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Sparky206

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Posts posted by Sparky206

    Tuning Rb25, Power Drops Off At 5000Rpm

    in Engines & Forced Induction

    Posted · Edited by Sparky206

    The car is being tuned using an ostrich emulator on the R33 std ECU which will then be burned to a permanent chip once finished. Tuned by toshi who has done many cars on here this way

    I believe the cat is a high flow, but it was there when i purchased. I've had it off before and its definatly 3" and you can see through it with a spiral type alloy fins inside

    I did not do a run without the exhaust

    Base timing was checked and is correct at 15 degrees

    Have not checked cam belt, but have not touched it either

    The plugs are copper, and have only done about 5000km, but this will be the first thing i change.

    As for wastegate problems, the boost drop is very gradual, and i cant see this accounting for a sharp drop in power and noticeable slowing of reving. It was so sharp that on some of the runs the dyno would stop recording after 5500rpm as it thought peak power had been reached.

    Also forgot to mention that the car would backfire once on some of the runs. Also the tuner said that the ignition timings we were running would usually cause pinging, but he was surprised that it was not.

    Thanks for the replys so far :thumbsup:

    Edit: My KW graph looked a lot like the torque graph above, but staying flat through the 6000-7000rpm range

    Tuning Rb25, Power Drops Off At 5000Rpm

    in Engines & Forced Induction

    Posted

    I'm in the process of getting my R33 S2 Rb25 tuned with nistune on a std R33 ECU. When we put it on the dyno yesterday, the graph showed a sudden loss of power at about 5000 rpm or 160km/h in 4th, with the car reving noticeably slower and occasionally backfiring. We wern't able to tune it out, the best we could get it was to stay flat from 5000rpm onwards, but this required a noticeable jump in ingnition timings around that rpm i.e. 17-18-18-21-23-24 ect. Highest power reading we had was 210KW

    dyno.png

    Uploaded with ImageShack.us

    The car has the following modifications

    FMIC

    3" exhaust

    Hi flowed hypergear turbo @ 14psi

    Z32 AFM

    GTR fuel pump

    Spark plugs are R5671A-7 gaped to .7 . I have investigated the coils before while experiencing rich and retard and have coated them in high temp silicon, but i could never find any cracks, or see any sparks in the dark.

    Boost started at 14psi and gradually dropped to 12psi by redline.

    Any ideas for whats causing this drop off in power?

    Replacing Fuel Pump

    in General Maintenance

    Posted

    I'm in the process of replacing my r33 gtst fuel pump with a 33gtr pump.

    I've removed the stock pump, but was unable to salvage the little rubber isolator that slides over the positive terminal on the pump.

    I'm not too keen on having a potential source of ignition inside the fuel tank, so where would i be able to get a similar one to do the job.

    Cheers

    Overboosting.

    in Engines & Forced Induction

    Posted

    I've had this problem for ages in my rb25. I have tried everything, different actuators, a high flowed turbo, a split and bellmouth dump pipe, but nothing stopped the creep. The only thing that i could find that made and difference was by placing a 2.5" restriction plate at the end of my 3" exhaust. That allowed the car to hold a steady boost level all the way to redline. I can't explain why, found the idea from a few supras who had the same problem. I have a feeling its to do with the tune, as im running stock ecu with mods, but when i get it re flashed i'll just up the boost anyway and let it do what it wants

    Boost Creep Issues

    in Engines & Forced Induction

    Posted

    Computer/tune?! :blush:

    The standard solenoid isnt even hooked up right?

    R33 boost normally tapers off at the top end, not the other way around.

    Have u had the car at an experienced workshop yet, or even on a dyno? maybe ur boost gauge is the problem. lol

    If its doing ur head in so bad, take it to an experienced shop.

    I know u replaced the actuator, but maybe theres a small hole in the diaphragm, does it hold pressure ok when pressurised?

    The standard solenoid isnt even being used, all i have is a vac line hooked straight into the wastegate, so its seeing the same presure as the boost guage. The boost guage is working, i can feel it hit R&R as it hits about 12psi.

    The diaphragm is inside the actuator? so it would have been changed when i changed the actuator

    Boost Creep Issues

    in Engines & Forced Induction

    Posted

    Black hose to the wastegate?! me thinks the way in the pic is the correct way to have it installed

    Those boost controllers r very touchy and sensitive to set. Does it still have the spring and ball inside it too?

    I immediately thought this too, but it was doing it with the old stock turbo as well apparantly. Sounds like an issue unrelated to the turbo itself imo.

    U may try leaving the wastegate full open on the dyno and see what happens, but often if it cant spool down low, it will barely get moving up top either.

    On the dyno try disconnecting the actuator rod off the actuator arm completely, hold the wategate flap it full shut with a long screw driver/lever and then at about 3000rpm let it go slowly so it can get full open by redline, hopefully then u can see if its still creeping at all.

    U sure the actuator rod isnt fouling/binding on something and stopping its full range of movement(unlikely on a skyline)?

    Black hose to the wastegate is to bypass the boost controller and just run it off the wastegates pressure. Its useless running a boost controller atm as it just creeps and hits R&R straight away.

    Ive checked the wastegate operation with a compressor and the arm has a full range of movement.

    Boost Creep Issues

    in Engines & Forced Induction

    Posted · Edited by Sparky206

    Thanks for the replies guys, to answer your questions.

    Yes i have a Hiflow cat installed

    Im nearly positive its plumbed right, although this is the first ive heard of the factory hose having a restrictor in it. Heres a pic to clarify (with boost controller installed, currently it has the black hose straight to wastegate)

    dsc00283s.jpg

    As for tune it is currently running the stock ECU, but im ready to get toshi to tune it, but i really wanted to get this sorted before i get a tune as it would probably be hard to tune with such a varying boost level.

