gearheadstik Posted February 27, 2009 Share Posted February 27, 2009 Hey guys, I just wanted to put something out there to be discussed and forewarn if your thinking of going the same route I did. I have been running a holset for a few years now and first thought it was a great thing... Now I'm starting to feel I should have saved up and bought a better built turbo. I just started going through my motor after letting it sit for a few months and have noticed all kinds of play in the shaft on the holset... I had just rebuilt it before last DNI. I raced that race and a few times at the track afterwords. I drove my car daily pushing 20psi when I was getting on it but not even a thousand miles. The problem is this was my second time doing a rebuild without putting any real mileage on it. I have read Big-Phil saying pretty much the same thing and at 70 dollars or so a rebuild and 400 plus a turbo if anything starts rubbing, I think I would have done better buying a water cooled ball bearing turbo?... I do not have a abundance of experience with turbos but think it must be heat and speed that we are sending through these units. I have run fully synthetic oil. The holset did a great job as far as boost and spool time, I loved it but cant be rebuilding every oil change.I'm just trying to save people like myself the heartache...Please discuss Big-Philon my first hy35 from an 06 dodge running 20-25lbs boost and had the oil pump set a bit higher than stock oil psi the turbo started smoking after about a year, so rebuilt it lowered the oil psi back to stock put it back in. Installed turbo timer, set at 3min at every shutdown holset started smoking again after about 4 months. Bought hy35 #2 running 25lbs boost, stock oil psi, 3min cool down at shutdown, turbo started smoking again after about 3-4 months! Rebuilt this one and now only run 10lbs boost. The chart above shows a waste gate of 36lbs? With my boost controller open ALL the way the most I could get from this turbo was 26lbs boost. I think I've been maxing this baby out. I never really noticed that the controller was maxed out. I was just driving and setting it to 25, which was just a %$#@ hair from maxed. Morel of the story Holset hy35 good for 10-17lbs, but your pushing it if you go higher. Now I DRIVE my car, this is my daily driver. I love this car, I love to drive it, I love the thumbs up I get down the road, I love the power, and I use the power ALLOT! I'm going to buy a Garrett GT35R next week $1300 brand new ball bearing. My first hy was $500, the 2nd was $400. I'm done with them. Quote Link to comment Share on other sites More sharing options...
jnjdragracing Posted February 27, 2009 Share Posted February 27, 2009 Gearheadstik, did Rip ever have any trouble with his Holsets when he used them? I have two that Rip gave me for our TT sbc. They are wh1e, Rip told me to replace the seals. Have you ever change the trust bearing in one of these turbos? Thanks for any info, Jerry Quote Link to comment Share on other sites More sharing options...
Guest 280ZForce Posted February 27, 2009 Share Posted February 27, 2009 i think the problem here is that these are made to see a lot lower temps and rpm on a diesel only engine. You start using these with regular pump gas on a normal engine as well, the temps get a lot higher and also spins the turbine a lot faster than they're probably built for. I understand you might get them a tad bit cooler running different fluids, etc, but it's still hotter than your standard diesel engine and spinning them a whole lot higher in revs. Quote Link to comment Share on other sites More sharing options...
gearheadstik Posted February 27, 2009 Author Share Posted February 27, 2009 I am pretty sure he never ran a holset, I do remember someone trading him some off semi trucks... They always ran the ebay specials.. I have rebuilt my HE-351's twice with no problems, but cant speak for the other models. Gearheadstik, did Rip ever have any trouble with his Holsets when he used them? I have two that Rip gave me for our TT sbc. They are wh1e, Rip told me to replace the seals. Have you ever change the trust bearing in one of these turbos? Thanks for any info, Jerry Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted February 27, 2009 Share Posted February 27, 2009 That is interesting. I have holsets on most if not all of my equipment. I run a 4 series holset on my peterbilt and it makes 36 pounds of boost and it's spinning way up in the map. I have no issues with any of them. I am having issues with my gas turbos and leaking oil. I am wondering if in fact the issue you are having is not related to too much heat and taking tension out of the rings. Quote Link to comment Share on other sites More sharing options...
