RB5-Black

I've been thinking about changing the TMIC on my RB5 for STI/P1 version is it worth it for the money ?

Craig.

john banks

The TD04L turbo is holding your car back.

It heats the intake charge too much and causes too much exhaust back pressure - in other words it doesn't flow much cold air.

You would do much better with a bigger turbo and the factory TMIC than you would with the factory turbo and a TMIC or FMIC. I've tried four different turbos and three intercoolers now, and the order I would suggest is to get your turbo first and add a FMIC later if you need it.

You will also need a fuel pump, and either/both fuel pressure regulator/550cc injectors depending on your ambitions.

The STi TMIC has a slightly lower pressure drop from its better core. If you are paying only £100 it would be a reasonable thing to do. If it makes the car overboost let me know and I'll tweak the map for you (no charge).

Personally save the money for a bigger turbo as that is where the smiles start.

[Edited by john banks - 1/17/2003 4:04:10 PM]

RB5-Black

the car feels like it has a flat at 4500 -5000 ish had thoughts about a fuel pump at the moment before doing anything else ?

john banks

Flat spot is possibly the boost control - in the cold weather it tends to go a bit higher as the turbo can spool up quicker. The ECU then pulls this back over the next while, and a nice initial peak can be followed by a slight trough which feels like a flat spot - with the boost hardware Subaru supply (=crap) then you sacrifice reponse if you don't end up with a slight peak in cold weather in high gears. Other causes are the fuel pump could indeed be weak, but far more likely are the spark plugs have a slightly wide gap or you could do with some colder ones (I use NGK PFR 7B).

RB5-Black

The car's going back for a service soon so I might spec my own plugs for that service

off to the search

thanks john

john banks

Get then to gap them to 0.7mm as well. Don't go for the standard Subaru plug on a tuned car like yours - better on a colder plug - like the one I recommend. Also specify a fully synthetic oil.