CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Turbocharger vs. supercharger

Anyone ever installed either a turbocharger or a supercharger? Pros and cons for either installation and performance? Guess I have a little too much time on my hands. Rocketman

First what type of car are you thinking about doing this too.

Turbo is “Free” HP because it uses the exhaust gas (which is going to be wasted any way) to spin the turbine which spins the compressor, which forces air into the motor. However it is a much harder install, as it involves oil lines, coolant lines (in some cases), exhaust modifications, blow off valves etc… Other down sides is lag, as it takes time for the Turbo to spool up to speed and really start working. In some cases you can actually do a 3 count… You know one, two, thrrrRRREEEEEEEE !!!

A supercharger is a crank driven air pump, that does the same as the turbo, but it takes HP from the motor to spin… It is simpler to install, as most are self oiled and they usually bolt on. Also on a plus side is Less lag, as its not really spooling up. The power is more linier then on a turbo charger.

I haven’t done either, but thought about it for a couple of cars. It would seem that a supercharger would be a lot easier, for all the reasons @gsragtop mentions, plus the need to decrease compression ratio with a turbo if significant boost is used, along with the need to plumb in an intercooler. Lower boost is often used on a supercharger, but the fact that the boost present througout the rev range makes up for that to some degree. Even Toyota sells ‘bolt on’ supercharger kits for several of their engines, they look pretty straightforward.

Just picked up a '93 Honda Del Sol . . . 1.5 liter with 5 speed, low miles, really strong. No A/C . . . no P/S, a TON of room in the engine bay, I could put another 1.5 engine in there. I’ve been thinking about a supercharger, lots of room. Rocketman

One weaknss to be aware of with turbochargers is that the bearings are lubricated by the engine oil, and they operate heated by the exhaust and spinning at vrey high ROMs, up to 200,000. The subject the oil to stresses that require synthetic oil to successfully withstand.

In addition, if the seal between the exhaust driven side of the turbo and the impellar that pushes air into the engine fails, oil can be drawn into/pushed into the engine’s itake. Modern turbos are far less susceptable to this, but it’s something to be aware of.

Both superchargers and turbocharges require that the injectors be capable of supplying additional fuel. Generally a complete kit will include new injectors and reprogramming for the ECU. In extreme cases a fuel pump with more capacity is necessary.

And both help fill up empty space under the hood and can get in the way during routine maintenance.,

You should realize this…They only work at wide open throttle or very near WOT…If you analyze your driving habits, most people find that 95% of the time they are at LESS THAN 50% throttle position, operating at manifold vacuum, not pressure.

Now if you are entered in some competitive event, they work GREAT! But for normal street driving, they just sit there wearing themselves out and doing nothing…

There was a time when manufacturers installed turbochargers to effectively increase the engine size without actually designing and building a new engine. Volvo was able to use 4 cylinder engines in cars that would otherwise require a 6 to deliver acceptable performance…You get a little mileage benefit this way too…

I have a Kenny Bell supercharger on my Mustang GT. Since I’m using the stock internals, I only run 7 pounds of boost. It’s good for an extra 130-150 RWHP depending on which tune I have installed on the ECU. Turbos typically run higher amount of boost, but that can be disastrous if the engine’s crank/rods/pistons aren’t up to the task.

Here’s a major con for both: Unless the block was built to withstand the higher pressure, you’re introducing significant reliability risks in addition to the odds of the turbo or the supercharger itself failing.

It isn’t a safe assumption to make that the engine can handle it.

For example, say your engine is designed to be 9.5:1 compression ratio, naturally aspirated, and you put on a turbo with 15 psi boost. That will give you the equivalent of a 19:1 compression ratio at sea level. If your engine was engineered with a factor of safety of 2.0 when it comes to stresses from cylinder pressure, , guess what? You just blew right through that and are now operating the engine at its failure point. Not good.

there our other options out there for more hp intake exhauste systems it all depends on what you want from the car or truck

+1 to eraser’s comment. Block, connecting rods, crank, bearings, headgaskets, everything gets subjected to more stress. And if you really want to test your engine’s limits, install an N2O system!

Also, if you add a turbo or a supercharger to an engine you also have to add more fuel. This may require intalling larger injectors or reprograming of the computer. If this isn’t done and the boost comes on the engine will run too lean resulting in a blown up engine.

Tester

Caddyman has it right - turbos will make you faster than superchargers. Superchargers will make you feel faster than turbos. So if you’re going for pure fun, and you’re not planning on winning races, get a supercharger. On your motor, if you keep the boost to 9lbs or under, you don’t need to build up the internals (of course, I’m assuming your engine is in good shape - if it’s not, fix EVERYTHING before boosting).

Now, that said, you have the D15B engine in there. It’s kind of an anemic little spud. You might seriously think about, before spending the thousand or so for the supercharger, spending less than that (assuming you have friends and can do it yourself) to put something with a little more performance potential in there. The B16A2 was also a Del Sol motor, and it was a damn good one. It takes some fiddling to get the tuning right when you boost it because of VTEC, but once you do, you’ll have a 200+hp Del Sol to scare passengers with, and even before the supercharger, you’ll have 160.

Y’know, Rocketman, I managed to get a substantial improvement in highway performance simply by installing a basic ram air system made out of shop vac hoses and plastic pieces cut from a storage bin. If you have time on your hands and the budget is tight, it’s an ide to consider.

You will probably need an airflow sensor designed for force-feeding…This stuff usually comes as a complete package…

Hehehe… somebody disagrees with my assertion that adding a turbo or supercharger to an engine not designed to withstand the extra load, which can be significant, can seriously risk engine failure. I wonder how long that person’s engines last. :slight_smile:

Who disagrees with you? All I see on this thread is technical points and warnings.

I would look at the pricing on a used hopefully not abused VTEC motor swap. Much easier and Honda did it out of the box.

I’m sure if you scour some Del Sol forums they’ll give you better info than we can

In addition to what others have said, I’d say a turbo will give you a little better mileage than a supercharger, which is on all the time and saps some HP from the engine to run it. Like others have said though, it is a LOT easier to install a blower than a turbo, and there is no lag to the boost with a supercharger, unlike a turbo, which takes some time to spool up.

If your money is burning a hole in your pocket, there are probably kits to do either one available if you have a popular motor.

If you want to go faster on the cheap, you may actually consider N2O. Someone did mention that it can wreck your motor, but if you run a modest amount of the stuff (say, 35-50 hp worth), this is unlikely unless the motor already has one foot in the grave. This will cost hundreds as opposed to thousands for adding a turbo or blower, and is easier on your engine as long as you don’t try the 300 hp kit. 35-50 extra hp in a car this small will feel like a lot, although it won’t be like in the Fast and the Furious movies where they hit the button and the skin starts peeling off their faces Nitrous (I don’t call it NNNAAAASSSS like the high school kids) is only “warp drive” in the movies. The only caveat I can think of is that a mild N2O boost is easy to do and can be installed in a couple hours. If you are looking for a challenge to keep you occupied for a while, you may want to go back the the turbo or blower idea.