I'm curious to know everyone's thoughts on this subject.

Why do you guys prefer turbos to supercharger? I keep hearing that turbos hurt your engine in the long run, is this true?Also, does anyone make a supercharger for 95 240sx SE? If so, who?

Pfffffft. Why do we get these questions. There is no supercharger offered currently because there's no place to put it. You have a 240, you should see that clearly. Take out your A/C, and you've got room, or build a new intake manifold to accomodate it. That's why people stay away from SCs. Turbos are available, make more power over a similar SC, and don't have the drawbacks of being belt driven. A turbo won't neccesarily hurt your engine, not anymore than driving it hard. Not properly tuned you can do damage, but you can do that by running low on oil, coolant, or by throwing scrap metal down the plug holes.

There are pro's/con's to turbos and superchargers. I prefer turbos, as do most (from what ive noticed) import/compact car fans. They are just more fun (CRANK THE BOOST!) But whatever.So ya im not goin to go into the details, but if you want to know, id be more than happy to tell you. . .

Flash

yahoo: UnderPressureMotors

I am a big turbo fanatic, i love cranking up the boost and watching the tach shoot to redline in an instant. The good thing about superchargers is that there is no lag and with an already torquey motor like the ka a supercharger will be great. Unstable-hybrids is soon gonna release a supercharger kit for the KA24de they are good guys, very professional. give them a call if you are interested in the kit they will lead you in the right direction.

yeah, i guess superchargers are cool. but dont offer as much flexibility. With a turbo, if you want to run really light you can turn the boost dorn to like 4 psi with the twist of a knob. When someone revs on you (damn hondas) turn the same knob the other way (flip the switch back, hit the button, whatever) and you could be running 12 psi. with a supercharger, you always push the same psi, you have to change the pulley on it to make more/less and i hear thats a b itch

flash

and that is why I prefered turbocharging over supercharging. I'm still in the development phase but I'm gonna go turbo over supercharger cause of the ease to change boost.

wanna save a few bucks on gas turn the boost down... when the time comes (those honda guys are in for it) turn the boost up.

Turbo all the way baby!

Turning off superchargers

Nowadays, you can control the boost of superchargers w/ electronics, and even turn a supercharger off...at least with some of the new ones.

Yeah, ive never heard of that kind.

SC's are great for V8's that have a lot of power to spin the SC, however in lower HP cars, turbo is probably the way to go since your basically taking something that would be just blown out of the engine and making gobs and gobs of HP with it (possibly). Plus, with a turbo you get that great sensation of acceleration at a given RPM.

Rick

I noticed a lot of people only seem to be focused on boost adjustability. I don't see this as being a big factor. Most people who are turbo'd only increase boost for the track when they are on race fuel. Otherwise, they run their max street boost all the time. If you've put together the kit well, you'll have no need to turn down the boost. The gas pedal becomes your boost control at that point.

Turbos are generally percieved as better due to their efficiency. Since they are powered by the exhaust gas vs the crank, they tend to take less power from the motor to make the same amount of boost. Superchargers in some cases have been known to rob as much as 40 hp from the motor to make boost. This sounds more like a rather large positive displacement charger. A centrifugal charger should require less power to turn. As far as turbos are concerned, consider that generally, 1/3 of the energy from combustion goes to spinning the motor, 1/3 goes into the cooling system, and the last 1/3 goes out your tailpipe in the form of pressure and heat. Turbos use this energy to spin the compressor. It does rob some power in the form of backpressure though.

Compressor efficiency is also another area where some superchargers are lacking. And with many positive displacement units being mounted as an integral part of the intake manifold, they tend to leave out intercooling.

Now as far as space, it is a little more critical to locate the supercharger where it can be run off of a bet, but I truly see no reason why either a centrifugal charger or even a small to medium positive displacement unit will not fit in the 240sx. For those who have doubts, take a look ath the Miata kit from Jackson Racing. It uses a centrifugal unit which mounts on the exhaust side of the motor. Then a pipe is routed to the Throttle body. This could also be intercooled with relative ease.

If Vortec would fabercate a SC set up. That would be cool because their would be a lot of 280Hp KA's driving around.Or the best set up would be the Jackson racing set up just replacing the whole intake,but im sure the Sc pulley snout would break off from troque on a KA.

280 HP is a bit optimistic I think. I wouldn't think they would be looking at over 7-9 psi and even on a decently sized turbo, 280 HP would be hard to acheive. Though it wouldn't be too far off. A supercharger tends to rob more power to run it, so it would probably be a bit less.

If Jackson Racing built a kit for the KA, I would expect similarities to the Miata Kit. The Miata Kit does not replace the manifold. It uses an adapter on the SC which has a pipe outlet. Secondly, I doubt the snout would break off. The KA is not a torque monster by any means. There are plenty of motors out there that can out-torque a KA anyday and many of them have superchargers available. I don't hear any measurable amount of problems with the snout breaking off. If it does, I would blame the installer for overtightening the belt. The torque transferred into the SC will only be as much as it needs to drive the SC. If it absorbed all the torque, there would be no torque left to push the car.

the crank on the KA is prone to negative harmonics and i have heard from a few turners of snouts breaking off. at high rpms of course.

What exactly do you mean by negative harmonics?

negative harmonics....look at the crank on an sr20 and then look at the crank on a ka. you will notice, except for the fact that the sr20 crank is beefier, that there are two piece counter weights on each crank "lobe". these are there to reduce the "shudder" or vibration created when the crank flexes and twists....and believe me the ka crank flexes like a rubber band. this shuddering effect can be oberved in ka's the rev past 7000, this vibration, flex, twisting of the crank is called negative harmonics. past lets say 600bhp and 7000rpm negative harmonics fliter throughout the entire engine block causing engine faliure.

AEBS in San Diego has broken ka blocks and crank snouts because of the harmonics of the crank. i would say the crank if the weak point on the ka. other wise it is tough