A3 1.8t performance testing

[Big_Al_A3]

Hi Folks,
I've just acquired my first VAG motor, a 2001 audi a3 1.8t. The car has just had an MOT completed and has a full service history.
The car does have a high mileage - 88k and I am really enjoying driving it but I can't help but feel that there is a distinct lack in power that I would normally expect especially in the high revs once the turbo has "kicked" in.
Is this normal for a car of this age i'm no car expert but other turbo charged cars i've been in there is a far more distinct boost of power and the power i'm getting feels very similar to a friends a4 avant which is 1.9tdi 125 and I assume is a lot more heavy but has a lower mileage.
If there are any ways of self diagnosing possible performance issues or is there a lifetime of a turbo charger after which it's wise to replace / rebuild?
If it is a case of testing on the RR as i've also read so much about how some people will "chip" a car to produce more power at the sacrifice of lifetime are there garages that can provide such a performance diagnosis service at a reasonable price?
Any help / tips will be great

[JohnnyM100]

I can't comment on formal performance testing but a lot of fuel & air passes through the engine during 88k miles.

As the car is new to you there are a couple of relatively cheap things to try.

1. Use decent branded petrol. BP Ultimate / Shell V-power for a couple of tanks in case the previous owner was a supermarket fuel junkie. Two tanks should be enough to clean most things out, or at least notice a difference.

2. Clean the throttle valve. There is a thread on this here somewhere, or a garage can do it fairly cheaply.

3. Inspect / change the air filter. If the car comes with Service history and receipts you can check when it was last done.

No guarantees that these will fix the problem but these are the cheapest things to try first.

I am assuming at 88k that the cam belt has already been changed. In a straight A3 1.8T 150bhp, the factory sets the timing for 95/91 RON fuel, so there is no real benefit in using "super" unleaded long term (as opposed to an S3/TT which is set to 98/95 at the factory). Look inside the fuel filler flap for confirmation.

However, since you can't get 91 RON unleaded in the UK, some garages (incl mine ) changed the timing to suit 98/95 RON when changing the cambelt.

This is more than just ECU ignition retardation / ECU anti-knock - Cambelt timing does make a difference as the balance between pistons & valves is altered everso slightly. Note that RON is not about calorific value of the fuel, but about speed of burning when ignited; higher RON = slower burn).

After my camblet was done, my A3 is not as quick on 95 RON (though BP 95 is ok) but really flies on super uleaded 97/98 from Shell or BP. I can't comment on supermarket fuel as I don't use it.

Hope this helps.

[JohnnyM100]

Oh, and forgot to say, the turbo is only at its best up to about 4750 revs.

with a post 1999/2000 engine you should also have variable valve timing to help you to the red line.

However, with turbos it's all about torque so best to keep it in the range of the turbo & no point red-lining:

Officially: 1750 - 4600
Realistically: 2500 - 5500

[Space Cadet]

Couldn’t have said it better. (Had a Golf MK4 GTI with the same engine, mine was still literally like new at 70k.)

Check that the cam-belt has been changed, obviously if it hasn’t then do so ASAP, one small tip if you are having the belt done is to re-new the water-pump, its really inexpensive and is a belt change if it fails at a later date (as I found out the hard way!!).

Before you use better fuel first use a petrol additive cleaner from Halfords, you add it to a tank of fuel and it cleans out the fuel lines and injectors etc. Then definitely use decent 99 Ron petrol, I always use V-power, on a turbo car it should give some helpful BHP as well as keeping the engine clean long-term. If you are not going to constantly use it then definitely do so every 3rd tank say.

Then as mentioned put a decent non-oiled panel filter in like Pipercross.

As long as the cam belt has been changed there wont be any problems getting the car re-mapped, should increase it to around 190’ish bhp and give you that added oomph that you are wanting, and if you use 99 fuel you can have the timing and boost etc mapped for the better fuel, potentially could give a safe 200bhp with the filter and fuel.

[Big_Al_A3]

Cheers for the tips, I hadn't considered using a more expensive branded petrol, I only just filled up with supermarket cheapo unleaded but will go for a higher fuel grade next time. Will have to check my service notes later to check if the cam belt has been changed or not.
Is there any reccomended type of fuel cleaner to use or am I ok with any suited to a turbo petrol engine.
cheers again

[Space Cadet]

Supermarket petrol is from a supermarket, although it won’t have been made by them it won’t have the same expensive additives etc, hence the price. EVO magazine a year or two ago tested the performance figures and also took internal photographs of the staff cars engines and then ran them all on Shell Optimax (then 98 Ron, now called V-Power and is 99 Ron) for a few months and all performed loads better and the engines were spotless inside.

I do very little miles therefore always use V-Power, I can appreciate that may be you might do loads of miles and therefore don’t want to spend the extra cash every tank. If you don’t want to then at least do it every other go, ideally every time, your turbocharged engine will love it!!

For a small example, my girlfriends Mini Cooper (1.6) feels much zingier with V-Power, so did her Ka before hand and they are only low powered cars.

I’m not an engineer, but as far as I know the 1.8T has a knock sensor and will advance the timing automatically to take account of the higher octane fuel, hence adding bhp. As a side effect the V-Power will clean the engine up giving more efficiency and more bhp. For the extra cash it’s a no brainer.

The fuel cleaner is just to get the ball rolling, go for a decent brand and read the differences between the different makes, you want one that you pour the whole bottle into either a full tank or half a tank and be done with it.

Once you’ve done this, run the tank right down to the red line so there is only literally fumes and then fill up with V-Power, then when you get home disconnect the battery wait for a while, re-connect and the ECU will take account straight away of the higher octane petrol.

As mentioned, find out about the service/cam-belt and also for the sake of £35 get a Pipercross filter, which along with the additive and then the V-Power fuel will get it back up toward full health.

And then if your funds allow have it re-mapped, it really is easy as pie and reasonably inexpensive, circa £450, Revo do a good map for the 1.8T and if you are confident you are going to use 99 fuel pretty much all the time you can advance the ignition and boost even more, should be around the 200bhp mark.

If you are hands-on, for the sake of a few quid you could change the oil, filter and plugs, wont cost the earth and you can be confident that they’re all done and up to scratch.

Essay over.