1.8T vs VR6

[Kevin Bacon 5]

I can see where Matt is coming from - Rather than making an NA engine that gives plenty of torque and power (which takes skill if it's to remain drivable), using a turbo can be seen as the easy way out. Sod the flow characteristics, so important in NA, and just force loads of air in artificially instead. *I* don't see that as cheating, but rather a different approach, especially when you have multiple car platforms to consider - where a 3.0 V6 isn't always feasible.

 

As mentioned before, the germans have never particularly favoured forced induction, especially BMW..... but even they've gone supercharged on the Mini and all their Diesels are turbo-charged. So basically, all the big marques that snubbed turbos in the 80s as crude and unreliable are now starting to eat humble pie. Who'd have thought a 2.0 Turbo would be standard fitment in the Golf GTI 10 years ago?

 

BMW will take longer to see the light, especially as they've publically stated they don't like turbos, but they will get there.... :wink:

[PhatVR6 0]

I was in a 225bhp revo'd 1.8T the other day. it felt a bit slow....and it didn't make any nice noices at all, just a feeble whistle and a bit of a wtooosh when you backed off the throttle.

 

they feel like trains, whrer you can sort of feel this big surge of torque, but ti doeasnt' actually feel like it's making th car go any quicker?!?!

 

still don't like them. so dull it's untrue....

[dr_mat 0]

There's also the horror stories of unreliable turbos - my next door neighbour when i was a kid had an MG Metro Turbo. I'm sure it was a lot of fun, but it cost em a fortune... Of course, they've changed now, I know that. Just saying ...

(How come the turbos fitted to diesel engines never seemed to show the same fragility as the petrol ones? Do they simply not spin as fast?)

[dazzyvr6 0]

diesels dont rev as high as petrol engines

[dr_mat 0]

Yeah I know that, but the turbo spins driven by exhaust gas, just like in a petrol car... Are you telling me for sure the turbo doesn't spin so fast on a diesel?

[Kevin Bacon 5]

The 1.8T and TDi engines came onto the market at roughly the same time and I've not heard any reports of either failing prematurely yet (running at standard boost levels). Maybe it's too early too tell?

 

Not sure about the max speeds diesels spin their turbos at. Unlikely to be as fast as a petrol engine. TDis run very cool so there's also less strain on the turbo bearings. The exhaust front pipes on Peugeot HDIs have a post burn fuel system that heats up the exhaust gases to the required temperature for the particulate filter to work, that's how cool they run!

 

Pretty clever stuff really, a bit of pre-burn fuel to reduce diesel clatter, the main slug for the power burn then another squirt to heat the exhaust up - And they still return 52mpg :shock:

 

I remember the good old days when you had to let the engine idle for a few mins to let the turbo slow down if you'd been thrashing it. My mate just pulls up in his Cupra R and turns the engine off straight away! So there have defintely been advances there too.

[Guest]

Let's start with the N/A aspect. If you were to take the N/A 1781cc 5v/cylinder engine and add on another two cylinders, you'd get a 2671cc (bore & stroke is the same as the 2.7 V6 used in the Audi S4 / RS4) in-line 6 producing ~190bhp-225bhp.

 

So, 12v VR6 output or better from 190cc less. The key here is the increased valve curtain area of the 3 inlet valves that gives good flow at low lifts. The internal EGR ports in the 20v head also allow a reduction in pumping losses at low load conditions, giving an efficiency improvement.

 

And another point - why does everyone seem to think that you have to know HOW to make a turbo work in order to have an opinion on it?

 

Simply because if you know how turbos work, you would understand how innaccurate this is :

 

My statement is based on the fact that simply by modifying a few constants in the ECU you can increase the power of any 1.8T from it's factory output to silly numbers.

 

A straight remap as described without any other component changes will gain 40-50bhp maximum (we'll set aside fantasy RR numbers for the moment). Even on a 225 engine that's only 275bhp max, which is near enough supercharged VR6 terrritory so nothing outrageous. The K0-3 turbo (used on 150bhp engines) can flow enough for 240bhp, the K0-4 (210-225bhp engines) enough for 300bhp so how come they don't get that from a remap? It's nothing to do with the fuel, btw.

