Anyways, I've got a question. I've been reading up on FMICs and seeing how they work with a supercharged car b/c I feel as if it'll be a lot cheaper than an actually A/C. I've found one I'm actually serious about buying although, I've reasearched it and found out that I'm going to lose PSI. I've also read that If I get a 9psi pulley it will compensate for the loss. See this is the complication, I don't have bigger fuel pumps nor do I have a better fuel regulator. All I've got is a stock comptech pulley and everything that came with the supercharger kit. So, If I put a 9psi pulley without any of that but have a FMIC will it blow my motor? Will a 7psi pulley be enough to carry the weight? I don't want to lose any power, rather be the same rwhp or a little better. What do you guys think?

thanks
jerome

 

I think you might be a little confused about what's going on here. If you get a FMIC (ie, air/air), you will have extra plumbing and extra volume in the I/C itself. It is this larger volume that, when you try to compress it using the same pulley as when you had the air/water I/C (stock), that you will lose boost. In this case, you can no longer call your original pulley a "7#" pulley nor can you call the new pulley a "9#" pulley because they will no longer be giving those pressures. If you go with the smaller pulley (what you call the 9# one), you "might" get the pressure in the manifold back up to the previous 7 lbs (or so). You won't know exactly how much till you measure it. Therefore, if the manifold is still seeing the same final pressure with the FMIC as it did when the old I/C was in place, your engine won't know the difference and thus, your fuel pump, injectors, etc will work the same. If you end up with more "real" boost than before, then you'd still have to get new parts just like before. It's not what pulley you put on, but rather, it's what the pulley you put on does. And this applies to both water/air or air/air FMIC.
For street use, a FMIC is mostly for looks (IMO). I'm not so sure there is any real mechanical advantage to having one. You'll need a smaller pulley to compensate and the added plumbing may be more sources of leaks. The boosted air has a lot longer distance to travel before the engine can use it. Depending on how much more volume you add, you might even begin to get supercharger "lag" (if there is such a thing).

ps. I take it you've been reading this thread:
https://www.s2ki.com/forums/index.ph...ic=239336&st=0

 

Air to Water is better for the 1/4 mile track than anything else. Reason why is you can put new ice water in for every run. Well atleast you can on the vortech applications.

Air to Air yes you will loose a little pressure with the extra tubing but it will provide a much better gain on the street and will be unable to get heat soaked.

Spin the blower higher and you will make up for the loss in psi. So like lets say you install this thing and ur pressure drops 2 psi or so. Throw in the 7 psi pulley and you go back to the stock boost level. Through in the 9 psi pulley and you will be around 7 psi and so on. All depends on what boost loss you have.

And who ever says the Air to Water is better on the street is on crazy IMO.

Air to Water - 1/4 mile track application
Air to Air - Daily driven street/road racing/autocross.

If my logic is wrong please correct me.

 

Most of what you say is generally true, but in this particular application it doesn't really work.

You mention that there is a little extra tubing. Try about 10 times the length. The placement of the SC in the Comptech and Vortech kits is about 20cm from the throttle body. If you reroute the piping down through the fender, out in front of the radiator and back up through the other fender to the throttle body you are increasing the path to about 2 metres.

You also mention that you can't get heat soak with AA. True, but the amount of heat generated by this low boost (and only at close to WOT) is minimal and the cooling capacity of either AW intercooler more than adequate for anything but the most stressful driving.

Effectively what I am saying is you are underestimating the loss of an AA FMIC and overstating the disadvantages of the AW.

 

There seems to be a lot of discussions and theories about heat soak but my intake after the intercooler is always icey cold. Mind you, I am only boosting to 14+psi and I boost every where I drive and my milage is really crap...something around 11-12mpg.

I even test it on the dyno and it was still cold.

Like everything on my car, the intercooler system is slightly modified to improve heat exchange but it is still a A-W intercooler. So in practice I don't think the AW IC is that bad. The only bad thing about it is the extra weight but you can't win everything in life.

 

Ok, lets say both are even heat exchange wise and he just wants the front mount for cost reasons and the bling. Spinning the blower faster to make up for the lost pressure will fix that problem. Of course you would reach your peak boost at a different RPM. So you would be making 7psi at about where you would make 9psi if you had the regular aftercooler.

 

If by 'spinning the blower faster' you mean use a smaller pulley then assuming you picked the right pulley you would reach peak boost at the same RPM.