Jump to content
SAU Community

Recommended Posts

Hi all i seem to have a boost creep problem after installing a high flowing exhaust system (jjr split dump, 3inch catco and power extreme II cat back), it boosts up to about 14 psi as the revs rise up (I even manually tied the flap all the way open). After doing a search it seems maybe the turbo cant flow enough through the wastegate housing or dump pipe any ideas? Will a bellmouthdump pipe help me? can i dremel out the wastegate housing a bit maybe?

My car is a s1 r33 with r34 intercooler and pod that is the limit of mods. Any help or ides welcome.

cheers.

added brand new hks actuator today but, its overboosing when the gate is manually tied totally open the absolute min boost is 14+ psi problem seemed to start after installing high flow cat. Ill try dropping the exhaust tomorrow, going to try friends bellmouth too. The exhaust is brand new and the car makes very good power with it way more than the stock system. Is it hard to increase the wastegate size can it be done just using a dremel? If i can get it down to 10 psi i will be happy. thanks for the replys

Its definitely not 'normal' for a stock turbo to boost creep.

My first point of call would be the dump pipe. The dump is what directly has an affect on the boost control in a closed system.

Maybe its just a bad one; possibly the point of merge for the wastegate split is a tad messy (not well matched) inside that restricts wastegate flow.

maybe I should dremel the dump pipe out a bit first then (the fitting was average with respect to the lining up of the flange bolts and the lining up of the waste gate pipe to the flange hole, I didn't think it would of had a huge effect at the time, soon see though) Im not really keen on taking to the turbo with the dremel. I just want to dremel something now!!

It is not an exhaust freeness problem.

You either have a problem with vac hose plumbing or with your actuator.

There is absolutely no need to dremel out anything.

I've never had any problems, even using highflowed turbos pumping out 20+ psi. Standard size hole is fine.

Ok I definitely wont dremel the turbo then. The pipe and actuator are brand new as that is what i thought the problem was too but still overboosted so i disconnected the actuator arm from the wastegate flap and put a zip tie on the flap so that it was all the way open to me this says that i should make very little boost but when I took it for a drive it still had no problem boosting to 13 psi but not till high up in the revrange. Thanks for all the input.

It is not an exhaust freeness problem.

You either have a problem with vac hose plumbing or with your actuator.

There is absolutely no need to dremel out anything.

I've never had any problems, even using highflowed turbos pumping out 20+ psi. Standard size hole is fine.

Its deifnitely not a vac hose/actuator problem. As per his first post he has tied the wastegate wide open and it still boost creeps.

I would definitely be looking at the wastegate dump to turbine dump merge point.

Pic attached.

post-382-1185580689_thumb.jpg

Ok the dump is off, too me it looks like the wastegate is exiting straight onto the flange maybe (the blackened part) oh and the best part a bolt snapped of in the turbo and my o2 sensor is stuck in the pipe.

cheers

post-36364-1185581700_thumb.jpg

Edited by SevenAngryPenguins

Another thing to check.

With the dump on does the wastegate foul with the dump when attempting to open it fully? Possibly the dump is preventing the flap from opening fully? Unlikely but worth checking while its all off.

Compare the opening angle to that of the std dump if you still have it.

I always throw some antisieze on the thread of the o2 sensor. Supercheap have little satchels for around $1 each.

mine is same 13psi what ever i do ,it wont boost lower :P .my dump is a single track but big size.autos are 5psi standard but manuals are 7.2 standard boost without intercooler /exhaust.

ive tried alot of thing but to no luck yet

the 2 things i would look at are:

1, when the wastegate is open is the air still able to flow past it. the wastegate may be opening without fouling, but it may be blocking the path of the air through the wastegate pipe of the dump pipe.

2, chech where the wastegate pipe blends back into the dump pipe. the one i had the pipe was welded off to the side of the hole. it didn't leak but when you looked at it from the inside half of the hole was covered. so i got the die grinder out and opened the hole up. i had to take a section out about 4cm x 0.7cm.

Drop the exhaust, just before the cat, and see if the creep goes away.

