turbo experts 4agte

[reecegze]

Hey guys i am just wanting to know if this is a big turbo for 4agte. Ive got my t28 turbo hiflow to this and it seems to be very lagging ..I am leaning towards actuator is faulty but i am getting full boost at 6000rpm in 1st 5200rpm in 2nd/3rd so its seems weird when the suppiler rekons i should be full spooling by 4000rpm
Ive check for leaks and removed my MBC but its still not boosting properly.. I am using a stock 7psi t28 actuator that i put on with not knowing the condition before hand. It opens fine but might be opening under boost pressure to easy ? causing it to lag all the way to high boost

SO any info is appreciated

Comp wheel:
T3 super flow wheel
48.3 inducer, 60mm exducer, 12 fins 6long 6 short Trim 65


Turbine:
65mm TB34 11 fin turbine wheel,
Internals:

T04E 360 degree thrust bearing

[dave2221]

ahhh i know the problem....

need to add more boost.... i think i run about 86psi on my turbo.....

:p lol

[3s-86]

Hey mate

How much boost does it get at 6000 rpm?
What size is the A/R exhaust housing?
Should be cast on the outside or stamped on the inside.

To check wastgate diaphram, suck on the hose to it
then block it with your tongue and check if it holds vacuum.
If it holds vacuum then adjust the actuator thread so it's
a bit shorter then test drive. If it gets more boost sooner
keep winding till it reaches your max boost level.

See how you go

[reecegze]

hey mate thanks for your quick reply.. I am only boosting 10psi.. its a .64 housing but hiflow obviously.. What do you mean by that.. stick a hose onto it and block the hose to see if the actuator has a vaccum ? Also this actuator is none adjustable via thread. Should i upgrade to a 14psi actuator ?

[3s-86]

Fit a vacuum hose on the actuator long enough
for you put it in your mouth, then suck on it to
create some vacuum then block it with your tongue
for about a minute. If it pulls vacuum and holds
it you will know when your tongue gets sucked into the hose.
If the actuator is faulty it won't suck your tongue into the hose.
You have to check the actuator first before you go out and buy a new one
to pinpoint the problem. It could be that the actuator has got enough tension
on the wastegate flap, is it hard or easy to open the wastegate flap?

[Gunner]

you need to add pressure via the vacuum line, usually by using something like a cooling system pressure tester.

This way, you can see what the actuator is doing under boost, what happens under vacuum is irrelevant, unless it is a dual diaphragm actuator

[reecegze]

its seems pretty stiff when using hands on the rod to pull it open ill try this tomz thanks mate .. Stressing :S

[reecegze]

ill nitro test it tomorrow using gauge lines.. I am hoping that its f$cked or i am f@cked for having such a laggy turbo.. Anyone got some insite on the specs of the turbo ???


you need to add pressure via the vacuum line, usually by using something like a cooling system pressure tester.

This way, you can see what the actuator is doing under boost, what happens under vacuum is irrelevant, unless it is a dual diaphragm actuator

[Gunner]

test the actuator, all your cooler pipes, anything boost related, do a comp test, if all is ok with that then take your turbo back to the dude that did it, and tell him it doesn't work.

As for size, i can't comment. I don't know whats done to it.

[Gunner]

better yet, get a good tune, that might wake it up.

[reecegze]

Hey mate the specs are on top post.. ill look over it tomorrow and see what i find its running stock 4agze ecu so no retune . Thanks guys


test the actuator, all your cooler pipes, anything boost related, do a comp test, if all is ok with that then take your turbo back to the dude that did it, and tell him it doesn't work.

As for size, i can't comment. I don't know whats done to it.

[--Redwork--]

Mate.. ^^^^ theres half your problem right there... STOCK ECU = Big fail.

Also why did you get a hiflow.??
Something like a 2560 would makes heaps of grunt and are only cheap...
Or even a Hypergear turbo.. there like 800 bucks... NEW..

I highly doubt your acrtuator is causing the problem...
If your making 10psi and its staying stable then there shouldn't be a problem...
If there was you'd either make too much boost or almost none...
Also... How are you making 10psi with a 7psi actuator and no actuator adjustment/ boost controler or bleed valve.

What your base timing set at...??
Not enough timeing will cause it to be lazy as well...

Other thing to consider are
Cooler piping size.
Exhaust manifold design and your Exhaust..

May even be that your turbo is makeing more or less boost down low than your supercharger did and the computer can't handle the mixtures properly causing it to either lean out or run over rich... Both are not good...


Ist thing I would do....

Spend a $100 and throw it on the dyno....
That'll tell you if the fuel mixtures are right and give you a graph of your power and boost curves... And more than likely the bloke running the dyno will know alot more about how to make it work better than us...

