rebuilt turbo - working , now its seized?!
10-31-13, 08:22 AM
#1
rebuilt turbo - working , now its seized?!
Paid a local shop to rebuild my S4 turbo. Had him modify it and make it equivalent to a BNR stage 1. Turbo has 2300 miles on it. only about 100 of which are with the external wastegate that was just modified.
Last night on the way to the drag strip I turned up the boost controller a bit to see if I could get it to hold closer to 13 or 14 psi. I did 2 successful pulls and cruised for the next 15 minutes to the track. On my way there I get told its closed due to fog and meet up with my friends. We stop and chit chat for 5 minutes or so, hop back in and go grab a bite to eat. I tried to get on it and it wouldnt build boost. I figured maybe a coupling that popped. We get to our destination. I see no visual leaks. I reset the MBC to "stock" thinking it was overtightened or too loose. We eat, head home and still it's no good. We stop at a rest stop and I pull off the intake and try to spin the turbo. it spins, but it has some resistance to it. I started the car and the turbo would not spin at idle. a small tap of the gas would get it moving however. No in and out shaft play, and it doesnt appear to be touching the compressor housing with side to side shaft play. A buddy asked if the stock wastegate flapper we welded shut maybe let loose, we had only tack welded it shut in one spot (RotaryEvolution you were right...). Once I made it home I checked and verified that the flapper is opening on its own. That explains the lack of building boost. Now what would explain the lack of spinning up? Did I over-rev the turbo causing a problem with the bearings? Am I over-reacting and need to just get it welded shut again? Does anyone elses turbo not spin at idle?
Last night on the way to the drag strip I turned up the boost controller a bit to see if I could get it to hold closer to 13 or 14 psi. I did 2 successful pulls and cruised for the next 15 minutes to the track. On my way there I get told its closed due to fog and meet up with my friends. We stop and chit chat for 5 minutes or so, hop back in and go grab a bite to eat. I tried to get on it and it wouldnt build boost. I figured maybe a coupling that popped. We get to our destination. I see no visual leaks. I reset the MBC to "stock" thinking it was overtightened or too loose. We eat, head home and still it's no good. We stop at a rest stop and I pull off the intake and try to spin the turbo. it spins, but it has some resistance to it. I started the car and the turbo would not spin at idle. a small tap of the gas would get it moving however. No in and out shaft play, and it doesnt appear to be touching the compressor housing with side to side shaft play. A buddy asked if the stock wastegate flapper we welded shut maybe let loose, we had only tack welded it shut in one spot (RotaryEvolution you were right...). Once I made it home I checked and verified that the flapper is opening on its own. That explains the lack of building boost. Now what would explain the lack of spinning up? Did I over-rev the turbo causing a problem with the bearings? Am I over-reacting and need to just get it welded shut again? Does anyone elses turbo not spin at idle?
11-01-13, 10:41 PM
#2
It has journal bearings, not ball bearings. I don't really know if they'll spin at idle, but it will have some resistance to spinning. If it spins and doesn't catch, and it has no in/out play, you're 99.9% probably good to go. I only give the 0.1% because I haven't seen or felt the turbo myself.
11-02-13, 01:45 PM
#7
BTW, the worst experiences I ever had with turbochargers was having an area shop rebuild stock turbos and modify them to be "hybrids" with larger compressors (not BNR). I think I had the shop build like 9-10 of them and all except 1 or 2 failed in some way. Many leaked oil from day 1. Most smoked. The compressor nut came off of one while running, causing it to eat itself.
All of them spooled like crap and made crap for top end power. One time a stock turbo car pulled 3/4 of a car length on the car with the hybrid turbo in a 0-80 pull. It was literally the worst of both worlds. YOu also have the disadvantage of having to modify the turbo, LIM, intake tube, and possibly compressor outlet pipe/coupler to fit the new compressor. I have never wanted to fool with a hybrid stock turbo since then. There's not much point to it...you should either run an untouched original turbo in fair condition, or take the plunge and swap to all new/aftermarket T4 style stuff.