If the creep goes, something in the exhaust maybe restricting flow. Check also for any air leaks to the actuator.

itrs the other way around dude.

your wastegate isnt flowing enough. perhaps try putting the standard dump pipe back on. that will solve it.

Its deifnitely not a vac hose/actuator problem. As per his first post he has tied the wastegate wide open and it still boost creeps.

I would definitely be looking at the wastegate dump to turbine dump merge point.

Pic attached.

Oops, silly me. I didn't read the first post carefully. Just thoguht it was the usual wrong plumbing/faulty actuator

ok this is what im thinking that the wastegate flap was fouling just a little as it feels different to move now than when i did when the dump pipe was on. I don't have the old dump to compare too but when i place the dump pipe gasket over the pipe the top hole (waste hole) doesn't look like its even close to lining up with the turbo waste gate. I'm not sure I think i will just buy a bellmouth dump pipe and see how it goes after i pull the turbo off to get that damn bolt out!! Maybe should highflow it while its off hmmm......

post-36364-1185602642_thumb.jpg

Edited by SevenAngryPenguins

Hi Chris,

The waste gate is fouling on the bracket that holds the turbo heat shield or it is hitting the side of the flange.I had this very same problem but due to work commitments had no time to really look at it for a year.When I did look I found the original dump flange was a lot thicker than the stainless with separate waste gate.So the waste gate arm was hitting the bracket holding the heat shield stopping it from opening more than half way.I could wind the boost up to 14lbs but any more and boost would go crazy fluttering up and down.Bear in mind my turbo was high flowed and would operate better with a bigger exhaust wheel but with a standard turbo and hence smaller turbine wheel you would get the same thing happening at a lower boost setting.You only have to take the cover off and take off the circlip with a fine screw driver then pull the actuator rod to take some pressure off the lever and lift it off.Now that the wastegate arm is free to move it should be able to swing around to face directly over the dump pipe at a right angle to the flange.If not,well,there is your problem.

yeah my arm hits on the heat shield and then it seemed to drop down into a slot and to move it back it had to be lifted up (has bit of up and down movement) this is stock setup though..... how far does the actuator need to travel? my flap operates correctly with the pipe removed not sure about when its on ill check when the turbo is off, should i modify my heat shield did this solve your problem?

Edited by SevenAngryPenguins

Hey i got similar issues i think i got an xforce turbo back 3inch with hi-flow cat and FMIC and airfilter no boost controller gettin a reading of 12psi and car seems to not wanna rev past 5000rpm...nethoughts?

Because the flange is thinner the bracket is closer so just put 2-3 thin washers in between the flange and bracket to space it out a bit. Only has to be the difference between the old flange and new,so only a couple of mil.

