"slab" - The New, Better Daily

[Taz_Rx]

Put it this way, I'm confident enough to write my "I told you so" now!!! :)

 

You're talking about something that spins in the order of up to 100,000rpm. How much inertia will 1g have at that speed!?

2x things are likely to happen:

1, It lets go big time and snaps a shaft etc.

2, It'll flog out your brand new bearings and seals causing play, which causes wheels to touch housings, which casues wear and a loss of compression, which altimately gives you a completely f@$ked turbo.

 

Ok you've got the opinion of somebody "fairly experienced with turbos". PLEASE do yourself a favour and ring somebody who WORKS ON TURBOS like:

 

Statewide Turbo's

182 Stoney Rise Road

Devonport, TAS, 7310

Phone / Fax 03 64249611

 

.....And ask them what they think about it.

 

They are official Garrett distributors BTW. :hmm:

[Taz_Rx]

Worth a watch.....

 

 

They can test turbos up to 250,000rpm!!!

[machg]

Put it this way, I'm confident enough to write my "I told you so" now!!! :D

 

You're talking about something that spins in the order of up to 100,000rpm. How much inertia will 1g have at that speed!?

2x things are likely to happen:

1, It lets go big time and snaps a shaft etc.

2, It'll flog out your brand new bearings and seals causing play, which causes wheels to touch housings, which casues wear and a loss of compression, which altimately gives you a completely f@$ked turbo.

 

Ok you've got the opinion of somebody "fairly experienced with turbos". PLEASE do yourself a favour and ring somebody who WORKS ON TURBOS like:

 

Statewide Turbo's

182 Stoney Rise Road

Devonport, TAS, 7310

Phone / Fax 03 64249611

 

.....And ask them what they think about it.

 

They are official Garrett distributors BTW. :D

 

 

Said person does work on turbos, and has experience with Toyota turbos too. In reference to your second post, I might try spooling the turbo up with compressed air myself, before re-installation, just to see if it spools up nice and freely by air pressure alone. Its was really interesting when I first installed the turbo (before exhaust was fitted) the impeller would barely turn at idle, and yet it seemed to spool up fine, is this usual for turbos, Si?

[Taz_Rx]

So it would not spin at idle, but give the throttle a blip and away she'd spool?

That sounds more like a symptom of knackered bearings, but you're changing those. Let us know what its like after the re-build.

 

My T25G basically mymics what the engine is doing:

Try and start the car - turbo start spinning

Idle - Turbo "idles" quick enough that you can't see any individual blades

increase engine RPM - turbo RPM increases.

 

As for balancing thing - I can't make you do anything you don't want to, but I think what you're planning is just ludicrous, and will ultimately be a waste of money (on the turbo and re-build kit). Did you ring the guy in Devonport? You don't need to tell him who you are, I've rang him a couple of times recently and he's always happy to help.

 

I'll quickly explain one more thing to you. The gap between the compressor wheel and front housing is sort of like that between a piston and the bore it runs it, except with no piston rings. If the wheel touches the housing (though play or un-balance) it will grind down both surfaces like this.....

 

 

Once this happen you will loose "compression" in the turbo just like severly worn rings. The compressor will still be making pressure, it'll just struggle to hold it past the front cover as it'll be leaking through the newly created gap.

Will you still get boost - Yes, because this is governed by the waste gate (which is oblivious to your wheel-housing issue) and will still control boost to the same pressure. The turbo itself is just going have to work twice as hard as half the pressure it makes is leaking back out the front cover!!

[machg]

So it would not spin at idle, but give the throttle a blip and away she'd spool?

That sounds more like a symptom of knackered bearings, but you're changing those. Let us know what its like after the re-build.

 

My T25G basically mymics what the engine is doing:

Try and start the car - turbo start spinning

Idle - Turbo "idles" quick enough that you can't see any individual blades

increase engine RPM - turbo RPM increases.

