Hi guys, my t28 pooped itself so I got a hks gt turbo on the car last night. I have a hks evc5 and it was working fine on the stock turbo making and holding a bar of boost. Put the stock actuator on the his turbo and turned the vain to 0 for the first drive and it hit 1.2 bar and fuel cut. It consistantly over boosts with the gain on 0 but if I turn it off it sits at half a bar fine. Any ideas. It's plumbed in ok and was working perfect two days ago.
so borrowed an adjustable hks actuator that is supposed to come with the turbo, set it to make as little boost as possible. plumbed it up without the boost controller and makes 1.2 ish bar and fuel cuts still. the turbos no bigger than a stock t28 and I cant see why it makes 1.2 bar, I know the stock actuator works fine, so the actuator wasn't the problem
In 1st post you say you had half a bar with ebc switched off,then swapped the stock WA for the HKS one and I guess you have run
a vac line from the compressor housing > WA? but with the HKS you are stuck on 1.2 bar and hitting FC
how much preload has the rod got with the HKS at full de adjust and how does that compare to the stock WA rod preload
Or stick and air line on the WA and read what pressure it opens at
Reading that it did drop to 7/8 psi on stock WA points to the HKS at fault some how
all I can think of atm
sorry I should have been clearer, was typing on my phone though. today with the stock actuator before I fitted the hks it was making 1.2 with the line plumbed from intake to WG, so I swapped the hks one in to see if that would fix it. I thought maybe the arm on the stock one was too short etc. no difference with the hks.
so to sum up with both stock and hks wastegate plumbed from the intake pipe to WG it makes over 1.1 bar and hits fuel cut. and the flaps opening and free I checked that. obviously I haven't been able to tell if th wastegates opening when on boost while driving, but I cant see why the stock one wouldn't be as it was working two day ago
cobble together a pump with a pressure gauge onto the WA ,air line at a petrol garage or a foot pump or bike track pump etc anything with a gauge
just need an old car tyre valve or cut out the valve from a pedal bike inner tube then jammed into some rubber hose that steps down to the WA size
pump it up and read off at what pressure the lever move's/opens
Are you using an aftermarket turbo elbow as in the divided type with a divider bridge bolted inbetween the 2 exits
like this http://www.ebay.co.uk/itm/200sx-S13-...item56488a27ad
as thinking the wastegate valve could be fouling on the bridge and stopping it open fully to vent
but then I guess you have checked that it opens when swapping actuators,edit: yes you have
pressure test the actuator insitu and check its opening at ?? pressure
and is it more than half a hole preload? as in WG rod hole to WG lever pin (the bit the circlip goes onto)
Blew air into both. Actuators, both working fine. Put my stock actuator back on, and now for some reason it holds half a bar from 2.5k to 4.5 k and then it just over boosts massively. Doesn't make any sense.
All I can think of is the gate is not opening fully or enough for the exhaust gas/drive to bleed off
as it reads like the wastegate lever is clamped shut giving you this unlimited boost
If the exit elbow was pulled off you could give the WA some pressure and visually check it opening the WG valve
Is the vac line for the WA plumbed into the inlet plenum itself? is the line clear to blow through and not crushed (zip ties?)
So I have found another thread on here about boost creep and the wastegate hole is too small to bleed enough off to Leo the boost down when running a full three inch exhaust. It's seems it's hit and miss for different people, but would make sense as I have put a full 3 inch exhaust on at the same time, but I didn't think this would make a difference. Going to try my snalled exhaust to create a bit of back pressure and slow the boost creep down and then if that works I'll get the wastegate port opened up a bit.
That sounds like a load of poo. Whats your exhaust got to do with the wastegate not opening?
Is your vac plumbing via the EVC solenoid or direct to actuator?
If its going via the EVC maybe the stepper motor is interfering somehow.
My 2p worth
Where did it say in his post it stops the wastgate from opening?Originally Posted by CrazySx
That sounds like a load of poo. Whats your exhaust got to do with the wastegate not opening?
Is your vac plumbing via the EVC solenoid or direct to actuator?
If its going via the EVC maybe the stepper motor is interfering somehow.
My 2p worth
He is correct what he is saying about boost creep and it's all to do with back pressure in the exhaust. If you have a 2" exhaust boost struggles to get out of the exhaust because of the back pressure, this helps keep boost stable. If you put a 3" exhaust on it can have so much less back pressure that the wastgate struggles to bleed enough gas away from the turbine causing the turbine to spin faster thus more boost.
Hope that helps you understand, it is a common problem across all turbo'd cars. For instance in my supra I have to put a restricter ring in my straight through exhaust to stop it from over boosting and it holds a stable 1bar, without it it will creep to 1.5bar.
Yeah i got that wrong.. oops.. teaches me for skim reading.
I have a 3 inch exhaust turbo back including elbow and i hold a bar on the actuator and boost controller... so...
It's all sorted now, need a bigger wategate if I'm gonna run a 3". It seems a bit hit and miss on what cars it affects, my mates s14a with a 3" held a bar fine.
Does depend on which turbo with the sr20det but standard t28 is usually no issue
So the hks turbo has a smaller WG?
Hks has more blades on the turbine wheel so might just be the same size wastgate but turbine can spin faster with less gas.
To be honest I don't know if this situation is creep I was was just informing you that boost creep is not poo, it's real and I know that standard t28 doesn't have an issue with it.
The only way to tell if it's creep is if the boost hits a point where it holds then suddenly starts climbing with the revs.
It is definitely creep, put the stock elbow and actuator on and it now holes half a bar till around 4.5k and then climbs upto over a bar. I'm just going to buy 555 and z32 and go for power now. I'm gonna do it eventually if I don't do it now so might as well just go with it.
If you do that and run boost at the max creep it won't creep anymore it will just hold that boost all the way if you know what I mean.
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