Jump to content
SAU Community

Recommended Posts

Sorry i dont know much abotu wastegates could someone explain to me how a wastegate works, ie: if you have a 12psi spring in your wastegate does that mean even if your boostcccontroller is set to 20psi, you only get 12 pounds of boost or how exactly does a wastegate work, does it slow a car down???

Link to comment
https://www.sau.com.au/forums/topic/306669-wastegates-and-boost-controller/
Share on other sites

The waste gate is a flap that opens to bypass some of the exhaust gas from the turbo. it has a signal line (an air line) from the intake piping, that fills with pressure when you come onto boost. when you reach the boost pressure your wastegate spring/boost controller is set at, there will be enough pressure to open up the wastegate, effectively stopping your turbo from boosting too much.

If you have a 12psi spring in your wastegate and just run a air line to the wastegate, your car will run 12psi. (all things being equal).

if you have a boost controller in there, it 'bleeds' off some of the air in the signal line, so the wastegate will take more pressure to open. i.e. 20psi instead of 12.

but its not advised to run 20 psi (some will say even 12) on a stock turbo, especially with no tune.

i see you have an R32, 20psi on a stock rb20 is a little risky too...

Well thanks for that information, btw i have a r32 without an engine atm XD, still buying an engine.

So say i get a stock rb26dett, i have an external wastegate fitted with a 12psi spring, and my boost controller is at 15psi. The wastegate would instead run 15psi?

so do wastegates make the car slower or what? and what about the BOV?

okay then with an RB26, if its stock, it wont have an external wastegate.

both the turbos will have their own internal wastegates.

ditch the external wastegate man, you wont need it, unless your putting a big single turbo with different manifold(s) on.

just use the standard internal wastegates.

btw, wastegates and boost control dont make a car slower at all - wastegates are a need on every turbo car, not an extra thing that you put on.

dunno where you got that from, but a boost controller and wastegate is a means to control boost. the more boost, the more power, the quicker the car.

but you cant run more boost with out having it tuned of youl blow your motor.

as for the BOV, dont touch it. leave the stock one in. a BOV is a valve that opens up when you take your foot off the accelerator pedal, and vents the excess air that the turbo is still flowing out. has no performance benefit at all, except maybe a bit less lag between gears. a BOV helps keep the turbo healthy.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
    • I fashioned a ramp out of a couple of pieces of 140x35 lumber, to get the bumper up slightly, and then one of these is what I use
    • I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there. Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.
×
×
  • Create New...