2.0 tfsi remap ?

[onianbag]

hi all,
as some of you remember my A3 3.2 got a whack in the back from a truck and is now destined for the scrap heap :-(

thinking about getting a 2.0tfsi TT (supposed to be more agile than the 3.2) and just wondering if any of you who've had it chipped on a non quattro version have had probs getting all the power thru the front wheels?

 

[Staz]

get quattro get quattro get quattro!

 

[onianbag]

i know, my last 3 have audi's have had quattro but they only do the 3.2 tt with it at the mo, and i think i fancy a change of engine - lighter more economical blah blah

 

[Staz]

yeah that's what's stopping me getting a tt. I think they look great. But I want quattro and I want TFSI.

when EVO reviewed the TFSI they said you hardly notice that it's FWD. Although add another 40bhp and you might!

S3 for me then!

 

[mikep]

I remapped a number of 2.0Tfsis, no problem getting the power down on the 2WDs.

Quattro is a good option for that amount of power (265bhp) but you lose about 15% through Quattro but the power does get down much better in all weather conditions.

 

[Staz]

you lose about 15% through Quattro but the power does get down much better in all weather conditions.

How can that be when 0-62 times are 0.1 second faster and the top speed is the same?

 

[MattS]

Interesting, I have 2WD and in very wet weather I sometimes wished I had specced up Quattro. But for how often I drive it in the pouring rain it does not matter so much.

After looking into the gear ratios, the 2WD cars have a different final drive than quattro.

I have 2WD and 257bhp & 274lb/ft with Bluefin (Which is brilliant) and yes in the wet, if you drive like an idiot you can get the wheels spinning in 3rd gear.n But if you drive well, grip is still very good.

I have recently changed from the conti's to Toyo Proxy T1-R's and they have very much improved things in the wet, and much better grip in the dry.

I am also getting the 3.2 Anti roll bar kit fitted which can improve front end grip by 10-15%.

 

[MattS]

How can that be when 0-62 times are 0.1 second faster and the top speed is the same?

The quattro is a lot heavier than 2WD, but Audi change the gear ratios to overcome the extra weight to keep it the same performance as the 2WD, the only reason the quattro is 0.1 second quicker to 62mph, is the initial extra grip from 4wd, 2wd will always have a little less grip off the line in the dry.

 

[Staz]

So in what way are the ratios changed?

 

[mikep]

How can that be when 0-62 times are 0.1 second faster and the top speed is the same?

Generally the Quattro system loses about 15% over the 2WD, it's simple physics, you're driving 4 wheels instead of 2 through additional transfer boxes etc. But they're getting better, the earlier quattro systems lost about 25%!!

As for the performance figures, it depends who did them and under what conditions.

 

[MattS]

They have a different final drive, the lower the final drive on a car, the faster it will accelerate.

Take the Vectra VXR for example, which a friend of mine has done. It runs the F40 6 speed gearbox with a final drive set up for a V6.

If you fit the F40 6 Speed from the Vectra 2.0 turbo, acceleration can be increased in quite a big way, for example, 0-60 in 6.1 seconds standard, to around 5.7/5.8 seconds with the lower final drive.

The down side to this is your top speed will suffer. In the Vectra VXR's case it is estimated the top speed will drop from the factory 161mph to around 150mph.

In the Quattro's case, Audi will alter the gear ratio's to a lower final drive to overcome the extra weight. This is why 2wd A3's have a slightly higher top speed than quattro.

 

[Staz]

15% just seems a huge amount. that's 30bhp (yes I know you can do the maths of course). That's the difference between the S3 and Leon cupra. But the S3 is faster in every way. Can you see where I'm coming from?

I know extra cogs is loss of power but 15% doesn't sound right. And I understand that you can close the ratios in to increase acceleration but to counteract 15% you'd lose a lot more than only 1 or 2 mph from the top end.

 

[MattS]

I totally understand where your coming from but that comparison does not quite work if you know what I mean.

Both cars as we know, both 2wd and 4wd have 197bhp and accelerate to 60mph within 0.1 seconds of each other.

The only way to keep the cars performing the same is to alter the gearing of the quattro compared to the FWD, what Audi do exactly is not known but this subject is always a hard one to explain!!

 

[Xedos]

I think the 2WD is visibly quicker side by side on a motorway over the quattro. That said with the weather of this country Im thankful of the extra traction.

 

[Staz]

what Audi do exactly is not known but this subject is always a hard one to explain!!

Please try. I'm intrigued. According to the audi site the weights are the same and the quattro top speed is 1mph more than 2wd. I know that's not true obviously but I'm finding evidence of differences hard to find. I'd like to see a full specification list of both cars from the same source (preferably audi of course lol).

Really I think quoting any loss of power due to the final drive in a percentage form is wrong. The losses gained from adding more cogs are caused by the friction between them right (please correct me if I'm wrong) and the level of friction doesn't increase in proportion to any power increase. So I'd say that there's a loss of a certain bhp no matter what the engine power is. And I certainly don't believe it can be any more than 5 bhp.

 

[Spin140]

I don't know a great deal about the tehnical stuff but did have a Mk5 Gti 2.0TFSI remapped and full Miltek exhaust - RR at 252bhp, no real problems with traction, obviously in the wet the traction lights would flash if being silly but in the dry the electronics kept everything well under control, I also used Bluefin which is excellent, so its personal choice really, the only negative I could think of to mention is if you select Quattro the boot is noticeably shallower......