gearheadstik Posted February 27, 2009 Author Share Posted February 27, 2009 Dr hunt, what do you mean about taking tension out of the rings? Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted February 27, 2009 Share Posted February 27, 2009 The rings in a turbo are somewhat like piston rings, when you get piston rings hot they loose tension against the cylinder walls and tend to use alot of oil. Same goes for turbo seals. That is why they make turbo timers for gas turbo cars. Quote Link to comment Share on other sites More sharing options...
gearheadstik Posted February 27, 2009 Author Share Posted February 27, 2009 Do you think that's the problem... Mine has never smoked bad, just has too much play too often... If several people think that's the problem I will be buying one. Quote Link to comment Share on other sites More sharing options...
gearheadstik Posted February 27, 2009 Author Share Posted February 27, 2009 One more point is that I installed a oil restrictor as discussed in old threads... I since have read about non ball bearing turbos not needing them. I know the factory units do not have them.. I have always tried to let my car run for a while before killing the power, but it is hard to do at the drag strip when being hard on it and trying not to let the motor get so hot... If you guys think the install of a timer and maybe removing the oil restrictor will make this go away, I will try another rebuild before writing off holsets. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted February 27, 2009 Share Posted February 27, 2009 Is there anybody that makes a bearing of slightly more resilant material that will withstand the hotter temps produced by running on gas motors opposed to diesel? Seems like the turbo is not the problem, just heat, which with engineering and a little creativity could possibly be cured? I know we have several machinists on the site, maybe upgrading the material used to rebuild the holsets would lead to greater longevity? -Ed Quote Link to comment Share on other sites More sharing options...
ktm Posted February 28, 2009 Share Posted February 28, 2009 Turbo timers are used to help prevent coking of the oil upon shut down, especially for non-water cooled turbos. If you drive the car hard prior to shut down, the turbo temperatures will be quite high. Shutting the car off immediately (this is especially true with non-water cooled turbos) stops oil flow instantly. The oil is allowed to sit in the turbo and overheat/coke-up. The turbo timer keeps the car running to allow the oil to continue to flow and helps to prevent coking. I do not know if there are different materials used for turbos built for diesels and those for gas engines. I would imagine that there may be as Justin stated. Porsche recently overcame the heat issue and is using the variable vane technology in their Porsche turbo now, a technology historically used in diesel turbos because of the heat issues. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted February 28, 2009 Share Posted February 28, 2009 I have only had my Holset running on my Z for a very short time and it has been parked all winter. So far I love the turbo, great setup for a L28! I am not saying that in the future I may feel not feel differently about Holsets but I hope not. I would be interested to hear any other bad experiences people have had with them. One thing I do know from my personal experience is that people make far too big of a deal about shaftplay. To some extent I think it is normal after some use. I have used turbos that have been deemed "worn out and no good" turned around and used them anyway with great success. One guy gave me his turbo because his mechanic told him his turbo was toast, and I ended up using it for two years with no issues. Another turbo I used for a short time was one that I had been given a upgraded compressor wheel and housing for stock L28 turbo. The wheel had touched the housing and burred the tips of the wheel and scratched the housing. A guy that had worked at a turbo shop said the turbo was un-salvagable. Well being the cheap bastard that I am, I decided to clean it up a bit with a dremel. The guy from the turbo shop was at the track that day when I ran a 13.4@103mph with it. He could not believe it. Before the upgrade the best that I had done was 14.5 Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted February 28, 2009 Share Posted February 28, 2009 I'm feeling kinda lazy and don't really want to look up the enthalpy for our E10 gas blend and Diesel to determine the theoretical Kelvin they both exothermically produce at the moment, maybe later on in the weekend. However I would be curious as to the temps difference. I would also be curious to know if people experiencing "premature rebuilds" are using turbo blankets and wrapping the exhaust manifolds. It would also be interesting to see the temp difference between a tubular header as opposed to the cast headers at the turbo inlet. Also curious if coatings on the header and or turbo would help lower any of the temperatures as well. Just bored and this has my attention this evening. -Ed Quote Link to comment Share on other sites More sharing options...