All of them spooled like crap and made crap for top end power. One time a stock turbo car pulled 3/4 of a car length on the car with the hybrid turbo in a 0-80 pull. It was literally the worst of both worlds. YOu also have the disadvantage of having to modify the turbo, LIM, intake tube, and possibly compressor outlet pipe/coupler to fit the new compressor. I have never wanted to fool with a hybrid stock turbo since then. There's not much point to it...you should either run an untouched original turbo in fair condition, or take the plunge and swap to all new/aftermarket T4 style stuff.
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11-02-13, 01:53 PM
#8
i've always said that, i hate hybrids although they do have their place for simplicity in installation but the drawbacks will always be there.
the snail is too small for anything over a bone stock turbo, the mismatch in the hot to cold will always hurt spool, and the turbos make marginally more power for the increased lag, which actually hurts your overall power band length. then there is the issues with the wastegate, it's efficiency and keeping a level boost curve.
a stock turbo makes about 275ish whp, a hybrid can do about 375 before it turns into a grenade with the pin removed. that's not a huge difference when you add in the lag and aren't strictly using the car for drag racing where you might actually keep it in the revs to keep the boost up.
put the effort into a universal turbo and you will be much happier in the end. you could theoretically do it for the same price too...
the snail is too small for anything over a bone stock turbo, the mismatch in the hot to cold will always hurt spool, and the turbos make marginally more power for the increased lag, which actually hurts your overall power band length. then there is the issues with the wastegate, it's efficiency and keeping a level boost curve.
a stock turbo makes about 275ish whp, a hybrid can do about 375 before it turns into a grenade with the pin removed. that's not a huge difference when you add in the lag and aren't strictly using the car for drag racing where you might actually keep it in the revs to keep the boost up.
put the effort into a universal turbo and you will be much happier in the end. you could theoretically do it for the same price too...
Last edited by RotaryEvolution; 11-02-13 at 01:57 PM.
11-03-13, 08:27 PM
#9
I've never watched mine with the intake off while running, so that I can't vouch for. But I do know that it won't spin completely free, there is always a little bit of resistance.
How much resistance we're talking here is at question though. I'd say that if you give it a twirl with your finger tip, it should probably spin around a few times before it stops. It's still resistance, but not much.
I had a few... hiccups... when building mine. I found a shop in FL that actually knew what they were doing (eventually) and he found some of the reasons mine kept eating themselves. First, the other shop I was using was statically balancing the wheels separately. Second, the bearing cartridge (CHRA) was scored, so it required a little machining and some oversized bearings. The turbine shaft was slightly bent, so he straightened it out and machined it as well. That turbo came back spinning smoother than ever, and I haven't had a single problem with it since. And I still ended up on top vs. going for a separate turbocharger. It's pretty convenient, since I already had the stock exhaust manifold and a 3" RB downpipe for the stock turbo, so it all got to go back on. Had I gotten a universal turbo (as nice as that would have been) I'd have had to purchase:
-a new manifold
-a new downpipe
-an external wastegate (then plumb that in to the exhaust... no screamers)
And when the cost of a universal turbo is more than it cost me to build my own hybrid, it's easy to see why it was so much more desirable.
How much resistance we're talking here is at question though. I'd say that if you give it a twirl with your finger tip, it should probably spin around a few times before it stops. It's still resistance, but not much.
I had a few... hiccups... when building mine. I found a shop in FL that actually knew what they were doing (eventually) and he found some of the reasons mine kept eating themselves. First, the other shop I was using was statically balancing the wheels separately. Second, the bearing cartridge (CHRA) was scored, so it required a little machining and some oversized bearings. The turbine shaft was slightly bent, so he straightened it out and machined it as well. That turbo came back spinning smoother than ever, and I haven't had a single problem with it since. And I still ended up on top vs. going for a separate turbocharger. It's pretty convenient, since I already had the stock exhaust manifold and a 3" RB downpipe for the stock turbo, so it all got to go back on. Had I gotten a universal turbo (as nice as that would have been) I'd have had to purchase:
-a new manifold
-a new downpipe
-an external wastegate (then plumb that in to the exhaust... no screamers)
And when the cost of a universal turbo is more than it cost me to build my own hybrid, it's easy to see why it was so much more desirable.
