After watching a re-run of chop shop, on there was a company that claimed to be able to make a bolt on supercharger to any car. It got me wondering if the VRS could. After looking if Golf GTi's had been done it seems you can.Just curious if anyone had tried it and if you get any noticeable benefits,supercharger whine, etc? Or is it a ripoff with stupid claims just to say youve got a supercharger in your car? (like adding resistors )

Curiosity

Edited 28 July, 201016 yr by Rhoobarb

I think I would be a good mod but you would need a lot of work done for custom mapping.

For example you could get the supercharger to give you power upto say 3k rpm and then the turbo to take over after that.

However cost wise not sure I reckon you would prob be looking around the £5k mark

You already have a turbo charger, which is more efficient as it works of the waste exhaust gas as opposed to the super charger which works off engine power.

A supercharger would probably give you more low down boost before the turbo cuts in, but then you'd have to step if off the drive path somehow when the turbo is on boost (IMHO)

You already have a turbo charger, which is more efficient as it works of the waste exhaust gas as opposed to the super charger which works off engine power.

A supercharger would probably give you more low down boost before the turbo cuts in, but then you'd have to step if off the drive path somehow when the turbo is on boost (IMHO)

it'd be original and good, however id wager the power delivery would be quite crude and as carl says the mapping would be expensive and difficult.

it would also be alot more cost effective o just stick a hybrid k04 on the car and dive off with 380hp, also any more torque so low down in the rpm range would equate to horrendous wheel spin

So its possible but neither feasible in terms of cost or power delivery, but if money wasn't a factor and delivery could be provided, say to a 4x4 Octy then it could be a good car. Interesting. Would it be better and cheaper to change to a twin turbo setup (if possible) than single turbo upgrade?

Kind of going off the Octy 2 topic but, a further question would be, would there be any point in adding a supercharger to a twin turbo sequential system?

Interesting stuff though.

it'd be original and good, however id wager the power delivery would be quite crude and as carl says the mapping would be expensive and difficult...

Power delivery would be very linear, as it's directly related to rpm, that's the point of an s/c, it's just like having a much larger capacity n/a engine, you don't get a sudden surge of power.

As said though, wouldn't be worth the time and effort when it already has very good turbo setup.

You don't need a supercharger when you have a K04 turbo

Minimal lag, and as much power as you could ever wish for in a FWD car

Max torque is currently available from 1850 rpm on the octy VRS so it has a good bit of low down grunt already

A S/C can of course be added, you must already be aware of the smaller 1.4 turbo/sc VAG engine.

On the VRS youd have the supercharger for lower rpm, possibly on a clutch to stop working ( being a restriction ) at high rpm, then you can afford a bigger turbo as the 'lag' ( which is actually the boost threshold the way most of you lot describe it, I've yet to know anyone who understands this on this site ) will be eliminated with the supercharger.

I'd imagine a bit of custom pipework and some manifold trickery would be needed and then some pretty good mapping if the standard ECU could do whats necessary, if not a new ECU would be needed too. I'd imagine accurate boost control would be the hardest part.

Is it worth it? I doubt it, as a well set up and developed single turbo engine with the right cams and mapping will have decent low down tractability and big power, and you'll probably get to a point where the temperatures are too hot to handle before you reach the limit of a well developed single turbo application

£5k is optimistic IMO to get a sc fitted and resolved so it drives like a 'factory' car

Personally I dont like superchargers because of their parasitic nature, i'd like to see a well developed sequential turbo set up with a little turbo spooling at low rpm to help with the boost threshold on a big **** off turbo, but its bloody hard to do!

Edited 28 July, 201016 yr by VRsMatt32

It's variable geometry turbos fitted to the Vrs's, they give you all the benefits of a supercharger -- torque from very low down the rev range, 1700rpm in the new octy vrs's case -- which incidentally is sooner than a twin screw (the best type) S/C can deliver full boost (12psi) bolted onto a BMW M52TU engine (2200rpm).

The VNT turbos have none of the drawbacks of superchargers (parasitic drag, 2bhp in very good cases, can be much more though).

Since when did the petrol vRS have a VNT turbo?

Since when did the petrol vRS have a VNT turbo?

Since the special edition. IHI call it VGS, but seen as the VAG turbos from IHI aren't from IHI proper but from an IHI / Borg Warner joint venture the docs jump between VNT and VGS but means the same thing, variable vane rather than the k03 wastegate type turbo.

I thought only Porsche had managed to use Variable Vane Turbo's on Petrol cars so far? The temperatures destroy them pretty quickly

Yes that was my understanding too, VNT on a 2.0TFSi and you'd be able to get some awesome torque though

The diesel vRs has a variable vane turbine, not the petrol one. Borg Warner are now KKK Warner and are not twinned with IHI.

Porsche are indeed the only people using a variable geometry turbo on a petrol car, but they use some mega-expensive aerospace materials to survive the 1050degs c exhaust temp, not really suitable (yet) for production cars.

People do indeed get confused between lag and "boost threshold" as they are not the same. Lag is when you put your foot down (no matter what the revs) and there is a slight pause before the full response is felt. This is due to the inertia of the turbine and compressor wheels.

Boost threshold is when the tubocharger is not able to provide any/enough boost pressure as the exhaust gas pressure is not sufficiently high enough (not even getting into what surge is....).

Superchargers do have parasitic losses, hence why a lot of modern superchargers are electromagnetically clutched, so that when they're not required, they don't operate.

The problem with sequential turbos is complexity, driveability and emissions, all that extra metal needs heating up before the catalyst will work.

Variable cam timing can help with turbocharger spool up, seen on the latest Audi, Ford and Fiat engines.

Twin scroll turbines can also be used, you have two different paths for the exhaust to go round the turbine depending on the engine speed, to make the most of the exhaust gas energy present...

I hope this helps (it is in nowway exhaustive - pun intended) and hasn't complicated the issue!

Totally wrong on boost threshold and lag..........

Boost threshold is the engine rpm at which the turbo makes full boost........so if you have a huge turbo on a small engine its not lag that most people say it is, its just that it has a high boost threshold

Lag, is the time it takes for the turbo to make full boost once the engine is at the rpm able to give it full boost

Erm, isn't that what I wrote?

Edited 1 August, 201016 yr by Staedtler

Erm, isn't that what I wrote?

Erm..........NO! The bit you wrote that i've highlighted in bold highlights exactly why

People do indeed get confused between lag and "boost threshold" as they are not the same. Lag is when you put your foot down (no matter what the revs) and there is a slight pause before the full response is felt.

Edited 1 August, 201016 yr by VRsMatt32

Sorry, should have made it incredibly explicit rather than just getting the point across.

Lag is when you put your foot down (no matter what the revsas long as the turbo is at the minimum revs required to make full boost*) and there is a slight pause before the full response is felt.

* the one rev in the rev range where a turbo actually makes full boost or where you choose to wastegate it?