Help with Overboost, hybrid turbo problems Options

[Insanity-74]

Just fitted my hybrid ct26 turbo yesterday..and it overboosts like mad...even with the max boost at .95 bar and the actuator set at 35% it still hits 1.18 bar, but the performance is slugish and uninspiring...any ideas on how to set up the boost controller, or what I can do to control the overboost?????


YEY its 2007

[Punisher]

You're wastegate isn't working for ****... something along those lines anyway.

The way you are talking it sounds to me like you are using an electronic boost controller.. right?

Give a little description of your boost controller setup and the wastegate setup please.

[Insanity-74]

OK, here we go...boost controller is an Apexi AVCR, the waste gate actuator is off of my old ct20b and was working fine with the old turbo.

decat pipe fitted and a mongoose exhaust.

cheers for any help
Nial.

[Punisher]

Well, I really hate it when people respond to my questions like I'm a 5yr old... but.. did you check to make sure the actuator arm is long enough to open the gate full way?

At 35% duty cycle you shouldn't even be touching your target boost..

I'm using an external gate and I usually have my duty set around 60% for 14-15psi target..

If you properly set the avc-r up... then the only other reason why you'd be getting boost spike is the wastegate assembly itself.. so either the actuator or the gate or a combination.

Did you try setting the avc-r off?

I have a 3.5psi spring in my gate and if I set the avc-r to off I'll only hit 4-5psi..

[Insanity-74]

Well, I really hate it when people respond to my questions like I'm a 5yr old... but.. did you check to make sure the actuator arm is long enough to open the gate full way?

At 35% duty cycle you shouldn't even be touching your target boost..

I'm using an external gate and I usually have my duty set around 60% for 14-15psi target..

If you properly set the avc-r up... then the only other reason why you'd be getting boost spike is the wastegate assembly itself.. so either the actuator or the gate or a combination.

Did you try setting the avc-r off?

I have a 3.5psi spring in my gate and if I set the avc-r to off I'll only hit 4-5psi..

I`m not responding like your a 5 year old, what makes you think that?????? didnt mean to offend....

I`ll try with the avcr off and see what happens. As far as I know the actuator is fine, although I do have some doubts over the efficiency of the wastegate port.

[Punisher]

no, I wasn't saying anything about you.. I ment for myself.. Like when I post a question and someone responds with some n00b answer like "did you check to see if it's plugged in?" .. lol

The wastegate port might not be large enough or efficient enough as you stated.. but on the avc-r just change the boost control to off.. if you still have a high boost issue then either the actuator isn't working properly or the arm isn't long enough.. or the port isn't very good heh... You can figure it out

[Insanity-74]

Aaaaah...a bit of crossed wires.........hmmm maybe thats it.....wonder if I reconnected the vacuum piping correctly?????

I do hope its plugged in...maybe I should check that too. that would be embarrasing wouldnt it.

Cheers for the help.....will take it for a blast now and see what happens...will report back later.

[Insanity-74]

Even with the AVCR "Off" it still boosts to 1.2bar....I guess this means that the actuator is at fault then??????

[presure2]

connect a hose direct from your turbo to your wastegate actuator, and cap off the other outlet on the actuator.
if you overboost still, you know its the actuator, or the wastegate itself.
what type of hybrid are you running?

[Insanity-74]

connect a hose direct from your turbo to your wastegate actuator, and cap off the other outlet on the actuator.
if you overboost still, you know its the actuator, or the wastegate itself.
what type of hybrid are you running?

Will give that a shot...I using a ct26 stage 2 hybrid.

This post has been edited by Insanity-74: Jan 1, 2007 - 9:19 AM

[presure2]

connect a hose direct from your turbo to your wastegate actuator, and cap off the other outlet on the actuator.
if you overboost still, you know its the actuator, or the wastegate itself.
what type of hybrid are you running?

Will give that a shot...I using a ct26 stage 2 hybrid.

exactly what does "stage 2" mean?

[Insanity-74]

connect a hose direct from your turbo to your wastegate actuator, and cap off the other outlet on the actuator.
if you overboost still, you know its the actuator, or the wastegate itself.
what type of hybrid are you running?

