picco97

Hello all members
I have novi1200 SOS 3" and 3.4" pulleys with both to custom cut pulleys like RR pulley for prevent belt slip
and I was wondering what's guys hit the PSI 3" and 3.4" pulleys
according to SOS pulley chart, 3.4" for 13 psi 3" for 16 psi but I searched forum and some people hit 16 PSI with 3.4" pulley
and some other people hut over 20 psi with 3" pulley. I know all result depend weather and elevation but a lot of different result from original SOS chart
my area is sea level, and I want 16 PSI for both pump and E85 tune 450-500WHP range
please reply here what psi hit for anyone run those pulleys

soulicious

I've seen up to 21psi on cool nights with 11.0:1 compression, e85, not much over sea-level, stock exhaust, and a 3.0" RR with 5.45" crankshaft pulley. That was 500whp+ Dynojet with good tension. I'm pretty sure that my exhaust was holding me back a little. 18-19psi was typical during hot summer months.

MorngWoodStewie

Spinning it faster does help. The 1200 iirc is a bigger stage 2 SC that sos provides.
The other reports im basing my opinion on is what happens when either the install is very efficient and a clean install performed, no leaks, no piping cock eyed into a coupler ya know, stuff like that. This is where the attention to detail comes in and even In FI everything counts still.

You can only base your expectations off that chart, if you come up short then u can ask what's going on.

If u got the 1200 I don't think you'll have a problem hitting your goal, does it matter how much psi it's at as long as u hit your goal?

s2k manic

I am running a 6.75 crank pulley and 4'' blower pulley on my novi1200. I am also running my own air to air in Texas summer heat I see 17 psi and 18+ psi in 70 degree weather. I have my boost cut set at 18.2 due to 3bar map sensor and I hit that at 8400 rpm with some methanol. I have iat's 10-20 degrees below ambient temp. I have 19.5-21psi at the blower outlet depending on weather so the 1200 is very efficient. My intercooler setup would be cost prohibited if you can't build it your self due to the use of aluminum 90 degree bends and mandrel bent piping so all silicone couplers are in strait pipe areas 3'' diameter with dual tial bov's and a cold air intake that it 4'' to 3.5'' up to the blower. I also have a second idler pulley and the longest belt I could run. keeps the belt from slipping. It makes around 450 whp 300tq on an f22 with upgraded springs and ti retainers. I have the sos tb comptech 4-1 header and 70mm t1r.if you run stock or restrictive exhaust or even too small a filter it will have negative effects on boost and power. with the baffles in I saw almost 20 psi due to restriction and I have hit the serge line on the compressor because of the air density. vtec is now set to 3300rpm to keep from building too much boost on the low cam. there are lots of variables to pulley boost ratio. good luck to you

E4RTH WORM JIM

3.4" 19psi @9100rpm

I live in the U.K.

liquid_helix136

3.4" I see 13psi in winter and 11-12psi in summer at 8500. Dyno sitting around 400. I've got a 3" headerback exhaust

s2000Junky

I dont know if the op is running an fmic, but there is typically 2-3psi loss difference if so on same pulley compared to someone running the standard aftercooler. I ran 2 different pulleys with my aftercooled 1200 at sea level. With a 3.8" I saw 13psi at 9k. With a 3.2" I saw 19psi in winter and usually 16.5-17psi in summer. This was also on a lower 9.6:1 comp engine. So I may have been short maybe 1psi compared to a stock engine.

Id say if 16psi is the target, id go for the 3.4" if aftercooled, and if running an fmic id go with a 3". Keep in mind, if you go 3" you will be over spinning the blower after 8000rpm approximately.

rmerchant3

I am running the 3.4" on the 1200 currently. I see 16psi at 8000rpms. This is with an URGE header, 70mm test pipe and exhaust. Located 290' above sea level.

I wouldn't recommend going any smaller unless you plan on running E85 or other high octane fuel.

s2k manic

so looking at my pulleys it seems I have the equivalent of a 3.2" blower pulley with 19 psi now that we are seeing cooler weather here in Texas.

s2000Junky

That's the pressure I saw in cold temps with my 3.2 also.

I saw average 3psi difference between summer and winter, which is pretty significant really. Probably 30-40whp worth. I could never feel much difference because I could never get any traction in any gear in the winter lol