Originally Posted by Ostrichsak
You need to be careful the way you keep talking about the elevation. Our fuel here is also lower octane to offset the thinner air and in addition you don't want to run a vehicle on the ragged edge at elevation because then what happens if you want to drive it to a lower elevation? The 2.825" (and subsequently the 2.85" stealth) pulley is a good increase in performance while maintaining a margin of safety. The difference between the two pulleys you're talking about is only about 10hp and that's at the crank. Will you feel a difference? Probably but it won't be huge. Is it worth all the added danger you'll incur from running on the ragged edge? No way. If yo're not going to to what is required for each step then don't push it. To me, the 2.828"/2.85" pulleys are the logical step for those who don't want to invest a lot of time and money. You buy a $150 pulley and a $50 tool and swap them out one afternoon. Done. The gains of 15-20hp for that investment of time & money is a great return on investment. The next step to a 2.7" will require the same $200ish investment and same amount of time but in addition you're going to spend 2x the money and time for maybe another 10hp. Your gains are very diminishing on that investment and IMO it's just not worth it on a truck of this size, weight & gearing. 10hp on a 2nd gen Tacoma is NOT 10hp on a little Honda Civic as you won't feel it as much. I also am not willing to permanently modify my supercharger for another 10hp gain and am already risking my factory warranty just running the stealth 2.85" pulley. I also don't see swapping pulleys back and forth regularly as an option. I want to give my truck just a tad more oomph while maintaining the famous reliability.
That's my $0.08 anyway adjust for inflation so take it for what it's worth.
i hear what your saying, but the fact is the 2.8 pulley netted me 10 hp a total waste of money!
what i can tell you is with the 2.8 pulley i had no issues with fuel when i went to AZ and towed a trailer with a sand rail weighing about 9,000 and was boosting almost the entire way to glamis without issue.
we are nearly -3PSI MAP less pressure here verses seal level. this means if people running the stock setup or in my case with the 2.8 without issue we can add those 3 PSI back at this elevation and the truck wont know the difference. i have discussed this at length with 2 tuners at this elevation.
but my game plan is to buy the swappable pulleys, monitor the AFR (i have a wide band o2 installed) i can also monitor EGT at the cats and every other engine parameter with my ultra gauge.
if i have a problem i have absolutely no intention of bringing my truck to the dealer for a warranty repair. i intend to find out how small of a pulley can be used here and then go up 1 size and call it good.
also the swappable pulley comes in 2.5,2.6,2.7,2.8 i think the 2.6 is as small as I would be willing to go, not quite 2.55 but smaller than a 2.7
to be honest i don't full boost very often, if i did it's only to get up to the speed limit.
and actually our fuel is the same octane as at lower elevations, they do put 10% methanol but the fact is because we have less pressure here with or without a SC we have less pressure by 3 psi, therefore even though the mechanical compression ratio doesn't change the effective compression ratio is also lower by about 25%. so 91 octane is not as necessary here as it is at sea level. although my Acura TL pings like a mother if you don't fill with 91 oct.
i run the 91 in the taco and have never had any problems.
also my corvette Z06 will not run very well without 91 it not only pings but it flat out sputters! also the stock compression ratio of the taco is no where near as high as my other mentioned vehicles and is less prone to pre detonation even boosted.