[addikt]

i have a custom t28 also and mine seemed a bit laggy but have just put a bleed valve on it and its getting a look over on the dyno.but it wasnt that bad so u may have a issue

[reecegze]

I stated in my first post ive got Manual boost controller.. The 4agze ecu is awesome for boost man ..I ran 10psi on my stock t28 for 133kw on standard afm. I am after opinions on this turbo specs, it was hiflow by hypergear and runs a atr28ss core.The reason i am asking is my stock t28 ran fine @ full boost @3700 in every gear.. Now its struggles to make boost in 1st, full 10psi @5200 in 2nd/3rd Reason i am asking about the turbo specs to see if its the turbo is at fault

The dyno sheet is on power figures forum somewhere .. its start to rich and goes richer

[350hp4agte]

are you sure your waste gate isnt stuck open

[reecegze]

yer took the dump pipe off and checked the paddle swing its fully closed.. I might try to vise grip the paddle shut and see if it loads up faster.. Only frustrating as my stock t28 was much more fun with the response

[--Redwork--]

Have you changed anything on your engine besides the turbo.???
If you are using the stock actuator off your previous turbo and have changed nothing else bar the turbo then its a good chance the turbo is either simple too big or is a dud...

Not being a turbo builder I gave no idea what those wheel trims you have are capable of flowing..
I cheaked around for a power rating on your turbo...
Aparently these turbos are capable of 220rwkw's...
And from what I could find about the comp wheel, it seems there more efficient at high boost...
So despite being a resonably small packaged turbo, its quite capable of moving alot of air....
I think that even if there was nothing wrong you shouldn't expect full boost till around 4300- 4500 rpm.

What type of manifold do you have.???
The nice shinny ebay ones would be terrible for response.
Either the cast Ebay ones or Kelway (prefered) would be the pick...

I can't think of much to suggest you try...
Most ppl have covered the common problems that would affect your performance.

I would triple cheak everything to make sure all clamps/ flanges ect are tight then throw it on the dyno.
Get them to do a printout of your boost curve Vs rpm and your power band..
Then at least you've got something to show the guys that built your turbo that something is definatly wrong..

I wouldn't recomend clamping your wastegate closed and then tying it out to see if that helps...
WAY too easy to over boost and potentially break something...
Theres virtually no way you engine could cope with the very possible 25 plus psi that could occur from doing this...
Structurely it might survive but the ECu will have a melt down as I'm sure it's not programmed to deal with much higher than factory boost levels.

Anyway.....Good luck..


OMG Huuuuuuuggggggeeee post. LOL

[3s-86]

Shit man!

Hey mate I think if you had a T28 before then go back to it
if spooling was early. I think the turbo your using has too big internals for
for the ECU as ZE computers have a map for early boost response from the
supercharger. Therefore your Ecu is running wrong spark timing
and air fuel ratio mixtures & fuel pressure regulator doesn't bump pressure up until
the map sensor detects boost. That's what makes an engine lazy & late spooling
the turbo up!
The only other solution is to fit an aftermarket ECU mate.

[Hen may possibly be a nut]

^^ I'm going to call bullshit on that. Firstly a MAP isn't built for "early boost" or "late boost", but then again I'm having serious trouble understanding what you are trying to say.

Plus I know plenty of people who have run stock 4AGZE ECUs on turboed engines and they have worked well. Yes, going aftermarket give you tunability which can help, but the factory ECU does a reasonably good job.

As for the problem, I'd be leaning toward something leaking, bent or rooted. Unless it's was accidentally rebuilt to T88 specs, I can't see why it's not hitting full boost til over 5000rpm.

Hen

[reecegze]

i just tested my actuator on my turbo.. It opens at 6psi to vent.. bellow seems fine. I took my car for a drive with MBC disconnected full boost of 6psi @ 5200 its makes around 3-4 psi @4500. My intercooler pipes arent leaking, It was running fine with my old t28 turbo with blown seals.. only thing that has change from the old t28 to the hiflow t28 is the actuator as the old one wouldnt reach.So i am thinking the tension on the actuator isnt enuff :S i dont really wanna put the old one back on as there is difference between them in mounting now. Anyone know where i can get a adjustable actuator from ?

[reecegze]

That does make some sense .. but the stock t28 makes awesome response and power on stock 4agze electrics. It just runs very rich down low



Shit man!

Hey mate I think if you had a T28 before then go back to it
if spooling was early. I think the turbo your using has too big internals for
for the ECU as ZE computers have a map for early boost response from the
supercharger. Therefore your Ecu is running wrong spark timing
and air fuel ratio mixtures & fuel pressure regulator doesn't bump pressure up until
the map sensor detects boost. That's what makes an engine lazy & late spooling
the turbo up!
The only other solution is to fit an aftermarket ECU mate.

