Jump to content
SAU Community

Recommended Posts

Got my PFC tuned in my R34 tuned the other day. When I picked it up (from XSpeed in WA) they had found that it was making best power at 14psi and had set it to that! I though the turbo would have been running out of efficiency at about 12psi or so higher in the rev range? Boost obviously did taper off higher in the rev range but they said to leave it at that.

I told them I didnt think it would be safe to run the turbo at that boost all the time, but they assured me it was!!?

Anyway I was very happy with the perfomance (was making about 203rwkw) with a very good power curve but I decided that I would turn down the boost a bit (to 12 to 13 max, with 10-11 for everyday use) but before I turned it down I let my dad take it for a spin. He was quite impressed :happy: I did notice though on the hand controller that boost did actually hit 1.05kg/cm2 at one point though :P

Anyway the next day I turned down the boost to about 11psi and I was driving it off boost for the whole day (testing to see how good I could get the fuel economy). Today I pushed it again and now it seems to make a wierd noise exactly at about 5500RPM. Seems to be coming from the drivers side, I think. It sounds a bit like when you let the air out a balloon when your squeezing the hole bit with your fingers, and only starts at about 5500RPM and get louder as the revs rise. It doesn't seem to be loosing any power but I have not really tested that as I don't like pushing it with that noise.

I visually checked any hoses that carry any pressure best I could and couldn't see anything that would be obvioulsy leaking. Does anyone have any idea on what it might be?

Edited by JustinP

Do you have a t-piece for a boost gauge? check that - mine has split a couple of times and makes a high pitch squeel when it does - but i do notice a drop in boost pressure when that happens. maybe check intake manifold aswell? Not really sure what it could be.

Someone here is bound to say that if your tuner thinks 14psi on a R34 turbo is okay, then you should find a different tuner. Many guys on here have had theirs blow at 10/11/12 psi when pushed so I would be cautious. What yuo have done by turning the boost down is right.

Maybe there is an air leak, turbo gasket problem, have you checked that?

i ran my 33 on 14psi for about 8 months, turbo was still going. they do seem to go a lot better at 14psi than 11 or 12, contrary to popular belief.

sure they may last a shorter period of time, but they may not. if people have had thiers blow at 10 or 11 then shouldn't everyone just run it at 7psi to be safe? the ones that blow at low boost have probably spent a lot of time at redline (doing burnouts, etc), by a previous owner, etc. because that its really what kills a turbo, running big boost and then holding it high in the rpm.

Do you have a t-piece for a boost gauge? check that - mine has split a couple of times and makes a high pitch squeel when it does - but i do notice a drop in boost pressure when that happens. maybe check intake manifold aswell? Not really sure what it could be.

That was my first thought being on that side of the car. I visually checked it all and couldn't see anything but I might pull all the hoses off and check them properly.

There is no engine problem either in the bottom end or the head that would ever make a sound like that is there? I couldn't imagine that being possible but it's my biggest fear killing the engine when it's only got 70,000k's on it :happy: I won't mind if the turbo goes eventually, I will just replace it with a GCG highflow :huh:

Someone here is bound to say that if your tuner thinks 14psi on a R34 turbo is okay, then you should find a different tuner. Many guys on here have had theirs blow at 10/11/12 psi when pushed so I would be cautious. What yuo have done by turning the boost down is right.

Maybe there is an air leak, turbo gasket problem, have you checked that?

Yes I was very suprised when they said that. And its a pretty large / professional workshop... I don;t think I will use them again. The general service they gave me and didn't really involve me in any of the tuning process, just kinda took the gave it back :happy: I should have gone to Top Racing like I was thinking of initially.

I do have a big leak where the dump connects to the back of the turbo due to a snapped bolt, but I have had that for a while and that makes a completly different noise.

As long as I know the engine itself or even the turbo couldnt make that kind of a noise I will be happy as at least I know serious damage is not imminent.

Thanks guy for your input too :huh:

i ran my 33 on 14psi for about 8 months, turbo was still going. they do seem to go a lot better at 14psi than 11 or 12, contrary to popular belief.

sure they may last a shorter period of time, but they may not. if people have had thiers blow at 10 or 11 then shouldn't everyone just run it at 7psi to be safe? the ones that blow at low boost have probably spent a lot of time at redline (doing burnouts, etc), by a previous owner, etc. because that its really what kills a turbo, running big boost and then holding it high in the rpm.

Yer I am suprised how hard it goes at 14psi compared to 12psi on the stock turbo. Maybe I will run it at 13 most of the time. I would not be too bothere if the turbo died in a year or so as then I can upgrade. I just don't want an exploding turbo to kill my motor too!

yeah thats the only bad bit.

What are the chances of this actually happening anyway? Has anyone here ever experienced an exploding ceramic exhaust wheel sending dust and crap back up into the engine which has caused engine damage? I know it certainly happens (even though i find it hard to believe stuff could get back up there with the amount of gas being pushed out), but is it like a one in hundred chance or is it actually common when a ceramic turbo lets go?

its not the exhaust side, its the compressor side starting to wobble and then sending fragments into the motor.

have a chat to justin911. he had his let go at the drags and a piece of the compressor wheel get wedged in the butterfly and it was reving its arse off without touching the accelerator.

its not the exhaust side, its the compressor side starting to wobble and then sending fragments into the motor.

have a chat to justin911. he had his let go at the drags and a piece of the compressor wheel get wedged in the butterfly and it was reving its arse off without touching the accelerator.

