Hi im wanting to fit a manual boost controller on a TK M20B 94 subaru impreza wrx i have read this. http://stefanostadal.homedns.org/car_mods_engine.htm
and was just woundering if it would be the same as my 94.
any advice would be gratefull as i have been quoted £80 for someone to fit one and it doesnt look that difficult to do so i fancy a go myself

 

Dangerous territory!

 

So you reccon pay the £80 ??

 

No I mean completely forget the whole thing!

 

Dawes MBCs are a very good and cheap form of boost control as long as you know what you're doing.

Fitting it is very simple, IMO setting it up you need to monitor boost and AFR's, then once set up always monitor knock.

You will lose the ECU's "limp home" mode which limits boost when the ECU sees a problem, so bear that in mind.

 

dont cut anything find a spare but of pipe the same size find the pipe you need to connect it to pull off and put the valve in turn bleed valve OFF (closed) now take a short steady drive keep an eye on boost make sure its NOT going any higher than it was before then if all ok turn 1/4 of a turn take a steady drive watch boost does not go any higher than you want it to keep doing till you get the right boost but dont go and test under full power till your sure its not going to go way to high and kill your engine when all done but allways keep an eye on the boost just to make sure the valve doesnt come undone over time

 

Agree with both replies above, although fitting an ebc will also lose the ecu's ability to limit boost as you are bypassing the solenoid it would use to do this. I used to run a relief-valve on my GT4 and was very happy with it, I only upgraded to an ebc because one came along at the right price and I wanted the ability to turn the boost down from inside the car. My ebc (I think) is playing up in my scoob and so I'm thinking about another relief valve as a short-term cheap option. Obviously make sure you monitor everything closely no matter what you fit - aftermarket boost gauge is a must.

 

It really does only take a few mins to fit.

If you are not monitoring the AFRs, then it is an idea to check to see what a known 'safe' level of boost is.

A boost gauge is essential and a knocklink recommended. I would also borrow a AFR gauge to set it all up.

For £80 you could have it fitted and setup by someone who knows at a RR such as WRC technologies who will also give you a power readout and ensure its within safe parameters.


Bob

 

Good point - sorry I should have mentioned about fueling. The GT4s were known to have enough fuel for a given amount of boost - funnily enough the people that blew engines were the ones that ignored this information. Similarly with the Scooby, I know that I have mapping to 1.3 bar as I had a Unichip mapped at Powerstation.

 

Thx for your advice everyone