I'm considering the purchase of a 2005 or 2006 S2000. I live at altitude where there's a 20-25% drop in power for NA cars. I'm not really looking for a massive power increase, but rather just to account for that loss and perhaps score a bit of extra torque at the same time.

My initial feeling is to go the supercharger route cos I feel it's less 'messy' than a turbo...

 

get supercharger, simple bolt ons are not worth it if ur looking to get power out of that

 

get the S/C simple bolt and go with enough power to satisfy


Peace
David

 

The sc'r may be bolt on but it isn't simple. Expect 10+ hours to install.

You could always move down to sea level

 

S/C+A/C.

 

Wouldn't get any work done if I was that close to a beach...

 

Ballantine, if you have to be CARB legal or pass emission tests an SC/AC is your only (legal) choice. That is the way I went, and I love it, but I'm not at all sure that it is the best way for you to go. I'm no expert, but I believe you'll still be way down on power where you need it if you go with a centrifugal SC. I'll explain why, and if I'm wrong one of the experts here can teach us both something.

You are seeing a 20-25% drop in power (and torque) at all engine speeds. This is the direct result of a 20-25% reduction in charge density at all engine speeds. Look at the torque and power curves published by Comptech:



It looks to me as if the only place below VTEC where you'll see a 25% increase in power is the bump around 5,000. Looks like you'll be at or above a 25% increase once in VTEC, but you'll still be down on power any time you're below 6k.

You'll still feel an improvement a thousand RPM or so below VTEC, but you won't be back to stock levels.

A PD blower or turbo can bring in more boost at lower revs, and I believe an Axial Flow could be made to do the same, so if you don't have to worry about smog checks I think you'll be happier with something other than a centrifugal SC/AC.

 

I would agree on the SC, but you might want to consult with folks in the forced induction forum, Ballantine.

Have you driven the S in stock form yet? It's mighty powerful to begin with, y'know.

 

Thanks guys...

I have been driving a few stock models at some 2nd hand dealers and your right, it is still a very swift (and FUN!) machine... I could probably exercise some restraint and drive it as is, but there's nothing wrong with a little extra power, eh?

Interesting graph, but does the Comptech system not use a boost sensor for lower engine speed and retard timing accordingly (which would explain the close to stock power below 4K RPM)?

I don't need to be CARB compliant, but 'scuse my ignorance Red MX5, you'll need to explain those terms PD blower and axial flow. My reasons for choosing SC over turbo is primarily because I see SC as much easier to install, and having less stock parts customisation than a turbo installation

 

Ballantine, the power curve is a result of the boost curve. The only controls on the Comptech system are an ESM, FPR, and bypass-valve.

The ESM keeps the cars ECU from seeing boost. The FPR increases fuel pressure as boost increases. The bypass-valve opens under vacuum. There is no timing retard (though the car has a knock sensor and will retard the timing if knock is detected).

"PD" is short for "positive displacement." All the CARB legal superchargers (both of them) for the S2000 are centrifugal, which means that they only make boost at high engine speeds. A PD blower makes boost at low revs (and high), so it would do more to offset the effects of altitude in normal driving. An Axial Flow supercharger is a type of turbine, and behaves like a centrifugal supercharger, BUT, an Axial Flow system can be over-boosted to get boost at low revs, and then throttled at higher revs. On this car turbos also make good boost at low revs, so for what you're trying to achieve, and since you don't care about CARB certification, the centrifugal superchargers are a poor choice (IMO). You need 20% more power below VTEC as well as in VTEC, and they just won't do that. Take a look at the BRP supercharger, the AxialFlow Engineering supercharger, and the LoveFab turbo. I have not worked with LoveFab but I have every reason to believe that they can give you exactly what you want and need.

I have a friend who moved from central Georgia to the Rockies and now lives on top of a mountain outside Denver. His drive home after work was driving him nuts because his 300E Benz was so down on power at the higher altitudes, so he designed and fabricated his own supercharger system, just to get near stock power at altitude. You don't need a lot of boost (just to offset the altitude) but you need it in the rev range you use most often, and a turbo can be set up to give you boost wherever you need it. LoveFab knows turbos, so they're the people I'd be talking with.