Jump to content
SAU Community

Recommended Posts

Hi All, 

Haven't really been active for a long time on here. Asked some questions on the R33 Owners page on Facebook and got some unhelpful responses so I thought I would try this community again (always been good).

I haven't driven my 33 much at all lately since I bought my fourby but I like to take it out for a bit of a spirited drive on weekends when I get a chance. The last couple of times I've gone out I noticed that for the first 10 minutes or so my 33 makes full boost no worries but progressively over time it struggles to make 1 bar of boost (typically 1.3). 

I understand that heat soak is an issue but it has never been this bad since I've owned it. 

Car is a R33 with RB25, ATR45SAT Hyper Gear Turbo, Apexi AVCR boost controller, 3" exhaust with Venom cat, Pod filter in an enclosure, Blitz SE return Flow, Haltech ecu, Nismo 740CC injectors. 

Things I've checked 
- Exhaust manifold studs - 6th cylinder was loose, done them up
- Turbo to manifold studs - one or two were loose, done them up 
- Changed all main vacuum lines 
- Boost leak tested, no noticeable leaks, sprayed joins etc 
- Checked over silicone joiners - no noticeable leaks or splits 

I do notice however that the upper section of the intake manifold has what looks like oil on the surface. I checked this when i used the boost leak tester and didn't hear or see anything. When I got back from the last test drive after I thought I fixed the issue, I boost leak tested it just to be sure and didn't hear anything obvious

I always thought that it might be the intake manifold expanding as the engine bay heats up or the exhaust manifold leaking as it heats up.
I thought I would ask here if anyone has any suggestions or personal experience on what I should be looking for with regards to this issue. Any help would be greatly appreciated. 

Apologies if this is in the wrong section, please let me know and I can have it moved. 

Thanks in advance for helping!

  • Like 1
Link to comment
https://www.sau.com.au/forums/topic/475966-boost-pressure-loss-over-time/
Share on other sites

1 minute ago, KiwiRS4T said:

How big is your intercooler? Is hot weather a factor? How do you test for boost leak? Do you make a rig and subject it to say 20 psi and see if it can hold it?

hey mate, i think the specs for the cooler are 620 x 266 x 76mm, I noticed it before Sydney got stupid hot recently but can wait till it cools down again later this week and check again. With the tester I have a nitto connector in a step down plug from bunnings but it doesn't have a gauge on it so I can't see if thats holding pressure. To test I just pressurized it from 5 psi, checked for leaks, 15 psi, checked for leaks, 20 psi checked for leaks by spraying joiners and the manifold 

Hope this helps.. might be worth changing my boost leak tester design tho 
 

How hot was it when you drove the car? I find you always need more duty cycle on the EBC during much hotter weather or simply set it up on closed loop which your Haltech could easily manage instead of using the AVCR.

12 hours ago, Dose Pipe Sutututu said:

Random thought, do you want a spare ATR45SAT with ball bearing centre? ?

 

13 hours ago, iruvyouskyrine said:

What wastegate actuator? Diaphragm may be leaking when hot

Its a Turbosmart replacement, its a possibility for sure but another reason for me to go high mount with external wastegate 

 

12 hours ago, Dose Pipe Sutututu said:

How hot was it when you drove the car? I find you always need more duty cycle on the EBC during much hotter weather or simply set it up on closed loop which your Haltech could easily manage instead of using the AVCR.

I can't rememeber because its happened a few days when I drove it. I would definitely like to test again on a long drive when the 40+ heat pisses off in Sydney. When I asked the tuner i used (going to try someone different next time - cough cough Johnny) they said that they don't use haltech to control boost because it requires adjusting in the ecu which is harder than doing it with a controller. 

Now I think of it I could always just up the duty cycle and see how it goes. 

12 hours ago, Dose Pipe Sutututu said:

Random thought, do you want a spare ATR45SAT with ball bearing centre? ?

I thought it sold already?  I was considering it when I saw you post it lol. 

  • Like 1
  • 2 weeks later...

Still haven't gotten around to checking this out further. Might just find someone to smoke test it while I'm at it in case I've missed something obvious. Might also get an inspection camera under the exhaust manifold and check if its cracked anywhere obvious

On 2/1/2019 at 7:57 AM, Dose Pipe Sutututu said:

Still have it, only sold the manifold and gate 

As much as I would seriously love this, I plan on selling the car soon enough. Haven't driven it for a while, the poor thing just gathers dust. The purpose of finding and fixing this issue is to make it more desirable to a buyer lol

Went to see @jmknights93 over the weekend and worked out what part of my problem may be despite hearing no audible leaks. 

mvyebUc.jpg
gIuTEpm.jpg

It looks like the intake manifold gasket is blown out and probably torn and pushing itself out further. I have new gaskets already knowing this day would come so I'll probably change it in the coming days or weeks. 

Thanks for everyone's input, I'll make an update when I get around to it. 

  • Like 1
  • 1 month later...

