Jump to content
SAU Community

Recommended Posts

The turbo (the actual compressor housing?) or the turbo wastegate actuator? You've said it's gone to the actuator as well as it going to the turbo..

Sorry I do mean actuator when I say that. The red hose is connected to actuator, if you look closely in the picture you can almost see it.

  • Replies 51
  • Created
  • Last Reply

Top Posters In This Topic

Possible that debris fell from somewhere and smashed the turbine. Perhaps the turbo was spun pretty hard then removed and sold to you, and you just got unlucky? Just change the turbo again. Get an R34 turbo if you can for a little upgrade ;):P.

Yeah I thought this too but it's happened 3 times, after everyone's opinions though I'll try a couple different things out when I'm changing over to the new (did you mean rb25 neo) turbo?

The line on the gauge you are talking about is halfway to full in positive pressure? If so from memory that seems about right

Perhaps there is to much heat in the exhaust side, maybe its running to rich?

Does it backfire, shoot flames or have poor fuel economy?

Edited by 89CAL

The line on the gauge you are talking about is halfway to full in positive pressure? If so from memory that seems about rightPerhaps there is to much heat in the exhaust side, maybe its running to rich?Does it backfire, shoot flames or have poor fuel economy?

Yeah man 3 quarters so inbetween positive 7 and half. Too much heat on the exhaust side does sound like a high possibility actually because I heard that those ceramic wheels don't handle too much heat very well... It does have pretty poor fuel economy, it back fires sometimes, I think it does run rich because when I bought it. It had an N/A manifold on it and the lines were blocked. But ecu and injectors were still turbo (the car is a factory gtst)

Did you use the same w/g actuator on all the turbos? could also be a boost leak too, if its leaking badly the w/g will not open when it should

The boost reading seems to be normal also and all turbos have had their own actuators!!

Point being if there is a boost leak, the waist gate actuator will keep closed and spin the turbo harder until it reaches normal boost level.

Ohh okay!! So a boost leak would just be from loose or split piping from any pipes on the turbo side??

Although it would be running awfully rich if it did, how has your fuel economy been?

Hmm well i get about 300kms to a tank give or take. Regardless of how the car is driven, and I've done and re done all of those pipes a few times now.. Is there a simple way to try and find a boost leak? Or shall I just change all the piping and all of the boots cause they're pretty old could be split or anything

First up, the point on the intercooler piping where the boost sense is taken from (red hose nipple) is on the wrong pipe. Sure, if nothing else is wrong, it will work there, but if you have one of a couple of other problems that position will make more trouble for the turbo. If, for example, you have a restrictive intercooler (or a rag in the intercooler as the classic line goes - but it does happen from time to time!) then you will be reading the boost pressure AFTER the restriction. So the turbo will be pumping to quite high pressure, but the engine and the wastegate only sees a lower pressure and everything seems normal - except you destroy ceramic wheels. Same sort of thing can happen with a boost leak although that will tend to be a problem regardless of where the tappnig is done.

And I would like to point out to people that it's not really heat that makes the turbines come apart or separate at the joint to the shaft. It's overspeed. If you're running retarded or otherwise hot in the exhaust side then the high temperatures will lead to high shaft speeds. So it is a little hard to say whether the chicken came before the egg or the other way around.

I would definitely do two things. I would fit another tapping point to the intercooler hot pipe and I would get a known good boost guage and hook it up to both of those tapping points (not at the same time, obviously) and see what the real boost is, and see if the dash gauge can be trusted.

Also, with respect to what boost the dash gauge is reading....+7 (hundred mm of Hg) is pretty close to 14 psi. Therefore the halfway line is 350 mmHg and is about 7 psi. If you are running halfway between those then you are up over 10 psi. That's high enough already - the car will likely be edging into R&R at that point. If the boost gauge can't be trusted, then your actual boost pressure is anyone's guess.

If the vacuum hose goes straight to actuator assuming the actuator is working then it shouldn't be boosting more then what it should. Its a simple analog pressure valve.

Those turbos re almost 20 years old with unknown conditions, not much of a point of buying them 2nd hand. Since you went through few its probably worth high flowing one of your dead turbos, you can then run what ever boost your engine and mods are happy with, for much better performance.

