mbcs rule ok
Turbo Mini Forums

Chaps
sorry for starting a new thread on this but me and wil_h are confused


I have confused myself about MBC;s can I play a what if game

Say your actuator is set to 4PSI

your MBC to 9

So off we go down the road, the mbc is closed , there is no waste gate creep and we are now approaching 9PSI
The MBC opens ... letting the Actuator open straight away l without that waste gate creep ) so the most efficiant use of that boost has just happened ....
Now

WHat happens ; I still have my foot planted to the floor

I assume that when the actuator drops of the boost the MBC closes again ,

SO

does this mean that the MBC is constantly opening and closing while you are trying to blast out full speed ahead, fluctuating between 9PSI and 8.9something PSI ?

Steve

PS I sound like I am waffling but hey ho !

TurboLessTosser

i want to know this also! i thought it was just like fitting a 9psi actuator.

ps steve, think u should set mine to 9psi when i go driving it? Or leave it to 8psi all t he time?

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

tis tru I am confused

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

The way I understand it is that Yes this will happen. but maybe not quite as much as 0.1 psi. and your really not goning to notice much difference between 9 & 8.9 Psi.

also the same would happen with the Electronic boost controllers and these have been used for years for VERY high boost aplications with no problems at all.


Its not like fitting a 9psi actuator in theory its better, as with a 9psi actuator you will still see wastegate creep as the boost aproaches 9psi but with the mcb all boost is hidden from the wastegate until it hits 9psi........in theory!!

This is a cheap soloution to boost control and as such is unlikly to be perfect. but its still alot better than a bleed valve. I Think its somthing you shouldn't worry too much about. small drops in boost are only going to mildly effect performance if at all. where as the only other cheap alternative, the bleed valve could see boost spikes and popped engines.

if your concerned in some way spend the extra money on a actuator or EBC.

hope that helps

Sounds about right to me

9 valves, 4 wheel drive, 3 cylinders, 1 turbo, which got nicked

great stuff! I have mine with quite a bit of length on it, it goes from the turbo area up to the bulkhead where ive mounted it next to the wiper motor, wanted to keep it away from heat and somewhere to get access to it, should it be ok with all tht length?

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

Shouldnt be a problem, although in theory, I guess the closer you can get it to the actuator, the better, althoug I would imagine, in practice, it would be nigh impossible to tell.

9 valves, 4 wheel drive, 3 cylinders, 1 turbo, which got nicked

what would happen if you had a 10psi actuator and the mbc set to less than 10psi, say 8psi for example, would the boost be 8psi or would the fact that there is a 10 psi actuator mean that this is the minimum boost.
sorry if it makes no sense but i am still learning :)
cheers
DAN

Yes, 10psi would be the minimum.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

haha this is getting mad

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3