Thread: 91 Galant VR4
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Old 01-09-2010   #5
Pushit2.0
15min late to the world
Re: 91 Galant VR4

the main reasons you want the injector to point right at the valve is for emissions and a low idle rpm and idle quality. The 160lb/hr injectors are the secondarys, which will only be used when needed, so idle and low rpm/vacuum the engine should run off a fairly small primary injector in the stock location. The farther up stream you place your injector, either a primary or secondary the more power the engine will make. I found testing where a 1000 horse power engine gained around 50 hp from moving the injectors 14" up stream from the valve, I think they said they started at 7". But the engine had to idle at 1700rpm. The reason I found for the more power is the fuel takes heat out of the incoming air, thus its more dense and the engine makes more power. Also they did not find injector angle to be much of a factor but anything from perpendicular to 45deg to the incoming air was good, anything more then 45 either did not change or hurt power. As far as the injectors angling in there is not enough room on the runner to have them next to each other, and I did not want a fuel starving issue, so the angle makes the space from 1 injector to the next about the same.

~John
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Last edited by Pushit2.0; 01-09-2010 at 11:33 PM..
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