Does Twin Turbo mean 2 Wastegates

[Mikesone]

Hi

I'm hoping one of you can offer some advice on how twin turbo's work.

I understand that the 2 turbos work in parallel, 3 cylinders each (I guess)

And that adding a Boost controller changes the thresholds that the wastegate will actuate.

When I looked at the two turbos on my car (98 Legnum) they both 'look' as if they each have a wastegate, and both wastegates are plumbed back via metal and rubber piping to the inlet manifold.

If I'm correct in there being two wastegates, where do you plumb the Boostcontroller to ensure both wastegates are controlled by the Boost Controller.

Thanks

[Rossco Type-S]

There certainly are two wastegates, don't know about the boost controller though-been wondering that myself.

[bradc]

You definately have 2 wastegates, one in each turbo. I'm not sure about plumbing it in myself, but if you do a search for boost controller installation, you'll get quite a few picture guides on how to do it.

[Nick Mann]

There is only one dump valve. As the turbos work together not sequentially, 3 cylinders driving each as you said.

I'm afraid I can't answer your question with any confidence, though.

[AllBeItMine]

boost is controlled by a single line off the inlet elbow just before the throttle body.

the black plastic elbow has a vacum line coming off it (coloured red) which links to the factory boost control solenoid - then splits in 2 to each of the wastegate actuators. boost pressure is bled off at this point - before the split, to get the desired presure to go to each actuator

so when installing an aftermarket Boost Controller - you just need to replace the factory solenoid in its current position to effect both actuators. All the plumbing is already there.

[mpau009]

Yeah, iv just installed my boost controller using LegVR4s advice, and this diagram, the only thing i would add, is that if your controller doesn't plumb back into the intake (like my gizzmo one), then it pays to block off the other hose that returns from the stock controller, as it will let in unmetered air.

Also, i took the feedback vacuum hose from between the fuel pressure regulator, and its control solenoid, as i was told that it gives a more accurate read than the one to the BOV, and its easy while the pipes are out of the way.

[Mikesone]

Brilliant
Thank you all for your help.

I ordered the Turbosmart Manual dual boost controller just before Xmas so will let you know what difference it makes when I install it. (Now I know how)

Just for the record, I did the MAF screw adjustment which I found made the VR faster, (My VR's bog standard with the Cat still inplace).

I've also now removed the Mesh that sits in front of the MAF and after the air filter, I found this made a bigger difference than adjusting the MAF screw.

I'll let you know if removing the Mesh shows any downsides, but nothing as yet the car just feels more sprightly.


Thanks again