11-03-13, 08:47 PM
#10
Turbo did not spin at idle. with the car off the turbo would spin about half a turn when spinning the compressor by the nut.
I did find the source of my smokey exhaust. I'm gonna assume the death of the turbo is from last year on my 6 port turbo. I had about 100 miles on the turbo, The turbo was over-revved due to not having twin scroll hooked up allowing the flapper to close on its own(oops....) and the night it detonated cracking the rear iron the hotside was glowing red (double oops)
I'm going to rebuild it with a gpopshop kit and put it up for sale. I have another hybrid coming with a 60-1 compressor wheel this time so hopefully I'll break 300 wheel. That turbo will probably be rebuilt as well. Does the compressor backplate dictate the seal type or can I order a dynamic seal kit without any problems? there is a local cruise I'd like to attend tomorrow so I'd like to order the kit on monday to make sure I have time to get it in before saturday.
I did watch a rebuild video. I was surpised how simple it was. Only thing I need is a caliper so I can verify clearances on the shaft.
I did find the source of my smokey exhaust. I'm gonna assume the death of the turbo is from last year on my 6 port turbo. I had about 100 miles on the turbo, The turbo was over-revved due to not having twin scroll hooked up allowing the flapper to close on its own(oops....) and the night it detonated cracking the rear iron the hotside was glowing red (double oops)
I'm going to rebuild it with a gpopshop kit and put it up for sale. I have another hybrid coming with a 60-1 compressor wheel this time so hopefully I'll break 300 wheel. That turbo will probably be rebuilt as well. Does the compressor backplate dictate the seal type or can I order a dynamic seal kit without any problems? there is a local cruise I'd like to attend tomorrow so I'd like to order the kit on monday to make sure I have time to get it in before saturday.
I did watch a rebuild video. I was surpised how simple it was. Only thing I need is a caliper so I can verify clearances on the shaft.
11-03-13, 08:59 PM
#11
I watched this video last night. I was suprised how simple the innards are. I assumed they werent so simple.
Another thing I've been thinking of. the turbo is not getting coolant through the LIM. I blocked that off. Coolant lines are the rear iron nipple, and the back of the water pump housing. I assumed these two would work and wouldnt cause any issues.
Another thing I've been thinking of. the turbo is not getting coolant through the LIM. I blocked that off. Coolant lines are the rear iron nipple, and the back of the water pump housing. I assumed these two would work and wouldnt cause any issues.
11-03-13, 09:13 PM
#12
I feel bad for whoever you sell it to, if that is the case. Not only have you read in this very thread that experienced turbo rebuilding/specialty shops have difficulty getting them right, but then you decide you're going to do your first ever turbo teardown and rebuild based off of a youtube video, and sell it to someone else to install and use. Wow.
11-04-13, 08:10 AM
#13
I'm not enough of an ******* to sell it if I put it together and it still feels off. Hell, If it fails I'd give the person a refund for it being a piece of **** turbo. The plan was to replace this turbo, rebuild this and sell it for what I'm paying for the replacement. The replacement is only $150... I spent $550 getting the stupid thing rebuilt 2000 miles ago!
11-04-13, 11:02 AM
#14
I'm not enough of an ******* to sell it if I put it together and it still feels off. Hell, If it fails I'd give the person a refund for it being a piece of **** turbo. The plan was to replace this turbo, rebuild this and sell it for what I'm paying for the replacement. The replacement is only $150... I spent $550 getting the stupid thing rebuilt 2000 miles ago!
I mean, no offense, but you're the same dude who actually had to ask if it was normal for a turbo not to spin freely.
The first few engines I built, I built for myself to put into cars and test. I didn't feel comfortable putting it out there that I would rebuild engines for the public until I was at least sure that I could do it properly and had a few under my belt as proof.
11-04-13, 12:04 PM
#15
That video is the equivalent of a well-intentioned noob attempting a rotary engine rebuild. He got most of the steps right, but I wouldn't send him any work.
-Zero parts inspection
-Minimal cleaning (in part 2, he says how critical it is to clean out the piston ring land. So he blows on it and continues assembly)
-Torques compressor nut to "what I feel like is good"
-Didn't mark or balance the rotating assembly. You might get away with it on a stock rebuild, but he should at least note it.
