Update:
As some of you may already know my car has been suffering from boost creep for a while. I have tried different things to fix the issue but nothing seems to work. First, the tuner tried different spool times and other variable changes in the tune and it didn’t work. Also, Bigboost sent me a spacer for the wastegate which supposedly helps the gate to open more so, I installed the spacer and still no luck. The problem is the internal wastegate can’t flow enough of the exhaust out due to an increased in exhaust velocity created by cylinder head work. I mean every time I go WOT the wgdc goes to zero (wastegate fully open position) and literally the boost keeps raising with no control. BTW, wastegate has been tested and it’s working as is supposed to. So, looks like an external wastegate is my only solution for boost control.
View attachment 30763After long days of frustrations and false promises I decided to get rid of the Bigboost turbo kit and swap it with the new Speedtech kit with external wastegate.
I’ve talked to Jeff@speedtech for several months now about my situation and how his new N55 turbo kit with external wastegate would solve my issue. It’s basically the N54 turbo kit but without O2 bungs in the manifold. Anyhow, Jeff has been really helpful, knowledgeable and was able to answer all my questions and concerns in timely manner. After waiting patiently for a few months, the kit is finally here. BTW, the kit hasn’t been released yet but it will be soon.
Turbo selection:
I’ve been running the BB 3.4 kit with 6564 turbo for almost 2k miles now and I felt that turbo was kind of small for my car. The turbo spools faster than I anticipated, full boost (23-24psi) was by 3200 rpm. Based on that, I knew I have to get a bigger and laggier turbo. BW turbos always has been one of my top selection so, I used the MatchBot calculator on the BW website. After comparing different compressor maps, turbine sizes and A/R’s, I figured BW S369S-XE is the best for my application.
First impression:
This kit is all about quality. It so well designed and looks very promising. The cast manifold is all cnc inside and outside so, no unfinished, uneven or excess casting specially on the inside like other kits. It came with high quality silicone hoses and end flanges are welded very well too.
View attachment 30764
View attachment 30767
View attachment 30769
The kit came with high-grade silicone hoses which should work with high temperature with no problems. Anyhow, I got some DEI gold tape to protect them from the heat. There’s a few places that might get hotter than I would like from being that close to the turbo. Also, I got PTP T3/T4 turbo blanket which fits perfectly in the turbo.
View attachment 30770
View attachment 30771
View attachment 30774
Other Mods:
I will be getting rid of the JB4 and moving on to flash only. Nothing wrong with the JB4, it just difficult to find a good tuner and one that wants to work with JB4 these days. I will be using GFB G-force III to control boost and AEM wideband for AFR safety. Also, I’m planning to run DI only now that I got the SpoolPerformance Helix 4x.