First up, the point on the intercooler piping where the boost sense is taken from (red hose nipple) is on the wrong pipe. Sure, if nothing else is wrong, it will work there, but if you have one of a couple of other problems that position will make more trouble for the turbo. If, for example, you have a restrictive intercooler (or a rag in the intercooler as the classic line goes - but it does happen from time to time!) then you will be reading the boost pressure AFTER the restriction. So the turbo will be pumping to quite high pressure, but the engine and the wastegate only sees a lower pressure and everything seems normal - except you destroy ceramic wheels. Same sort of thing can happen with a boost leak although that will tend to be a problem regardless of where the tappnig is done.

And I would like to point out to people that it's not really heat that makes the turbines come apart or separate at the joint to the shaft. It's overspeed. If you're running retarded or otherwise hot in the exhaust side then the high temperatures will lead to high shaft speeds. So it is a little hard to say whether the chicken came before the egg or the other way around.

I would definitely do two things. I would fit another tapping point to the intercooler hot pipe and I would get a known good boost guage and hook it up to both of those tapping points (not at the same time, obviously) and see what the real boost is, and see if the dash gauge can be trusted.

Also, with respect to what boost the dash gauge is reading....+7 (hundred mm of Hg) is pretty close to 14 psi. Therefore the halfway line is 350 mmHg and is about 7 psi. If you are running halfway between those then you are up over 10 psi. That's high enough already - the car will likely be edging into R&R at that point. If the boost gauge can't be trusted, then your actual boost pressure is anyone's guess.

Do you think oil starvation could be the problem???

If the vacuum hose goes straight to actuator assuming the actuator is working then it shouldn't be boosting more then what it should. Its a simple analog pressure valve.

Those turbos re almost 20 years old with unknown conditions, not much of a point of buying them 2nd hand. Since you went through few its probably worth high flowing one of your dead turbos, you can then run what ever boost your engine and mods are happy with, for much better performance.

Hi Stao.....read my post. There are ways it could happen. Anything that causes that signal to be lower (where it is sourced from) than the turbo's outlet pressure will permit it to work too hard.

Do you think oil starvation could be the problem???

Maybe....but what happens when you have that is that the turbo spins up and gets hot, then the bearings gall and sieze and the sudden shock would be what shakes the turbine loose. But I wouldn't expect the shaft to spin nicely afterwards, and it sounds like yours still have been.

