I've got a HKS adjustable dumpvalve (vent-to-atmo). Is it better to adjust it tightly or do i have to put it wide open ? Why ?
(Tightly: peep sound like a young lady... Open: woeshhhhh)

 

Nobody in the whole UK that can figure out an answer to this ?
Too bad.

 

Just for you mate, I'm going to make a guess based on logic and experience rather than technical knowledge. If I'm wrong you can be rest assured someone will correct me, if I'm right........Happy Days!!!!

I would have thought that it would be best to experiment and find out which setting suits your car best. I had a DV on my scoob and found three main differences
1. It ran richer, note pops and flames on overrun.
2. It seemed to hold boost better
3. However, possibly a bit more laggy and slower to spool up. I'm guessing that this is because the system is less 'charged' than with standard recirc valve.

Using those nuggets of info I would say that to have your DV fully open will release the most air on lift off, run richest, hold boost best/well but seem more laggy. Having it tightly set will release less air, perhaps not hold boost quite as well but be more responsive and leaner. I'm sure you can suss out any settings inbetween yourself.

As every car seems to run slightly different from each other, particularly depending on what other mods you have, it would be impossible to tell you exactly which specific setting to use.

Hope this helps, watch the replies now as I'm proved wrong.

Disco

 

Thanks, i've been trying a few different settings last days, and i like very open best. Difference in performance is minimal, also because we don't have much occasions to drive at full throttle here. My biggest concern is: does it do any damage if i set it too open ? Until now it doesn't leak at full throttle in 4th and 5th, like some other dv's do. But the system of the HKS is (at least i think it is) constructed so that it cannot leak. Don't know the exact technical details though.

I'm gonna try and put it wider open today and will let you know if it makes any difference. For now thank you very much from the country of wooden shoes, mills and chees :-)