I have a forge dump on my 250 but it's teed with the standard valve still in place. This results in no noticeable difference in performance (doesn't lose any) and gives me a slightly less chavvylike dump whoosh . I'm going to have my car remapped next week .....I'm assuming the boost will be increased .......I've got a stronger spring for the dump valve but if I use that how will that affect the std recirc valve ? Or is there no need to change the spring? Confused.com
Don't disconnect the standard dv if you want to keep the vta sound down there's no need lots of mapped car run standard valve Bare in mind once mapped more boost may make your vta louder anyway, hence time to use bigger spring.
Why run both When he is fitting a stronger spring to his Forge valve. If you want the noise keep the Forge if not sell the Forge and keep the standard one.
Compromise! By keeping both it lowers the the noise of the vta which may increase even with larger spring once mapped. Like the op said "it gives a slightly less chav like whoosh" running both
Will the Forge one even open at all with a stronger spring with the standard valve doing its thing? Slightly less chav, than chav, But still chav.
Good point James if running both it may not need the bigger spring! Thinking about it If the vta noise is deemed to chav the sensible thing to do would be remove the vta altogether and look at the induction noise of a performance panel filter or induction kit instead.
Mine has an hks ssqv,(was on the car when I brought it) I'm putting an adapter on it to convert it to recirc and plumb it into where the pcv went in the intake hose now that's not used. Hopefully it will be quiet.
Did it before on a blitz bov too. The hks is a good bit of kit I'm just getting fed up with the noise. That's why I'm keeping it on but recirculating it.
Update. Just had the car remapped today. Rolling road showed 270 before (mods are forge cooler, panel filter, Scorpion 3inch catback ) the guy was wondering if it already had been mapped by the previous owner??? I dint know the answer but it would be a bit strange if it was as he would've only added 20 horses! Anyway, he downloaded the map, ran her up a few times and it now makes 310 so I'm well pleased with that. The main difference is from 3000 revs onward where the power deliver is much smoother now. I left the dump valve fitted as is (ie tee'd with the std recirc) and that's fine although it's running a higher boost now
