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Got the port to a slightly ovaled 23.5mm and some pretty major housing work to promote good flow to the port. Definitely improved, I can get to redline without creeping too much past 10PSI on a 7PSI wastegate.
Got the port to a slightly ovaled 23.5mm and some pretty major housing work to promote good flow to the port. Definitely improved, I can get to redline without creeping too much past 10PSI on a 7PSI wastegate.
Nice job man. That's pretty much how mine is. I don't think it will get much better.
Hi all I am new at this forum.
If I had known about this thread before, I wouldn't have bought this turbo.
So i bought kraken kit with gbc22-350 on 1.8 engine. 02MicaMiata before you build your engine what it was your engine ? 1.6 or 1.8?
I port the WG about 23mm but overboost is still there. i still using garrett actuator 0.5bar but is to hard to oparate correctly.
What actuator do you suggest to use. starting boost at 0.3bar i think. hopfully to priven overboost.
why they still selling this turbo to us ? anyway
Hi all I am new at this forum.
If I had known about this thread before, I wouldn't have bought this turbo.
So i bought kraken kit with gbc22-350 on 1.8 engine. 02MicaMiata before you build your engine what it was your engine ? 1.6 or 1.8?
I port the WG about 23mm but overboost is still there. i still using garrett actuator 0.5bar but is to hard to oparate correctly.
What actuator do you suggest to use. starting boost at 0.3bar i think. hopfully to priven overboost.
why they still selling this turbo to us ? anyway
I had to use a better wastegate with more actuator movement than the stock Garrett unit. Mine is a Kinugawa with a 0.5bar spring.
Not sure if you have a catalytic converter or not, but mine would boost creep to over 200kpa even with the wastegate wired open sans-cat converter. Once I installed a cheap 200 cell, no more creep issues
I had to use a better wastegate with more actuator movement than the stock Garrett unit. Mine is a Kinugawa with a 0.5bar spring.
Not sure if you have a catalytic converter or not, but mine would boost creep to over 200kpa even with the wastegate wired open sans-cat converter. Once I installed a cheap 200 cell, no more creep issues
im having to revisit again on mine, track day, no notable creep, but cold winters night creeping too much for my liking.
i had mine at 22mm and basically no real porting for the channel, which was fine for warmer climate.
so looking to try again and work the channel to the hole itself and go to 23mm.
issue is these turbos seem to be advertised for jet ski’s, quad bikes and the likes, that likely have small exhausts, creating enough back pressure/restriction to not see creep.
but I agree, it’s pretty bad Garrett didn’t foresee this issue on free flow exhausts on actual cars!
as per earlier posts, I measured the opening of the Garrett 0.5bar and they barely flinch the flapper at this pressure! I went to forge 0.7bar units which open way more than the garretts, fixed a good chunk of the problem by itself.
i have 2 of these on my car, is an expensive option to swap them out for something else and retune at this point, so trying to port again.
im having to revisit again on mine, track day, no notable creep, but cold winters night creeping too much for my liking.
i had mine at 22mm and basically no real porting for the channel, which was fine for warmer climate.
so looking to try again and work the channel to the hole itself and go to 23mm.
issue is these turbos seem to be advertised for jet ski’s, quad bikes and the likes, that likely have small exhausts, creating enough back pressure/restriction to not see creep.
but I agree, it’s pretty bad Garrett didn’t foresee this issue on free flow exhausts on actual cars!
as per earlier posts, I measured the opening of the Garrett 0.5bar and they barely flinch the flapper at this pressure! I went to forge 0.7bar units which open way more than the garretts, fixed a good chunk of the problem by itself.
i have 2 of these on my car, is an expensive option to swap them out for something else and retune at this point, so trying to port again.
I ported 3 separate times trying to minimize the material removed. Hindsight I should have just gone for it, but I learned a good bit with my tests. I started by just porting the hole, didn’t notice much difference. Pulled it off again and started to ramp in, noticed creep slowed a lot. For my setup, the ramp in porting was very important. I got more aggressive with the ramp in and ported it oval to maximize the surface area for flow.
You’ve got a pretty sweet build! Are you running catalytic converters? That honestly was the best thing to curb creep 100% on my setup
I order the forge one with 5-10psi spring to test, hope for minimum output 0.7bar, i will come back for the resolds
I change to the forge actuator and had the same issue.
So after many tests i decide to replace the gbc turbo with psr 2860 gen2.
same from Kraken 3" exhaust, no cut.
I HAD THE SAME PROBLEM.
So i replaced my entire exhaust system with 2.25" and problem solved for normal weather. Now we try to fine tuning for cold weather because again i have overboost.
Dang, that’s a lot of expense! 2 turbos and 2 exhaust systems adds up. Did you ever try a catalytic converter? Mine was a creep killer for like $40
Noo don't worry i exchange the turbos and the 2.25 exhaust it was my previous one.
Today the tuner made some changes, now doesn't have overboost in this cold weather, Saturday i will go for a track day to collect some more logs.
The car now works fine.
I also have a kraken top mount and a gbc 22-350, I ported my wastgate and portmatched the turbo to the manifold. I have boost control in the lower rpm’s to keep the wastegate shut but my low boost table (0% duty cycle) goes to 1.2 bar or 17psi. High boost is 1.7 or 25psi. I do have a 3” exhaust all the way back, but it annoys me greatly that a .7 bar or 10psi spring boosts this high, Belgian weather isn’t favorable to light high powered rwd vehicles! In the near future I’ll be swapping to a different actuator and will keep you posted if it fixes the issue!
I've heard of 1 person going external and it solved the boost creep.
In my case, i solved this after 2 port jobs and running a CLOSED loop boost control setup. Preload i set to 1.5 turns.
My external boost controller it appears was not helping matters, as it was OPEN loop, it couldn't adjust Gain to lower duty high up the revs to level out the boost, hence i was getting creep no matter what as it ran a fixed Gain setting, so crept beyond where i wanted it.
Maybe i didn't even need the 2nd port job and it was just a boost controller issue.
Worth considering at least. In the end i went with purple springs in forge actuators with the closed loop boost controller. Runs a solid 0.9 bar low/mid/high rpm now even in cold weather with 2 of these turbos either side of my V6.
I have tried porting the housing as much as I can but my turbo would still creep up to 16~ psi with the wastegate wired open. So I don't think my boost controller would help. I've decided to have someone mod my manifold for an external wastegate
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