Jump to content
SAU Community

Recommended Posts

Hi all.

R33-25t mods:

FMIC

Apexi pod with CAI

Full 3inch exh(no cat)

Splitfire coils

NGK copper .8mm HR7 plugs

Fully serviced - oil filter etc

Atomic boost tap

Alright, so before i used the factory solenoid earthed and got up to 13psi by the redline or so.. now with the Atomic boost tap(set to 7psi) it holds 7psi till about maybe 5k, then gradually increases to around 12-13psi by the redline, in any gear.... i hardly let it near the redline anyway.

i want this issue fixed.. any ideas how to? its a bit annoying at times.

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/
Share on other sites

Hi all.

R33-25t mods:

FMIC

Apexi pod with CAI

Full 3inch exh(no cat)

Splitfire coils

NGK copper .8mm HR7 plugs

Fully serviced - oil filter etc

Atomic boost tap

Alright, so before i used the factory solenoid earthed and got up to 13psi by the redline or so.. now with the Atomic boost tap(set to 7psi) it holds 7psi till about maybe 5k, then gradually increases to around 12-13psi by the redline, in any gear.... i hardly let it near the redline anyway.

i want this issue fixed.. any ideas how to? its a bit annoying at times.

By the sounds of it you had a boost creep issue even before you fitted the Atomic boost tap (what ever that is..never heard of one)...Earthing the factory solenoid should get a constant 7-10 psi depending on mods..exhaust, intake filter etc...

Fitting the boost tap (I assume this is just a bleed valve) will not fix boost creep...It can only make it worse..

Most common reason for boost creep is waste gate too small or restricted or waste gate not able to open fully...If you are using an internal gate check the actuator linkage and make sure it is not fouling on anything...

What I suggest is take off the bleed valve and unearth the soleniod so that you get minimum boost...then find out why the boost is spiking (check actuator). Fix this and only then play with the bleed valve...

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3743002
Share on other sites

i had one of those atomic bleed valves, there pieces of crap :) i sold mine after like 2 weeks.

get one of these

http://cgi.ebay.com.au/Turbotech-manual-tu...1QQcmdZViewItem

there was a 10000 page thread about them at one stage on sau, there good :yes:

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3743113
Share on other sites

RB2530 - thanks for that.. yes it was spiking even before i put the tap on.. when i had the facotry solenoid on there, even unearthed, it would spike up to like 14-15psi. Then i took the solenoid off, and hooked up the actuator straight to a pressure source, and got about 5psi, however that too would spike to about 14psi by the redline(in any gear)

the atomic tap(set to 7psi) has improved it but it still spikes. but only to 12psi or so.

iv got my guess on the actuator but im not exactly sure how to test it.. i was under the impression that i pull the actuator open and go for a lil spin(it shouldnt build boost at all).. and then what? what doe that proove??

EDIT - Justin911 - thanks for that i have just purchased that thru ebat! cos me $47 NZD so hopefully gets delivered to me by this week or next.

Edited by Ultimategtr
Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3743337
Share on other sites

RB2530 - thanks for that.. yes it was spiking even before i put the tap on.. when i had the facotry solenoid on there, even unearthed, it would spike up to like 14-15psi. Then i took the solenoid off, and hooked up the actuator straight to a pressure source, and got about 5psi, however that too would spike to about 14psi by the redline(in any gear)

the atomic tap(set to 7psi) has improved it but it still spikes. but only to 12psi or so.

iv got my guess on the actuator but im not exactly sure how to test it.. i was under the impression that i pull the actuator open and go for a lil spin(it shouldnt build boost at all).. and then what? what doe that proove??

EDIT - Justin911 - thanks for that i have just purchased that thru ebat! cos me $47 NZD so hopefully gets delivered to me by this week or next.

Pull the actuator open as much as you can and make sure the linkage on the flapper shaft rotates at least 60-70deg. I think that is a good start. It may be that the flapper valve is jamming on something when it is trying to open...or there maybe something broken inside the WG actuator that is stopping it from opening...If you have access to compressed air you can try pressurising the WG actuator. Use a tyre valve or something and just give it a little bit of air...DONT GIVE IT 100psi otherwise actuator go boom!!!

