# AXX Vs BWA 2.0 TFSI



## GolfRS (Feb 4, 2006)

I guess almost everyone knows there are 2 engines for the Golf V Gti with AXX being the "first" generation and BWA the newer one.
There seem to be differences between the 2 engines, with the more "obvious" one being the change in static compression from 10.5 to 10.3
This may seem minor, but for a turbo engine, its quite a bit.
The word going around is that VW took that step due to the "problems" caused by people putting substandard fuel into the AXX engine, which could endanger the reliability of the engine.
The newer engine is the one used in the new Seat Leon FR with also 200 BHP.
So my question is this to those who might know.Taking into consideration FSI engines are not that much influenced by compression ration per se, is the newer engine more powerfull (that iso the two engines actually produce the same STOCK ??) or is one potentially more tunable?
Surely a small decrease in compression might help up boost a little, but it must also decrease the TFSI's ability to work more efficiently in an N/A way.Also, using a higher CR might have caused VW to use better matterials (first try at this engine) which might have been eliminated due to cost cutting....
And finally, does anyone know what other changes this motor has besides the CR decrease?Would appreciate the info http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
Cheers !!


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## crew219 (Oct 18, 2000)

They got rid of Stratified mode 
Dave


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## GolfRS (Feb 4, 2006)

*Re: (crew217)*

Are u sure this is the only change?I doubt it...Why would they lower compression for that.
Someone said the newer engine might be more powerfull, but i would guess stratified is....good no ??


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## Rabbit88 (May 15, 2006)

*Re: (GolfRS)*

I never liked the engine code lottery in the 1.8T. And this is making me nervous too.


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## GolfRS (Feb 4, 2006)

*Re: (Rabbit88)*


_Quote, originally posted by *Rabbit88* »_I never liked the engine code lottery in the 1.8T. And this is making me nervous too.

I feel you, but there are some things that are best to be known vefore hand.
For example....is the BWA motor stronger (newer) or another "price cut"...








MMine is an AXX btw


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## GolfRS (Feb 4, 2006)

Any more views on this subject ??


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## Theresias (Feb 11, 2004)

None of the 2.0T's neither the AXX, nor the BWA and BPY had a stratified injection mode.


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## PD Performance (Jul 1, 2004)

*Re: AXX Vs BWA 2.0 TFSI (GolfRS)*


_Quote, originally posted by *GolfRS* »_I guess almost everyone knows there are 2 engines for the Golf V Gti with AXX being the "first" generation and BWA the newer one.
There seem to be differences between the 2 engines, with the more "obvious" one being the change in static compression from 10.5 to 10.3
This may seem minor, but for a turbo engine, its quite a bit.


VW/Audi claimed the same between the AWW and AWP.. Yet everysingle part number is identical and the replacement engines carry the same part number. 
In fact the AWW had the lower CR rating but also the lower hp rating 150 vs 180


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## PD Performance (Jul 1, 2004)

*Re: (crew217)*


_Quote, originally posted by *crew217* »_They got rid of Stratified mode 
Dave

Stratified mode never existed on the turbo versions of this motor, only the NA.


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## GolfRS (Feb 4, 2006)

*Re: AXX Vs BWA 2.0 TFSI (PD Performance)*


_Quote, originally posted by *PD Performance* »_VW/Audi claimed the same between the AWW and AWP.. Yet everysingle part number is identical and the replacement engines carry the same part number. 
In fact the AWW had the lower CR rating but also the lower hp rating 150 vs 180

Well AFAIK the "newer" BWA has a 10.3:1 C/R which would make it...WEAKER if we are actually taling about same boost values...
Also i've read somewhere the BWA engine gets an extra 10 HP from chipping due to the lower CR, but thats just BS for me.
Would be curious as to WHY the BWA was introduced of not for the stratified mode cut....
More input please ??


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## Theresias (Feb 11, 2004)

*Re: AXX Vs BWA 2.0 TFSI (GolfRS)*

It's quite interesting to see that quite some poeple here claim to have a AXX/BWA, while at least according to the documents the NAR market only has the BPY.








The BWA has as you already explained a lower C/F of 10.3:1, while AXX/BPY have 10.5:1 - as far as we found yet, there are no more "real" differences.