The reason the aftermarket can get 300bhp+ with a turbo swap is because they don't have to meet the emissions regulations that the OEMs do during homologation but crucially they don't run more boost than a chipped K0-3 to do it - how? (This is rhetorical, I know the answer).

 

What if I was to say that there is a simple component that I can change on my 1.8T, without touching the intercooler, turbo, engine internals, intake or management that would reduce the plenum boost pressure but keep the power output the same and if I was to re-map afterwards would get me much closer to the 240bhp that the turbo is capable of, effectively giving me another 15-20bhp over a straight remap?

 

Finally, just to put a cat amongst the pigeons, people assume that turbos force air into the cylinders - they don't. Turbo engines have a worse V.E. than N/A engines, meaning that less of the available cylinder capacity is filled with intake air on the induction stroke, compared with the equivalent N/A. However, the density of that incoming air is, in a properly designed & functioning set-up, such that it more than offsets the reduction in V.E.

[dr_mat 0]

And another point - why does everyone seem to think that you have to know HOW to make a turbo work in order to have an opinion on it?

Simply because if you know how turbos work ...

 

I'm learning now, aren't I? Teach me more!! :)

 

My statement is based on the fact that simply by modifying a few constants in the ECU you can increase the power of any 1.8T from it's factory output to silly numbers.

A straight remap as described without any other component changes will gain 40-50bhp maximum ...

 

Right, and a straight remap (without changing any components on a N/A car will release what, exactly? 10bhp? And you're *still* telling me it's not easier to push the turbo engine?

 

The reason the aftermarket can get 300bhp+ with a turbo swap is because they don't have to meet the emissions regulations..

 

Clearly: I never commented on that. But, if we were to tell my remap man to ignore the emmissions regs and give me a fire-breathing chip for my N/A VR6 how much power would it liberate? I'm guessing 50bhp is expecting too much, yeah? I'm not talking about the 300+ bhp from 1.8T, turbo swap world, I'm talking about that +50 bhp you get from the factory engine for free (almost).

 

Finally, just to put a cat amongst the pigeons, people assume that turbos force air into the cylinders - they don't. Turbo engines have a worse V.E. than N/A engines, meaning that less of the available cylinder capacity is filled with intake air on the induction stroke, compared with the equivalent N/A. However, the density of that incoming air is, in a properly designed & functioning set-up, such that it more than offsets the reduction in V.E.

 

Interesting facts, but I haven't changed my mind. Must try harder.. ;)

 

Out of curiosity, where do you work, Blue Nothelle? You appear to know some stuff... :)

[Guest]

I'm learning now, aren't I? Teach me more!! :)

 

I've given away plenty. If I carry on at this rate, it could seriously jeopardise any chances of abandoning principles and setting up in business to rinse Max Power for VW-influenced chavs in Mk2 Golfs for sacks of cash while they thank me for the privilege! :D

 

Right, and a straight remap (without changing any components on a N/A car will release what, exactly? 10bhp? And you're *still* telling me it's not easier to push the turbo engine?

 

No, I'm saying that it's not as simple as just "whacking up the boost". While the bar can be raised higher with forced induction than N/A, the technical challenges that arise as a result, the chances and consequences of failure are greater also. You don't get something for nothing, there's a price, even if it's not immediately apparent.

 

Clearly: I never commented on that. But, if we were to tell my remap man to ignore the emmissions regs and give me a fire-breathing chip for my N/A VR6 how much power would it liberate?

 

N/A re-maps can only trim timing and open-loop fuelling. Without hardware changes to radically alter the air consumption (cams, headwork, VSR) it's nothing more than an optimisation/characterisation job.

 

Interesting facts, but I haven't changed my mind. Must try harder.. ;)

 

I'm not trying to convert anyone - I have a VR6 and a 1.8T. I prefer the VR6 for sound, character & top end (especially with the supposed 274 cams it has), the 1.8T for responsiveness at low revs. It is unfair to suggest that the 1.8T is a bad design, carried by its turbo - it's not and as pointed out, in a 6 cylinder N/A form could compare favourably with even with a stock R32 engine.

[corradovr6sc 0]

274 cams (standard?) No wonder it doesn't idle smoothly :?

[dr_mat 0]

...While the bar can be raised higher with forced induction than N/A...

 

..N/A re-maps can only trim timing and open-loop fuelling....