As for selling a home rebuilt turbo. What if it doesn't end up going well. Say the next guy takes a day off work to install his new turbo so he can go on his local cruise. Only to find out the rebuild is no good. Instead of driving, he has to pull it off and ship it back just to get a refund.
Just to be clear, I'm not saying you would do it on purpose, but the possibility of it happening is real.
It's easier to just sell it as a core.
I'm sorry you got screwed on your turbo shop hybrid, but the process is a little more involved than what is covered in the video.
-Zero parts inspection
-Minimal cleaning (in part 2, he says how critical it is to clean out the piston ring land. So he blows on it and continues assembly)
-Torques compressor nut to "what I feel like is good"
-Didn't mark or balance the rotating assembly. You might get away with it on a stock rebuild, but he should at least note it.
As for selling a home rebuilt turbo. What if it doesn't end up going well. Say the next guy takes a day off work to install his new turbo so he can go on his local cruise. Only to find out the rebuild is no good. Instead of driving, he has to pull it off and ship it back just to get a refund.
Just to be clear, I'm not saying you would do it on purpose, but the possibility of it happening is real.
It's easier to just sell it as a core.
I'm sorry you got screwed on your turbo shop hybrid, but the process is a little more involved than what is covered in the video.
11-04-13, 12:18 PM
#16
No offense taken RR. I didnt know where to go at the time and was hoping maybe someone could lead me in the right direction.
RXspeed, I realize he didnt do the best of jobs - I followed it as a visual guide to see how in-depth a rebuild is. Cleaning and measuring parts with a caliper isnt too hard really. Just time consuming. He also had some of the names wrong right off the bat - calling the compressor cover/wheel the turbine.
I guess I could always keep it for myself as a spare. I appreciate the considerate criticism
RXspeed, I realize he didnt do the best of jobs - I followed it as a visual guide to see how in-depth a rebuild is. Cleaning and measuring parts with a caliper isnt too hard really. Just time consuming. He also had some of the names wrong right off the bat - calling the compressor cover/wheel the turbine.
I guess I could always keep it for myself as a spare. I appreciate the considerate criticism
Glad it came off the right way. I've been 'that guy' before and it sucks.
11-04-13, 01:04 PM
#18
most turbo shops don't know their *** from a hole in the ground. i've had better luck servicing my own parts than sending them off to be butchered by someone else.
as soon as you take a turbo apart it becomes apparent just how simple they really are, i don't even trust third party balancing jobs because most of the time they aren't done properly and the turbos take a **** in short order. the wheels are actually fairly well balanced as they come out of the box, when you remove more material in order to try and match them further is where the problems arise.
as soon as you take a turbo apart it becomes apparent just how simple they really are, i don't even trust third party balancing jobs because most of the time they aren't done properly and the turbos take a **** in short order. the wheels are actually fairly well balanced as they come out of the box, when you remove more material in order to try and match them further is where the problems arise.
Last edited by RotaryEvolution; 11-04-13 at 01:06 PM.
11-04-13, 07:32 PM
#19
... i don't even trust third party balancing jobs because most of the time they aren't done properly and the turbos take a **** in short order. the wheels are actually fairly well balanced as they come out of the box, when you remove more material in order to try and match them further is where the problems arise.
It's like the guy that tries balancing your wheels and ends up putting 7 weights on it. If you don't get it right the first shot with one weight on each side, then take them off and try again. Unfortunately with a turbo, you can't put the material you ground off back on. I took a gamble with a local diesel shop and got screwed a few times over before I figured out that I needed to find a reputable shop to balance it. It only cost a little more, but had I done that in the first place, I would have saved about $300.
If you're serious about getting it done right the first time, send the CHRA and rotating assembly to Evergreen turbo in Ocala, FL. Charlie knows his stuff, and will not charge you for stupid things. You still build the turbo yourself, but he'll inspect the CHRA and all the parts, media blast all the appropriate parts, machine as necessary, and include oversized bearings if necessary. It'll be properly marked for reassembly, and I GUARANTEE that you will pay a lot less than $500.
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