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BOV Simple question


My name is Russell

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Any place who works with the desired size and material tube will have scraps they will give for free.

For example, you could have got the piece you made for free from Pitstop or Midas. Just rock in and ask if they have any 2.5" stainless pipe or whatever.. Usually they will point you to the bin.

Gaz

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Wastegate question:

Im wishing to use an external gate on my CA18DET. Ive got a tuned length steel low mount manifold.

Im resigned to the fact that ill probably have to modify it, either a W/G mount at the collector just above the Turbo.

Becasue im building it for the best smack in the back, break your seat mounts spool response, will i notice any drop in having the W/G on a remote mounted pipe, say 12inchs out of the way, or am i still best to wham it on at collector?

Also, my Turbo manifold has a larger hole in the outlet flange than the exhaust housing on the turbo..how much trouble will i get in if I match port the Turbo housing to suit? theres plenty of meat to remove, just wouldnt want to ruin the Turbo at all?

And since its lacking the wastegate actuator etc, im pretty keen to run an external plumbed back in down under the seat area/removeable flange for screaming! Now i see all these 'dump pipes' on trademe and they have two distinct holes and a splitter in between, but anyone else ive seen with an external setup just welds the flapper shut. This, in effect will render one of these holes on the dump useless and the whole setup oversize in my confined space..

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Can mount waste-gate directly off the exhaust housing of the turbs. I am running same manifold as you and have Gt28 turbo and is what I plan to do, or try to do :lol:

The trademe dump pipes are pretty shit. Weld flapper shut and then get custom 3inch dump would be my choice. I have the matching dumpipe to the manifold however so will just run that.

Gaz

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You can buy the flange to suit turbo from somewhere?

Your manifold is completely different from the pictures i saw.

Mine =

100_1748.jpg

100_1745.jpg

Theres just room (by the vice grips) to splice in a W/G port on either side that suits, probably the front side for rooms sakes.

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A bit off topic but whats a BOV for ? Has anyone even proven they do anything except make a woosh pfffft noise ?

Ive had cars with and without them (same cars) and theres no noticable difference, no difference in quarter mile times either.

I know the priciple behind them but is there any benifits ?

Something to think about.....

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While I'm thinking about it, my throttle body has two lug inlet / outlet type things that look to be for running coolant through them, is this correct and so i need to do this / whats it for?

Its designed to heat up the throttle body to avoid icing. You dont need to connect them up unless you live in the north pole. Ive disconnected these pipes in the past and havnt had any issues, Just my opinion though

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A bit off topic but whats a BOV for ? Has anyone even proven they do anything except make a woosh pfffft noise ?

Ive had cars with and without them (same cars) and theres no noticable difference, no difference in quarter mile times either.

I know the priciple behind them but is there any benifits ?

Something to think about.....

I think the theory is that it avoids any air being compressed by the turbo being pushed back against the compressor turbine when the throttle is closed immediately after boosting, ie between gear changes or just de-accelerating. I guess in super high boost applications a BOV is considered a necessity but for an every day performance car perhaps not. My Eterna didn't have a BOV and there was a distinctive surge/flutter sound between gear changes, especially when running over 10-12psi of boost - who knows if that was doing any damage to the turbo or not, when I pulled the turbo back out it had more or less the same amount of play when it went in originally.

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an exert from my a book by jeff hartman:

" ... equiped with a blow-off valve to increase the life of the turbocharger by limiting the surge forces against the compressor and bearings from sudden throttle closure, which produces instant high manifold vacuum downstream of the throttle and a high spike of overpressure upstream of throttle "

So nothing that phil hasn't already said.

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Ive seen decent quality turbochargers withstand years of surge on closing the throttle, and have seen cheap chinese ones barely withstand weeks... That may have just been because they're cheap chinese turbochargers though, and were going to fuck-out anyway.

Have also seen a mismatched turbo on a small capacity engine surge on full throttle... that'll just kill everything pretty quickly.

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