gpop turbo balance





#1
I can call gpop's in the morning but I'm still curious if anyone knows about this...

I had my Rajay turbo balanced by gpop. They used permanent color markers on both the turbine wheel and the impeller. One blade on each was marked in green and another blade on each was marked in black. The green blades are just somewhat on the opposite side of the black blades.

You would think they would line up, but if I line up the blades marked in green, the blades marked in black are not lined up... and visa versa... and they are off by a fairly significant amount.

The black blade on the turbine wheel also has a second mark at the lower outside end of the blade. But no matter what I try, I can't seem to line them up where it makes any sense. Am I missing something here, because I'm about ready to :banghead:
 
#4
:whistle:That would have been nice, but...

I mailed them the center section, turbine shield, spring ring, turbine wheel and shaft and impeller. They were already apart because I was replacing the F impeller with an E impeller.

When they returned everything, the impeller was bolted to the turbine shaft, but it wasn't installed in the center section so I had no choice but remove the impeller from the shaft in order to assemble the unit myself.

No notes or instructions were enclosed so I assumed the markings on the blades were used to position the turbine and impeller to retain the proper balance. Obviously I shouldn't have assumed.

But that probably explains why the bottom side of the turbine wheel and impeller, each have two perpendicular lines that run from edge to edge and form a cross. It sounds like I need to ignore the marks on the blades and line them up according to the lines/cross on the underside. It made no sense to put the lines there, considering you can't see them when they are in place, but I'll just make my own lines so I can make sure they stay aligned as I tighten down the impeller.

Does that sound right? :whistle:
 

Mr Bogus

Trouble Makers Inc.
Donating Member
Registered
#5
now why the heck didnt they assemble the thing if they had all the parts? hope they checked the bushing clearances etc.. torque on the nut is also pretty important..

I would be half tempted to send it back... (due to warranty issues if YOU assemble the cartridge.. call them and talk about it..)
 
#6
now why the heck didnt they assemble the thing if they had all the parts? hope they checked the bushing clearances etc.. torque on the nut is also pretty important..

I would be half tempted to send it back... (due to warranty issues if YOU assemble the cartridge.. call them and talk about it..)

The fee was $65 and that was just to do the balance so I'm sure they didn't do anything else.

But I agree with you beceause they charged me an extra $75 (one hour labor) because they said they had to disassemble the center section... something inside they needed to do the balance? They called to get my okay, but what choice did I have.

But now that I've learned more about this unit, I'm sure it didn't take them more than 5 minutes to remove six screws and pull the flange off the bearing housing. Since they still had 55 minutes of that extra hour left, the least they could have done was check clearances and assemble it so I wouldn't be stuck in this position.

Now I'm wondering what it was they needed from the center section.

Well, I'll discuss this with them in the morning and post the results later in the day.
 

Mr Bogus

Trouble Makers Inc.
Donating Member
Registered
#7
I have only seen one balancer setup and the wheels can not be installed in the housing.. The rotating assy is put in a set of bearings with a drive belt.. wheels are marked and then the unit is spun up with a stobe light that is triggered by the blocks moving..

They then grind a bit away on the wheel disk (cold side) or the center nut (hot side) to balance the thing... pretty neat process but sort of an art to know how much to whack off as adding weight back on is not very easy :laugh:
 
#8
Last ones i had done i think were independantly balanced, in discussion about the turbo they didn't seem concerned about the position of compressor in relation to shaft, which is way different to what i have known of before, where the shaft /compressor relationship is critical.
 
#9
I know they didn't need the housing, I only sent it just in case, so obviously they didn't plan to balance mine on the housing. At this point I'm guessing the position of my impeller in relation to the shaft is critical or there would have been no need to disassemble the housing at all. That's probably what the cross on the underside of the turbine and impeller is for... to line them up. But for crying out loud, enclose a note that tells me that. :poke:

I'm glad I posted this before hand because now I have more info. As soon as I know more I'll post here in case it helps anyone else out in the future. Thanks.
 
#10
I called gpopshop but I'll never deal with them again. :moon:

Jim answered, gave me an answer but had to check with Jerry to be sure. I can respect that but I had more to ask and I'm not about to risk my motor for someone who doesn't do the balancing, so I asked to talk with Jerry. Jim put me off until I had to insist. When Jerry came to the phone it was obvious Jim got him worked up. As a result Jerry became a know it all and tried to tell me what to do without listening to me, so I gave up and hung up on him.

He called back and left a message explaining how to line up the wheels but it was obvious he still didn't get it. Fortunately I was able to piece things together and figured out what to do.

The green marks on top the blades are used to balance the assembly and can be ignored so you only need to line up the black marks. Why they can't include that information when they ship out the turbo is beyond me but... Normally that would have been enough but MY turbine wheel had "two" black marks and they were almost 1/2" apart from one another. All I wanted to know is which one was the correct one to use, and this is where Jerry turned into a jerk because he didn't want to hear that he marked it in two locations and implied I was too stupid to understand. But he did make two marks and now I know why.

Once he finished the balance, he marked the top of a blade (the most obvious spot) that looked like it lined up with the center line of the cross. Only this time he made a mistake because the center line fell between two blades, so he marked the base of the blade instead which put the mark in the correct spot but he didn't clean off the first mark, leaving both there. Once I knew the center line of the cross was the guide, I knew which mark was the correct one. Had I picked the more obvious mark on the top of the blade, the one he kept telling me to use, the impeller and turbine wheel would have been off by almost 1/2".

I may be a pain at times but I'm not stupid. gpopshop did their first and last job here.

Anyway, I'm not sure if gpopshop uses this process for all their turbos, but it's here just in case anyone else needs to know this. I should get pretty far on the bike this weekend... I'm almost done. And again, thanks to this forum for the info. I never would have been able to piece this together without everyone's help.
 

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