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

    • Well, I can recommend the partial AV system translation CD I ordered from Car Audio Workshop in NZ. Whilst it didn't address the date issue, it has conveniently translated on-screen menu items into English, and now allows the GPS-received time to be offset in hours rather than minutes, so I can display Eastern Australian time accurately ( and bump it by another hour when daylight savings starts ).
    • Yuh, if it's 45°C outside, my car is driving in it.
    • I'd be curious to hear more. Otherwise, have you driven a modern x-trail? I wonder how it compares. Here in Australia they are/were popular for rentals and fleet vehicles. I have been in some and my impression was they are bad. But, this may have been very different in the 2000s at a good trim level. Twenty years is plenty of time to make the model worse. I do very much agree with the 2 silver cars in the garage approach. But, not driving because it's too hot would not leave a lot of time in the year for many Australians. I don't think you need to worry too much unless the car has actual issues with overheating. 
    • Back again. I returned to Japan in Jul/Aug to spend time with the car on my birthday and remind myself what all the sacrifice and compromise is for. It happened to line up with the monthly morning meet in Okutama, which I have been wanting to go to for a long time. It's a unique event at a unique spot with really rare, interesting, and quirky cars. It's where all the oldheads and OGs gather. The nighttime scene at DKF certainly has its place and should be experienced if you're into cars, but there's too much bad attention and negativity around it now. IMO the better time is Sunday morning at DKF or Okutama; it's more chill and relaxed. I'm glad I was finally able to go, but not sure it's worth the drive from all the way from Nagoya immediately the day before, unless I was already staying in Tokyo for the days right before the meet, because you have to wake up quite early to make it in time. Funnily enough though I didn't drive the car all that much this trip because it was just too damn hot. While there were zero issues and running temps were nominal and the A/C was strong, RBs already run crazy hot as it is. Sure, it took it all like a champ but something about driving these cars in the ridiculous heat/humidity bothers me and makes me feel like I'm asking too much of it. I'm just me being weird and treating the car like a living thing with feelings; I'm mechanically sympathetic to a fault. Instead I was mainly driving something else around - a KX4(silver) 2001 X-Trail GT, that I acquired in May. There's a few different flavors to choose from with Xs, but visually it's the Nissan version of the Honda CR-V. Mechanically it's a whole different story as this, being the top-trim GT, has an SR20VET mated to a four-speed auto and full-time AWD! It was a very affordable buy in exceptional condition inside and out, with very low mileage...only 48k kms. Most likely it was owned by an older person who kept it garaged and well-maintained, so I'm really happy with how it all worked out. It literally needs zero attention at the moment, albeit except for some minor visual touch-ups. I wanted something quirky, interesting, and practical and for sure it handily delivers on all three of those aspects. I was immediately able to utilize the cargo and passenger capacity to its full extent. It's a lot of fun to drive and is quite punchy through 1st and 2nd. It's very unassuming -in the twisty bits it's a lot more composed than one would think at a glance- and it'll be even better once I get better tires on it(yes, it's an SUV but still a little boat-y for my liking). So...now I have two golden-era Nissans in silver. One sports car and one that does everything else; the perfect two-car solution I think👍 The rest of the trip...I was able to turn my stressed brain off and enjoy it, although I didn't quite get to do as much as I thought. I did some interesting things, met some interesting people, and happened into some interesting situations however, that's all for another post though only if people really want to know. Project-wise, I went back to Mine's again to discuss more plans and am hoping to wrap that up real soon; keep watching this space if that interests you. Additionally, while working in the tormenting sweatbox that is the warehouse, I was able to organize most of the myriad of parts that my friend is storing for me along with the cars, and the 34 has a nice little spot carved out for it: And since it can get so stupid hot in there, that made it all the more easy -after I was standing there looking at the car and said 'f**k it'- to finally remove all the damn gauges that have mostly been an eyesore all this time. Huzzah. The heat basically makes the adhesive backing on the gauge mounts more pliable to work with, so it was far less stressful getting this done. I didn't fully clean it up or chase the wiring though; that will happen once I have the car in closer possession. Another major reason to remove all that stuff is to give people less reasons to get in my car and steal s**t while it's being exported/imported when/if the time comes, which leads us to my next point... ...and that is even though it's time in Japan is technically almost up since it's a November car and the X would be coming in March, I'm still not entirely sure where my life and career is headed; I don't really know what the future looks like and where I'm going to end up. I feel there's a great deal of uncertainty with me and as a result of that, it feels like I'm at a crossroads moreso now than any point in my life thus far and there are some choices I need to make. Yes, I've had some years to consider things and prepare myself, however too much has happened in that time to maintain confidence and everything feels so up in the air; tenuous one might say. Simply put, there's just too much nonsense going on right now from multiple vectors. Admittedly, I'm struggling to stay in the game and keep my eyes on the prize. So much so in fact, that very recently I came the closest I ever have before to calling it quits outright; selling everything and moving on and not looking back. The astute among you will pick up on key subtext within this paragraph. In the meantime I've still managed to slowly acquire some final bits for the car, but it feels nice knowing there's not much left to get and I'm almost across that finish line; I have almost everything I'll ever want for my interpretation and expression on what it is I think an R34 should be. 'til later.
    • Thanks for that, hadn’t used my brain enough to think about that. 
×
×
  • Create New...