_Modified by Theresias at 3:57 AM 8-22-2006_


_Modified by Theresias at 3:58 AM 8-22-2006_


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## aussie audi guy (Jan 28, 2003)

*Re: (PD Performance)*


_Quote, originally posted by *PD Performance* »_
Stratified mode never existed on the turbo versions of this motor, only the NA.

Depends - If you live in North America - Yes - rest of the world - No.


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## Theresias (Feb 11, 2004)

*Re: (aussie audi guy)*


_Quote, originally posted by *aussie audi guy* »_Depends - If you live in North America - Yes - rest of the world - No.

Again, this is wrong! The 2.0T NEVER had stratified mode. Not in Germany, not in north america and no where else in the world.


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## GolfRS (Feb 4, 2006)

I think he meant the engine codes..
In Europe AXX and BWA are the 2 engines available, while BPY..i haven't heard of....


_Modified by GolfRS at 3:24 PM 8-22-2006_


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## Theresias (Feb 11, 2004)

*Re: (GolfRS)*

BPY = North America
AXX/BWA = Rest of World


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## aussie audi guy (Jan 28, 2003)

*Re: (Theresias)*

From VW's own press site:
"The North American-spec 2.0L FSI Turbo engine should not be confused with the similar European-spec FSI powerplant, which features a third mode of engine operation, stratified charge combustion, to allow short periods of extremely lean burn. In such low-speed, light throttle conditions, the very slight amount of fuel added to the mixture can result in stoichometric ratios as high as 65:1 (the normal ratio for gasoline engines is 14.7:1) and periods of exceptional fuel mileage. Because of North America’s lower fuel quality (which would require special catalysts to handle the extra NOx emissions from our high-sulfur-content gasoline), this technology is not yet available outside of Europe. True stratified combustion will be integrated into this engine, and other VW (and Audi) FSI powerplants, when the high sulfur content of U.S. fuels is decreased in the next several years."
http://media.vw.com/article_di...=9755


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## Theresias (Feb 11, 2004)

Nice quote, but the reality is different. Also the quote is quite old and I guess this is why it differes from the current reality.
If you want me to, I'll make some logs (can take a while) and post 'em to show that strtified mode is not being used on euro-spec 2.0T's. Even the normal 2.0l FSI's have been changed and don't have stratified anymore - there's also a special adjustment available now to shut off the stratified mode for older 2.0l (non-T) FSI's that have problems with this.


_Modified by Theresias at 1:49 AM 8-23-2006_


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## aussie audi guy (Jan 28, 2003)

*Re: (Theresias)*

Cool - its possible - I'll check with our local VW tech rep when I see him in the next couple of weeks http://****************.com/smile/emthup.gif


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## seph (May 31, 2004)

*Re: (aussie audi guy)*

Keep us posted Guy. This is interesting


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## moogie (Jan 26, 2006)

*Re: (seph)*

I'm pretty sure Theresias is correct - the euro 2.0T has never had stratified mode, regardless of what the US press site may claim.
I have the first revision of euro 2.0T (AXX), and based on just driving it I would be willing to bet quite a lot on that it does not have a stratified mode. I've driven cars that do, and mine doesn't feel anything even remotely like that.
In addition to this, when the 2.0T was first lauched in Europe, I remember reading from many magazines that the 2.0T does not have a stratified mode - this was constantly mentioned because the current non-T 2.0 did have it at that time.
Just my .5c


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## Theresias (Feb 11, 2004)

*Re: (moogie)*

For those who want and do have the capability, you can log the current operating condition with VAG-COM (MVB = Measuring Value Block).

_Quote »_MVB 007.1: Engine Speed
MVB 007.2: Engine Load
MVB 007.3: Engine Coolant Temperature
MVB 007.4: Operating Mode
x00xxxx? = Homogenous (Lambda = 1)
x00xxx?x = Homogenous (Lean)
x00xx?xx = Homogenous/Stratified
x00x?xxx = Stratified
x00?xxxx = Stratified (CAT Heating)
?00xxxxx = Knock Protection


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## GolfRS (Feb 4, 2006)

The point everyone is missing and the reason for this post is WHY did VW develop another version of the same engine with a lower compression ratio.
Was it because of problems with AXX or cost cutting and using lower quality materials with BWA.
Since the HP rating is the same for the 2 engines, does that mean the boost is higher with BWA?
Also, it seems the new S3 engine uses the same 10.5:1 ratio as the AXX engine, and probably the same part numbers for pistons and rods.
Taking ito account manufacturers usually lower compression using modified pistons rather than flanges, something smells fishy.....
Oh...and please move on from the stratified debate.It doesn't really matter...does it....


