Im looking to fit one of these to my mk1 octy vrs i have a gauge so i can moniter boost, am i right in thinking that it replaces the n75 valve and if so what happens when i unplug it (eml on, etc)

If you want to adjust the boost you should do it via a remap.

 

Unplugging the N75 and using a manual boost controller will probably cause the engine to go into limp mode as the requested and measured pressure levels wont match up. I'd imagine the engine would have a fit, unless you had specially mapped it for a manual controller.

 

I don't see the point in a manual controller anyway. Either the boost level is safe or it's not. My mate had a stupid little boost controller on his EvoVI and he never used it for this reason. You never want it to overboost and you never want it to be gutless, so you set it at a sensible level and leave it there.

 

You can obviously avoid going to maximum boost yourself, using your foot.

I can only echo what Bodge has said, they're not recommended on our engines due to the way the ECU works with the N75.

 

Its pretty bloody pointless if you've got a good remap anyway. If you had switchable maps then that may be something a bit better. A mate of mine has a Mk2 Golf 20VT with one map at 150bhp to save fuel and one for full fat 300bhp. That makes more sense to me anyway but its a custom ECU and remap so very safe.

The problem i have is that my car hesitates very badly from about 4-4500rpm onwards had read somewhere that the car could be jumping into limp mode because of overboost, my plan was to fit a controller and tone down the boost and see if theres a difference, im thinking of going to shark in august to have the map redone was just trying to figure out whats causing this

BIG BANG TIME

BIG BANG TIME

??????????????

Youre trying to fix the symptoms, not the cause.  Go back to basics and resolve the core problem.

I am trying believe me ive done the usual switched the n75 still the same, ive took the split-r dump valve off as that was causing a boost surge got a cheap recirc on till my 007p gets here, i unplugged the maf and ran without it plugged in and seemed better gonna try again once i get the 007p on