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Discussion Starter #1
So I threw on a willy's whistler and I love the whistle it makes. Someone made a point to me though that fuel consumption can be increased with an increase in boost. Is this true and wouldn't it be killing my mileage to be running more boost through a new intake?
 

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very good question......I just changed back to the stock turbo for this resaon. On my truck, with 37s and lifted... i noticed that at low throttle it was runing hotter than stock and that on normal driving...flat on cruse controle.. that the boost was lower and the motor ran hotter. Clearly on a hill or high throttle or pulling a trailer the larger turbo was better,cooler, more boost. It it my conclusion that it takes more to spool a bigger turbo, and be more i mean throttle. my truck seams to do 1.5 - 2.0 mpg better with stock turbo empty no or very little load. In ust a slight head wind the turbo spools and i get boost ware i dont with a 62 - 12. So to anser your question yes i think boost is good. your fueling the motor eather way , but win its boosting it makes more power = better milage.........Well maybe 2 cents
 

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Discussion Starter #3
bump...seen some new stuff from guys on here about low boost pressure increasing mileage. Any other opinions??
 

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Boost pressure on a Diesel does not inherently increase fuel consumption; Diesels are throttled by fuel, and they inject the amount of fuel required regardless of how much boost pressure you're seeing.

That said, the boost pressure comes from burning fuel. So the higher the boost pressure, the more fuel you're burning. So driving by the boost gauge is a good way to stay mileage-minded.

An intake should drop your boost pressure, or else it's not doing its job very well.

A drop in the boost pressure will mean that the engine is operating a tad bit more efficiently, and therefore saving fuel; it is having to burn a tad bit less fuel to flow a given amount of air through the turbocharger.
 

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Boost is driven by fuel, so it takes fuel to make boost... Think of boost psi as a work meter, the more boost you have the harder the engine is working.... EGT's can be looked at similarly, but they are greatly affected by boost... Which is why you can be as hot at 1600 rpms at 185 hp as you are at 2900 rpms and 325 hp....

I use to accelerate at or below 10psi... Got about 15mpg. Now I do the same at 5 psi or less and get 17+...
 

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Discussion Starter #6
if this is true...why would people put boost foolers on for mileage??
 

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if this is true...why would people put boost foolers on for mileage??
Where did you hear that?

They don't... Boost foolers only trick the ECU at high boost levels, which are not conducive to good mileage... This allows a higher max boost, but only affects at levels above 32psi (325hp motors).. IIRC the boost foolers only allow the ECM to see 22psi????
 

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Like ah64id said, a boost fooler won't do s--- on a stock truck, except lower full throttle EGTs a bit. The only time one should be run is with a chip or aftermarket turbo...
 
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