Make My Gt30r Reach Full Boost Earlier....

[paulr33]

you should always run a spring to the target boost as close as possible

ie using a 10psi or 12psi spring and trying to run 18psi-20psi is going to be impossible to control for any good electronic unit

so my advice is to simply fit a better spring, go as close as possible to the target

until you sort out the mechanical spring side no electronic controller will work correctly

[Lithium]

Yeah I have asked a couple of times in this thread if anyone can point me to a supplier of reasonable priced actuators suited to the application - so far in NZ the cheapest I have found for one is ~$470NZ which is far too much for me at this stage.

The actuator/AVCR can hold 15psi or 17psi flat once it reaches it so I can't see any reason why it should be technically impossible to make it reach it quicker when the engine is clearly capable of doing so... I will post results of how Mondays experiment goes when I do it, seems no one seems to have tried it.

[GT-RZ]

I think somehow we are forgetting what an actuator does? An actuator does not snap open @ 'x' preset boost level, If an actuator is rated @ say 8psi then it will be fully open @ 8psi however it will gradually open up from much lower pressure. The whole idea of an actuator is to create a linear onset of power. Simply increasing the the preload will increase the boost rating of the actuator not necessarily help with response...

The only way to fix the problem and have ALL your boost hold until 'x' desired level is to fit a good mechanical one way pneumatic valve before the actuator or use an EBC (which is basically the latter but with other fancy crap added to it and in cabin control...)

If you soley rely on the actuator you will never have your turbo's true response potential, however you will have a much smoother increase in power and provide your driveline with less hassle. Depends what you want.

One of the reasons threads like this can go in circles, or seem like people are missing things is when people don't read the original posters posts clearly - you obviously missed the 800x600 image of the Apexi AVC-R EBC I have been using to fight this issue I have been almost tempted to get a ball valve to put on the feed to the AVC-R/actuator... though I really don't think I should have to consider that.

I agree i should not have placed EBC in there. Some do a good job and some do not.

My post is edited and imo that's the best way, unless you get an EBC that monitors boost in a similar way. With a pneumatic valve in place it cannot let any noticeable amount of pressure through to the actuator until it hits the set level then your away, which gives you no loss of boost untill you want it.

Then you can keep your current actuator too as it really does not matter.

PS; your right though, i never even read the first post only a couple of responses on the last page when i clicked reply... There is only so many fixes to these problems.

Edited August 15, 2009 by GT-RZ

[KiwiRS4T]

I use and recommend the Jaycar boost controller. It uses a solenoid (actually I used the stock R33 solenoid but any normally closed one will do) to regulate boost to the actuator (i.e. it is not a bleed type controller). It uses a signal from the injectors to regulate the solenoid and the realtionship between the duty cycle of the injector and the duty cycle of the solenoid is determined by a controller which is entirely user adjustable. I believe this method of control is unique to the Jaycar although someone may correct me if they know of another. With this system NO BOOST AT ALL gets to the actuator (apparently unlike your AVCR) until you want it to. With my ball bearing GCG highflow turbo boost build is really rapid to my max of 1 bar (about 16psi which I have chosen as the max because i have stock internals) and it can hold it for as long as the turbo can make it. I will soon have a dyno chart where i can show the boost curve (well more of a flat line with a short steep approach and some tailing off at the top). the only catch is the Jaycar has to be assembled although you could possibly get someone to build it for you ( I had to) but the kit for the unit and the hand controller come to about $150. If you are interested send me an email to [email protected] and I will send some information as an attachment although there is a 50 page thread here:

http://www.skylinesaustralia.com/forums/Ja...tro-t61207.html

[discopotato03]

That link doesn't work for me .

Sydneykid had a lengthy string in the Stagea section about that Jaycar Independent Boost Controller Kit and the Hand Controller kit used to programme it .

Was very impressed from memory , actually didn't he have it referenced off MAF meter signal voltage ?

Cheers A .

Edit , "Jaycar boost and fuel control" - that's Sk's thread in SAU .

Can someone post the link , stupid computer playing up .

Edited August 15, 2009 by discopotato03

[_Ryan_]

Haha not sure if you are joking or not - but just in case, I was free boosting. I backed off when boost hit 1.1bar - not when it stopped climbing. It was climbing FAST, and if I didn't lift off it would have kept going until something else stopped it

It was just a test to see if it will spool well if the wastegate doesn't open prematurely, and it does.

Fastrotor - Not sure quite what you meant, do you understand how an electronic boost controller controls a dual port/external wastegate? I'm a little tired, so could just be failing at reading you right.

The dual port actuator has two sides, one is the "compressor" feed which is just a line from a boost source - same as any other turbo setup without a boost controller. The other goes to a second port on the wastegate, which is used by electronic boost controllers to regulate boost. What they do in this case is let boost into that side of the wastegate to effectively beef up the actuators resistance to opening by pushing the wastegate closed - when the target boost level is reached the boost controller stops pushing boost into this side of the actuator and the the "normal" spring tension collapses to the original boost feed and wastegate opens.

What I did to prove the actuator would allow this to happen is just put the boost feed into both sides of the actuator, to ensure that it stayed shut- just in case somehow it could creep open... which would be possibly caused by a leak or restriction on the boost controller line.

If I am answering the right thing, does that make sense?

Ah, i misunderstood, thought it was setup to bypass the solenoid like many of us do on stock rb25's...

[KiwiRS4T]

I have replaced the Jaycar link with one that works. Yes it was another SK project but no the Jaycar boost controller has only 4 connections: power supply, earth, signal from any injector and output to solenoid. You may be think of one of SK's other projects - DFA, tech edge etc.

[Lithium]

I agree i should not have placed EBC in there. Some do a good job and some do not.

