What boost levels on Stage 3 are S4 oweners running!

[docwyte]

RS4 airbox, MAF, Y pipe and injectors, running 22-23psi tapers a bit to redline. Basically the off the shelf APR Stage 3 kit.

[mattsimis]

Who mapped it?

Mgiht be best to ask them, if youre blowing hot air instead of running in the efficiency zone of the K04 compressor map.

The higher the boost the easier it is for your turbos to pop right?

Im under the impression that K04's are good for 1.7 ish, no higher.

Im waiting for the likes of Doug or Mihnea or anyone else tha has far more knowledge than me to comment.

Yeah, but it was infact MRC who mapped it based on a generic pre-facelift K04 map and posted the ECU back to me. I mailed them several status updates later.

[saf]

If it is MRC who mapped it then I cant see why there is a problem with the generic map because as far as I know Doug has said in another post that stage 3 map should run 22 psi tapering down to 18 psi. So why is it running 28? Thats a huge difference.

As I said Doug is the best person to check with. What did he say when you mailed him the updates about you doing 28 psi?

I would be worried running those boost leves if Doug has said you should be running 22psi.

[mattsimis]

I did, but you know, was bit difficult getting a response if you know what I mean!

[ZeroK66]

Running the MRC500 setup...

23PSI peak running down to 20ish at red line. I do get spikes up to around 25PSI at times.

Have tubular manifolds
Lowered CR
Ported & Clearanced K04's
3" downpipes & 2.75" Dual catback
Full RS4 inlet + FMIC & custom intake pipes

[saf]

This has got me thinking. If I ran the same exhaust setup, lowered compression, RS4 Ypipe MAf and airbox, but instead used the RS4 IC's (good for 550 so should be fine), and the only other difference is the tubular manifolds and Straigh plan jane k04's, then I should be hitting 450 quite easily and hopefully 470 tops if my cars a good un.

Leon what RS4 inlet are you running. Is it just the MAF Ypipe and Air box? Also what are your views against lowering compression or not? I would have also thought with the dropped compression youd be running more like 1.7 bar boost instead of 1.6?

Thanks

[MarkB]

I personally wouldn't go for dropped compression unless you have a need to take the heads off. The labour charge for it is massive for little gain.

[saf]

Because of my high mileage 130K id just like to have a look at the heads. Its just for piece of mind. I thought I may as well drop the compression at the same time and get both things done at once. Its still an idea. But Im willing to get it done if its worth my while.

I just would like to know the advantages and disadvantages of lowering compression. One disadvantage is price but my mechanic is a friend of mine and the price he gave me for all the work is quite reasonable.

Ive heard also theres diadvantages in fueling when on the motorway doing long distance. But on the other hand Ive heaard all stage 3 cars without lowered compression will do a lot more on the fueling in this situation as well.

I know one advantage is that you can run more timing which means you can run more boost. What does running more timing meean as an adbvantage, and can there be downsides to this, reliability wise or wear wise?

[MarkB]

If the heads come off then lower the compression. I would for sure.