    I've given the car a run to redline with the wastegate arm disconnected, and as expected the car sat on 0psi the whole way

    Thanks again for the replies so far

    Boost Creep Issues

    in Engines & Forced Induction

    Posted

    I've been having an ongoing issue with boost creep for a while now, replaced a few things and just cant get it to hold a constant boost level.

    Car is an R33 series 2, has the following mods:

    - FMIC

    - 3 inch turbo back exhaust

    - Now has a hi flowed turbo, but did the same thing with stock turbo

    The issue is that the car will hit stock boost level as the wastegate opens at about 2500rpm, at about 4000rpm the boost will start rising again, to about 10-12 psi by redline. This is running a vacuum hose straight to the wastegate, adding a boost controller just moves the same symptoms to a higher boost, i.e. starts at 10psi then creeps to 15.

    Things i have tried/replaced:

    - Replaced wastegate actuator

    - Replaced split dump pipe with Bellmouth

    - Pressurized the vacuum hoses to 5 psi to check for leaks

    - Installed a 2.5" restrictor plate just before the muffler

    Interestingly the only thing that worked was installing the 2.5" restrictor plate, this had it holding boost levels either off the wastegate or boost controller, but obviously id rather not use this as a band-aid fix. Previous owned said it had started creeping when the exhaust was installed.

    I've checked the operation of the wastegate with a compressor and it seems to be working fine. The fact I've replaced it aswell would suggest its not a problem with the wastegate operation.

    Bit stumped on where to look now so any suggestions would help

    Cheers

    Flushing Coolant From Block

    in General Maintenance

    Posted

    Couple of questions after reading the thread

    Has anyone answered how to get the tap water out of the block once you've flushed it, but before you put new coolant in?

    Also with the air bleed screw on the top of the motor, how long does this generally take until all the air is bled? I left mine off for a good 10 mins and all it managed to do was make a mess by spitting coolant everywhere

    Massive Amount Of Smoke

    in Engines & Forced Induction

    Posted

    thats what i am hoping as i have a turbo ready to go. when you pulled your dump pipe off what did you see coz im gona do that tomorrow and would like to know what im looking for. You are correct with the boost issue as we had a lot of trouble when the hoses were pulled off on the top end rebuild. I never thought of that, all that shit is mumble jumble. Im guessing your right when i punched the accelerator i got 20psi and bang. atleast im hoping thats the case. a turbo swap is alot easier than a top end do over.

    Well when i took mine off there wasn't an exhaust wheel at all, and mine let go just coming onto boost so id say yours would probably be the same, pretty much unless you find an undamaged exhaust wheel, your going to be replacing the turbo.

    Make sure you clean out your cat aswell, and the ceramic dust stuck inside the dump pipe. I found all the remains of my exhaust wheel sitting in the front of my cat, i suspect that's where yours would be also

    Massive Amount Of Smoke

    in Engines & Forced Induction

    Posted · Edited by Sparky206

    Blown turbo would be my bet, when my exhaust wheel went, there was a shitload of blue/white smoke out the back. Take the dump pipe off, on mine it looked fine on the intake side, you cant tell from there.

    Looks like you've had issues somewhere with controlling boost, loose pipe or something thats bleeding off air and boosting high, then youve floored it, hit 20psi+ and the turbos just let go.

    Replaced Turbo, Now Sluggish

    in Engines & Forced Induction

    Posted

    Bit of an update, had a fair crack at it over the weekend and ended up sorting it all

    It ended up being 2 issues

    First issue was there was a boost leak somewhere. I bit the bullet and just took all the intake hoses off again and re did them all as tight as possible. Then boost leak tested it with a air compressor and it held perfect. This sorted the car running like shit, it was smooth again but still free boosted.

    Then i checked the wastegate actuator with the compressor and found that it was hardly opening at all. Ended up being the bracket it was mounted on has the arm at a too sharp angle, so that it was opposing the wastegates arc at a certain point. Changed the mounting position with a few modifications to the way it was mounted so that it was more straight on which fixed the issue.

    Cheers to all that had a go at diagnosing, now just goto fix the boost creep problem the cars always had.....

    Replaced Turbo, Now Sluggish

    in Engines & Forced Induction

    Posted

    I was the one who took the turbo off, so i saw it first hand, the shaft had sheered off flush with the seals.

    Had more of a think about it, as some of the intake hoses were a bit of a squeeze to get back on, if i have a split in one post compressor wheel, would it not just be acting like a large bleed off valve, which would then give me the symptoms i have like long spooling time, hearing spooling but not seeing boost, boost struggling to build past 5psi till 5500rpm+ and my waste-gate not working?

    Someone with a bit more knowledge care to tell me if im on the right track?

    Replaced Turbo, Now Sluggish

    in Engines & Forced Induction

    Posted

    Took the cat off just then and its not blocked at all, could see straight through it all the way around, and was only minimal bits of ceramic in there which i tapped out. Took the car for a very loud run around the block and there was no improvement, still struggled to build boost and would not hold with the wastegate.

    Will borrow a compression tester during the week and ill get those results.

    Although there still 2 things i cant work out

    1. The metal shaft + bolt that held the ceramic wheel on is still missing. There is not a chance that it made it passed the cat, so where else could it be?

    2. The wastegate is not operating. Its the 2nd one I've tried and i have the same hose as i used on the old turbo connected straight to the actuator.

    Cheers guys

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