 

I'm not trying to convert anyone - I have a VR6 and a 1.8T. I prefer the VR6 for sound, character & top end (especially with the supposed 274 cams it has), the 1.8T for responsiveness at low revs. It is unfair to suggest that the 1.8T is a bad design, carried by its turbo - it's not and as pointed out, in a 6 cylinder N/A form could compare favourably with even with a stock R32 engine.

 

I never said the 1.8T was a bad design, just that NA is the way for me, and that it's harder to get good outputs from an NA car. Sure the 1.8T probably would make a reasonable NA engine, with appropriately raised compression, but that's thanks to the development work done on the 1.8(non-T) more than the work done for the 1.8T, surely? It's also a good 5 years younger in design terms than the 12v VR6, which was designed at about the time the amoebas crawled out of the oceans and grew shells. To call it advanced is a travesty (apart from the Bosch "emission control" system attached to it.. ;)

 

So from your statements above: with a turbo you can crank the boost knob to increase torque by some 25% of the engine's output without *serious* problems (other than a bit of longevity). NA you can't do anything without changing hardware.. WHICH WAS MY POINT! :) :)

 

And finally: sadly I can't afford two cars, so it's EITHER VR6 or 1.8T (or TDi, actually!), so I chose the VR6, and I can't see me changing it unless it manages to click up the "p1ss off the owner" knob a couple more clicks... Unless you wanna donate a 1.8T to my collection.. ;)

[CoxyLaad 0]

surely you cant say that just adding another 2 cylinders onto a 4 cyinder block will give X horsepower?

 

What about the design aspect and all the other extra frictional losses blah blah blah

 

Just thought I would stick me oar in there :wink:

 

p.s. can we have some new smileys? these ones are crap :shock:

[Jim 2]

Theres loads of smileys! :compress: :norty: :rabiit:

 

But maybe a few new ones would be funky!

[Kevin Bacon 5]

Where's the yawn smiley? :lol:

[dr_mat 0]

We don't need it - you've been very quiet.. ;)

[Henny 0]

:roll:

[CoxyLaad 0]

We don't need it - you've been very quiet.. ;)

 

LOL very witty :D

[Kevin Bacon 5]

Witty? I wouldn't go that far, droll at best.

[dr_mat 0]

I wouldn't even go that far.. Anyway, as usual this thread made it to 4 pages. I did my best, but I really don't have the enthusiasm to push it any further. Can someone else take over? ;)

[Kevin Bacon 5]

I think you should keep going and Blue Nothelle might share some more of his knowledge :lol:

[Jim 2]

No - we all think forced induction rules.

 

Its just you that doesn't, ya weirdo :D

[dr_mat 0]

Ha, that's rich coming from a person who chooses to live in Coventry!! ;) :-P

[Jim 2]

If it wasn't for the fact that I work here, all my friends & family live here, and i'm too cowardly to move away from 'what I know' then i'd love to leave this city. It really is the pits sometimes.

 

The odd thing with Coventry is, if you drive out of the city for 15 mins you can find some really nice little quiet villages and stuff - but then you lose the convenience of city life! The traffic, the crime.. oh what wonders!! :D

[junbao 0]

Sorry to interrupt,

Workmate and i swapped car for the 25 miles home (he has 1.8T (180) mk IVgolf, I have the Vr6 rado). After the beautiful Vr6 noise, I had to open the window to check his engine was still actually there with me foot down.

 

Just gotta say, drivin the Gti (although refined (rar rar)) was total w**k compared to the corrado, no feel, no class, no ROOOOARRRRR!

Plus the gear shift was shocking, felt like i was beating the car with a stick!

 

J

[biggerbigben 0]

Sorry to interrupt,

Workmate and i swapped car for the 25 miles home (he has 1.8T (180) mk IVgolf, I have the Vr6 rado). After the beautiful Vr6 noise, I had to open the window to check his engine was still actually there with me foot down.

 

Just gotta say, drivin the Gti (although refined (rar rar)) was total w**k compared to the corrado, no feel, no class, no ROOOOARRRRR!

Plus the gear shift was shocking, felt like i was beating the car with a stick!

 

J

 

I agree, even though I have a 1.8T in my corrado! I love the sound of the VR6...!