Show off valve

[chunderlicious]

quick question, im only new to deisel and want to know how/if a blow off valve works on a turbo, ive been told it works and been told it doesnt... i dont see how it doesnt work; its excess compressed air, why wouldnt it work?

[slowhilux]

Wont work. No throttle body to create vacuum in the intake plenum. Modern EFI diesels it will work (ie; Toyota's 1KZ-TE, 1HD-FTE, 1KD-FTV), as they all have throttle bodies, and DO create a vacuum inside the plenum.

[Gribble]

What engine/truck have you got?

Odds are you cant without making an intricate system of vaccum solenoids and switches etc.

[adam.s]

Correct me if I am wrong (I have never owned a diesel), but the blow off valve on a petrol engine opens when the throttle is snapped shut (under vaccum), it is only really there so the gasses from the turbo are kept flowing and as a result, the turbine does not slow down.

When you get back on the gas, the turbo is already "spooled", and it's back pumping.

From what I have been led to beleive, diesel's don't have a throttle plate, and hence the turbo is never slowed down, so there is no point to having one on a diesel.

edit: beaten to the post !

[De-lux]

wont work... read this. very detailed


CLICK ME

[Gribble]

Correct me if I am wrong (I have never owned a diesel), but the blow off valve on a petrol engine opens when the throttle is snapped shut (under vaccum), it is only really there so the gasses from the turbo are kept flowing and as a result, the turbine does not slow down.

When you get back on the gas, the turbo is already "spooled", and it's back pumping.

From what I have been led to beleive, diesel's don't have a throttle plate, and hence the turbo is never slowed down, so there is no point to having one on a diesel.

edit: beaten to the post !

Thats half the idea, also on a petrol engine when the throttle shuts you get a pulse wave that travels back down the pipes and rapidly slows the turboshaft. Too much of it can root your turbo. But like you said it doesn't matter on a diesel because there is no throttle.

But if you want to run a blow off valve just to say;

HI LOOK AT ME I GOT A TURBO AND BLOW OFF VALVE ON MY CAR, HOW SIK AM I?

... then there is a way to do it. But because of its Grimace im not going to explain. Plus im going to the pub.

[BIg StEvE]

Speak to the boys and girls at the toyota surf owners forum! they have plenty of info on performance gains with reduced lag on there EFI diesels!

I believe it does make a difference!

www.toyotasurf.asn.au/forum/

Read it and weep!

[adam.s]

Correct me if I am wrong (I have never owned a diesel), but the blow off valve on a petrol engine opens when the throttle is snapped shut (under vaccum), it is only really there so the gasses from the turbo are kept flowing and as a result, the turbine does not slow down.

When you get back on the gas, the turbo is already "spooled", and it's back pumping.

From what I have been led to beleive, diesel's don't have a throttle plate, and hence the turbo is never slowed down, so there is no point to having one on a diesel.

edit: beaten to the post !

That's sorta true, but it's only if you are running BIG boost and snapping the throttle shut hard.

Low boost running no blow off valve is okay, some factory turbo's don't come with a BOV for that reason, but they feel like shit once you start turning the boost up.

Thats half the idea, also on a petrol engine when the throttle shuts you get a pulse wave that travels back down the pipes and rapidly slows the turboshaft. Too much of it can root your turbo. But like you said it doesn't matter on a diesel because there is no throttle.

But if you want to run a blow off valve just to say;

HI LOOK AT ME I GOT A TURBO AND BLOW OFF VALVE ON MY CAR, HOW SIK AM I?

... then there is a way to do it. But because of its Grimace im not going to explain. Plus im going to the pub.

[mickyd555]

this might be off topic, but what is the noise that a semi makes, kinda sounds like a blow off, but more of a whislte than a "choooo"...........

[spazbot]

wastegate

[mickyd555]

ok, now im really confused, i thoguht a wastegate was a blow off valve??


can you tell i know nothing about turbos.........

[Patroldude]

Hell - if you gonna trbo a petty motor people n really want a distinctive noise from turbo - do what ford did in the turbo sierra's... weld the waste gate up.

Makes a nice bang noise after 1.5 laps..... It killed motor real quick, but heck they got fastest lap time did they not most the time?
They would rebiuild it for next time - all good if you could afford it.

I recon the straight pipe with no muffleres sounds sweeeeet.

Mk

[carts]

Well Sam, tomorrow morning i am fitting a BOV to the 60 series. It will be a plumb back job as opposed to a fully sik pssst sounding one.

Since I intercooled the 60 with that huge front mount, the compressor surge has become huge. Running 12psi of boost, compressor surge hits 16-17psi according to the gauge, not good for the old turbo.