If you can get the WG open and wire it open and go for a drive and the turbo makes no or very small boost up to redline you have then proven that:

1. Your setup can flow enough exhaust through the WG to prevent boost spiking

2. The problem is centred around the WG and actuator and not some other bizarre condition elsewhere in the car...

BTW have you done any exhaust mods recently...I have heard of cases of aftermarket dump pipes designed in such a way that the flapper gets caught on a flange.....Also if there is a divider in you dump pipe and the WG flow is blocked for whatever reason it will cause spiking...

Apart from the above I am all out of suggestions..

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3743634
Share on other sites

hey thanks for that man, really appreciate it. makes sense too. ill have a go at it after work today.

well i have a TOMEI dump pipe(bellmouth design) and a front pipe. the flapper isnt being restricted by the dump pipe at all. i had a split dump pipe before which i thougth was causing the problem, but wasnt.

So if i go out for a spin with the actuator wired open and i dont get any boost, it means the exhaust is up to spec and not too restrictive right? then could it be the actual spring in the actuator? or what could it be?

sorry to ask these questions. i did try searching but the results were immense and i couldnt be bothered sifting through 100's of pages for answers.

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3743665
Share on other sites

hey thanks for that man, really appreciate it. makes sense too. ill have a go at it after work today.

well i have a TOMEI dump pipe(bellmouth design) and a front pipe. the flapper isnt being restricted by the dump pipe at all. i had a split dump pipe before which i thougth was causing the problem, but wasnt.

So if i go out for a spin with the actuator wired open and i dont get any boost, it means the exhaust is up to spec and not too restrictive right? then could it be the actual spring in the actuator? or what could it be?

sorry to ask these questions. i did try searching but the results were immense and i couldnt be bothered sifting through 100's of pages for answers.

It could be that the actuator has a problem where something inside it has broken or come away and is stopping it from opening as much as it should...I haven't heard of this happening before but there is a first time for everything...As I said before if you have compressed air available try pressuring the actuator and see how much it opens...But once again only add 15-20 psi tops otherwise you may blow apart the actuator...

I once modded an external gate so that I could adjust the spring tension..It worked well but when it was wound up the spring would bottom out (fully compress) and this limited the travel of the WG and produced boost spiking...

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3743748
Share on other sites

hey man, just tried it, i have the heat shield on my factory turbo.. do i need to take the heat shielf off?

with it all connected, i tried nudging it but it wouldnt budge??? should it be something that moves easily, or do i need some actual efford into it? i didnt pull much cos dont want to wreck it.

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3744096
Share on other sites

hey man, just tried it, i have the heat shield on my factory turbo.. do i need to take the heat shielf off?

with it all connected, i tried nudging it but it wouldnt budge??? should it be something that moves easily, or do i need some actual efford into it? i didnt pull much cos dont want to wreck it.

Not sure about the heat shield...Cant remember cause I haven't seen a stocker for quite a while...

The WG linkage will be tight and hard to move if you cant get a decent hold of it..Remember that it operates at 5-10 psi air pressure so a bit of effort will be required...do you have access to compressed air??

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3744287
Share on other sites

ahh ok thats cool then. i dont have #10 socket here so il have to leave it till the weekend, my dad has all the tools in the world inc compressed air..

ill pull the actuator apart this weekend. thanks for your help paul. much appreciated. ill post up when i have pulled apart the actuator.

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3744330
Share on other sites

  • 1 month later...

You wont be able to move the actuator by hand.. They are quite firm. My advice is the same as was mentioned and just use compressed air to operate the actuator to make sure its working properly. My guess is that you either have a faulty actuator or perhaps a leak in the vacuum signal hose to the actuator. You may be able to find this when you pressurise it with compressed air, if infact there is a leak.