Well, most of Skyline turbos that came in has no exhaust wheels. The way of how stock turbine shafts are made is by attaching a small section of the ceramic exhaust wheel into a steel shaft. Both elements has different expansion and retraction rates, and its always the section of attachment which breaks off at the ceramic end. The age and history of them probably don't help either, I won't be wasting money and time trailing 2nd hand turbos if its my car.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Thanks, I removed the fuse and the relay from the car and made my own circuit with them to test them with a test bulb.  I will look for the wiring diagram and go from there.
    • Jdm DC2R is also nice for a FF car compared to the regular hatches of the time.
    • Now that the break-in period for both clutch and transmission is nearly over I'd like to give some tips before I forget about everything that happened, also for anyone searching up how to do this job in the future: You will need at least 6 ton jack stands at full extension. I would go as far as to say maybe consider 12 ton jack stands because the height of the transmission + the Harbor Freight hydraulic platform-style transmission jack was enough that it was an absolute PITA getting the transmission out from under the car and back in. The top edge of the bellhousing wants to contact the subframe and oil pan and if you're doing this on the floor forget about trying to lift this transmission off the ground and onto a transmission jack from under the car. Also do not try to use a scissor jack transmission lift. You have to rotate the damn thing in-place on the transmission jack which is hard enough with an adjustable platform and a transmission cradle that will mostly keep the transmission from rolling off the jack but on a scissor lift with a tiny non-adjustable platform? Forget it. Use penetrating oil on the driveshaft bolts. I highly recommend getting a thin 6 point combination (box end + open end) wrench for both the rear driveshaft and front driveshaft and a wrench extension. These bolts are on tight with very little space to work with and those two things together made a massive difference. Even a high torque impact wrench is just the wrong tool for the job here and didn't do what I needed it to do. If your starter bolts aren't seized in place for whatever reason you can in fact snake in a 3/8 inch ratchet + 6 point standard chrome socket up in there and "just" remove the bolts for the starter. Or at least I could. It is entirely by feel, you can barely fit it in, you can barely turn the stupid ratchet, but it is possible. Pull the front pipe/downpipe before you attempt to remove the transmission. In theory you don't have to, in practice just do it.  When pulling the transmission on the way out you don't have to undo all the bolts holding the rear driveshaft to the chassis like the center support bearing and the rear tunnel reinforcement bar but putting the transmission back in I highly recommend doing this because it will let you raise the transmission without constantly dealing with the driveshaft interfering in one way or another. I undid the bottom of the engine mount but I honestly don't know that it helped anything. If you do this make sure you put a towel on the back of the valve cover to keep the engine from smashing all the pipes on the firewall. Once the transmission has been pulled back far enough to clear the dowels you need to twist it in place clockwise if you're sitting behind the transmission. This will rotate the starter down towards the ground. The starter bump seems like it might clear if you twist the transmission the other way but it definitely won't. I have scraped the shit out of my transmission tunnel trying so learn from my mistake. You will need a center punch and an appropriate size drill bit and screw to pull the rear main seal. Then use vice grips and preferably a slide hammer attachment for those vice grips to yank the seal out. Do not let the drill or screw contact any part of the crank and clean the engine carefully after removing the seal to avoid getting metal fragments into the engine. I used a Slide Hammer and Bearing Puller Set, 5 Piece from Harbor Freight to pull the old pilot bearing. The "wet paper towel" trick sucked and just got dirty clutch water everywhere. Buy the tool or borrow it from a friend and save yourself the pain. It comes right out. Mine was very worn compared to the new one and it was starting to show cracks. Soak it in engine oil for a day in case yours has lost all of the oil to the plastic bag it comes in. You may be tempted to get the Nismo aftermarket pilot bearing but local mechanics have told me that they fail prematurely and if they do fail they do far more damage than a failed OEM pilot bushing. I mentioned this before but the Super Coppermix Twin clutch friction disks are in fact directional. The subtle coning of the fingers in both cases should be facing towards the center of the hub. So the coning on the rearmost disk closest to the pressure plate should go towards the engine, and the one closest to the flywheel should be flipped the other way. Otherwise when you torque down the pressure plate it will be warped and if you attempt to drive it like this it will make a very nasty grinding noise. Also, there is in fact an orientation to the washers for the pressure plate if you don't want to damage the anodizing. Rounded side of the washer faces the pressure plate. The flat side faces the bolt head. Pulling the transmission from the transfer case you need to be extremely careful with the shift cover plate. This part is discontinued. Try your best to avoid damaging the mating surfaces or breaking the pry points. I used a dead blow rubber hammer after removing the bolts to smack it sideways to slide it off the RTV the previous mechanic applied. I recommend using gasket dressing on the OEM paper gasket to try and keep the ATF from leaking out of that surface which seems to be a perpetual problem. Undoing the shifter rod end is an absolute PITA. Get a set of roll pin punches. Those are mandatory for this. Also I strongly, strongly recommend getting a palm nailer that will fit your roll pin punch. Also, put a clean (emphasis on clean) towel wrapped around the back end of the roll pin to keep it from shooting into the transfer case so you can spend a good hour or two with a magnet on a stick getting it out. Do not damage the shifter rod end either because those are discontinued as well. Do not use aftermarket flywheel bolts. Or if you do, make sure they are exactly the same dimensions as OEM before you go to install them. I have seen people mention that they got the wrong bolts and it meant having to do the job again. High torque impact wrench makes removal easy. I used some combination of a pry bar and flathead screwdriver to keep the flywheel from turning but consider just buying a proper flywheel lock instead. Just buy the OS Giken clutch alignment tool from RHDJapan. I hated the plastic alignment tool and you will never be confident this thing will work as intended. Don't forget to install the Nismo provided clutch fork boot. Otherwise it will make unearthly noises when you press the clutch pedal as it says on the little installation sheet in Japanese. Also, on both initial disassembly and assembly you must follow torque sequence for the pressure plate bolts. For some reason the Nismo directions tell you to put in the smaller 3 bolts last. I would not do this. Fully insert and thread those bolts to the end first, then tighten the other larger pressure plate bolts according to torque sequence. Then at the end you can also torque these 3 smaller bolts. Doing it the other way can cause these bolts to bind and the whole thing won't fit as it should. Hope this helps someone out there.
×
×
  • Create New...