Hello everyone, i am new to this forum . I searched everywhere on the internet and checked with local tuners/garages all over Malta . I cannot find a solution to the problem i am having .

The car is a Honda civic eg with a b18c type r motor. At the moment it is bone stock internally .

It has id 1000cc injectors ,Borg warner t4 turbo Afi Turbo manifold with a tial 44mm external wastegate ( 4psi spring) . Tuned by a very good local garage on hondata v2 .
Problem is, we cannot get it anywhere close to hold 4psi on the wastegate spring . On 1st gear it's fine, 2nd gear goes straight up to 10 psi with boost cut coming on and on 3rd gear it goes higher than 16psi with boost cut coming on .

Has anyone ever came across this issue ? Iv'e checked and re checked everything . Wastegate is fine ,not leaking .

Before i had a cheap ebay turbo manifold which i ended up cutting another hole in it and welding another wastegate which solved the issue but i really dont want to do this to this turbo manifold. One is for the lack of space, and 2 i am hoping for someone to come up with another solution rather than chopping this manifold as well.

Im told that the wastegate isn't efficiently blowing out enough exhaust hence the boost going through the roof. But what can i do please ?

I never had this issue with my old integra with forged internals and 9.0 compression running 10psi .


Any help would be greatly appreciated

 

Do u use a boostcontroller? From where do u use ur vaccum line to the wastegate?

 

It looks like it is coming off the charge pipe/compressor elbow right off of the turbo outlet.

You have a parts combination issue there. Large turbine wheel/housing+ single 44 gate on small port + very small spring+ high strung motor...

 

In addition to a very large 44mm primary runner equal length manifold to boot. No WAY he'll stay at that low of a boost pressure with those hot-parts.

 

What boost controller are you running? This is an identical issue to what I had. My boost controller was like, choked off entirely. Essentially, it was killing the pressure source and not allowing my gate to open, therefore, overboost.. Post up some pics of your controller and how it's plumbed, I'm pointing fingers at that.

 

Super low wastegate spring + high volume manifold + large Borg Warner turbo wheel + T4 housing + single wastegate = Creep

In simple terms your setup is flowing "too well" so there is very little backpressure in the manifold which would ordinarily "help" keep boost low. Disconnect (block) the boost solenoid or turn it off in Hondata and log boost pressure versus rpm. This will tell you quickly whether it is a mechanical (flow) issue or a boost controller/software setup issue. If you want to be sure you eliminate any boost controller interference - run a vacuum line to the bottom of the wastegate only and leave the top port disconnected.

Try this and report back on your findings. Also make sure the wastegate isn't stuck and the valve can travel freely. I recently had a car with a Precision 46mm which had severe boost creep and it turned out to be a stuck diaphragm or valve which was the culprit.

 

Ok. After thinking over the issue and the explanation, I understand now why they said what they did and it makes sense based on your setup. Therefore, I retract my previous statement. If boost controller works at lower gear, it should work up high. The only explanation to why it wouldn't be working, would be just what was explained, you're not getting rid of enough exhaust. I was thinking on the lines of somebody overlooking a small issue, but it seems I'm underlooking a larger one. I had an identical issue, but I didn't take into account the differences in our setup.