S4 Upgrading

[Reggie]

Hey David, great write up on your mods, good to see you have finally taken the plunge. [img]images/graemlins/clap.gif[/img]

Whats this rumour I hear though, about you struggling to catch that old Renault 21 Turbo at Aintree last week [img]images/graemlins/blush.gif[/img]

maybe its time for some engine mods...... [img]images/graemlins/roflmao.gif[/img]

[DavidT]

Reggie, nice one.

Fill your profile in a little and I will tell you all about it.

David

[DavidT]

Sorry for the delay, responses to questions:

tombs:

Pricing as per AmD’s list, I’d prefer not to post their prices, but can pm them if you like.

They were able to do the work within 3 weeks, which I was pleased with.

Dippy:

You will not have ‘squat’ because you are running the harder, lower H&R suspension, so the car does not ‘sit back’ when you accelerate hard in the lower gears.

The ‘slop’ I referred to is the take-up or ‘play’ in the transmission when you apply the throttle. This was significant before (and in all the other S4’s I have driven), much reduced now. i.e. throttle response is much better and easier to move along in a traffic queue in a low gear.

I have also found an improvement in the gearchange itself, lighter and more positive in operation than with the tanoga shortshifter alone.

I read some stuff in the reviews section on Audiworld and having done the mod, I would say they are accurate.


Tweaky

Not noticed any transmission vibrations at all, done 700 miles including the trackday, so would have expected to by now.

The only negative about the DTS is that it sits low, further reducing ride height.


Reggie

You are a wimp, get on here and do some posting.


David

[Dippy]

The only negative about the DTS is that it sits low, further reducing ride height.

Well that rules it out for me then!

I have been 'looking' for driveline slack since I read your report, and I have noticed something: When I'm driving in traffic with my left hand on my knob ([img]images/graemlins/crazy.gif[/img]), I can feel it move back and forth ([img]images/graemlins/crazy.gif[/img][img]images/graemlins/shocked.gif[/img]) as I accelerate/decelerate, so I assume this must be part of the transmission shifting?

Other than that I haven't noticed any problem, and since I drive like a granny compared to the rest of you, I'll leave it as is.

Thanks for the info David.

[audi_biturbo]

Porsche 993TT brakes – went for these because I’ve heard good things about them, lots of people have them and anyway, whoever complained about Porsche brakes ? Also OEM pads can be had for £ 80 and the discs for £ 110 each, so servicing them will be cheaper than some (if not all) of the alternative brake upgrades for the S4

Hum cool I need to change my fron brakes very soon, can I still use the same caliper with this change? I'm from Switzeland, anyone already order these parts from here? Thanks!

[DavidT]

Audi_Biturbo,

can I still use the same caliper with this change?

Sorry, I have only just seen your question.

No, you need porsche discs and calipers together (they need bells and adapters to fit on the S4 as well).

[DavidT]

Well the adventure continues. After lots of fun on trackdays with the Porsche brakes/H&R coilover/Tanoga shortshifter/AWE DTS setup, my only obervation is that better brake fluid and reinforced hoses would be worthwhile to improve brake pedal feel later in the sessions. Other than that, I am really happy with the handling and braking.

So, it's time to invest in more power.

The options for a remap seem to be AmD or Revo (ABT are too expensive and MTM offer too little power for the money IMHO). I favour the latter because my perception is that it's a more modern solution, no soldering and has options to swap programs using the plug-in thingy. Also, and probably most importantly, they are highly regarded by many on this forum.

Additional considerations are miltek sports cats/catback exhaust (maybe even their dual system). This seems expensive though at £ 2200 for a 30bhp gain.

All opinions welcome.

[wazza]

Remap is well worth it. You really do not know what the car is capable of if you haven't tried it. [img]images/graemlins/nodder.gif[/img]
Reading between the lines on Dave's posts, it is not worth buying the cat back (unless you just want the sounds) but with the full downpipes/cats etc. you not only get the extra 20-30bhp, but it extends the power further up the rev range as well - i.e. the remap on it's own tends to run out of extra go at 5krpm [img]images/graemlins/thumbs.gif[/img]

[Golich]

Bi-turbo has nailed it on the head.

I have an AMD remap and I'm delighted with that.