Since it has a throttle butterfly, the BOV will work as a vacuum is created in the intake manifold upon deceleration.

I'll let you know how it goes.

[chunderlicious]

i dont want a show off valve i just wanted to know about it and its relationship with diesel....... man i got roasted!!!

[HJ60_HEATHUS]

this might be off topic, but what is the noise that a semi makes, kinda sounds like a blow off, but more of a whislte than a "choooo"...........

large trucks have handbrakes that are held OFF by compressed air, so when a truck stops and you hear a rush of air, the driver is actually engaging the handbrake, by releasing the stored air

also, they inject compressed air into the cylinder on the (i think) compression stroke inorder to slow the motor down, resulting in increase engine braking. the whistle you refer to would be the air running through the exaust system when the brakes are cut out

atleast this is what i've been lead to believe, please someone correct me if i'm wrong

[bigpat]

The function of a wastegate is to regulate the amount of exhaust gas that enters the exhaust housing of the turbo. This limits the turbo RPM, which ultimately limits thee boost. 90% of applications use an 'internal' 'gate, while the serious performance boys use an external 'gate.

As above, the BOV helps prevent flow reversion and compressor stall.

Flutter is noticed with intercooler installed. My friends SURF does it. Intercooler core is like a big sound tube.

The loud whistle from trucks is simply the turbo spooling up under 60 psi of boost!, which also results in a cool ( & loud) flutter noise on gear change!

[De-lux]

Hell - if you gonna trbo a petty motor people n really want a distinctive noise from turbo - do what ford did in the turbo sierra's... weld the waste gate up.

Makes a nice bang noise after 1.5 laps..... It killed motor real quick, but heck they got fastest lap time did they not most the time?
They would rebiuild it for next time - all good if you could afford it.

I recon the straight pipe with no muffleres sounds sweeeeet.

Mk

yeah my lil lux has that and i can vouch it sounds awesome

[adam.s]

this might be off topic, but what is the noise that a semi makes, kinda sounds like a blow off, but more of a whislte than a "choooo"...........

supercharger

[adam.s]

ok, now im really confused, i thoguht a wastegate was a blow off valve??


can you tell i know nothing about turbos.........

wastegate governs the amount of boost the turbo makes by opening/closing a flap at the back of the turbo which allows the exhaust gases to escape out the exhaust rather then spinning the turbine up

blow off valve does a completely different job.

[benhl]

The function of a wastegate is to regulate the amount of exhaust gas that enters the exhaust housing of the turbo. This limits the turbo RPM, which ultimately limits thee boost. 90% of applications use an 'internal' 'gate, while the serious performance boys use an external 'gate.

As above, the BOV helps prevent flow reversion and compressor stall.

Flutter is noticed with intercooler installed. My friends SURF does it. Intercooler core is like a big sound tube.

The loud whistle from trucks is simply the turbo spooling up under 60 psi of boost!, which also results in a cool ( & loud) flutter noise on gear change!

Correct ! - Mate works for Hasting Deering and we have had many similar discussions over rum. This is closest to the mark i believe.

[Gribble]

Well Sam, tomorrow morning i am fitting a BOV to the 60 series. It will be a plumb back job as opposed to a fully sik pssst sounding one.

Since I intercooled the 60 with that huge front mount, the compressor surge has become huge. Running 12psi of boost, compressor surge hits 16-17psi according to the gauge, not good for the old turbo.

Since it has a throttle butterfly, the BOV will work as a vacuum is created in the intake manifold upon deceleration.

I'll let you know how it goes.

Sik Bro!

You will have to bring it up one day, we'll go for a cruise to waitara maccas.

[droopypete]

this might be off topic, but what is the noise that a semi makes, kinda sounds like a blow off, but more of a whislte than a "choooo"...........

It is a scientifically proven fact that the combination of Coke a Cola, amphetamines and hamburgers results in uncontrolable flatulence a condition which is exaserbated by a high body fat coefficient and low IQ.

The noise you hear from the truck, is the driver "letting one rip", and the reason that some trucks make this noise and some don't, is that some of the smarter operaters have installed "reticulated methane injection systems" in their trucks, using a bell shaped intake made from Teflon coated titanium installed in the seat that channels the recycled methane into the intercooler where it's temp is reduced to 50c it then follows the same path as the regular air charge, making a "super mega mix" of oxygen/methane which results in an average 12.7% H/P gain, that is why you regularly see truck drivers drinking Coke and eating hamburgers when asscending a steep grade, they are quite simply riching up the mix, sadly, it also explains why they are always on their own.

