Forced Induction Vortech Pulley Question (Long Read)

tinker451

New Member
Feb 23, 2020
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Divide, Colorado
Hi all,

Ran into some questions as it regards to boost in my 92 LX project. Some background:

I had been tinkering with my buddies on this car starting in about 2004, and after many steps was just about to finish up in March of 2008 when my wife was diagnosed with lung cancer. Well all work on the car stopped and we never got back to it. My wife was ill and my buddy got to working on other things. My wife is one of the lucky few to have survived, but we found we could no longer live in the humid air of NJ and moved to Colorado, and live on the western slope of Pikes Peak. So my buddy never got to finishing it but kept it in his garage until this summer when it was shipped out to Colorado. We finally got to working on it a few weeks ago and it has been a rediscovery of what the heck I was doing. One of the question we ran into was boost out of the Vortech and what was appropriate for up here. (I live at 9400 ft now) I am pretty sure it was a 8lb kit Vortech V-2 SQ but it is only stamped V-2. I have no clue what the boost was supposed to be as all my old email with CHP are long gone. (I emailed them but have not heard back yet).

Engine details:
I bought a long block from Coast High Performance and was told to add certain parts to complete a build that was a blown 347 that passed the California sniffers (NJ was close). Things I can remember are it was a Sportmans block, all the Probe Industry goodies like forged pistons and rods, AFR 185 heads, 9.5 or 9.6 to 1 compression and onto that I was to add a Edelbrock RPM II plenum, a 70mm TB, 80mm mass air, 42lb injectors, and the V-2 Vortech kit. This was to be 540 FWHP and 450 RWHP at sea level (I don't remember the torque numbers) I was told the stock rails were good to 500hp, so no need to upgrade them. I do have a power pipe, but the point of that was to get the mass air in the fender well.

Some things have changed from NJ. Firstly I had bought all shiny parts and the EGR was butt ugly, so it went, along with the smog pump. No worries as I live in a county without emissions. Now for the bad. Combustion is ~35% less efficient up here, so my 450rwhp becomes closer to 300rwhp and I have read that you lose 2.5psi of boost per 5000ft I have no idea what the boost would have been with my engine but I am estimating ~6psi and then losing another 4-5psi with altitude seemed like I might be even worse off. (and if I don't get more air in there the 42lb injectors will be too much) So it would seem to be time for another pulley, but I am not sure which one to go to. The instructions indicate that I have a 3.33. I would like have enough boost to make this all worth it, but I don't think an after cooler is going to happen. I live most of my life between 8000-10000ft, the car will got to 5500-6000ft regularly and 4500 once in a while.

So after all that, with this engine and this blower, what pulley should I go to that will not slip? Do I need to change the crank pulley also? I would like as much as I can have at 9500ft while still being safe if I went to 4500ft. I figure if I want to take it to sea level, I might have to step up the pulley size for the trip. I did just buy trick flow fuel rails as if I go lower and make boost, I could exceed 500rwhp depending on the boost I end up with.

IMG_0028 2.jpg


Thanks for any help or thoughts you could provide
 
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