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Old 01-02-2015, 03:50 PM   #1
Wasted Income
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Re: JS LSX Turbo complete kits...anyone heard of this?

First off, the guy in the video is annoying. The guy who said he sounds like a used car salesman nailed it. lol.

Quote:
Originally Posted by BR3W CITY View Post
the 475 would be making over 450 at ~12-15psi,
That is on the low end. I helped tune a truck this summer that made 530hp/580 lb-ft at 10 psi with a 475 borg.

Quote:
Originally Posted by BR3W CITY View Post
DEcide on the turbo, and I'll help you pick a wastegate. Too large of a WG can make it tough to control at low boost levels (this is also partially determined by how the overall amount of exhaust pressure we have to work with, a function of both the displacement, piping and turbo selection). Too small of a wastegate will increase the chance of creeping and spiking.

Essentially, you want the smallest gate possible that still eliminates creep. This is why some will choose to go with twin-smaller WG's in place of a massive dump. Its easier for the smaller diameter valves/springs to have "crisp" control over the boost levels.
Depending on the turbo used, he might need as big of a gate as he can get. I had a Precision 46 on mine last year and it was creeping all the way to 15 psi with a 7 lb spring in the gate. I switched this year to a 60mm Turbosmart, and optimized the gate priority, and it still creeps to 10-11 psi with a 7 lb spring in it. With a large turbine and housing, there is just not enough backpressure to force exhaust out the WG. If i had a more restricive turbine, it would not be a problem to flow enough out the WG to maintain low boost. I don't really mind though, because 10 psi is as low as I'd ever want to go anyway
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Old 01-02-2015, 08:18 PM   #2
BR3W CITY
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Re: JS LSX Turbo complete kits...anyone heard of this?

Quote:
Originally Posted by Wasted Income View Post
If i had a more restricive turbine, it would not be a problem to flow enough out the WG to maintain low boost. I don't really mind though, because 10 psi is as low as I'd ever want to go anyway
We're not special enough for variable geometry turbos yet
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