[Sankar]

Ok. Now I understand it.

[Psycho]

Originally Posted by Sankar

Ok. Now I understand it.

Sorry looks like a part of my post didn't get through from my mobile. Mods please merge the posts as I am past the edit time.

Next imagine the diesel engine dropping revs and not being able to use the boost that has been built up and the wastegate opens to relieve pressure that slows down the turbos revs. Instead if a bov existed the turbos revs would remain high letting the boost build up way quicker making the car way more responsive.

[highwayblaze]

Originally Posted by F50

I would go for Volkswagen Golf GTi W12 650!!

Talk about annihilating your opposition.

They don't make that car. It was just an experiment. But yes about modifying a hot hatch thats greate inspiration

[jassi]

can the palio 1.6 be fitted with an rd601 and stage 1/2 mods done to perform well. The way i see it - its a petrol so you will still enjoy the high revs and is a 100bhp already so all you have to do add the standalone rd, get a CAI + FFE and porting/polishing maybe. the only thing which hasn't been done in a palio is a reliable turbo setup but maybe 1+ year down the road a small reliable 5psi job may become a possibility and can be explored

[headers]

Originally Posted by jassi

can the palio 1.6 be fitted with an rd601 and stage 1/2 mods done to perform well. The way i see it - its a petrol so you will still enjoy the high revs and is a 100bhp already so all you have to do add the standalone rd, get a CAI + FFE and porting/polishing maybe. the only thing which hasn't been done in a palio is a reliable turbo setup but maybe 1+ year down the road a small reliable 5psi job may become a possibility and can be explored

That would be a good experiment. If you are willing to go through it.

@psycho: Dont you think BOVs are required for high revving engines only? Cos the way i see it, if the engine anyway has an range of only 1000 rpm that is usable, the wastegate would do the job of saving the turbo.

The problems with turbos are they are designed for max boost at a particular rpm only, and any quick change in engine rpm should help the turbo release its boost fast. The BOV is used only in such cases. Nowadays, with turbochargers becoming a common entity in most modern diesels, not all of them have a BOV, or maybe even need a BOV.

The wastegate idles the turbo when not required is what i gather!

[vabs78]

Originally Posted by Psycho

... the wastegate opens to relieve pressure that slows down the turbos revs.

Ok. So can we say that diesels don't need BOV because they don't rev as high as petrols?

[v1p3r]

Originally Posted by vabs78

Ok. So can we say that diesels don't need BOV because they don't rev as high as petrols?

NO, high-revving engines or low-revving engines, BOVs are better for them all.

Originally Posted by headers

@psycho: Dont you think BOVs are required for high revving engines only? Cos the way i see it, if the engine anyway has an range of only 1000 rpm that is usable, the wastegate would do the job of saving the turbo.

Ok, let me put this in plain terms. WGs are set to open at a predetermined boost level in psi. If your turbo WG is set to 7 psi, it will open when the turbocharger is compressing air at 7 psi over atmospheric pressure, to prevent overboost. BOVs are designed to let off surplus air volume, as a result of the combustion process not requiring so much air. This is throttle-related, not pressure/psi related.

Originally Posted by jassi

can the palio 1.6 be fitted with an rd601 and stage 1/2 mods done to perform well. The way i see it - its a petrol so you will still enjoy the high revs and is a 100bhp already so all you have to do add the standalone rd, get a CAI + FFE and porting/polishing maybe. the only thing which hasn't been done in a palio is a reliable turbo setup but maybe 1+ year down the road a small reliable 5psi job may become a possibility and can be explored

You will DIE waiting for spares. We took 1 week and a 100% premium to find a stock clutch for a Palio 1.6. I know of 1 car that is still lying around trying to get twin Webers fitted because no one can find an injection harness.

Originally Posted by headers

I agree to the purpose of a BOV..but cant imagine the impeller touching any part of the turbocharger as it will definitely break into pieces..

I've seen it. How do you think turbos fail?

Originally Posted by headers

Also, agreee that the wastegate does the basic function of controlling the boost hence the BOV is not necessary!

Not true. Necessary is different to different people. I would think it necessary if you are hitting peak boost, which is very easy in diesel engines today.

[vabs78]

Originally Posted by v1p3r

NO, high-revving engines or low-revving engines, BOVs are better for them all.

Agreed. But its not a necessity. I am trying to understand how is the excess air let out if BOV is not there? If it is going back to impeller then its obviously bad for the turbo. But we see many turbo diesels running for 1 lakh+ of kilometers without BOV.
Does it have something to do with not having a throttle plate? but the excess air still has to go somewhere.

