S3 with rs4 injectors

Scoobycarl1

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Hi guys i am close to buying an s3 2007 thats well speced and very clean,it has 10 pot tarox brakes full miltec custom manifold coilovers etc etc,it has rs4 injectors and drives really well but on return from test drive the car was hunting a bit with the revs on tickover ? He had stated this in advert so was honest before i even went to see the car,he said it may have been because of rs4 injectors or maf related ? Its had a full top end rebuild at psi tuning along with new gt2871 turbo less than 3k miles ago.custom code stage 3 map, also has sachs uprated clutch and flywheel at midland vw and he has all reciepts.Does the idle thing sound bad or just a thing to live with as car seems to run very well ? Any help or advice please ?
 
refit the s3 injectors and up the rail pressure, idle will come back. rs4 injectors are the incorrect spray pattern and cause idle issues
 
It has got hpfp too so cant see why it would have em fitted anyhow ? Would it trouble any of you guys tho is what im asking ?
 
If the car has a 2871 turbo and other mods then it likely should be running RS4 injectors.

You need to know a LOT more about the build and spec of the car plus what boost and fuelling it's running before replacing the injectors.


If it's set up and mapped for the RS4s then it may well run lean in high boost with the S3 injectors.

Mine uses RS4 injectors and idles perfectly.
Uneven idling is usually a PCV issue.
 
Thanks alex was hoping you would chime in lol
All work was done at psi tuning with all paper work and print out of dyno mate,sorry but im new to audi so forgive my question but what does the pcv do ? Many thanks
ps i am going to call psi monday mate for more info
 
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The PCV system is the engines breather system and it's full of faults one of which can be uneven idling.

If the car has a GT2871 turbo then it's had a big turbo kit fitted.

You need to know which one(APR is the most likely given that particular turbo) and what boost level and power it's running.

It should be fitted with an RS4 fuel pressure regulator also even at Stg2+ spec on the stock K04 turbo and injectors so I would forget the rail pressure comments for the moment.

It should also have at least a catch can added to the breather.
You need to know the extent of the top end rebuild I.e were the valves replaced or head flowed etc etc. and if the pistons and rods were also uprated.

There are a lot of gaps to fill there but uneven idling dry to RS4 injectors is a myth perpetrated by one tuning company as mine runs a rather wilder spec than that and idles perfectly.

The spray pattern issue on the RS4 injectors is well known and leads to a bit of smoke at full throttle but even that can be reduced by proper mapping.
 
Car didnt smoke at all mate but i think a call to psi for more info is a must,he says it had a top end rattle so had top end rebuild and turbo was faulty so replaced that with the gt
 
Ok.
Get the full spec and we can go from there.
 
Thanks mate il call tomorow and post after work 👍
 
refit the s3 injectors and up the rail pressure, idle will come back. rs4 injectors are the incorrect spray pattern and cause idle issues

that's the caveat in my statement, "IF". and by pressure i meant fpr/filter

Sorry.....Didn't see any if in your statement,which is why I posted those comments up.


Also....very sorry to see what happened to your car,and wish you the best for getting it running again shortly.


My reading of the spec we can see on this car is that it's been reasonably well modded,with a turbo that should go to the mid 400's assuming everything else is properly set up etc.

As a part of fitting RS4 injectors,you would need the RS4 regulator,or the requested and delivered rail pressures would be unlikely to match,and the flow rates through the different injectors would also be incorrect if the mapping wasn't RS4 injector specific.

From looking at CC's website and pages,their Stg3 equates roughly to Revo's,which is a hybrid/BT kit spec.

The spray pattern problem with the RS4 injectors doesn't produce idle issues,but can produce some smoking under full load,and as I said was something that one tuner in particular used to make a big deal of,until they found that no-one was really interested in that aspect.

This is ATP's kit....

400HP - GT2871R Stock Location Turbo & Manifold for 2.0T FSI / TSI Models : atpturbo.com

Stock placement,and uses a GT2871 plus one of ATP's cast manifolds.

APR's kit uses the GTX2867 which will flow a bit more than the GT2871 so I think it's likely to be the ATP on reflection,but makes little difference in terms of the injectors,as most aside from APR use RS4 injectors for a hybrid or BT build.

On a humourous note,it always makes me smile when I see Tar-ox doing with 10 or 12 pots,what AP can do with 6.
 
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The brakes do very well mate,i know what you mean tho lol,i imagine the pistons are half the size of ap's on the tarox
 
The brakes do very well mate,i know what you mean tho lol,i imagine the pistons are half the size of ap's on the tarox

It's just a long standing joke in certain areas to be fair.

They work well enough,but's a bit of a gimmick.....I once suggested them as a possible for one of my Cosworths,to my then engine builder/tuner,and his reply was unprintable.

They are certainly better than the lumps of pig-iron that the car comes with.
 
Hi guys i am close to buying an s3 2007 thats well speced and very clean,it has 10 pot tarox brakes full miltec custom manifold coilovers etc etc,it has rs4 injectors and drives really well but on return from test drive the car was hunting a bit with the revs on tickover ? He had stated this in advert so was honest before i even went to see the car,he said it may have been because of rs4 injectors or maf related ? Its had a full top end rebuild at psi tuning along with new gt2871 turbo less than 3k miles ago.custom code stage 3 map, also has sachs uprated clutch and flywheel at midland vw and he has all reciepts.Does the idle thing sound bad or just a thing to live with as car seems to run very well ? Any help or advice please ?

Nothing to worry about with this sale my friend. I live local to Scott. No expence was spaired by him or the prev owner
 
Sound mate was you guy with s5 ? I love the car mate just need to be sure as you can understand 👍
 
Ask him about the macdonalds incident lol i nearly pi$$ed myself lol
 
Wasn't me with the s5.... Of course mate. You've got to be sure. I know that too well. My s3 had no power to the rear wheels when i bought it. Wasn't wise enough to know back then and payed the price £££! :/
Haha he just told me. Sounds like an ideal brake test for those 10pots...
 
Lol.are you owner of a nice yellow 8l at all ? My brother has just bought a nice 8l dark blue i love it
 
No i do see one around here ofen though. Do you live near... Mines silver 8L
 
Im in solihull bud,his next door neighbour had yellow 8l on drive looked nice
 
ImageUploadedByTapatalk1402872658534037
 
Cheers. Looks better on film tbh. Needs a re-spray i think. Yeah a few things. Just had a fresh uprated k04 put on it and a 3" down pipe from pipeworx. Feels a lot faster than it was but needs a bigger fuel pump now. Thats why i was on here. I started reading the first thread i come to and it was describing my mates car lol weird ha
 
Just an update as i have spoken to pete at psi tuning and was not helpfull at all, i spoke to his secetary first who remembered scott (owner ) but said the car was in a bad way and running rough when it arived ! The next call to pete he said he cant remember every car (fair enough i think) and to email my enquiry that way they can fish the details out and get back to me ok i thought but a working week later and nothing ! I can only go on what i know and it isnt much so im out ! Not the car for me so still looking lol
 
Good result in the end then.

That's saved you buying a bad car and paying for fixing it.

If something doesn't look and feel right just walk away.

Good luck with the search.
 
Yea mate thanks for advice anyhows, its a nice looking car but if in doubt and all that its a no brainer to me mate.
 
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