That makes more sence. Although I wonder if the nylon compressor wheel on an R34 turbo would reduce the chance of this over a steel wheeled 33 compressor wheel?

I think the idea of a steel exhaust wheel is that they can take more heat and spin faster without shattering like a ceramic wheel would. Dunno about the nylon compressor ones, but i'd GUESS that a steel compressor wheel is stronger than nylon?

I've always beleived that the nylon wheels only let go when the rear ceramic wheel breaks. (shaft unbalances and the nylon fins hit the inside of the turbo). 33 and 34 turbo's still have ceramic rear wheels (I think? Definately the 33's do), and I think that is where your main worry should be. Too much heat and too fast RPM for the rear ceramic wheel will make it break... THEN your front nylon wheel will thrash around until it breaks, and sends plastic through your cooler and into your intake manifold... and so on.

id say ratio of compressor dying to exhaust wheel dying would be 10:1

most common is the exhaust wheel dying, ive only ever seen one compressor die and that was justins

"Today I pushed it again and now it seems to make a wierd noise exactly at about 5500RPM. Seems to be coming from the drivers side, I think. It sounds a bit like when you let the air out a balloon when your squeezing the hole bit with your fingers, and only starts at about 5500RPM and get louder as the revs rise"

thats the strangest explanation detonation Ive ever heard

what was the knock reading?

either that or your getting some comp surge ?

Edited by 1400r
"Today I pushed it again and now it seems to make a wierd noise exactly at about 5500RPM. Seems to be coming from the drivers side, I think. It sounds a bit like when you let the air out a balloon when your squeezing the hole bit with your fingers, and only starts at about 5500RPM and get louder as the revs rise"

thats the strangest explanation detonation Ive ever heard

what was the knock reading?

either that or your getting some comp surge ?

That was the only way I could explain the sound, it's a strange noise. Actually it also sounds a bit like a belt slipping, but it's definately ait escaping somewhere. Also I noticed last night it does seem to loose some power when the noise starts. It wasn't detonation. Knock reading was below 40.

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

    • Seat of the pants assessment of the new intake: The car is way less "doughy" when hitting the loud pedal, especially off idle when stopped or in traffic, I did use a cheapo lazer thermal thingo to measure the temp around where the pod filter got its air, it was between 55 - 60°C, in saying this the car was shut off and not moving, so the OEM intake pipe was not supplying any fresh air to where the pod was when the car was at least moving A weird bonus was induction noise on the throttle in the cabin increased a bit,  I was worried that I was actually going to lose some of that induction noise I love so much, outside though, when I got the daughter to do a WOT drive by pass for me, the induction noise has increased alot when on the throttle, not quite ITB doort, but well up there I'm extremely happy with the results and have been exploring the country roads in the region  As for house mods: 1.New front fence is up and is awesome, it really upgraded how the joint looks from the street, and the added security is nice 2. Electricians have replace some interior lights, and with more lighting in the garage, a few new motion detecting lights out the front above the garage, front room, and at the front door, which I have already found heaps helpful coming and going, also now has fancy pants CCTV all round the house The only hold point for power though is the solar and batteries due to supply issues, although this will happen over the next few weeks 3. I have done a heap of landscaping out the front and I'm almost ready to do a new small retaining wall with some nice blocks to replace the brick and cemented in rocks around the raised garden beds cemented in river stone "was the fashion at the time" the house was built. I currently have a pallet of retaining wall blocks and 2 bulka bags of 20mm blue metal to replace the wood chip that is in the raised garden beds around the house 4. I now have 3 big raised garden beds for out the back to grow some vegetables, about 70cm high, 200cm long and 100cm wide 5. My 2 compost bins are already pretty full with brown, green and kitchen waste from the landscaping I'vedone so far, but they will probably take a few months to break down, so anything else that gets chopped, trimmed, and kitchen waste will just start filling the base of the raised garden beds to about 30cm before I start throwing 40cm of good compost, and stuff, for the vegetables to grow in, I'll need a few ton of compost and soil, but the local supplier can sent me bulka bags of the stuff Basically the logs, wood chips and a few strategically placed rocks for drainage, will give the beds some good organic materials down low to break down over time, and they will hold moisture during the warmer months to save the water in my big arse water tank if we don't get alot of rain So, all in all, the car and house mods are going well, and I'm really enjoying being retired, I sleep in too 0700 and slowly plod around inside until I feel like actually doing anything, and only work in the yard for as long as want, which has actually been alot over the last few weeks,  although when you look at it, it seems that not a huge amount of work has been done,  until I look at the before I started the work pics Happy days and good times indeed 
    • hahaha yeah. Plan is to get side skirts and probably just rear pods. But going to do them one-by-one. I've got a set that I really like from RHDJapen, but that one isn't shipped to AU. So need to find someone who can get it for me
    • Here's an idea, answer the questions I asked you as they are trying to work out WHY the LSD will be binding up in a straight line.
    • You haven't driven many modern cars then have you? Most of them have sfa steering feel with their stupid electric bullshit steering systems.
×
×
  • Create New...