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VTA will be grand so long as it's a good spring in it to keep it shut. Ideally you'll get a little chatter from it at low boost (like 5-7psi) and then proper dump at full boost. There's no real mapping for it on a standard ECU - the air that's vented is lost and the ECU adds the fuel for it anyway (unless it's still in closed loop in which case the ECU compensates when it sees the change in mixture at the o2 sensor, then relearns the compensation the next time around if it doesn't dump).
Normally only an issue with 20 quid ebay valves that don't hold a seal properly, quality kit should be no problem just giving the occasional extra pop out the back.
Pcv and breathers vent back into inlet...this air that is vented back contains oil vapour/fumes which in turn can then cause det and degrade the ron rating of fuel as it isn't a clean burn. Aos helps counter act this
so the aos is beneficial at any point imo....
It's just a catch can really that returns to sump via oil filler neck. Mine doesn't even divert into inlet anymore, I blocked inlet and then diverted pipe into a wee bottle down beside water incase of big blow by which can be caused by hard launches which can still dump oil into the inlet. So now it's only clean air ever entering the inlet.
I first used it on my hawk sti then onto the hatch both when on top mounts and now with front mount
while I drive around in slow traffic trying to keep a steady pace in say 3rd , the car feels like I'm in 4th gear with slight juddering. If I change to 2nd I'm sitting at 3.5k rpm and ut feels to high. Say the car in front slows, I lift off and it I get a slight judder. When I go back on the accelerator (gently) it judders again.
Only feel it in 1st , 2nd and 3rd between 2k and 3k rpm.
is that the GRB STUMBLE ?
My worry is that it's the feeling it had before rebuild , and there was a load of oil in the intercooler. Haven't checked i/c yet as everything else is fine , and my mechanic said I didn't need an AOS. I still would have liked one just for peace of mind.
Mine stumbles generally whilst accelerating hard from lower revs, but not always. Never on deceleration. Always at around 2800. It's apparently an oscillation in the fuel, and can move up or down or get fainter after the "fix" More common with higher power. The argument rages on about it on Nasioc . Hopefully I will know more in a couple of months
Mine stumbles generally whilst accelerating hard from lower revs, but not always. Never on deceleration. Always at around 2800. It's apparently an oscillation in the fuel, and can move up or down or get fainter after the "fix" More common with higher power. The argument rages on about it on Nasioc . Hopefully I will know more in a couple of months
hedgecutter, has your car been mapped and if so what has the mapper said about it?
hedgecutter, has your car been mapped and if so what has the mapper said about it?
martyn J mapped it; the stumble was initially like hitting a wall, very violent upon WOT, I went back to him and he said it wasn't boost cut, map was fine, but we felt a tiny misfire. He recommended hotter plugs, but no mention of the stumble. All the stumble info I have comes from Nasioc. He did say that it was hard to make the twinscroll hold boost, so I have a 3 port bcs lined up
martyn J mapped it; the stumble was initially like hitting a wall, very violent upon WOT, I went back to him and he said it wasn't boost cut, map was fine, but we felt a tiny misfire. He recommended hotter plugs, but no mention of the stumble. All the stumble info I have comes from Nasioc. He did say that it was hard to make the twinscroll hold boost, so I have a 3 port bcs lined up
Hotter plugs? Did you go from a grade 7 back to a grade 6? RCM put in standard grade 6 plugs in mine and I've just bought a set of iflr7h and was planning on gapping them to 0.6mm.
Hotter plugs? Did you go from a grade 7 back to a grade 6? RCM put in standard grade 6 plugs in mine and I've just bought a set of iflr7h and was planning on gapping them to 0.6mm.
some stumbles have also been fixed by upgrading the fuel pump and tweaking the map to alter the switchpoints from low/medium pressure. It can be tuned out somewhat by playing with the load compensation tables on some cars too but I've not come across a single definitive fix for it.
for what it's worth my car has a stumble from 2200 to about 3400, not terribly bad but I can feel it in the lower gears when moving in slow traffic.
Hi guys finally got round to ordering some bc coilovers for the hatch from scooby parts ( nice price ) , now I’m looking at getting some aftermarket wheels probably some XXr 571, I think they’re called lol ,, the problem is it’s just a bit of a minefeild reguards fitment and width etc etc ,, so really looking for inspiration for fitment and sizes that work and also to see some sexy wheels 😬 , so if you could post pics and say what offset and width your running that would be great 😬
Thanks in advance Alex
Last edited by kershaw-330s; 26 January 2018 at 11:56 AM.
18 January 2018, 01:33 PM
