natho

Guess i'll find out for sure, I have a single VF30 going on in the next few weeks. I've spoken to someone else who did this and apparently his EJ208 off boost with a GTX3076 feels like a TT on 5psi.

i found with my modded primary turbo i needed significant tweaks to wastegate duty cycle. i did this in the tune, but you could use a manual boost controller instead. i looked at using the vf27 in the ported exhaust housing that i have, and while the centre fits the housing, the same doesn't work the other way - the vf31/32 centres don't fit the vf25/27 exhaust housings. i never ended up trying it, i figured the extra space would create more lag, but who knows? pretty much given up on the TT now and going single again soon. while the ported turbos and ecv do help, nothing gets away from the changeover, and worse, how long it takes the ECV to close again, which is a real problem if you want to shift and end up just on the primary again. it's either 4000rpm or 6500-7000rpm.

dw65c is apparently a straight fit

The ECU on my RevD keeps ECV positive pressure engaged after changing into the VOD. The engine is still in vacuum at this point so this would help pull the ECV shut, as you've described above. I think unfortunately it's just extremely slow to close.

i'm not aware of anyone doing what you've described. a few people bypass the positive pressure circuit entirely though. from what i've read, the ecv will be almost fully open when it has 4psi positive pressure. the default configuration has a solenoid bleeding off quite a lot of the boost to this port when ecv positive pressure is activated.

seen similar problems on another forum - apparently the small rubber hoses to the thermostat housing were kinked. might be worth double checking those?

i just put my modded primary turbo on this weekend. i believe the exhaust housing is a p18 - it's a ported one that billsy used on his setup a while ago. vf32 ball bearing chra, vf31 comp cover which is a straight fit. slightly laggier than the stock vf33, with a stronger midrange prior to transition. unfortunately i still have some work to do to minimise the VOD, but i'm leaving this until the rest of the mods are done. up next are dump pipes (still stock), a ported ecv and ported exhaust housing for the secondary. if all of that doesn't keep me happy, it'l be time to convert to a single turbo.

I have a limited understanding too - but an AFR near stoich will not make max power, and generally is not sustainable under load with boost - at least not without direct injection, which i believe can inject fuel later in the combustion process than when knocking would occur. Reasons like this are why the modern direct injection cars are so much more economical.

I wouldn't say that all cars are tuned badly. We are tuning for best power and response, they have to tune for emissions too. I've heard tuners say if their tunes require emissions testing it's always a case of compromising on everything else to meet the emissions standards. Mind you the TT Legacy is definitely an exception at least with an ADM tune - it's terrible. Either there is an underlying issue that develops on all cars, or they simply did a shocking job tuning it. They ping everywhere!

You definitely need to bridge the flash connector - that was what I forgot when doing this recently. It's the one shown here as 2003-5 connector: http://www.scoobypedia.co.uk/index.php/Knowledge/ConnectingToYourECU. I just used two wires and bridged the pins in the plugs myself. My ECU is a A4SH701K and I have been tuning the car successfully. I'm yet to work out what all the TT parameters are, given it's not a real time tuning system, trial and error is very time consuming. Someone was nice enough to send me their modified map to get started which has helped.

I haven't been able to find the jdm pinouts. Any chance you could send me a copy? Nathojg at gmail dot com.

has anyone here compared the Rev D wiring the bugeye WRX wiring? i've just spent a couple of hours going through the workshop manuals and not only does it show the same 5 plugs, but there's only about 20 or so wires to change - a few additions (TGVs), a few deletes (TT stuff), and a few simple pin swaps. surely it can't be that easy? might have to get hold of a bugeye ECU and confirm. maybe the "MY2003" Liberty manual i'm reading is showing an older revision of the wiring?

i don't think theres any need to 'reinvent the wheel'. there are plenty of good single turbo setups out there and the parts to fit it to my b4 are easily obtainable. it'd be a different story if getting single turbo manifolds/piping was hard. if i'm running a single turbo ECU i may as well ditch the twin setup altogether.

where is this wiring kit available from?

don't want parallel as it'll be much laggier. to be honest i'd be happy with a TD04 or VF35 - something with a mid range punch more than top end. the ADM bugeye has TGVs but not AVCS. i could use an ECU from one of these, re-pin, and use OpenECU to remove the CELs relating to TGVs. only downside is the local tuner uses ecutek so i'm not sure who i'd get to tune it. i still think the best option is to get a complete motor/turbo/loom/ecu and swap it all in. will be a bit more costly but also the most straightforward.