Re Revo - A little bird told me they were going out of business. In fact the same little bird told me quite a few bad things about Revo. But then I don’t listen to everything I’m told - Just worth checking into. (I'd have a look on the S3 posts of this site and Audi-sport.net - too see if there has been any problems with REVO I’m not saying there are any posts – I’ve not looked)

Another alternative is APR, I'm told they are heading the plug n play option. (if they haven't already – (I believe this maybe the source of Revos problems)

APR were always slightly cheaper than anyone else and look to offer some pretty decent products using full CADCAM technology.

If your budget is tight, I'd go for just the remap. However, if you can afford it I’d have the AMD tailored remap to suit the full exhaust system this has got to be the best option.

As I say that I can’t help but warn you that a friend had the full system fitted to his remapped S3 and he gained some stupidly low BHP figure i.e. something like 5bhp!

I would definitely want some guarantees out of Milteck if I was spending near 2K on one of their exhaust systems. I certainly didn’t get any satisfaction with them when I was prepared to buy their CAT back only if they would take it back if I didn’t get the at least a 5-8bhp increase – That’s how much confidence they have in their product!

[Dippy]

I've said this many times before, but I'll say it again:

It's the shape of the torque curve that counts, not the peak torque and certainly not the peak bhp (which is just a function of torque and revs anyway).

The Miltek cats allow the system to breathe better, reducing back-pressure. This has more effect the higher the revs. So whilst they may only give an extra 30bhp or so at the peak, the main advantage is that torque is increased over the whole range, but especially the top end.

In other words, as every S4 owner knows (both stock and chipped), it is better to change gear at about 5500rpm than take it to the redline as torque drops off rapidly above 5500rpm. But with the Miltek cats it does not: The engine delivers it's push right up to the redline, and the power curve is almost flat.

[Joshie]

I've said this many times before, but I'll say it again:

hehehe - I think we get the message Dave (the Schoolmaster) [img]images/graemlins/biggrin3.gif[/img]

[bazza]

Hi im new to the forum [img]images/graemlins/jump_clap.gif[/img]
I was just reading this post and when i got to the end of it, i noticed that i have not seen any mention of Oettinger. Is Oettinger not a good choice ?????

[Dippy]

Welcome to the forum.

I think you'll find that Oettinger is very rare in the UK and hence does not receive many reports. This in itself is unfortunately a reason not to choose them: In choosing a tuner one needs to have enough independent reports of a) how good they are and b) that the ratio of problems is low, in order to gain confidence.

[TurkS4]

In other words, as every S4 owner knows (both stock and chipped), it is better to change gear at about 5500rpm than take it to the redline as torque drops off rapidly above 5500rpm. But with the Miltek cats it does not: The engine delivers it's push right up to the redline, and the power curve is almost flat.

Dippy...your da man!! [img]images/graemlins/thumbs.gif[/img]

Not every S4 owner......I had a problem when taking each gear change to the red line. When changing up I was not getting the turbo rush I was expecting, just the usual acceleration, however, after reading your words (above), i tried the 5,500 rpm method and boy does the car pull. I can now feel the turbos pulling the car like a steam train when changing gear at 5,500rpms and gradually feeding in the power.

I find this more pronounced when changing from third to fourth and onwards. However, I do have one question....do you apply this method from first to second to third as well, coz my car does not seem to pull in second until around 5,000rpm?.

You thoughts please?

Thanks....Jem

[Dippy]

Jem,

If you take a look at the torque curve (see AmD's) you will see how the torque drops off rapidly from 5500 rpm. In fact on AmD's graph it is more pronounced for the chipped run - IMO there was something wrong with that car before it was chipped. You'll also see that torque is strongest between about 2000 rpm and 4000 rpm.

Now as I'm sure you know [img]images/graemlins/wink.gif[/img], acceleration is directly proportional to force (torque) divided by mass (the weight of your car), so the in-gear acceleration will be fastest in the torque range 2000-4000rpm. As to when to change, it depends on how many gears you want to use. Since it takes time to change gears, sometimes you might prefer to stay in one gear at higher revs rather than change. However in general taking an S4 with stock cats to the redline is rarely preferable to changing up a gear.

As to your 2nd gear issue, my knowledge is weaker here. The torque curves you see are done in a single gear (I guess 3rd) in a false environment (a rolling road with a big fan). I can't be sure what the variance is in different gears with different engine loads.

However my car has a fairly peaky torque around 3000-4000 rpm and to me this seems consistent in all gears. Are you sure that you're not just seeing turbo lag or hesitation?