Good luck,

Deren

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3863136
Share on other sites

Hey guys, just incase somebody else has this problem, i spoke to my mechanic and he thinks that because the exhaust is so free flowing and efficient now (no cat and good dump pipe) the wastegate hole is too small to let the air through, thus the boost creep. So he told me that a solution would be porting the wastegate, but the thinks that modyfing a standard turbo is too costly and pointless. He also says that skylines tend to just run rich, so the surge of boost won't actually hurt the engine too much, just will equal in a bit of smoke coming out and risk of R&R happening. He suggests taking it to the dyno and checking the mixtures just to be on the safe side.

I would like to ask how much porting the wastegate would actually cost if anybody knows? And also is it possible to do it yourself.

Also he said that a tune (SAFC) would come in handy just to correct the A/F ratios abit so less damage to engine and better performance.

If porting the wastegate is too $$$ im just going to get a jaycar digital fuel adjuster and run 10psi and fix up the A/F ratios up top so the car runs smoother.

Hope this helps anyone

Link to comment
https://www.sau.com.au/forums/topic/211835-boost-creep/#findComment-3870424
Share on other sites

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

    • To expand on this to help understanding... The bigger/longer the block is, the more it's going to work to sit on your far away high areas, and not touch the low stuff in the middle. When you throw the guide coat, and give it a quick go with a big block, guide coat will disappear in the high spots. If those high spots are in the correct position where the panel should be, stop sanding, and fill the low spots. However, using a small block, you "fall off" one of the high spots, and now your sanding the "side of the hill". Your little block would have been great for the stone chips, where you only use a very small amount of filler, so you're sanding and area let's say the size of a 5/10cent piece, with something that is 75*150. For the big panel, go bigger!   And now I'll go back to my "body work sucks, it takes too much patience, and I don't have it" PS, I thought your picture with coloured circles was an ultra sound... That's after my brain thought you were trying to make a dick and balls drawing...
    • Oh I probably didn't speak enough about the small sanding block for blocking large areas.  In the video about 3 minutes in, he talks about creating valleys in the panel. This is the issue with using a small sanding block for a large area, it's way too easy to create the valleys he is talking about. With a large block its much easier to create a nice flat surface.  Hard to explain but in practice you'll notice the difference straight away using the large block. 
    • Yep I guessed as much. You'll find life much easier with a large block something like this -  https://wholesalepaint.com.au/products/dura-block-long-hook-loop-sanding-block-100-eva-rubber-af4437 This is a good demo video of something like this in use -    You have turned your small rock chip holes into large low spots. You'll need to fill and block these low spots.  It's always a little hard not seeing it in person, but yes I would go ahead and lay filler over the whole area. Have a good look at the video I linked, it's a very good example of all the things you're doing. They went to bare metal, they are using guide coat, they are doing a skim coat with the filler and blocking it back. If what you're doing doesn't look like what they are doing, that's a big hint for you  
    • The odometer does go up when driving.  Does this tell it is an issue with the speedometer itself?    Where can I look for replacement cluster? Or speedo? I can likely do the repair.. Will ER34 cluster work on HR34? Or do I need a HR34 20GT S2 specifically lol   
    • Mine's a bit bigger at 70x150mm roughly. The spots are flat, just can feel the edges if I dig my nail into it. I did fix some other other ones by both using my finger to sand that small spot (I'm a bit wary of doing this and creating hot spots and a bigger mess) and I also did sand over it flat and others, but this also worried me a bit because if I create an overall low spot on the panel on paint that is good.  Correct me if I'm wrong but as long as it's flat even if I can feel the edges, I can put filler because it will all be level once I sand it? I can see myself going in a circle after sanding guidecoat with 320 grit if for example the panel is flat with my hand but because I sanded the guidecoat I could have created a low spot again somewhere. Unless where I'm going wrong is what I mentioned previously where I didn't go low enough on the grits. It's 1 step forward and 2 step backwards here haha. I'll probably need to experiment with it more. Last time I go back to bare metal lol.
×
×
  • Create New...