Ok I have a vortech for a non-rev up on my non rev up motor and I have a 3.33, 3.12 and a 2.87 pulley and also a 32 tooth jackshaft pulley and a 34 tooth. I have the stock inter cooler and a bigger inter cooler, and I have the fmu for 8:1 stock and can convert it to the rev-up kit size 10:1... I have one step colder spark plugs to go on as well. and the rest of the car has an injen true duel exhaust stillen test pipes and 5/16 md plenum spacer... and my main question is with what I have what is a good set-up to run? which combonation... of items

 

O and the rest of the car, and the rest of the vortech kit is stock

 

If your not going to upgrade the fuel system . Stick to the stock FMU and jackshaft pulley . And dont go any smaller than the 3.12 for you serp pulley . Get it tuned and you'll be safe

 

well how good would it be to leave the 3.33 pulley and change the jackshaft pulley instead? and if I did upgrade my fuel system to 550 injectors and a walbro 255 and maybe a fuel return system... would I want to run the 2.87 pulley the 34 tooth pulley and the bigger inter cooler? would that still be safe on the stock block? cause I don't know have any idea what psi or power that would be making?

 

try it and see what numbers it makes. so far no one has done that.

 

Keep in mind the blower is rated at 53k rpm's max? Use whatever combo of pulleys and cog's that provide max power at not much greater than 53k rpm. Larger I/C is a plus for any combo. A RFS also a plus w/o the upgraded rails.

 

There is something that seems no one ever thinks about when figuring blower rpm speeds . When you use thier calculator on the web site . No one take into concideration that belt slip plays a big part of it .

I believe with a serp pulley system you will NEVER over spin a blower . The calculator doesnt figure in belt slip . You can put into the calculator a set of different size pulleys to max out the blower . With that set up - if there was NO belt slip you would be making close to what the blower is rated for in psi . [20 psi ] And no one ever does end up making that much boost . If you ran a all cog pulley set up like I did you would understand it better I think . Now with a smaller pulley set up , you will get to that slip point faster . But once it does the blower belt starts to slip a little and the rate of PSI GAIN starts to drop off . And the blower isnt turning as fast as you think .

 

I agree that you'll be overspinning the blower but belt slip will be a big issue and probably prevent you from getting all your power unless you address it

I personally wouldn't even attempt both the 2.87 and 34 tooth pulley without extensive breathing mods - cams, headers, cats, full exhaust etc, but that's just me. So far, most people with vortechs that have gone to 13+ psi on the stock block without race gas or water/meth injection have had some bad days with their engine

 

Engine mods will make a slight difference on when a belt starts to slip . But it still doesnt get the blower spinning to its max with a serp pulley system . Its the serp pulley its self that is the draw back . You cant get the blower spinning any faster than the serp belt system allows . We have seen serp pulley mods that have helped , but doesnt stop it from slipping . Once a belt starts to slip the rate of gain slows and finally slips enough to where boost starts jumping up and down but never really keeps gaining . And when the belt is slipping the blower isnt gaining rpm . This why you will NEVER over spin a blower with a serp pulley system . The blower gets to hard to turn for the serp pulley to hold