 

As for balancing thing - I can't make you do anything you don't want to, but I think what you're planning is just ludicrous, and will ultimately be a waste of money (on the turbo and re-build kit). Did you ring the guy in Devonport? You don't need to tell him who you are, I've rang him a couple of times recently and he's always happy to help.

 

I'll quickly explain one more thing to you. The gap between the compressor wheel and front housing is sort of like that between a piston and the bore it runs it, except with no piston rings. If the wheel touches the housing (though play or un-balance) it will grind down both surfaces like this.....

 

 

Once this happen you will loose "compression" in the turbo just like severly worn rings. The compressor will still be making pressure, it'll just struggle to hold it past the front cover as it'll be leaking through the newly created gap.

Will you still get boost - Yes, because this is governed by the waste gate (which is oblivious to your wheel-housing issue) and will still control boost to the same pressure. The turbo itself is just going have to work twice as hard as half the pressure it makes is leaking back out the front cover!!

Yeah, thanks for that. I am aware of the tolerances involved in turbo design. I suppose I got the turbo for very little $$, and the kit was not a huge outlay either. I have spoken to a bloke who is very well known by all in Tassie, who has worked on turbos for quite a few years, told him the specifics of the turbo, rebuild kit, pull-down procedure and intended application (standard boost) and he felt dynamic balancing was going to be unnecessary. I have to balance his and your advice, my own mechanical experience and weigh up the cost/benefit analysis. I might give statewide turbos a call and find out cost (assuming they actually do dynamic balancing) time frame and feasability of getting the turbo balanced. I suspect the time and cost will be more than I can afford at this point in time. I called statewide turbos and Andrew's away, so I will have to call back on Monday.

Edited August 7, 2009 by machg

[machg]

Assuming its not ridiculous $$$, I think I might get the thing balanced, for peace of mind, if nothing else, such a shame no-one in Hobart does this...

[machg]

Well I called Andrew at Statewide Turbos, and he was pretty good to deal with, however he won't balance turbos he hasn't worked on himself (understandable really). He said he'd rather you give him your stuffed turbo and he rebuilds, balances and (I assume) warranties. Minimum charge is usually in the $700 - $800 region, which is probably pretty good given the work involved. His rebuilds are absolutely complete, no re-used internal components except for the turbine and compressor wheels (and main shaft?) if completely undamaged. Unfortunately I don't have that kind of money. He said it might be O.K. if not too far out of balance, and pointed out that by running an intercooler, I have a degree of engine protection should the thing go bang, as any pieces are likely to lodge in the cooler rather than get into the engine. That was good enough for me, so I have re-installed the turbo, and it seems to boost O.K. and no more smoke, yeeeehaaa! Here's a couple of shitty pics of the paint job (only 1 coat)

 

 

 

 

[Toy-Yoda[RL]]

[machg]

LOL, thanks. Drove car home (50km) and it ran like shit. Pulled injectors (yet again) all good, but spark plugs 2 and 4 looked suspisciously oily. !@#$%^&* Oh well, it came good 3/4 of the way home, so hopefully it was an abberation from sitting inactive for so long. If it ever stops raining I will be able to do more painting.

[machg]

Car is running superb ATM, hopefully that's NOT an abberation, LOL

[machg]

As alluded to in the subtitle, another day another shit fight. Diff is rooted this time. Ridiculously noisy whines, then whines and clunking sounds and pissing oil out of driver's side diff housing. Given the power of this thing (unintetional wheelspin 3rd gear dry, any gear wet) I don't think doing up the borg-warner weldy I've got would be a recipe for long term happiness. Is there a true bolt in option that will handle the grunt? I am thinking hilux, but would like to keep stud pattern if possible. Just want the thing to be driveable, arrrrrrrgh!

[Toy-Yoda[RL]]

Try this guy maybe?

[Falken_KE30]

Might find the van is leaf spring rear ben :P

[machg]

Yeah, I'm running leafs. Thanks for responses anyway.

[Falken_KE30]

Maybe try a T series diff? just get the leaf spring mounts welded on.

 

Dunno how much stronger that would be, but might be worth looking into if you get diff cheap and you know how to weld