General: I'm supercharged w/o the aftercooler and at 7 lbs with no engine management. I dyno'ed at about 280whp on my stock exhaust with cat, brand new clutch, and with heavy 18 in. wheels.

Great job guys! Can't wait to see your final numbers and impressions!

Pushin9: How much welding was needed or did you just use silicone connectors?

 

Thanks for sharing your numbers. Do you have a dyno chart I can reffer too? But in order for it to really benefit me, what dyno was that? The one I'm gonna jump on is a dynojet. I'm gonna see if I can dyno both 7lbs with and without the FMIC as well.

 

Oh, good...a perfect chance to rant.

But before the rant part...VERY NICE WORK, Kratos...Kudos for having the balls to do something different and for tackling the project yourself. I admire anybody who welds so that probably means more coming from some of the other guys who have posted. Nice choice of IC, too...cast end tanks, ftw.

And most guys who use the "r" word when talking about bov's secretly like the sound of a nice blow-off valve. Just don't confuse a bov's sound qualities with its effectiveness. Stock 1G dsm bovs are among the best out there up to 15-20 lbs but they don't make very much noise.

Also if you end up short a t-clamp or two don't worry. You can always just double clamp with crappy worm clamps. I have a connection on my galant set up with doubled-up el-cheapo' clamps and have zero leakage at 20psi. And I don't think that pipe-end even has a bead.

Slimjim, about your comment on boost drop: you are thinking like a turbo guy which, I see by your sig, you are. When you introduce a restriction to the intake system (like an intercooler) you WILL reduce boost at the throttle body...UNLESS you increase the boost ahead of the restriction. Your boost control system (mbc and/or boost gauge and/or ebc, and your waste gate compensate for the loss but your turbo is working a little harder to make up the difference. One of the big advantages of a turbo vs. a supercharger is the turbo has "boost to burn" up to the limits of the torbo's design.

Since superchargers boost levels are completely dependent on engine rpm they don't have the luxury of just turning up the boost to compensate for new restrictions.

In my experience a quality FMIC of reasonable flow efficiency won't result in more than a pound or two pressure loss. But my experience is with turbos putting out between 12 and 25 lbs boost where a couple of lbs isn't a big deal and where you can turn the boost up a little to compensate (at the cost of reduced thermal efficiency).

Not surprised the S2K "aftercoolers" (more on that in a sec) get heat-soaked. BTW, you may find your air/air setup does too in heavy traffic. Mine (in a turbo galant) does. Of course it's a little hotter down here on the Gulf Coast than up there in the Great White North.

Now the rant...

WHY do these supercharger companies insist on calling an air to liquid intercooler an "aftercooler"? Maybe this has been discussed before and its a minor point but it has always bugged me. An "aftercooler"? Like there might be such a thing as a "precooler" or (worse) a "beforecooler"? Like you would cool the intake air to ambient BEFORE you compress it? Like it isn't ALREADY ambient? /RANT

BTW... in my turbo world, an air to liquid intercooler is a hot setup. (as in good, not as in thermally sucky) Simplifies packaging and permits a really short rout from torbo to throttlebody.

oh...and I don't think bigger pipes cause pressure drop...they only improve flow. And longer pipe routs don't cause significant pressure drop either. Additional lag, maybe.

 

Just got off the phone with my tuner! I will be on the dyno Friday at 5:00pm!! So I will be able to give you all my before and after numbers and whatnot.

I guess the first problem is that I know nothing about BOV's ... I will give you a better review at the end of the week after my tuner is done. and Yes I was at 9psi.

[QUOTE=mrsteve,May 21 2007, 09:59 AM]But it seems like your priority here is getting the loudest noise from your BOV and not increasing power output.

 

A blow-off valve isn't just for show. It is an important part of any turbo system.

Here's what it does...Let's say you are accelerating...hard (imagine that!) and you let off the gas to shift. When the throttle plate closes the stream of high pressure pulses from the thrbocharged intake air hits the throttle plate and backs up...eventually these pressure pulses bang into the impeller inside the turbo. This is hard on the turbo's internals. The blow-off valve can tell when you let off the gas and it simply vents the excess pressure off into the atmosphere.

That's a really simplified explanation. Here are some better ones, if you are interested:

Blow off valve: What it does and how it works

This one is from Answers-dot-com

I don't know how important such a device is in the supercharger world, since centrifugal superchargers have much different impeller designs from turbochargers. Also you are talking about fairly low boost levels on an S2K.

 

tof, you are talking about BOV on a turbo though. For our Centri superchargers, its all for show and sound. We all know that.


You sure bout that? I thought bigger pipes and longer routes would mean thats extra space of air to fill?

 

[QUOTE=pushin9,May 21 2007, 08:27 AM] I had one butt weld.

 

Ahh...so you are saying compressor surge is not an issue with a centrifugal supercharger? Or do they have some type of bypass to keep them from building pressure at less than full throttle?

Last supercharger I had was a JR roots type and those don't have a surge issue since the bypass reroutes excess air back through the system when you close the throttle and there is vacuum in the intake.

As to the pipe stuff...yes, bigger pipes hold more air. So pressurizing them takes longer. But they still end up with the desired boost pressure. Again we are talking about lag, not pressure drop.

Forgive my mix of knowing some stuff but being really ignorant of others. I have lots of turbo experience but have never been involved with centri. type superchargers. I'm here to learn.

 

I removed the air pump so I no longer have that hose. Second I don't get any CEL's AEM EMS

 

That is correct because the supercharger is belt driven from the crank pulley and the impeller speed is RPM dependent. VS a turbo being driven from the exhaust you will see a surge and need the BOV.