a wastegate in the intercooler pipe.

[ILLEGAL]

i first noticed this at this years 4&rota nats.. it was actually on this very same car. it seems a wastegate is used in the intercooler plumbing as a way to control the boost during staging. i have no idea how this works.. well i have my theories but wouldnt mind starting some discussion on this idea. if any one has had experience with a setup like this what is the advantage of running this sort of thing?


i hope STM dont mind im using their pic.


http://i672.photobucket.com/albums/vv88/2ILLEGAL/internet%20images/HD2wastegatebov.jpg

[Adam.Findlay]

a wastegate is essentially the same as a blow off valve just a spring, a diaphram and a piston with a pressure differential system to regulate movement of the piston. cant say why they used a gate instead of a BOV though. i remember reading it somehwere

[Adam.Findlay]

To complete the intercooler plumbing Bam still needed to fit the Tial 50mm BOV, and the Tial 44mm wastegate. The BOV works in the conventional way and eliminates compressor surge when Mike lifts at the end of a pass. The wastegate is used during staging to ensure consistent boost every time, and instant response from the turbocharger when mike leaves the line.

copy pasta from stm themselves

i assume the blow off valve opens when the engine is in vaccum and the gate opens underload to stop "overboosting" during staging.

[Kenneth]

My guess would be to as a pop-off valve which limits peak boost by bypassing air rather than exhaust gas. Bypassing exhaust gas slows the turbo down, bypassing boost pressure allows the turbo to flow the maximum air at the set pressure ratio. It also means that boost pressure will never exceed the set amount

[ILLEGAL]

yeh nah, they do have a bov aswell to control the turbo surge when they lift off the throttle... this wastegate is used to control boost and aid in response of the huge turbo off the line.. what im thinking is ...

.. as the turbo reaches the desired boost level while using a launch control.. the wastegate in the intercooler piping starts to open meaning the exhaust gas continues to flow 100% through the turbo. so when the gear is engaged and the engine is loaded up there is full boost already there?? just like a pressure relief valve?

im only interested because im trying to get my car boosting off the line without lag.

[Fully]

.. as the turbo reaches the desired boost level while using a launch control.. the wastegate in the intercooler piping starts to open meaning the exhaust gas continues to flow 100% through the turbo. so when the gear is engaged and the engine is loaded up there is full boost already there?? just like a pressure relief valve?


Yeah, "With the 2 step launch control it is possible to have over 30 psi of boost on the start line if we want, and with the clutchless Liberty transmission there is no boost drop on gearshifts"

[Adam.Findlay]

pressure relif valve those are the words i was looking for before :)

[ILLEGAL]

how do i get that sort of boost off the line? i think i only get around 2psi? im not sure if its more but i do know the wastegate is not opening. i have the MAPECU2 LC set to 6000RPM and still no help.. i can launch off the factory limiter which is around 7300RPM on my car and this helps off the line, there still is lag in first! do i need to sit on the limiter for longer? or should i place my 50mm wastegate on the intercooler pipes like this and run 100% exhaust through the turbo?

note: this is my race/weekend car.

[Fully]

Use an after market ECU and free yourself from the constraints of the factory ECU.
here's a few links to read up on.

http://www.msextra.com/doc/ms3/launch.html

http://www.linkecu.com/products/engine-management-ecus/g4-photos-files-etc/Brochure%20G4%20Plug-In.pdf

or L8 ECU
Here is a launch with a l8 ecu http://www.youtube.com/watch?v=YlUnApr7rys

[ILLEGAL]

thank you

[Kenneth]

Yeah, that is (in different words) exactly what I said :P


.. as the turbo reaches the desired boost level while using a launch control.. the wastegate in the intercooler piping starts to open meaning the exhaust gas continues to flow 100% through the turbo. so when the gear is engaged and the engine is loaded up there is full boost already there?? just like a pressure relief valve?