Will give that a shot...I using a ct26 stage 2 hybrid.

exactly what does "stage 2" mean?

I have no idea ...it seams to mean different things to different people...basically its had a thicker shaft put in, 360deg bearings and a bigger compressor wheel and some internal machining.......its a shame they didnt put some effort into porting the wastegate a little...it might have solved this problem.

[Punisher]

I'm personally betting it's the actuator or something along those lines.. not a ****ty wastegate port... but ya never know.

[Insanity-74]

I think you might be right....I gave the actuator a good squirt with some dry silicone lube and it seems to be a little better.

[x_itchy_b_x]

i guess id just check the tension one the actuator rod by trying to move it around with my hand. also check it the way Manny said. never know the diaphragm could be ripped or something it happens. but i'm willing to bet its the actual AVRC or the presets you have programed in it. i tried to get a blitz profec b to work and damn it took me almost 3 hours of playing with it to get it to work properly. made me appreciate a MBC so much more lol.

This post has been edited by x_itchy_b_x: Jan 1, 2007 - 6:54 PM

[Punisher]

Yea.. but MBC's blow.

The avcr is rather easy to use... and if you set the boost control to off the avcr lets the wastegate work normally..

[delusionz]

Digging up an old topic here, But I'm going to post in this one rather than start a new thread.

My problem is identical,

ST205, Generation 3, 3S-GTE, Formerly with CT20B turbocharger (died around 134,000kms)

Long story short, I went to Toyota to inspect my car and repair/replace faulty turbocharger so I ended up with an "Upgraded CT26."

Exactly as Nial describes, Low end power became crap, Boost response sluggish, Also hitting 1.2bar and fuel cut at 5000 rpm in 3rd gear, 1.1bar at 6000 in 2nd gear.

My mechanic hooked up his air compressor to the actuator hose, and we observed the actuator rod start to move at 10psi, we also heard the gate flap open and closed. So we diagnosed the wastegate as working as normal.

Then he capped and blocked off the factory TVSV line & nipple and went for a test drive. The results were still the same only this time 3rd gear is even more sluggish from the low end than before.

The only thing I can think of is to use an intake or exhaust restrictor (not what I want to do) or have the turbo wastegate bored out (how far can this go?), or go with an external gate and new manifold setup (**** throwing more money at it, I just want this thing to be fast like any other stock GT4 and work properly!!!).

Now where does this lead me, Help Nial? What did you find out over the last 2.5 years? Did you end up going back to the CT20b? How do you UK guys sort it?

[lagos]

I just want this thing to be fast like any other stock GT4 and work properly

You shouldnt have let toyota put a ct26 on your car when you had a ct20b.
1.2 bar is too much boost for the ct26. Turn your boost down to 1bar or less, reset the ecu and see if it helps.

This post has been edited by lagos: Aug 19, 2009 - 12:21 AM

[delusionz]

I wasn't informed until the job had been done and I glanced over the fine print after I was presented with the bill.

I was under the full understanding that I was getting the original turbo for the car repaired, I had no idea that the repairs also included a damaged housing and ****ed shaft and turbine/compressor wheels (basically everything.)

Toyota basically shafted me for breaking down in a far away place and basically needing to get back on my feet in a short time frame, the option of towing and going back home 300kms and missing out on being with pops for what I believed could possibly be his final days did not seem appealing to me.

Toyota make ****ing awesome cars, but they are SH*T when it comes to service.

1.2 bar is too much boost for the ct26. Turn your boost down to 1bar or less, reset the ecu and see if it helps.

You didnt read my post properly, Nor did you read Nials original post. You cant turn the boost down, theres nothing to turn down... A boost controller only lets you turn boost up. I don't even have a boost controller.

[lagos]

you have a factory boost controller.
disconnect it and cap it off and install a ball and spring manual boost controller.

You are hitting too much boost because you still have the factory tvsv hooked up, and you installed a full 3in exhaust. Once you cap off the tvsv and install the boost controller, youll be able to dial in a lower boost setting.

This post has been edited by lagos: Aug 19, 2009 - 12:56 AM