A4 1.8T 150bhp engine

[mossya41.8t]

Hi after owning an 2001 B6 1.8T SE for a few months now i'm just after abit of info, its done 95k with full history.
This is the first petrol turbo i've owned and was just wondering for how long should the turbo boost for under acceleration as mine seems to hit about 3000 rpm then it just feels like its naturally aspirated.... Is this right?
Or should it continue to boost through the rev range.
Would just like to know the views from other people to see if their cars are the same.

Thanks

 

[golf]

I bought mine at 95k, and it was pretty lethargic at 150 bhp. You could barely even feel the turbo kicking in, but at 3000 RPM you could hear it spool if you listened to it very carefully, and the torque would be noticeably felt.

Maybe you're just expecting too much from it? The K03 turbo is tiny and the factory map is very gentle and easy going to increase the turbo's life span and fuel economy.

If you're certain that there's something wrong, what other symptoms does it have? The turbo could be on its last legs. I had mine remapped the first week I bought it and this was too much for the turbo, as the bearings soon went. A bad turbo can be identified by blue smoke from the exhaust, loss of performance and a high pitched whine from the turbines.

Alternatively it could be any number of things such as a boost leak, bad MAF (Air meter), torn DV (diverter valve), faulty N75 or N249 (sensors which help control how much boost the turbo produces) or even a simple case of a loose hose or pipe somewhere.

Are there any warning lights on the dash? You'll have to get it scanned through Vag-COM to pinpoint the error otherwise it's trial and error, and this can prove to be very expensive.

Hope this helps.

 

[mossya41.8t]

Hi thanks for your reply, like you say maybe i'm expecting too much. The only fault that has ever come up was the engine oil light, but I got that problem sorted as it was the common sludge issue. Had the sump and rocker off and cleaned all the crap out, new filter and oil etc - never had a problem since.

The turbo sounds noticeable louder (whistle) when the engine is cold at low revs, but once spooling up sounds normal. I've had a look over the engine to see if theres any split pipes but all seem ok, apart from the breather pipe at the rear of the rocker cover, thats split but would't think that would cause any problem.

Could it be that the spring in the diverter valve is weak and opens earlier than it should? There only £20 from audi so might be worth replacing that - the part was a 710P.

Think i'll try that then may get a remap, how does your car perform now you've remapped it?

 

[docurley]

Buy a boost gauge this will show you what’s going on with your boost and is a good indicator if you have a problem.

 

[golf]

Hi thanks for your reply, like you say maybe i'm expecting too much. The only fault that has ever come up was the engine oil light, but I got that problem sorted as it was the common sludge issue. Had the sump and rocker off and cleaned all the crap out, new filter and oil etc - never had a problem since.

The turbo sounds noticeable louder (whistle) when the engine is cold at low revs, but once spooling up sounds normal. I've had a look over the engine to see if theres any split pipes but all seem ok, apart from the breather pipe at the rear of the rocker cover, thats split but would't think that would cause any problem.

Could it be that the spring in the diverter valve is weak and opens earlier than it should? There only £20 from audi so might be worth replacing that - the part was a 710P.

Think i'll try that then may get a remap, how does your car perform now you've remapped it?

It was noticeably quicker after the remap but if you have problems with the car the remap will serve only to highlight them as I soon found out with the turbo going. The best thing for you to do would be get it scanned by a diagnostic computer.

 

[Xmay4444]

The turbo in that enginge kicks in at about 1850 or 1950 rpm and keeps going till 5800rpm.
Most manufacturers nowadays make the turbo kick in earlier and at lower revs so as to eliminate turbo lag and also that sudden rush of power that old cars used to have.

110 kW (150 PS; 148 bhp) @ 5,800 rpm; 220 N·m (162 ft·lbf) @ 2,200-4,200 rpm

 

[mossya41.8t]

Thanks for all you replies, ordered a diverter valve from audi so will fit that and see if it makes any difference.

 

[aragorn]

The 150hp engine was originally designed to provide good tractable torque and good fuel economy, its not a performance engine like most turbocharged petrols from other manufacturers

It was designed to fit into the range along side most manufacturers 2.0 NA options, as at the time (1995) most of the 2.0 engines in similar cars produced around 140-150hp.

As such the turbo is tiny, and the boost pressure set very conservatively. Also need to bear in mind that the B6 is a heavier car than the B5 it was originally designed for, so performance is going to be lacklustre at best. Most B6's had at least the 163hp option, if not one of the higher power levels.

The power delivery from a stock 150hp 1.8T is very linear, theres a bit of a surge around 2-3k as the turbo comes on boost, then it tends to pull quite gently thru the revs. It wont feel like a Focus RS or VXR or whatever becuase its simply not designed to.

A remap will liven it up a bit, improving the midrange and top end, but it will still only make around 190-200hp, which in a B6 chassis isnt going to set the world alight. Unforutnately, due to those constraints to which the engine was originally build, getting big power really requires a turbo change, and while people may fit K04's etc, they're still a bit poor, maxing out around 230hp, not worth the money imo. You're really looking at something like a T28, or perhaps a tweaked K04 that someone like Scroll offers, and be aiming for around 250-300hp, if you want the car to be fast.

 

[J7USS]

Mossy - Think im a little late but you should have saved your money and got a Hyperboost valve or Forge as in my experiences (3 times now) ive suffered lag on the standard 710 diverter valve and on this blue one, soon as I put my Forge back on it drove loads better without the dead spot!!

 

[mossya41.8t]

Yeah a bit late but thanks anyway, already got the audi valve so will fit that and see if theres any improvement, although after reading everyones replies I have a better idea of what to expect from the engine as standard.

So theres possibly nothing wrong with the car, and its just me expecting it to have more of a 'kick back in your seat feeling' . If I get it remapped is the standard set up ok for 190-200bhp or am i better off having 2 intercoolers?

 

[howdy quattro]

i've just had mine mapped up mossy and i'd definately advise a fmic as the next move once you've got it done, or even have it fitted before getting it mapped so that you can see from the dyno the improvements made by having the fmic in place. plus a de-cat couldnt hurt either!!

 

[J7USS]

I still havnt fitted my FMIC, should have done it but too eager to fit the front end on.
Get yourself a Milltek (turbo back), Remap and a 'Decent' diverter valve and maybe an uprated 'Panel' Filter and you'll be surprised with the Power upgrade you have....

....then if you want to take things a little futher then FMIC (as suggested), uprate your N75 Valve (bring that turbo in earlier without going OTT and blowing the 'Sewing Machine' up)....oh and a Stiffer TIP like a Forge or even better, an ally one!!!

 

[howdy quattro]

if your wanted to relieve that fmic kit onto someones hands juss i know just the person who is real uber-keen for one right now!!!!!

 

[J7USS]

Haha, yeah I wonder who that is!!
Im going to find the time next week even if it means burning the candle at both ends. Just means I have to take the front bumper off again..

 

[howdy quattro]

hmmmmmmmm, well, if your sure..........but if you change your mind!!! seeing as your online il save myself 10p and put it towards my fmic kit and ask you now!! where did you get your kit from and how much did it set you back, and if you say you got it from the states i'm gonna keeeeeel you!!!

 

[J7USS]

...Indeed I did get it from the states..Not!

I bought it from a guy in Northampton who I got my first HIDS from for the red arrow. It was originally for the red one but amazingly I forgot I had it,lol, it was in the shed for donkeys and I rarely went in there (Spiders Den..) then clearing it out - well the mrs did and it appeared.
I paid £190 for it with all the bit n bobs. Its got as far as my cousins unit collection Fumes and Dust!