balanced seperately (static balance) not as good and the bigger the turbo (wheel size) the more it will make a differance,

IE stock S5 balanced seperately not such a big deal minor variations it can handle.
try that with a bigger turbo IE: to4r, t-76, t-88 and it will be more apt to do damage.

clipping the turbine wheel has advantages when the wheel is too small, it will aloow more gas to flow with less resistance raising the chokie point of an overly small wheel. however you will pay for it in responce and spool time, better to get a properly sized wheel and houseing combo

good luck


kenn

initial D is REAL!

Thanks for the reply. I havea s5 t2 hybrid with a to4 intake side. I noticed BNR sells their hybrids with clipped exhaust sides, so I had my turbo builder do the same to mmine.

So if the intake was balanced seperatea and the exhaust balanced, Do you think I couild just bolt it up together? I didnt make any marks,a nd Im consdiering getting it rebalanced. Thanks

kenn_chan

clipping the exhaust side on a Hybrid stocker is pretty much a requirement in order to get enough flow. The larger compressor wheel makes up for it a bit, but you will need to balance after clipping it.


By clipping it you normally create a minor imbalance between the front and the rear, think of it like a teeter totter, the turbine wheel gets lighter, and the compressor stays the same, this increases the chances of an imbalance problem. throwing a larger compressor wheel on just compounds this problem.

my suggestion is to go ahead and get it balanced properly, it will last much longer if you do.

cheers

Kenn

initial D is REAL!

Do you think its ok to run the to4 intake side, but not have my exhaust clipped?
Right now I have a clipped and balanced exhaust wheel sitting on the side, the one I have in my car right now is stock.

You think I can get away with installing the seperatley balanced parts together , or does it matter that much that they get balanced together?

kenn_chan

Is the to4 wheel and compressor cover already assembled as a cartrisge with a turbine wheel? if so, I would say run it, and heres why. it will make slightly more power before it hits the choke point of the turbine wheel, not as good as it could be, but better than stock, and your air intake temps should drop slightly due to better efficiency.

if its not assembled then its the same as if you assemble it with the clipped wheel.

you could assemble it yourself, and run it. you have approximately a 30% chance chance that it would line up in such a fashion that it would not damage itself. All it takes is for it to be far enough off that it creats a imbalance that the oil pressure, journal and thrust bearing cannot handle and you are looking at a dead turbo, and possibly with the injection of enough metal parts a blown motor.... your choice

would I use a modded stock turbine like you are proposing? yes, but only if it had been balanced properly (safer for engine) other than that I would wait until I could get it balanced properly so that it would be safe.

kenn

initial D is REAL!

Im getting it balanced then

CarbonR1

iTrader: (2)

A few things to clear up;

Balancing the turbine and compressor wheels separately is called component balancing.

VSR balancing is a high speed balance, and is done with both wheels on the CHRA.

Balance on the wheels is not like a teeter totter. The important balance is rotational balance, not the balance between the two wheels. Naturally, the aluminum compressor wheel is going to be lighter.

Usually, component balance is good enough. Most rotating assemblies will cause more noise from imbalance, and not as many turbos fail from imbalance as commonly perceived.

Kevin

kenn_chan

All true, but the additional loading that the bearings must handle due to imbalance is magnified when one side of the cartridge or the other is substantially lighter or heavier (think t3/t4 hybrids) than what the bearings were originally specced out for.

The whole analogy of a teeter totter while possibly poorly worded was the best that my mind could come up with while multitasking my real job and answering somebody who needed help.....Maybe I should have said like useing the wrond counter weight when rebuilding a rotary, or like useing the wrong counter weights when building a 355 stroker v-8, sorry for my poor analogy skills

FYI many turbines die from imbalance it just requires a slightly higher than normal loading on the journal bearings (think compressor surge) to cause problems due to wheel imbalance to drop up.

Better that he should wait until he gets it properly balanced and know its safe than to do it halfway and have it cause problems, especially since most people who are going hybrid tend to due it due to cash restraints, or budgetary reasons, I think the last thing he wants is to replace a turbo, or an engine. while nothing more than aluminum dust will make it through the IC even that is not good for the apex seals nor rotor housing.

Kenn