[vikram_d]

I think the excess air in diesels is just fed back to the intake of the turbo. I might be totally wrong though.

[headers]

Originally Posted by v1p3r

I've seen it. How do you think turbos fail?

What have you seen..after the turbo has failed..have you opened it to see the impeller touching the housing? No offense V1p3r..just plain understanding..OK?

The way turbos fail is a catastrophic one.. We will not be able to get any pieces of parts if the impeller touches the housing inside! The clearances are very precise.

The way, turbos fail - or the impeller fails cos of reverse back pressure is if the impeller blade breaks - the impeller breaks due to the stresses on its blades and the very high rpm it rotates in.

The stress reversal is very bad for the blades and they turn red hot while rotating. IF a reversal happens, the blades cannot withstand the stress and tend to break at a certain point. That is how the impeller breaks and the turbos fail.

I also believe that the clearance between the impeller and the housing is necessary for the turbo to generate the boost. The shape of the air path is an involute and that is what creates the necessary boost, when the impeller rotates inside the Turbo.

I do agree that a BOV will help easy the load on a Turbocharger, but it is not necessary on all engines as the wastegate does most of the job. Again a turbo is a very expensive piece of equipment and hence most manufacturers who use a turbo also look at reliability.

Today turbos are used in most diesel engines, more because of the emission standards than for power.

Ofcourse, we crazy petrolheads love a turbo and the BOV whistle for our modding is a different experience altogether. When you take a turbo off the market and try to fit it into your car, the scenario is different altogether.

Originally Posted by vabs78

Agreed. But its not a necessity. I am trying to understand how is the excess air let out if BOV is not there? If it is going back to impeller then its obviously bad for the turbo. But we see many turbo diesels running for 1 lakh+ of kilometers without BOV.

Pl ready my reply above..its cos of emission norms..

Originally Posted by vikram_d

I think the excess air in diesels is just fed back to the intake of the turbo. I might be totally wrong though.

Depends on the EGR circuit, it is not fed back in all cases, only a small portion is depending on the sensor at the exhaust!

[FourWheelDrift]

Could this car form the best base for a modded Indian hot hatch ? Tata indica challenge race car | Straight Frm The Heart

Afaik, all petrol Indicas use a cast iron block and forged crank ... which could withstand some serious boost pressures ...

Anyone have a PETROL Indica Turbo ?

[v1p3r]

Originally Posted by headers

What have you seen..after the turbo has failed..have you opened it to see the impeller touching the housing? No offense V1p3r..just plain understanding..OK?

None taken, dude. Yes, I have opened up turbos to see the inside of the housing. You can make out gouge/scrape marks on the inside of the turbine housing, and there will be some play along the shaft, as the impeller is not sitting still. The blades are made of a much tougher material than the housing, so they normally don't suffer.

AFAIK, EGR and turbo air work on separate circuits. EGR deals with foul exhaust gases, and turbo air is fresh air, which may be in excess. I am not too conversant on EGR technology, so I cannot elaborate.

[headers]

Originally Posted by v1p3r

None taken, dude. Yes, I have opened up turbos to see the inside of the housing. You can make out gouge/scrape marks on the inside of the turbine housing, and there will be some play along the shaft, as the impeller is not sitting still. The blades are made of a much tougher material than the housing, so they normally don't suffer.

AFAIK, EGR and turbo air work on separate circuits. EGR deals with foul exhaust gases, and turbo air is fresh air, which may be in excess. I am not too conversant on EGR technology, so I cannot elaborate.

Hi again,
Its great that you have had the opportunity to open the turbocharger..But did if fail?

I agree that the blades are made of a tougher material but they are not strong!! I hope you understand the difference.

EGR, AFAIK sits on the exhaust manifold, and sends feedback [for the AFR ratio] and also a portion of the unburnt gases along with the fresh charge back into the cylinder. This helps reduce NOx gases in our emission.

[vikram_d]

Originally Posted by headers

EGR, AFAIK sits on the exhaust manifold, and sends feedback [for the AFR ratio] and also a portion of the unburnt gases along with the fresh charge back into the cylinder. This helps reduce NOx gases in our emission.

Based on your own knowledge, how did you equate what I said to the EGR system? I was talking about the excess air coming out of the wastegate.

[headers]

Originally Posted by vikram_d

Based on your own knowledge, how did you equate what I said to the EGR system? I was talking about the excess air coming out of the wastegate.

The excess air coming out of the WG is a fresh air. The EGR works on the exhaust gases to monitor the NOx gases.