gearheadstik Posted February 28, 2009 Author Share Posted February 28, 2009 My setup uses a powdercoated stock manifold and turbo housing... then manifold and exhaust pipe were wrapped.. turbo is blanketed.. The play in the shaft is enough it has started rubbing on the intake side. This being said, I have not realy taken shortcuts besides the timer.... Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 2, 2009 Share Posted March 2, 2009 I watched Phil's latest video... he was running that sucker at 25psi. I think 10-15 should show no problems. Also, Phil was running rich top end, creating more heat, and if his timing was agressive up there... even more heat. A good tune and slightly less timing might yield a much longer life. Quote Link to comment Share on other sites More sharing options...
ktm Posted March 3, 2009 Share Posted March 3, 2009 I watched Phil's latest video... he was running that sucker at 25psi. I think 10-15 should show no problems. Also, Phil was running rich top end, creating more heat, and if his timing was agressive up there... even more heat. A good tune and slightly less timing might yield a much longer life. Turbo-charged gasoline engines run around 1400 to 1500 degrees F when under boost (some cooler, some hotter). Diesel temps, on the other hand, are usually around 900 degrees and can exceed 1000 degrees under heavy load. You can run 1400 degrees at 15 psi and 1400 degrees at 25 psi, it's all in the tune. FYI http://forums.hybridz.org/showthread.php?t=125586&highlight=egt Phil was running methanol injection without tuning for it IIRC. Running 100% methanol and not pulling primary fuel and adding timing can cause you to run quite rich. Quote Link to comment Share on other sites More sharing options...
PanzerAce Posted March 3, 2009 Share Posted March 3, 2009 I watched Phil's latest video... he was running that sucker at 25psi. I think 10-15 should show no problems. Also, Phil was running rich top end, creating more heat, and if his timing was agressive up there... even more heat. A good tune and slightly less timing might yield a much longer life. Shouldn't over rich be running cooler than normal? I was under the impression that as you leaned a mix out it would get hotter and hotter (to a certain point though, obviously lean it out enough and it'll start cooling down again). Quote Link to comment Share on other sites More sharing options...
ktm Posted March 3, 2009 Share Posted March 3, 2009 Shouldn't over rich be running cooler than normal? I was under the impression that as you leaned a mix out it would get hotter and hotter (to a certain point though, obviously lean it out enough and it'll start cooling down again). Not necessarily. If you are too rich then the fuel mixture is still burning as it leaves the cylinder and enters the exhaust manifold. This holds true if your timing is too retarded. Leaning out only increases temps until you reach 14.7:1 at which point any further increase in AFRs will decrease temps. You are at your hottest at 14.7:1. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted March 3, 2009 Share Posted March 3, 2009 Turbo-charged gasoline engines run around 1400 to 1500 degrees F when under boost (some cooler, some hotter). Diesel temps, on the other hand, are usually around 900 degrees and can exceed 1000 degrees under heavy load. You can run 1400 degrees at 15 psi and 1400 degrees at 25 psi, it's all in the tune. FYI http://forums.hybridz.org/showthread.php?t=125586&highlight=egt Phil was running methanol injection without tuning for it IIRC. Running 100% methanol and not pulling primary fuel and adding timing can cause you to run quite rich. Ahh your right... forgot about the meth injection. Thanks for the temp references. So essentially you would have to eliminate 400 degrees roughly to get it even close to diesel temps? Even though the temp stays the same with different pressures, the turbo is still doing more work at 25psi than at 10psi. Like your motor does more work at 9000rpm than it does at 3000rpm. Quote Link to comment Share on other sites More sharing options...
GrayZee Posted March 5, 2009 Share Posted March 5, 2009 I have been thinking about the idea of gasoline engines running hotter than diesels and therefore shortening the life of the turbo, although it sounds plausible at first I don't agree with it. How many turbochargers are there out there that are specifically designed for use with gasoline engines? Percentage wise the numbers are very small. Without question diesel engines are the king of turbo applications, mostly medium to heavy duty trucks. Futhermore how many gasoline engines are there out there with turbochargers that are capable of much more than 250hp? There is alot of engineering that goes into designing a turbocharger, I doubt very much that alot of turbos have been made with the car modification scene in mind. The market is way to small to justify it. Take a GT35r for example, I do not know the exact model but I have heard that you can find that turbo on a european market medium duty Volvo truck. I would bet that any 300+hp turbo you can buy from a Garrett dealer has had it's roots in some sort of diesel application. Quote Link to comment Share on other sites More sharing options...
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