Newbie brakes, exhaust and ECU

[droberts]

I've just bought a year 2000 S4 with 79K miles. The car feels fresh (1 owner, fash) and nothing major needs doing (apart from brakes). The car is standard and ready to embark on some upgrades!

So far, I'm impressed with the mid-range torque, my only criticisms of the car are lack of stopping power, rather quiet exhaust tone, and lack of breath above 5500rpm. I have a separate track-day car so the S4 will be for fast road use only.

Reading the forums, I've identified the following upgrades I'd like to make straight away, and was hoping you guys could advise (I'm obviously trying to keep price down without cutting too many corners):

1. Brakes (front and rear), retaining standard 17" alloys and 70:30 brake bias:
a) would like AP 6-pots and 330mm discs, but are pricey and probably overkill for road use only?
b) Porsche 993tt calipers and discs would suffice for fast-road use, the ECS Tuning Stage3 calipers and 322mm discs coupled with ECS Tuning 255mm rears, standard rear calipers, new brake lines and OE pads.
c) Stoptech 332mm front upgrade kit (slotted), together with slotted Stoptech 255mm rears new lines and Hawk pads all-round.

2. Exhaust, reatining standard cats and downpipe:
a) Milltek Dual Cat-Back
b) Milltek Single Cat-Back

3. ECU upgrade (including changing both diverter valves):
a) AmD Stage 1 (a bit pricey but like the idea of dyno before/after)
b) APR Stage 1 (does this really generate 382 lb.ft?)
c) MTM

At the moment I'm favouring options 1c), 2a) and 3a). I may just do 1c) and 2a) and wait for the ECU, but am told 3a) is the difference between night and day? Anything else I should consider before raiding the piggy-bank?

[jeffw]

There are a number of UK specialists doing brakes for the S4 (AmD, QST (Moveit)) so would be worth talking to them prior to buying US kit.

The cat-back exhaust doesn't make a hugh difference (if at all) to the power, for that you need the full system.

Remap/ECU upgrade is fine but....your K03 turbos (assuming they haven't been changed) have been a fair distance and remappng will bring the day of inevitably replacement closer.

If you can only do 2 of these do the brakes and remap.....but accept that you will probable need to replace the turbos (IMHO of course) soonish

[JonnyX]

Hi,

Why not take advantage of the excellent $$ exchange rate at the moment?

For brakes and suspension try stasis engineeriing (www.stasisengineering.com). They are very highly
regarded on the audiworld s4 forums. I think if you upgrade the brakes it will highlight the deficiencies in the
stock suspension system even more (dive). A member on here (prawn) has had dealings with stasis, maybe
he can comment on quality and customer service.

For exhaust, autospeed performance are highly regarded (http://www.autospeedperformance.com/). I believe
the tru-dual exhaust is very good (but loud). Milltek seem to be good for the more subtle sounds. As for
performance, I am also sceptical of catback exhaust claims. However, this report by the reputable Don Pavlik
would appear to indicate there may be some benefit:
http://www.audiworld.com/tech/eng26.shtml

For a remap, there is AMD, MTM, APR, Revo, Jabbasport. I would recommend talking to all of them to find
out exactly what you are getting for your money. remap/rechip are used interchangeably by most when
they are truly very different things. I think most people actually end up with a re-chip despite what they ask
for. S2tuner/Mihnea could comment far better than me here.

HTH

Jon

[JonnyX]

Also, 79K miles - has your cambelt been done ?(And water pump)

[droberts]

Thanks for the quick feedback folks.

The cambelt was done by Audi at 74K. Not sure about the water pump, pulleys and pre-tensioner - but will find out.

I've summised from other forums that 100K is about what you can expect from the K03's. I agree that a mild(ish) Stage 1 tune is bound to put more pressure on the turbos, but I'm hoping most of the 79K is motorway (one business user) and thus may last me another 40K with care (I'm already used to waiting in the car to let turbos cool-down).

