uxon

I plan to put a bit bigger turbo into my 04 WRX, so I could reach 300-320BHP - it would be either td04 hybrid or vf35, nothing bigger for sure. Apart from other supporting mods, I wonder if upgrading a stock wrx TMIC is essential?
On one hand I read somewhere that when exceeding 300BHP STI TMIC is a must, while on the other hand I see people in Classics swaping their stock TMIC for the WRX one (non STI) when they are going for 300+ BHP mods.
So, my first question is: should I make the extra expense and swap stock TMIC for an STI one?
And if yes, which version of STI TMIC should I look for? Only from bugeye/blobeye (are they really an improvement)? I have read somehere that fitting TMIC from drive by wire throttle STI ('06+?) might be problematic? But newer TMICs seem to also have better capabilities. How can I distinguish between blobeye and hawkeye TMICs? Is it possible to fit in 08+ TMIC to my 04 WRX without too much hassle?

Cambs_Stuart

iTrader: (3)

If in doubt, contact Matty at MB developments.if you do upgrade the TMIC you will also need to change the under tray other wise you won't be ducting air over the entire surface.
Not sure if a sti intercooler is nesscessary for that power, especially for the expenses, but I'd really recommend the silicone y pipe. That really helps air flow.

uxon

I already have silicone y-pipe (bought together with PPP ecu). I also already have large blobeye scoop (but with stock wrx tmic and splitter).

Linksfahrer

Hi Uxon , I can tell you what not to do . As I did it wrong.

For a TD05 16G, I had bought a CX racing TMIC that is about a 3rd bigger than the Sti 8's
It was cheap and it does keep the inlet temps down, but it has a significant disadvantage it needs more time to spool it full. I can therefore understand the Classic guys going with the WRX 04 TMIC , as this is a considerable jump for them from Std.
To get the same performance for a heavier 04 WRX you need more power.

Personally I don't like the optic of the large scoop, but the Sti undertray is a useful upgrade.
even if you keep your WRX scoop. It allows you to cool a wider area of the Sti IC.
The issue with still using the WRX IC is you will suffer rising intake temps fairly quickly in traffic and in particular while doing rolling tuning. This means its hard for the tuner to compensate his settings each run for what is a moving target.
I'm currently at 312bhp , but the car drives like a dog. No appreciable torque till 4k.
So I'm working backwards to improve this , and will use a SC36 and a 3inch 200 cell downpipe and a relative narrow Harvey uppipe, all to improve spool.
If you go for a larger turbo then its important to match the right size/taper uppipe diameter / TMIC volume for the choice of Turbo. I would agree at 300 Bhp the Sti one is preferred.
Rather take a Turbo one size larger than you think you currently need for your target bhp and then keep the boost level down. This will also help keep the exhaust gas temps down. Which in turn will help keep everything else cooler. The VF 35 will get you there with other support mods for fuel, but you are pushing it for a TD04 Hybrid. However good the idea is, you might find it gasping a bit at the top end. Both will be at running 1,5 bar at 4 K to get the headline numbers. The safer pressures to run for WRX pistons are 1,2 -1,3 bar.