Finally  got around to changing the gasket and washers. I found out that not only was the gasket super swollen but one washer was completely missing and pressure wouldn't have been applied in that section of the plenum. Since changing the gasket the cars been running great, idles awesome and no more significant boost pressure loss

 

Thanks for everyone's input and help :) 

  • Like 1

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

    • Fark what are the changes of that snapping like that, clean. Nek minnit, custom radiator goes in, with built in oil cooler like those discontinued PWR ones from yesterdeacades ago
    • I thought I'd do a write up on an auto transmission fluid change for a the nissan 7 speed Automatic. At some stage the genius engineers decided that the fluid in the trans was "for the life of the transmission", (which seems kind of self supporting to me) and removed the dip stick and fill tube (funnily enough there is still a casting for it). Anyway, for this job you do need 2 specialist tools in addition to regular hand tools, jack and good chassis stands. You need a way to pump fluid up to the transmission; I got one of these but there are plenty of other options: https://www.ebay.com.au/itm/364584087070 Don't trust the generic listing though, it does not come with the required adapter for the Nissan 7 Speed. You need one of these, can't do the job without it: https://navarapart.com.au/product/genuine-nissan-patrol-y62-d23-np300-navara-re7-dipstick-fill-connector1 You need a heap of compatible transmission oil. Could be Nissan, could be anything else rated for Nissan Matic S. You need at least 10 litres, I had 15 to give it a better flush... Also, you need some biiig oil catch trays, at least one of these, or bigger if possible (volume was fine, size was very marginal): https://autobarn.com.au/ab/Autobarn-Category/Tools-%26-Garage/Specialty-Tools/Oil-Service/Garage-Tough-Oil-Drain-Pan-Black-16L---GT1068/p/TO03191 Finally, a measuring jug is very useful if your pump does not have volumes marked on it, I got a 6l one: https://www.repco.com.au/oils-fluids/fluid-accessories/measuring-jugs/penrite-measuring-jug-6l-pmj006/p/A5322648 Oh, and gloves.....this stuff is horrible (not as bad as diff oil, but getting there) ....First, jack up your car.....
    • So I mentioned the apprentice, @LachyK helped take the bonnet off. We just undid the nuts on the hinges and unclipped the gas struts, then pulled the bonnet back a little as the front was catching on the front bar.  I had a good look at everything today and have removed the rams, repaired/reset the hinges and bolted it back together like it never happened. I'll do a separate write up on the repair, and I also removed the poppers from the Fuga today too to save grief down the road.....as said above it is at least $5k to repair retail. I'm also happier about my ability to prepare a race car, and less happy about Nis-nault's engineering (I can hear @GTSBoy sAfrican Americaning) because the top hose of the radiator didn't slip off.......it snapped clean off. By practice I put the hose clamp hard up against the flare on a neck to make it least likely to ever move (thanks @Neil!). I guess that puts a little more pressure on the end of the pipe as it is further away from the rad, but still, that is pretty shit. I've put it back on for now as there was a fair bit of neck still there, but obviously there is no lip on the neck any more so I don't think I'll track it again until I have a new rad. Speaking of which....more research required. It looks like Koyo makes a standard size radiator in ally which I'll grab in the meantime, but I really want something thicker so might have to go custom in the medium term (ouch) Coolant still needs a refill and I have the pressure tester on it over night, but other than a wash down of the engine bay it seems alright. And @MBS206 noted something noisy on the front of the engine and I think I agree....time for a new accessory belt and tensioners I think.
    • our good friends at nismo make a diff for it, I have one (and a spare housing to put the centre in) on the way. https://www.nismo.co.jp/products/web_catalogue/lsd/mechanical_lsd_v37.html AMS also make a helical one, but I prefer mechanical for track use in 2wd (I do run a quaife in the front, but not rear of the R32)
    • What are we supposed to be seeing in the photo of the steering angle sensor? The outer housing doesn't turn, right? All the action is on the inside. The real test here is whether or not your car has had the steering put back together by a butcher. When the steering is centred (and we're not caring about the wheel too much here, we're talking about the front wheels, parallel, facing front) then you should have an absolutely even number of turns from centre to left lock and centre to right lock. If there is any difference at all then perhaps the thing has been put back together wrongly, either the steering wheel put on one spline (or more!) off, and the alignment bodged to straighteb the wheel, or the opposite where something silly was done underneath and the wheel put back on crooked to compensate. Nut there isn't actually much evidence that you have such a problem anyway. It is something you can easily measure and test for to find out though. My money is still on the HICAS CU not driving the PS solenoid with the proper PWM signal required to lighten the load at lower speed. If it were me, I would be putting either a multimeter or oscilloscope onto the solenoid terminals and taking it for a drive, looking for the voltage to change. The PWM signal is 0v, 12V, 0V, 12v with ...obviously...modulated pulse width. You should see that as an average voltage somewhere between 0V and 12V, and it should vary with speed. An handheld oscilloscope would be the better tool for this, because they are definitely good enough but there's no telling if any cheap shit multimeter that people have lying around are good enough. You can also directly interfere with the solenoid. If you wire up a little voltage divider with variable resistor on it, and hook the PS solenoid direct to 12V through that, you can manually adjust the voltage to the solenoid and you should be able to make it go ligheter and heavier. If you cannot, then the problem is either the solenoid itself dead, or your description of the steering being "tight" (which I have just been assuming you mean "heavy") could be that you have a mechanical problem in the steering and there is heaps of resistance to movement.
×
×
  • Create New...