I've previously downloaded Autospeed's true dual movie - exhaust sounded very nice. I was hoping the Milltek dual system would sound as good (anyone got any sound clips?)

I agree the US prices are good at the moment, I'm trying to balance price against concerns regard warranty and ease of replacement. I.e. Milltek are very well received on the forums, are local and seem professional, I'm not sure how good Autospeed would be on warranty? Regards brakes, I'm sure the Stoptech calipers and discs are superior to the Porsche 993tt items (and will probably buy them for that reason), but equally I can walk into my local Porsche dealer and get OEM replacements for the 993tt solution when necessary.

Excuse my ignorance regards remapping v rechipping: what are the benefits of one versus the other? I'm not bothered about hiding the fact the ECU's been fettled with (i.e. no warranty concerns). I'm sure my wife would like Revo's ability to drop back to standard settings, but other than that my main concerns are reliability and smooth, consistent power delivery. Most seem to claim the same basic +50bhp and torque anyway.

[S2tuner]

Hi there,


Okay, for the mod nutters here, here's how it all works:

A rechip (i.e. M*M stage 1, stage 2, Superchip$, etc etc) involves just a chip change. The new chip contains some modified parameters that should provide a decent and reliable (for most of the reputable companies at least) HP increase on most of the cars. Some cars won't take a generic chip, because of an engine being different to another, but generally with a stage 1 chip, you'll just have less HP and/or potentially fault codes. This form of tuning is what I call a generic chip. The chip can be installed either via OBD2 or via chip removal/replacement which involves soldering.

The actual remap involves a real-time emulator to be used, in order to be able to modify only the parameters being used by the ECU. Many generic chips out there have mods in areas the CPU never uses, simply because someone assumed the CPU might use those areas. Thus, a remap has the ability to be car and engine-specific, as well as being customer-specific. You want more torque at 2000 RPM but a little less boost above 6000 because you never go there? Well you should be able to have it. Also, if your engine has a particular reaction to a certain combination of factors that needs ironing out of certain map areas only, this will be greatly facilitated if you get a chip custom tailored.

Generally speaking, there aren't lots of people offering custom remaps currently in the UK. AFAIK only Jabbasport offer it to a certain extent, but how custom it is, I don't know, as I have never seen them do any ECU work ever. I have never met them either.

Custom tuning can be performed on development ECUs, so your own ECU is actually never touched and is just flashed through OBD2 at the end of the mapping session with the chip that has been done on the emulator. As far as switching goes, a double-chip version with standard and mapped performance can be had from various sources.

On a stock S4, you can get as much as 310 reliable HP and 500-ish Nm of torque, 325-ish on a dual cat-back from Milltek. Abt do offer a chip with 320HP on a stock car/exhaust but the number of Abt-ed S4 owners that I know personally and that go through a set of turbos every year is simply unbelievable.

I guess that's the price to pay for 10HP more than the competition.... In the USA, Giac do offer a chip with around 330 crank HP on a totally standard car, well, guess what? All their users go to K04s within a couple of months upon being GIAC'd. I guess this could also be called pro-active marketing and securing K04 kits sales...

Anyway, I hope this helps,

Mihnea

[KayGee]

You referring to Revo setup, where you plug a dongle in the OBD port or a Cossie style switch on the dash to move between different maps?

Not seen anyone offer one of these for the S4, been thinking about doing this to mine.....however it seems the eeprom on the Audi isn't just a fuell/pressure map so not quite so easy, switching chips on the fly by redirecting the CS signals might be expensive.

Any thoughts?

[S2tuner]

The REVO setup doesn't switch between several chips, just between a set of different settings, with IMHO always the same fuelling.

I'm speaking about a proper switch that changes between 2 or more different chips. I am going to implement the same solution as APRs actually, by using the cruise control stalk. Also, the switch is going to be wired through unused ECU pins so no wires are coming out of the ECU.

Switching on the fly works great, a friend of mine has already tested this setup and even an S4 works.

HTH,

Mihnea

You referring to Revo setup, where you plug a dongle in the OBD port or a Cossie style switch on the dash to move between different maps?

