Definitely sounds like valve springs are starting to fail, limiting how much you can push it. It's amazing the difference you notice when you get them changed, you find all this high RPM power that you never had (even if the valves dont stay open). I would say he is experiencing issues maintaining power at higher RPM.

I actually got those figures a bit wrong originally. Stock (but with the CAI and K&N) it came up at 201KW. After tune it's 226KW. I did get the maps and the original 201 is a nice smooth curve. The curve after the tune is not a nice smooth curve.

It was 38 degrees yesterday when the tune was done. Could this have had an impact on the result?

I'm not going to divulge the tuner here because he deserves another go if it's not right. As I said though, the car certainly goes far better. Seems to go harder from lower in the rev range and pulls harder when it's given it's full head of steam.

It was suggested that the tune has been done conservatively because without bigger injectors and replacement vavle springs it might be stressing things a bit (could be a sales pitch I guess, but I have read similar things elsewhere on this site). I thought you could go to about 300kw without any further upgrades.

Thanks to all respondents so far for your imput

Edited February 6, 200719 yr by silverchris

Couldnt hurt trying another tuner... but 38 degrees is a bloody hot day to be tuning a car (the air inside the workshop was probably hotter than 38!)

Maybe get them to give it another go on a cooler day, maybe early in the morning?? Can you post a pic of the dyno sheets?

Dyno sheet will be posted later today

Without injectors you will usually not go above 240-260rwkw. This is because they are maxing out and each dyno will read differently.

You might find you have soft valve springs as it is quite common to have them fail above 250rwkw.

To get to 300rwkw, you will need injectors, springs, fuel pump and possibly a new cooler.

Here's the dyno sheet from yesterday's tune.

I'm really interested in any feedback re the results.

Thanx

Attached dyno sheet yesterday (see above post).

Can I get feedback on what people think given all the posts above.

I still think that with edit and custom tune you should be able to get around the 230 to 240 rwk's. But as stated there are allot of variables... if your not satisfied go back to the tuner and ask for a re tune as your not satisfied. At least give him the opportunity of fixing it... If all well fails seek another tuner... Silverchris there are going to be allot of people telling you what or what you cant do, Good luck in your quest for more power.

38 degrees on the dyno with a few back to back runs will take a bit of sting out of it, may cause you to drop 10 or so rwkw. But as others have said there could be other variables.

It would also help to see boost and AFRs to see how conservative or otherwise the tune is. I would certainly take it back in cooler conditions as see what it runs up.

May just need a little tickle

Did you have the plugs re-gapped? Looks like a very rough power curve, definitely having trouble keeping power up there! Look around 3500rpm, where max boost would be... there's the first dip in power. If you put any more into it you would probably hear the valve springs give way.