I have seen some posts suggesting forced induction goes against the design intent of our S2K's and it is generally an evil thing to contemplate. I am curious as to exactly why some of you feel that way. I myself am on the fence but I feel the car should be a little easier to launch and it would be nice not to hide from Saleens and the like, therefore a supercharger sounds good to me.

For those of you who hate the idea of forced induction, is it the normally-aspirated-horsepower-per-liter record concept? I cannot imagine you fear unbalancing the car or otherwise affecting handling. RWD with a Torsen LSD can take a lot more thrust, delivered smoothly, and put it to good use.

Some of you are opting for turbos. I'm curious why you want more HP right where our sweet spot is now. Most of us agree that we kick serious butt in VTEC during roll-ons. I can understand it if you're after an insane Japanese-style top end rush like an inline-4 sport bike.

Your thoughts?

 

I guess some persons are just natural asipration freaks...who knows...

 

Well, it is completely out of sync with the design intent, but I don't think anyone implied it was evil.

Obviously, any normally aspirated car is not intended to run forced induction (although some, like the SR20DE from Nissan and the 3.0 I6 from Toyota are essentially the same as their forced induction brothers of the same family, just without the turbo and a couple of tweaks).

However, in the case of the S2000, you have a car that is so optimized for maximum normally aspirated potential (arguably more than any other car out there), that forced induction is less attractive than it might be on another car.

For example, in addition to my S2K, I own a formerly normally aspirated car that now has a supercharger. But it isn't nearly as optimized for normally aspirated performance. Stock, it made 67 hp/liter, redlined at 6500 rpm (limited to 7100), has a compression ratio of 9.1:1 and a cylinder head/engine architecture/cam timing designed more for midrange than top end. It took to boost very well and I can run plenty of it on the relatively low compression ratio. It kills my S2K in roll on acceleration, BTW.

The S2K, on the other hand, is all about normally aspirated. 120 hp/liter, 8900 rpm redline, 11:1 compression, big bore/short stroke, lots of valve timing overlap on the high end. It's already a highly stressed engine from the factory (rpm/compression), and adding boost to it adds even more. The compression ratio doesn't allow you to run much boost without making engine alterations, hence limiting some of the potential normally associated with forced induction. Additionally, the big overlap up top is actually not so bad with a turbo, but not so good for a supercharger (more intake pressure/no increase in exhaust pressure means mixture gets blown out the exhaust valves). And the large bore/short stroke may mean slower spool up times for a turbo (although with the tradeoff of more top end potential). Seems kind of bass-ackward to buy the most highly tuned NA car in existence right now and then slap an FI system on it - but that's just my opinion, and having driven a supercharged S2K, I did have a lot of fun in the process.

In terms of superchargers vs. turbos, don't forget that a proper turbo will significantly outpace the Comptech system on the bottom end while providing equivalent or higher top end power. That's because the Comptech uses a centrifugal blower which doesn't provide much boost till the engine spins up, therefore it magnifies the stock engine characteristics. A good turbo, OTOH, will spool up by 3000 rpm or so and provide you with a wallop of torque down low. The best option for street driving would be a positive displacment blower, but Jackson Racing has no plans, thus don't expect to get an Eaton model (they seem to have the rights to sell Eatons in the Honda market)

Oh, one more thing, the stock ECU programming is not good for FI. Due to the single plane manifold, the ignition timing is seriously advanced in the 4000-5000 range, which means that you have to limit boost there or risk detonation (see posts from Comptech about the issues they faced trying to run more boost in prototyping).

Forced induction is a wonderful thing, I love it. But to do it right on the S2K requires undoing a lot of what Honda has wrought and no one has done it very effectively - yet.

UL

 

Ultimate Lurker,

Excellent post.

As far as the philosophy, Honda does not believe in forced induction on it's street cars. They produce turbocharged racing engines for CART so it is not that they don't know how to do it. I can't recall that they have ever produced a turbo or supercharged car and as far as I know they only produced one turbo bike (CX500). They believe in perfecting the combustion process in naturally aspirated engines. So old man Honda would not have approved if that is what you are asking. He viewed forced induction as an easy way out for his engineers and therefore no challenge. It would teach them nothing. Want more HP? Just dial up the boost. Where is the art in that?

 

Honda does make and sell turbocharged cars in the Japanese market.

Ted

 

Bieg,

Honda has dabbled just a bit with FI in production cars. The Honda Beat micro car (660 cc 2-seat convertible, looked like someone left a Miata in the dryer too long, not legal in the US for safety reasons) used a small turbo to add power. R&D also had some AWD supercharged Integras running around, but they never made production.

Clearly, as you said, Honda knows how to do turbos when necessary (F1, CART, etc.), so I'd say you're right when you say corporate philosophy plays a role in their abscence in production cars (after all, Subaru, Mitsubishi, Nissan and Toyota have all made prodigious use of turbos at one time or another, why not Honda?).

UL

 

Bieg, Honda produced TWO turbocharged motorcycles for the street. The first was, as you said, the CX500 Turbo. The CX500 Turbo had a lot of turbo lag so Honda decided to try again 2 years later with the CX650 Turbo. The CX650 Turbo had much better performance and ran with the 1100cc motorcycles of the time. Both the CX500 and CX650 turbos are collector's items now.

I think Honda did the turbo bikes because other Japanese motorcycle manufacturers (Yamaha, Kawasaki, and Suzuki) were producing a turbo model of some sort.

 

i remember reading somewhere (atlasF1.com or something) that Mugen/Honda's turbocharged engine was so successful in F1 racing FIA banned it.

 

I enjoy the S for it's respnosiveness... I like the tight handling, and the quick downshifts into immediate power.. to me a turbo would numb the overall feeling of the car. I would imagine it would take a fairly good sized turbo to fill up 2 liters at 9000rpms. I would however, like a complete head package with some crazy cams, wierd sounds and a 9500+ redline... something along the lines of what numerous Type R guys already have done. Just my ideals, doesn't have to be anyone elses.

 

I don't mean to get off on a rant here, but when it comes to the S, I believe it should be "to each his own." The true purist, if adhering to what they profess, would not even add something as simple and appearance-improving as Rick's console cover. On the other hand, there are others who want to constantly push the edge of the envelope in terms of appearance/performance.

The purists are the same type who stayed at home 150 years ago rather than set out to conquer the unknown in the West. The pioneers, on the other hand, were willing to stake their fortunes and their very lives just to see what lay on the other side of the next hill, mountain or valley. And thus, it remains to this day. On a linear scale I guess I tend to lean toward the purist side, but I eagerly await the results of the expensive experimentation undertaken by others to plumb the performance possibilities of this wonderful machine.

Please note that the above analogy is not intended to make a value judgement about either group. The stay-at-homes are just as valuable, in my opinion, as the pioneers. Both types, as well as every variation in between, are necessry to make the World go around.