Turbo piping.

[Paul Hassell]

Somewhere I have seen a schematic drawing of a T5 turbo and all its associated piping, including recirc valve, wastegate, bcv, etc..

Anybody have any idea if it was on this forum or if not does anybody have a link please.

[t5lover]

I should think pedro be along soon mate :)

[Dangerous Dave]

If this is the one you mean matey....

Diagram for 850 engine turbo (x70 range use a different bcs)
http://i150.photobucket.com/albums/s101/bomb192uk/mbcinstallation.jpg

[t5lover]

Your quicker then pedro is today mate lol

[JelT5]

Your quicker then pedro is today mate lol

he's too busy goat herding mate lol

[t5lover]

Pmsl am not saying anymore to that lol

[Niles]

vacuum hose routing for 850's and the early 70 series
11202

[Dangerous Dave]

Your quicker then pedro is today mate lol
He's getting old, someone has to pick up his loose ends LOL

he's too busy goat herding mate lol
LMAO, theres goats involved, but not herding......

[p fandango]

Your quicker then pedro is today mate lol
they've actually got me working today, i'm going to put in a complaint lol

[Paul Hassell]

Thanks very much guys, just what I was looking for.

Sorry for the idiot question, obviously the boost pressure is set within the ECU and I guess the boost pressure is monitered by the BCS via the green pipe from the turbo, but how does the rest work ???

[p fandango]

Sorry for the idiot question, obviously the boost pressure is set within the ECU and I guess the boost pressure is monitered by the BCS via the green pipe from the turbo, but how does the rest work ???
boost pressure isn't measured at all until ME7 came out, the BCS (boost control solenoid) is controlled by the ecu to basically divert air away from the actuator to raise the boost levels (by diverting air back into the intake pipe). The ecu is preprogrammed with set cycle patterns for the BCS, determined by load,rpm, speed, air temperature etc

[Paul Hassell]

boost pressure isn't measured at all until ME7 came out, the BCS (boost control solenoid) is controlled by the ecu to basically divert air away from the actuator to raise the boost levels (by diverting air back into the intake pipe). The ecu is preprogrammed with set cycle patterns for the BCS, determined by load,rpm, speed, air temperature etc

Can that diverted air be vented to atmosphere instead of back into the air intake pipe ?

and when the pre programmed boost level is met and the BCS lets the actuator open the wastegate, where does the extra boost go??

Sorry for the questions but I have a problem with the race car and trying to get my head round how it all works.

[Dangerous Dave]

Can that diverted air be vented to atmosphere instead of back into the air intake pipe ?

and when the pre programmed boost level is met and the BCS lets the actuator open the wastegate, where does the extra boost go??

Sorry for the questions but I have a problem with the race car and trying to get my head round how it all works.
The air can be vented to atmosphere, but the reason it goes back into the intake pipe is because it has already been accounted for by the MAF (albeit a tiny amount). The ecu knows how much air is in the system and fuels accordingly (in basic terms).

The surplus boost is recirculated back into the turbo inlet via the compressor bypass valve (CBV) which is bolted onto the compressor housing. The pressure from the inlet manifold holds the valve closed, then once the throttle is closed the pressure drops and the valve opens releasing the pressure into the turbo inlet. Apparently this also helps to reduce compressor stall.

Note - the ecu can only guess what the boost pressure is, so if there is a leak or related problem then the ecu will still carry on regardless (until another sensor picks up a problem).

[p fandango]

Can that diverted air be vented to atmosphere instead of back into the air intake pipe ?
i wouldn't of thought so tbh, when under vac pressure i'd of thought it would let unmeasured air into the system


and when the pre programmed boost level is met and the BCS lets the actuator open the wastegate, where does the extra boost go??
its fed back in before the exhaust turbine, i'm sure someone must have pics looking into the exhaust housing


Sorry for the questions but I have a problem with the race car and trying to get my head round how it all works.
hope we can help & its an easy fix

[Dangerous Dave]

Sorry for the questions but I have a problem with the race car and trying to get my head round how it all works.
Whats the problem?

[Paul Hassell]

The air can be vented to atmosphere, but the reason it goes back into the intake pipe is because it has already been accounted for by the MAF (albeit a tiny amount). The ecu knows how much air is in the system and fuels accordingly (in basic terms).

I am not running a MAF on my engine as I am running Emerald management which does not require one.

The problem I seem to have is the sound of the engine, which i think is turbo related. since melting my exhaust internals at Coventry recently the car sound like it is chuffing like a train which is wasnt before, I am wondering if the sudden amount of extra back pressure might have damaged something internally.

The car doesnt seem to have lost any boost or power but sounds awful.

[Dangerous Dave]

Are you using a MAP sensor instead then?

I'm guessing you've checked the exhaust manifold for cracks?

[Paul Hassell]

Are you using a MAP sensor instead then?

Yes I am running the Emerald approved MAP sensor.

The exhaust manifold seems to be ok as far as I can see, and I must admit it does sound that sort of noise, but it doesnt seem to be down on power at all although I havn't had it back on the rollers since.

[Dangerous Dave]

The exhaust manifold seems to be ok as far as I can see, and I must admit it does sound that sort of noise, but it doesnt seem to be down on power at all although I havn't had it back on the rollers since.
Fair enough, it might be worth taking it off just to check before you start looking at internals. I would have thought a little leak (even if it were a component other than the exhaust manifold) would make a lot of noise but would not neccessarily lead to reduced performance.

Perhaps other components under immense stress are at fault. Maybe a spark plug? I dunno, I'm just thinking out loud. Someone else with more experience/knowledge might have a better idea.