A negative side to the "reticulated methane injection system" is that the methane is so volitile, all plumbing must be made from Teflon coated titanium and the seals are constucted of uranium depleted polystyrene and must be replaced after 5000 liters of Coke (or about 10 days) and mechanics must wear a full protection body suit (with respirator).

I hope this helps.
Peter.

[eliteforce32]

gold u sick basturd

[Shadow]

i'm pretty syre large diesel trucks do have a plumb back blow off valve, thats why it doesnt sound like a ricer blow off, rather a muffled blow off.

my field research comes from traveling logan road next to B-Doubles K

[stumped]

this might be off topic, but what is the noise that a semi makes, kinda sounds like a blow off, but more of a whislte than a "choooo"...........

It is a scientifically proven fact that the combination of Coke a Cola, amphetamines and hamburgers results in uncontrolable flatulence a condition which is exaserbated by a high body fat coefficient and low IQ.

The noise you hear from the truck, is the driver "letting one rip", and the reason that some trucks make this noise and some don't, is that some of the smarter operaters have installed "reticulated methane injection systems" in their trucks, using a bell shaped intake made from Teflon coated titanium installed in the seat that channels the recycled methane into the intercooler where it's temp is reduced to 50c it then follows the same path as the regular air charge, making a "super mega mix" of oxygen/methane which results in an average 12.7% H/P gain, that is why you regularly see truck drivers drinking Coke and eating hamburgers when asscending a steep grade, they are quite simply riching up the mix, sadly, it also explains why they are always on their own.

A negative side to the "reticulated methane injection system" is that the methane is so volitile, all plumbing must be made from Teflon coated titanium and the seals are constucted of uranium depleted polystyrene and must be replaced after 5000 liters of Coke (or about 10 days) and mechanics must wear a full protection body suit (with respirator).

I hope this helps.
Peter.

awesome i was thinking it was 'bout time for another episide of Dr Pete

[Hekta]

Correct me if I am wrong (I have never owned a diesel), but the blow off valve on a petrol engine opens when the throttle is snapped shut (under vaccum), it is only really there so the gasses from the turbo are kept flowing and as a result, the turbine does not slow down.

When you get back on the gas, the turbo is already "spooled", and it's back pumping.

From what I have been led to beleive, diesel's don't have a throttle plate, and hence the turbo is never slowed down, so there is no point to having one on a diesel.

edit: beaten to the post !

Thats half the idea, also on a petrol engine when the throttle shuts you get a pulse wave that travels back down the pipes and rapidly slows the turboshaft. Too much of it can root your turbo. But like you said it doesn't matter on a diesel because there is no throttle.

But if you want to run a blow off valve just to say;

HI LOOK AT ME I GOT A TURBO AND BLOW OFF VALVE ON MY CAR, HOW SIK AM I?

... then there is a way to do it. But because of its Grimace im not going to explain. Plus im going to the pub.

Get one of these!



http://www.takakaira.com/accessories/nightpager/nightpager.html

[Gribble]

That is sooo Grimace.

[droopypete]

this might be off topic, but what is the noise that a semi makes, kinda sounds like a blow off, but more of a whislte than a "choooo"...........

It is a scientifically proven fact that the combination of Coke a Cola, amphetamines and hamburgers results in uncontrolable flatulence a condition which is exaserbated by a high body fat coefficient and low IQ.

The noise you hear from the truck, is the driver "letting one rip", and the reason that some trucks make this noise and some don't, is that some of the smarter operaters have installed "reticulated methane injection systems" in their trucks, using a bell shaped intake made from Teflon coated titanium installed in the seat that channels the recycled methane into the intercooler where it's temp is reduced to 50c it then follows the same path as the regular air charge, making a "super mega mix" of oxygen/methane which results in an average 12.7% H/P gain, that is why you regularly see truck drivers drinking Coke and eating hamburgers when asscending a steep grade, they are quite simply riching up the mix, sadly, it also explains why they are always on their own.

A negative side to the "reticulated methane injection system" is that the methane is so volitile, all plumbing must be made from Teflon coated titanium and the seals are constucted of uranium depleted polystyrene and must be replaced after 5000 liters of Coke (or about 10 days) and mechanics must wear a full protection body suit (with respirator).

I hope this helps.
Peter.

awesome i was thinking it was 'bout time for another episide of Dr Pete

Thanks

[GRIMACE]

I am gonna run a silent system on my rangie after i fit the supercharger as I am gonna be using a boost controler (wolf ems).... I have been told I will still get sum feedback throught the snorkel I just hope its not to much

[slowhilux]

Show me a truck turbo that has a wastegate.....................