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Discussion Starter #1
These are a few questions i've had for a while and havent really seen discussed on here...

I have the TRD supercharger and boost gauge...when you start up the truck, the gauge pegs at 20hg vaccum and the more gas you give the closer it gets to full boost. Now does the SC only give more power when it's pushing boost? or does it start to give more power as it decreases the vaccum? Theoretically, if you could hook up a boost gauge to an NA tacoma, would it always be pegged at full vaccum, or would it go up to 0psi at full throttle? I know the basic idea of what a supercharger does, just never read up on the specifics.

Second question, lets say you're going up a hill or need to pass someone or something, what would yield better gas mileage...downshifting to use the engines natural power, or just laying on the gas and boosting?

I'm pretty sure I had some others but cant remember right now, so thanks to anyone who can clear those up for me
 

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YoTRacer158 said:
These are a few questions i've had for a while and havent really seen discussed on here...

I have the TRD supercharger and boost gauge...when you start up the truck, the gauge pegs at 20hg vaccum and the more gas you give the closer it gets to full boost. Now does the SC only give more power when it's pushing boost? or does it start to give more power as it decreases the vaccum? Theoretically, if you could hook up a boost gauge to an NA tacoma, would it always be pegged at full vaccum, or would it go up to 0psi at full throttle? I know the basic idea of what a supercharger does, just never read up on the specifics.

Second question, lets say you're going up a hill or need to pass someone or something, what would yield better gas mileage...downshifting to use the engines natural power, or just laying on the gas and boosting?

I'm pretty sure I had some others but cant remember right now, so thanks to anyone who can clear those up for me

Downshiting would yield better gas mileage. Anytime you are in boost, you are using more fuel. Boost and fuel delivery have a linear relationship.

Back to your first question.....Remember your boost gauge is hooked up to your SC not your engine. On a NA engine there would be pressure but techinically it can not be refer to as boost.

Hope that helps.
 

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Discussion Starter #3
so the higher revs from down shifting would use less gas than pushing boost?
 

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Supperdoddy,
I dont really agree with what you mentioned:
You go uphill with s/c and hit around 6psi to do so....and your engine is at 2200 rpm (about 70mph)...it would use less gas then 4000rpm at same speed.

U are correct on boost = more air = more gas but the revs also has alot to do with this as well. Higher revs = even more air needed and gas.
 

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YoTRacer158 said:
Theoretically, if you could hook up a boost gauge to an NA tacoma, would it always be pegged at full vaccum, or would it go up to 0psi at full throttle?
It would go up near 0 psi at full throttle. The harder the engine is working, the lower the manifold vacuum.
 

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It would go up near 0 psi at full throttle. The harder the engine is working, the lower the manifold vacuum.
Bringing it back from the dead. Did you guys ever get anywhere on this? I just put my SC on and I had the same question. Going up an incline I either pull -8 vacuum 3rd gear or push +5 or so boost in OD. Wich one is gonna save the UNFREAKIN believable expensive fuel? Thanks Guys:D
 

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Discussion Starter #7
Damn talk about a blast from the past. I just started trying to do my best to keep it out of boost going up hills.
 

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I know a way to test it out. Connect up a laptop to the OBDII and bring up the real time mpg readout. Then hit the hills, my guess is the lower gear and higher rpms will give better mpg than pushing higher boost and lower rpms.
 

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did you all notice any kinda mpg differece after the s/c install vs stock?
Not really. First tank I dogged onit a little to feel it out, power breaking with 32"s, sliding around corners and stuff, straight acceleration but not a lot, and suprisingly got the same mileage as if I never put it on and drove normal! Good power and all, need the URD crap, but second tank kinda knocked off the horseplay and got roughly the same mileage? I dunno done a lot of towing and in one really mountainous area with a 5000lb trailer I got 11mpg! Lot of boost though! Towing on straight terrain i got 14.5 mpg mostly out of boost. In town normal 17 or so, highway sometimes 19 on cruise at 67 miles an hour.
 
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