I bought a Leon Cupra for my mk1 golf swap, and it has a few things broken from the crash. One of them is the wastegate, got crushed to the firewall. VW dont sell it as a spare, and the junkyard I give me a very high price or sell me the whole turbo. So I bought a new Forge one: http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=0001&product=FMACVAG01 Here is where I have my doubts. How do you regulate it? just leave it in its natural position, or do I need to pressure test it in some way? The N75 controls the wastegate, but can it control it in any position? Any experiences? Thanks!
the w/g is not controlled by n75, that controls the turbo vanes the w/g is purely operated by vacuum all you need to decide is how much adjustment it should be set out on the thread bar
forge one has optional spring rates... OE K04 is going to be ~9psi spring you should pull some preload on the thing so its held shut.. 3mm to 5mm or so should be sufficient for that.
Erm... no. w/g is actuated by pressure on the wastegate actuator, which opens the wastegate puk itself, bleeding boost down the downpipe before the turbine. N75 is the control solenoid in the +ve boost feed pipe to the actuator, which bleeds air out back into the intake, thereby "leaking" pressure out so the actuator does not open until it see's its preset pressure - eg 9psi in this example. Think of it as a 9psi leak from N75 duty cycle and 9psi of static preload on the actuator, so ~18psi of boost is produced.. - Crude example.
On other forums they advise me to regulate the opening of the WG for the stock presure(0.9bar) for the K04 to open. Dont know if its a MUST or just a recomendation...............
its a starting point. if on OE ecu it will try and control to a requested boost via N75 bleed anyhows
VW do fit variable vane turbos to some diesel engines. No idea how the boost is regulated tho. Not interested in diesels personally
When using stock wastegate, how can you control boost, other than with the ECU? Boost controller? How much boost will a K04-023 handle?
you introduce a leak on the feed pipe to the actuator, by mechanical means or electrical means (solenoid + controller) K04 on mapped motors run 15psi with 20psi overboost typically as a guide
So, the control will be with one of these: 1BAR and 1.3BAR overboost, is a little low for what I've heard people use. I heard around 1.5 to 2.0 BAR range... Will this kill the turbo? (most likely...)
from k04 ??? yes, ill advised. maps I do are in the range I said and they dont explode. If twiddling that bleed valve be sure to check knock and air fuel ratios... you dont want to go lean under WOT... it goes very wrong very fast
Thanks for the input! I have a friend that is making these: With this, I should be able to control the Air/Fuel. With boost up to 1BAR/1.3BAR, what kind of numbers am I able to see?
Wideband? Not sure what it is... I'm using stock managment, so, I believe I will not use wideband.... Correct me if I'm wrong. I will not use it for tuning, but for keeping an eye on things!
it will flick up and down and up and down on the std switching lambda.. on steady cruising also, under wot it should go into the richer side of things (usually green leds) but its not telling you if its just off stoich rich or full on rich on the narrow band lambda. Your risk on adjusting boost and not being able to more accurately monitor a/f is running lean. why not get the stock management mapped?
I will get the managment mapped. This will be used to keep an eye on things, like if something is really wrong or something. I'm not going to tune things up with this
So I fitted the forge specific one in its place. Then took the turbo to a specialist to get it regulated; he set it to open at 0.6-0.7 bar(thats the vacuum pressure from the N75, not the boost pressure). Now its back on the engine, and I have a question. When I trie with my hand to move it. It opens the WG about an inch, then it goes harder and I dont want to force it. Is this normal? Or shold it open completely?
