few questions bout s40 turbo

[scottambrose]

would fitting a dump valve cause any damage or problems to the car. its a 2.0 t w reg.

also would a manual boost controller be a good or bad idea for upping the boost abit. ive got a guage and its at about 11psi at the mo.

[Filterlab]

Replacing the dump valve would cause no harm at all, although having said that the Volvo standard DV is actually very good and fitting an atmospheric type (I assume that's what you're planning) can sometimes yield a drop in performance.

I'd be very careful with fitting an MBC, they can cause fatal damage very quickly unless handled exceptionally carefully. Personally, albeit more expensively, I'd go for a remap / new ECU which will give much better results and be a lot safer. A remap addresses issues such as fueling and cooling, something that an MBC doesn't.

However a few of the chaps on here have MBCs fitted very successfully, and they do enable control of the boost to a fine degree.

[PaulZX]

I'd reccommend a dyno setup if you're going down the MBC route, as the operator should match the fuelling to the boost (if he knows his onions)...

[scottambrose]

ok thanks the dump valve is a bailey one. also i have a problem where sometimes when i start the car it misfires. if i turn it back off then on again its fine. doesnt do it all the time tho.

[Enigma666]

Check your coil packs and plugs for the misfire..
The dump-valve must be a twin piston type or it wont work and the car will run like crap

I really wouldn't bother with one unless you want the tish noise on gear change.

MBC "should" be fine....but I personally again would save and get a remap.
The problem with the S40 is torque steer....also you have the weak 2.0T block...too much power through that and bye bye con rods (my mate did the exact same).
If you want more power...be safe and get a remap as the MBC is all about low end torque and wheelspin

[Filterlab]

Enigma's advice is spot on. As he mentioned the 2.0 block is a little weak in comparison to the 1.9 so correct cooling and fueling will be essential for tuning.

[scottambrose]

i have m.i.l intermittant signal when ive read the codes. any ideas.