My post is edited and imo that's the best way, unless you get an EBC that monitors boost in a similar way. With a pneumatic valve in place it cannot let any noticeable amount of pressure through to the actuator until it hits the set level then your away, which gives you no loss of boost untill you want it.

PS; your right though, i never even read the first post only a couple of responses on the last page when i clicked reply... There is only so many fixes to these problems.

Yeah sorry I was a little short, posted on a few forums and had a head of people telling me to do things I had already tried and mentioned haha. Fingers crossed that trick does something useful, if it is it could be handy for others looking at similar solutions. I will post the result either way when I get the valve

[psi]

I have a pressure releif valve set at 11 psi, then the air goes from there too my good old turbosmart boost controller(single stage!). I have a 9psi spring and I can (within reason) change the way the boost comes on.

Currently the setup is easily holding 16psi on a 45mm external gate.

I can have the valve shut until any preset value I dial in, I can even make a boost spike if wanted.. and the whole system cost less than $100 fitted! Never had a single issue with it.. and its been like that on 3 different cars and hasn't stopped in the last 9 years!

its so basic to look at, but it does an awesome job and I dont think that I'm ever going to change it!

[R31Nismoid]

With my ball bearing GCG highflow turbo boost build is really rapid to my max of 1 bar (about 16psi which I have chosen as the max because i have stock internals) and it can hold it for as long as the turbo can make it. I will soon have a dyno chart where i can show the boost curve (well more of a flat line with a short steep approach and some tailing off at the top). the only catch is the Jaycar has to be assembled although you could possibly get someone to build it for you ( I had to) but the kit for the unit and the hand controller come to about $150. If you are interested send me an email to [email protected] and I will send some information as an attachment although there is a 50 page thread here:

http://www.skylinesaustralia.com/forums/Ja...tro-t61207.html

The GCG turbos come with a better actuator IIRC - hence you wont be having as noticeable problems. You'll be lucky to be moving 2-3 psi from memory

[Lithium]

I could be wrong, but I thought my actuator indirectly came from GCG - it was sent to me from someone in Australia

[R31Nismoid]

purchase for general and their specifically made hi-flow could be different actuators in terms of supply.

being one is generic garrett, one is a setup they package themselves inhouse etc etc.

its just speculation, but i just remember someone posting something about the GCG hi-flow turbos having different actuators to vanilla purchases, which would make sense

[Fastrotor]

Any results Lithium ? Eagerly awaiting the results.

Gary

[Lithium]

I had some fun during a gap in the weather today, so here is the new pressure relief valve I got from Norgren:

I took advantage of the opportunity of doing these changes under the supervision of Tomei:

I did my first tests with the twin port wastegate as I need to remodify the setup to suit the old wastegate (changes were needed for the twin port) as my relief valve is best suited to a single port actuator... and the dual port actuator seems to be rated to 7psi vs my old actuator's 12psi. As a result of this I had some boost level oscillation, but that was no surprise.

My flatmate is going to reweld up my old actuator setup so I can re-install that - and going by tonights testing I suspect its going to finally have the type of boost control I have been hoping for:

I was a little weary of it potentially boost spiking, but no issue with that at all - with the soft spring it hits 1bar and drops back a couple psi and then rebuilds it in reducing swings but I expect the harder spring and a bit of tuning to sort it out.

[SLAPS]

My crappy Garrett actuator came inside a Garrett turbo box all packaged up OEM like.

480009-0009 or as some call it GAR480009-0009 or GRT rated at 1bar.

As listed on ATP's website

They are just a lazy actuator unfortunately. Hindsight as they say.

Most go the large can actuators if you want decent boost control out of an IW.

18psi Large Can (not available in AUS I believe as I couldn't find one)

MTQ have the 14psi version. Identical and is near impossible to lift off its seat and important for IW's has a LOT of travel unlike the crappy Garrett item.

Either that or I guess try a non-Garrett 1bar actuator.

As for twin port IW actuators I was told to steer clear of them.

Edited August 17, 2009 by SLAPS

[Fastrotor]

Got that single port back on yet Lithium ?

Gary

[Lithium]

Yep, just went for a thrash and I really need a passenger to help me keep an eye on it - it builds boost good and quick but I can't tell if it holds flat or not Its a bit too quick to safely watch that, and it feels good but I don't think its quite perfect yet. I need a passenger to keep an eye on or film things.

[Fastrotor]

I'll book the plane tickets tonight

[JonnoHR31]

ever tried a profec b? i have the same turbo using a 12psi actuator (all mtq had in stock at the time) and i've held up to 21psi perfectly. can set the boost the soldenoid starts letting boost to the actuator.

1. sell avc-r

2. buy profec

3. profit

[Lithium]

Well I got someone to drive the car for me and take vid, I have been trying to set it up to target ~1.1bar - so far the tune we have got in there is very conservative, basically so I can suss boost control out enough that a dyno session would be justified without popping the motor so its not going to be

making the best use of the air its getting at the moment. Either way, this should give a rough idea of the spool now I've had a tinker with the AVC-R and boost relief valve.

I have a mate driving, basically gave it a stomp from around 2900rpm in second which was where it was previously at its worst: http://www.youtube.com/watch?v=-AYS8ixmMPY

I suppose I should add as I don't know what other peoples .82a/r GT3076Rs are like on their RB25s - but this is much much better than I was getting before, and my mate wasn't giving it 100% throttle (don't know if or how much difference that'd make). It isn't PERFECT but I consider the boost relief valve experiment a success, considering the money spent vs. gains had. If there is a better solution for the same or less money, I am still keen to hear but this is definitely keeping me a fair bit happier.

Edited August 20, 2009 by Lithium