Could anyone shed some light on the effect of the Z32 if the cat converters are bashed out? How would the gas temp sensor in the cat react? And would this higher amount of flow cause my BOV's to be louder. They were really shit until i took the valves out and cleaned them, theyre pretty decent now but i still want them louder. It is a stock exhaust system on a 2+2 TT Auto.. cheers
Your exhaust has no direct link to your BOV's lol... The gas temp sensor doesn't affect anything engine/ECU wise so don't worry about it - you're probably better off buying high flow cats as they give you a better flowing exhaust and are still semi legal when it comes to emmissions. I've heard that highflow cats/gutted cats won't have much of an effect powerwise anyway (unless your cats are blocked). Didn't stop me from buying a pair of magnaflow high flow cats tho! But yeah if you want louder BOV's you have to adjust em yourself or get louder ones
Yeah but doesnt more flow going into your turbos make the bovs louder? Im going to get a stainless catback Npower system off ebay soon. Thanks for the info on the cats tho. To adjust the bov do u just tighten the valve with a spanner? is it bad if its too tight?
I've never tuned BOV's nor do I ever plan to have em so I don't exactly know - but there should be instructions on the BOVs themselves (though I would imagine you would have to loosen em to get em to open up more). Your BOVs are connected to your intake system, not the exhaust - more flow into the exhaust wheel would make you spool up faster and maybe have more power but assuming you're planning to run the same boost level you shouldn't hear any change in the BOV's
tightening BOV's don't make them louder. They adjust the spring preload to help stay shut for high boost or less preload to help them open easier for low/normal boost settings. Only need to tighten them if they are opening and leaking air under boost. Regarding your Cats. They will have NO effect on your BOV volume. lol. If you want louder BOV's, go out and buy louder ones like HKS super seq. or something expensive like that. That's bound to scare old ladies on the footpath when you're boosting past. lol.
So if i adjust the valve to open up a bit more then it will allow the bov to actuate at lower revs? Another quick question. Some people refer to BOV as a wastegate? Mechanics even say it. Isnt the wastegates located on the housing of the turbos, and theyre just like a little opening and hoses connect to it?? Because im installing my boost controller and the diagram shows hoses coming off the wastegate ?
Yes, but don't unwind too much as it can lower the pretention on it and start to creep open on boost causing a boost leak. They shouldn't. As they're 2 completely different things. Google is your friend to find out the differences. But in summery, wastegate is what you use to control how much exhaust gas you put through your turbo exhaust wheel (how much you make it spin, thus how much boost). So that's why a boost controller is connected to your wastegate actuator, which holds the gate shut till you want (eg: 12psi) then the gate opens and doesn't allow your turbo to boost higher than that amount. BOV releases boost pressure from the charge pipes/intake quickly after you take your foot off the accelerator, to stop compressor surge.
Thanks Benny. That summary is much more easier to understand lol .. Ill try finish off installing my boost controller now.. JUst another quick question.. Whats a safe tune up? i believe stock boost on each turbo is 9psi?
I'd recommend doing it safely on a dyno, and checking for knock. But it's fair to say that a lot of people are running a stock setup with 12psi (or even more sometimes) with no dramas. Just be careful, and always run 98 octane fuel aswell when boosting to help minimise chance of pre-detonation. - oh, and make sure your running a decent aftermarket boost guage aswell, stock isn't a very good guage to go by. (Notice how subtle i was posting that boost figure without accepting any liability? )
hahaha yeah u cant even tell that its in bold .. Im installing my boost guage tomorrow, i have to pick it up from a mate first.. Can that solder straight onto the boost wire on the cluster?? or do i have to run a t piece from the wastegate actuator where the boost controller line is ?
NO! a new guage. run new hose - but NOT from the actuator lines. You must run that from a vacuum source. eg: a nipple from one of the charge pipes, somewhere off the balance pipe, nipple under the throttle bodies. But not from the actuator. I hope you've done your research before installing a new guage and the boost controller on how to connect them, properly.
ohhh ok i get it now.. my cousin wil be helping me out hes a mechanic, but he wants me to do all the work so i can learn how to do it myself which cuts me up because i know he can install it in a flash :/ ..
in time, you will appreciate the lesson your mechanic cousin is teaching you. or i can just tell you - learn your car. get familiar with it, so when problems arise, you fix it yourself instead of paying someone else (or bugging your cousin) to fix it for you.
Haha true true... Everytime a problem arises i seem to figure out how to fix it i just dont have the mechanical mind or hands on skill.. I would have loved to become a mechanic i love working on my car, its just shit money in the trade :/
Ya me too always had my car serviced and repaired at the workshops. The zed has been my first real mechanic experience, so the tech section and occassionally hogging my mates hoist has made it easier
stay away from npower, get a a pair of quality mufflers and have an exhaust shop fab up some mandrel 2/5" for you, get some hi flow cats as well. the bov's will open up at lower rev's possibly idle if you adjsut them to the weaker settings, adjusting them to max would give you flutter. go throught he tech section most of your questions are already answered there