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## PD Performance (Jul 1, 2004)

*Re: (GolfRS)*


_Quote, originally posted by *GolfRS* »_The point everyone is missing and the reason for this post is WHY did VW develop another version of the same engine with a lower compression ratio.
Was it because of problems with AXX or cost cutting and using lower quality materials with BWA.
Since the HP rating is the same for the 2 engines, does that mean the boost is higher with BWA?
Also, it seems the new S3 engine uses the same 10.5:1 ratio as the AXX engine, and probably the same part numbers for pistons and rods.
Taking ito account manufacturers usually lower compression using modified pistons rather than flanges, something smells fishy.....
Oh...and please move on from the stratified debate.It doesn't really matter...does it....

Since you are in europe I am assuming I would go to the dealer and actually check the part numbers of the pistons etc etc etc.. If they are all the same then there is no real change.. again this would not be the first time they said they changed the CR but never did


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## GolfRS (Feb 4, 2006)

*Re: (PD Performance)*


_Quote, originally posted by *PD Performance* »_Since you are in europe I am assuming I would go to the dealer and actually check the part numbers of the pistons etc etc etc.. If they are all the same then there is no real change.. again this would not be the first time they said they changed the CR but never did

Well some "sources" say the parts between the Gti engine and the S3 engine are the same as far as the rods and pistons are concerned.They didn't however discriminate between the AXX or BWA engine code.
AFAIK also VW changes motor codes when a change is made in the motor, be that a small part, or even the software that comes with it.
As for the C/R, i am pretty certain its something motor companies don't have a reason to lie about, and that change was already known from the first Leon TFSI models with 185 BHP here in Europe.
BTW, i wouldnt be surprised if the S3 engine is just a reprogram of the Gti engine with some minor "glitches" covered (see fuel pump).


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## PD Performance (Jul 1, 2004)

*Re: (GolfRS)*

Again my example comes right from VW/audi
The AWW engine code in the US was 9.3:1 the AWP was 9.5:1 yet every part number for every part of the engine is identical and if you order a replacement engine they are identical. So they have "lied"


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## GolfRS (Feb 4, 2006)

*Re: (PD Performance)*


_Quote, originally posted by *PD Performance* »_Again my example comes right from VW/audi
The AWW engine code in the US was 9.3:1 the AWP was 9.5:1 yet every part number for every part of the engine is identical and if you order a replacement engine they are identical. So they have "lied"

Ok i can understand that, but please find me a reason then for the engine code changes !!
It would logically cause more cofusion to use 2 different codes for the same engine....
There was also another form of the TFSI engine here in Europe used by the DTM A4 if i remeber correctly.They also claimed "different pistons" for the 20 HP bump.....Just curious.....


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## PD Performance (Jul 1, 2004)

*Re: (GolfRS)*

In the case of the aww vs awp it was immo 2 to immo3 in the ecm coding and 150 to 180hp.. however there is no mechanical change to the engine.. just some reason they claimed different CR.... they don't need a reason to give engines different codes.


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## James Cole (May 15, 2007)

*Re: (PD Performance)*

any updates on the bwa engine differences?


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## gtiiiiiiii (Mar 6, 2004)

*Re: (James Cole)*

yeah, mine's better. http://****************.com/smile/emthup.gif


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## naphi_shift (Dec 26, 2005)

*Re: (gtiiiiiiii)*

not that im backing this up, so take it for what its worth
but i remember browsing a post on the vortex saying the newer 07+ GTI's went from forged internals to cast internals...
again, thats just what i remember reading


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## naphi_shift (Dec 26, 2005)

*Re: (naphi_shift)*

oops, forgot to subscribe too.


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## James Cole (May 15, 2007)

*Re: (naphi_shift)*

So what's the conclusion?


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