My bro's friend 8 second civic
10-18-2009, 12:48 AM
#41
n00b
Join Date: Jun 2006
Location: GTA
Posts: 14
Nice car indeed... The dual wastegates help with spiking and provides much easier boost control. Engines running at high boost also create high exhaust pressures, and although you may think that one single big wastegate can do the same, it is not what it seems.
One big wastegate has a large valve, which equates to a large surface area being subjected to exhaust pressures. Since exhaust pressure pushes the wastegate valve upwards, the larger the surface area, the more force is pushed upwards. You often run heavier wastegate springs to keep it shut and run more boost. One single big wastegate (like a 60mm) has a huge surface area, and to run 30+ PSI of boost for example will require a VERY heavy spring. Too heavy of a spring then you lose resolution in boost control and you often run into huge boost spikes. You also lose the ability to run lower boost if needed for better traction during launching.
Two wastegates will allow both gates to run a reasonably sized spring without the drawbacks of one huge heavy spring on a big wastegate.
Aside from that, the other reason to run dual wastegates is to provide a separate path for exhaust to bleed pressure on a twin-scroll or divided turbo setup. Twin-scroll/divided manifold setups are divided into two separate sections, thus, allowing quicker spool (common practice on turbo diesels). Having two wastegates, one on each "scroll" provides equal venting on both sides of the scroll.
Anyway, here's a video of the same drag car over at DMT.. No numbers are released, but you can see it do a few quick dyno runs:
Videos & Updates (check out August 2009 videos):
One big wastegate has a large valve, which equates to a large surface area being subjected to exhaust pressures. Since exhaust pressure pushes the wastegate valve upwards, the larger the surface area, the more force is pushed upwards. You often run heavier wastegate springs to keep it shut and run more boost. One single big wastegate (like a 60mm) has a huge surface area, and to run 30+ PSI of boost for example will require a VERY heavy spring. Too heavy of a spring then you lose resolution in boost control and you often run into huge boost spikes. You also lose the ability to run lower boost if needed for better traction during launching.
Two wastegates will allow both gates to run a reasonably sized spring without the drawbacks of one huge heavy spring on a big wastegate.
Aside from that, the other reason to run dual wastegates is to provide a separate path for exhaust to bleed pressure on a twin-scroll or divided turbo setup. Twin-scroll/divided manifold setups are divided into two separate sections, thus, allowing quicker spool (common practice on turbo diesels). Having two wastegates, one on each "scroll" provides equal venting on both sides of the scroll.
Anyway, here's a video of the same drag car over at DMT.. No numbers are released, but you can see it do a few quick dyno runs:
Videos & Updates (check out August 2009 videos):
10-19-2009, 04:48 PM
#43
Member
Thread Starter
Join Date: Aug 2009
Location: TORONTO
Posts: 648
ya man my brothers pictures will be delayed a bit
he just put a turbo on his car but the turbo was no good
so now he needs to get a new turbo
i will let you ppl know once everything will be running .. hopefully sometime before the winter
he just put a turbo on his car but the turbo was no good
so now he needs to get a new turbo
i will let you ppl know once everything will be running .. hopefully sometime before the winter
12-01-2009, 11:04 PM
#64
Junior Member
Join Date: Mar 2003
Location: Guelph
Posts: 184
ETD built this car many years ago, use to be owned by mike p.
Yes it did have a turbo d-series in it 2 or 3 years ago.
very nicely built car, John is one of only guys that i would still trust out there to build my stuff i can't do
Yes it did have a turbo d-series in it 2 or 3 years ago.
very nicely built car, John is one of only guys that i would still trust out there to build my stuff i can't do
12-02-2009, 02:07 PM
#65
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Thread Starter
Join Date: Aug 2009
Location: TORONTO
Posts: 648
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