[nelpd96|]

I would be trying your acctuator, that is the exact problem that I had with mine not two days ago. It looks like everything is great and good to go but the reality is that it was open just a fraction and that was all that it needed. I adjusted the actuator rod and it was good to go, back to doing what it should be. Even with a highflow you should be seeing some boost before 5500rpm. The other thing that you have to think about is the fact that because we have the ZE engine it will be slower coming on boost than the equivilent GE engine with the same turbo and boost etc. This is because the lower compression ratio means that there is less BMEP generated by the engine at a given rpm.

Cheers
Paul

[3s-86]

Hey (Hen may possibly be a nut)
What would you know about ECU's and maps mate?
I'm a mechanic and fit aftermarket computers all the time!
What I'm trying to say is that he has changed the turbo
and now everthing is way out!

Back to the subject
It sounds like you will have to change the actuator now that you
talked about disconnecting boost controller etc.
The internals on the exhaust side after hiflowing sounds a bit on the
larg side that's why you have lag up high in the revs.
What did you ask for when you went to get the hiflow done?
I would suggest get a new adjustable actuator from a turbo
outlet like GCG turbos, you may have to stuff around with making a bracket
to fit it.

[reecegze]

yer thats no probelms hes sending me a 14psi adjustable actuator turbo builder rekons new turbo is force manifold pressure to open the stock waste gate and needs to be pre tension heaps or new one... ill also finish this and run in of the turbo ..I requested faster response or same as gt28r and med/top end power.. dont get me wrong this turbo feels awesom at 5200 @10psi but its to late for my liking. Ill let you guys know how it goes anyway

cheers

[biggo]

Id have to agree with henny, on both the ecu and the turbo being built to t88 specs. I run a stock ecu and have abosutly no problems. I have a t25g on mine and see full boost by 4500rpm, starts spooling around 3200rpm. I can even drive it on the highway no worries.

I think racespec make an adjustable accurator or maybe it was just the mount? Could be worth trying tho.

[reecegze]

See biggo no offence but even 4500 is very late for a t25g.. I ran a t28 s14 "gt28r" and i saw full boost at 3800ish which was fun.. I put visegrip on the actuator to hold the wastegate closed, as the exhaust gases are to much for the 7psi spring tension.. It worked it brought my 10psi full boost done to 48000 rpm. I have to choice to keep this turbo or get the rear housing machined to suit a .49 gtr rear with smaller front comp and smaller turbine.. Which would limit this turbo from 230kw to 200kw.



Id have to agree with henny, on both the ecu and the turbo being built to t88 specs. I run a stock ecu and have abosutly no problems. I have a t25g on mine and see full boost by 4500rpm, starts spooling around 3200rpm. I can even drive it on the highway no worries.

I think racespec make an adjustable accurator or maybe it was just the mount? Could be worth trying tho.

[--Redwork--]

200kw is still alot....

I would be eliminating everything else befor I changed the turbo again...
Wait till you try the new gate... if that makes it better then look at other things that might be the cause..

[nelpd96|]

There are simple ways that you can assist the engine coming on boost. If you have a look at my MS paint diagram hopefully it will make sense but basically this will do the same thing as the vice grips and allow the turbo to come on boost the same without having to have the vice grip on the engine.


Basically how it works is the the turbo has the fill the container before air gets to the wastgate, if the container isn't big enough put a restrictor in the line between the turbo and the t-piece. Something like a ball valve will allow you to adjust it until you get it where you want it. Just a though because even with a high spring pressure on you wastegate you will still get creep. The best was is still electronic boost control like I have but this is a cheap option. Last point is that I would be selling the turbo and buying another rather than putting more money into the one that you have.

Cheers
Paul

[reecegze]

Its not going to cost me any money to reduce the comp wheel , rear turbine wheel and use a .49 gtr rear housing. Hes sending me the 14psi actuator next week so ill test it out if still shit house i will be getting it reduce to give more low to midrange with max 200kw


There are simple ways that you can assist the engine coming on boost. If you have a look at my MS paint diagram hopefully it will make sense but basically this will do the same thing as the vice grips and allow the turbo to come on boost the same without having to have the vice grip on the engine.


Basically how it works is the the turbo has the fill the container before air gets to the wastgate, if the container isn't big enough put a restrictor in the line between the turbo and the t-piece. Something like a ball valve will allow you to adjust it until you get it where you want it. Just a though because even with a high spring pressure on you wastegate you will still get creep. The best was is still electronic boost control like I have but this is a cheap option. Last point is that I would be selling the turbo and buying another rather than putting more money into the one that you have.

Cheers
Paul

[reecegze]

My car is in perfect vaccum.. no leaks just seems a 65mm turbine wheel is lagging it up on the rear of the .64 housing


200kw is still alot....

I would be eliminating everything else befor I changed the turbo again...
Wait till you try the new gate... if that makes it better then look at other things that might be the cause..

[350hp4agte]

ya need a ebc i recon then it wont matter if the wastegate is to soft or what ever and turbo cars are so much better to drive with a good boost controler