Wastegate advice

[Dobby84]

Hi all, I am looking at buying an S2 very soon and would like some advise regarding wastegates.

My friend has a turbo with a wastegate that mates a lovely "chatter" noise which I want to reproduce on my S2.

Could anyone let me know how to go about this? What modifications do I need to do to get the chatter sound?

Also I wouldnt mind increasing the power slightly over standard but where is a good place to start?

Cheers guys.

[Dan]

http://en.wikipedia.org/wiki/Wastegate#Wastegate_chatter_myth

Just FYI.

[Dobby84]

Well there you go, you learn something new everyday.lol
from that article I assume that installing an aftermarket wastegate wont effect the noise too much then unless i increase the power output.

[S2central.net]

Tell us WHY you think an aftermarket wastegate will increase power output ?

As pointed out earlier - the 'chatter' noise is actually turbo stall...

If you want to hear it on an S2 or similarly setup machine - simply unplug (and block) the boost control line that goes into the throttle bypass valve.... That will prevent the valve opening on lift off/vacuum and you can provoke that 'chatter' noise you like so much... it also shortens life of the turbo and ADDS fractions of seconds to your acceleration times.

I bet my left nut that your mates turbo car doesn't have a working bypass valve.

[Dobby84]

I didnt mean the wastegate would increase the power but as the noise comes from the turbo, I though that the more powerful turbo the better the noise.

Ill have to try it out when I finally get my hands on an S2 (hopefull weekend after next)

where would a good place to start be for power increases? Im not after much at the moment due to budget.

[Dan]

ECU Chips. Talk to the man above (in this thread, not Jesus), since he is the vendor of homefries.

Alternatively you might find whatever you buy is already chipped. Mine came MTM mapped.

[prj]

You don't seem to be getting it.
Running your turbo without the bypass will kill it pretty fast.

[Dobby84]

In that case I wont do it.
not sure what my friends engine is doing then. Its a Carrado VR6 with a pro rebuild capable of 900bhp!?!

Ill speak to the guys who built it I guess

[Thuppu]

A tight dump/bypass valve can also make some chatter sound.

[prj]

In that case I wont do it.
not sure what my friends engine is doing then. Its a Carrado VR6 with a pro rebuild capable of 900bhp!?!

Ill speak to the guys who built it I guess

So, that would mean they don't really care about the reliability of the turbo.
Same as the Audi S1 rally cars, which didn't have a bypass valve, because the turbo was rebuilt often.

There is a very good reason it is fitted standard on all audi factory turbocharged cars since the late eighties.

[Dobby84]

Like I said Ill ask the question to my friend and the guys who built his engine for him. I know his engine isnt running 900 but the internals are rated to 900.
Maybe ill just go down the dump valve route then as I want a reliable motor.

[sam80quattro]

this is 1 of those arguments that an go on forever, ive known people run 2 bar of boost with no dumpvalve for 20k miles with no problems, also numeros cars running 1 bar of boost for 100k miles and no turbo problems. 1 of the reasons dumpvalves are fitted is the fact most people wouldn't want to hand over 30k for a car that makes a load of racket when backing off the throttle lol

[Dobby84]

Seems I may have opened up a can of worms then! lol
I havent even got the car yet but I wanna fiddle with it and thought this would be a good place to start as I love the noice of chatter but after reading the above maybe the dump valve noise will have to be settled for.

Does anyone have any opinions of this? Just found it on GayBay?
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT

[Dan]

Honestly, just get a stock-ish S2, get it chipped if it's not already and then just drive it for a bit. It'll be reliable and still enough power to have fun.

If that's not enough in 6 months time then start thinking of bigger upgrades.

[loxxrider]

I have run numerous turbos without dump valves including the stock k24 on the 200 20v 3b and it lasted quite a while that way until I took it off in favor of a Holset. It made a wonderful noise on the stock setup. Now with my Holset, my Tial 50mm valve is a bit tight and it flutters a bit. Holset doesn't seem to mind a bit

Also have a cousin with an 88mm turbo on a Ford 331 that runs sub 8.50 and has no dump valve at >40psi. No problems. I believe the old rally audi's replaced their turbos so often because they ran anti-lag constantly (IE idling in boost)...thats what killed the turbos quickly. The IMSA cars also ran no dump valve and I don't think they changed turbos nearly as frequently as the rally cars did. Thats just speculation though, I'm not positive about that. That said, there its probably a good idea to run one. By no means does it kill turbos extremely prematurely though.