Not seen anyone offer one of these for the S4, been thinking about doing this to mine.....however it seems the eeprom on the Audi isn't just a fuell/pressure map so not quite so easy, switching chips on the fly by redirecting the CS signals might be expensive.

Any thoughts?

[KayGee]

Got no cruise control, being a 1999 I'm told it can't be retro fitted, like the later models. Would be very interested if possible. Like the idea of having 450Bhp fire breather but mine is an everyday driver, dual map is very appealing.

[droberts]

JonnyX, thanks for the Stasis feedback.
I've been recommended Alcon calipers in the past and the 13" Stasis J-hook rotors are spot-on (just waiting for Stasis to quote me a price).
Interesting that Don Pavlik found it difficult to believe his own results on the Milltek . I notice it was the single 3" pipe, anyone seen any similar comparisons for the dual 2.25" pipes?

S2Tuner, thanks for the good explanation on chip v remap. Sounds wise to stay clear of Abt and GIAC, a reliable 500Nm (369 Lb/ft) of torque will do me.

Any APR or REVO owners out there who would like to clarify whether the switching between standard and performance settings is OK, do you see a significant difference in mpg between the two?

[jeffw]

For your information my K03s failed at 50K (having been remapped some time before) so 80K and a remap is living on borrowed time. Like I said don't be surprised if your K03s fail soon .......

[moktoya]

I've previously downloaded Autospeed's true dual movie - exhaust sounded very nice. I was hoping the Milltek dual system would sound as good (anyone got any sound clips?)

With confidence, i can assure you the car in that clip was equipped with the tru-dual AND downpipe/sport cats. No way it will sound like that with the catback alone. I had the Milltek dual on for a few months before the milltek cats went in and it was a totally different car post cats, sound and performaqnce-wise.

[DavidT]

I'm sure the Stoptech calipers and discs are superior to the Porsche 993tt items (and will probably buy them for that reason), but equally I can walk into my local Porsche dealer and get OEM replacements for the 993tt solution when necessary.

Interesting, why are the Stoptech's superior ? (being asked by someone who owns the big reds)

I get parts from my local Porsche dealer at a discount, and it is very handy.

Every pad supplier does a range for them too, another reason to go for them, even though they are more expensive.

[Nige_RS4]

With confidence, i can assure you the car in that clip was equipped with the tru-dual AND downpipe/sport cats. No way it will sound like that with the catback alone. I had the Milltek dual on for a few months before the milltek cats went in and it was a totally different car post cats, sound and performaqnce-wise.

I have an APR cat-back, and can confirm that the sound it produces is a near-perfect combination of subtle growl at low revs and an evil howl at higher revs + no boom = very happy with it. (The sound must be worth at least 50 BHP in pub talk!)

Just to let you know that there are alternatives to Milltek out there

[JonnyX]

Generally speaking, there aren't lots of people offering custom remaps currently in the UK. AFAIK only Jabbasport offer it to a certain extent, but how custom it is, I don't know, as I have never seen them do any ECU work ever. I have never met them either.

Once again, great info!

I have a jabbasport remap. I think it is fairly custom in that they can and do tailor it
for your requirements. My car was their for about 5 hours and was genuinely never
off the rolling road (not like the AMD remaps that I have personally experienced from
their waiting room where you hear exactly 2 runs per remap and the customer
gets handed 2 dyno plots, before and after). The dyno they gave me at the end said
334bhp and 480NM although they said they had seen 505nm out of it. I think their
dyno is a little optimistic although people say their dyno has to be accurate for the
cars they prep for domestic racing. They are nice outfit, however I thinks it's fair to
say that they have a lot more experience with the 1.8T and 1.9PD engines.

The reasons I choseJabbasport are:

1) They said they would remap it.
2) They only cost £480 inc.
3) I had heard great things about them on uk-mkivs.net (used to own a mkiv 1.8t)
4) I really begrudge paying AMD so much money every time I go
5) I had never been before.

Cheers,

Jon