Knackered Back Box

[podgey]

just been checking my exhaust and found a hole about two inches big! could this be to blame for my low boost .3 bar??

hope it is, as it would save a lot of hassle, was wanting a new system anyway, if it is the cause..?

cheers for advice

[BLOODUK]

I need a new mid section , but i cant find one

might have to go to... Kwick fit noooooooo :ffs:

[newtomymr2]

Could be the back box, turbo's rely on a bit of back pressure i think, a 2" hole might be causing your problems

[bfuller]

Could be the back box, turbo's rely on a bit of back pressure i think

They don't rely on backpressure whatsoever..

The bigger, and more free flowing your turbo exhaust is, the better.

So I doubt it would have caused boost problems. Check your actuator.

[ms-glanza-cyprus]

Let me add my two pence.

1. Turbos rely on freeflow exaust gasses and not backpressure. This can purely be seen when you add restriction such as a silencer on a backbox. Yes this might have caused the hole.

Adding to that an unbalanced mixture can cause a very bequiliar exaust gas which can corrode the pipes (this from expirience has happened to my old manifold but not on a toyota).

[podgey]

ok, thanks. whats the best way to check your actuator? BFULLER, CRX165 says hi!

[bfuller]

BFULLER, CRX165 says hi!

Hi Jonny :D

whats the best way to check your actuator?

Either get it pressure tested, or get a mate to watch and see exactly when it opens, whilst someone else is revving the car.

HTH

Ben

[boundsw]

when i had boost problems it was my actuator.

the spring was knakerd, and the boost was just blowing the waste gate open !

[Jimlad]

also check your hoses around the actuator mate.

[newtomymr2]

Could be the back box, turbo's rely on a bit of back pressure i think

They don't rely on backpressure whatsoever..

The bigger, and more free flowing your turbo exhaust is, the better.

So I doubt it would have caused boost problems. Check your actuator.

←

I stand utterly corrected

[Bibbs]

It'll be the actuator .. get a pump and guage on it and pressurise the intake on the actutor .. see what pressure it lets the boost go.

You can't check it without some kit .. revving the engine is pointless as you'll not generate substancial positive boost without the drivertrain being under load.

[podgey]

ok i will get it checked out. also with other turbo charged cars, when you rev the engine whilst stationary, you can hear the dump valve, with mine you cant. are all mr2s like this? or does that sound like a knackered actuator too? thanks again very helpfull

[Bibbs]

the BOV will chirp only on positive boost .. in neutral I can get about .1 car .. enough to chip the BOV.

Sounding more and more like the actuator ..