supercharger?

[johnl]

Wow, a 1.5L V12... I've always been fascinated by small-displacement engines with more than 4 cylinders.

That V12 sounds insane though!

Deever, read more carefully, that's a V16 (sixteen), not a 12.

Did you download the sound file? Copy it to CD and play it loud on a good stereo, and if you play it at the real DB (probably impossible...) your ears will bleed. It's an amazing sounding motor (not just volume, which was very very loud, but the complexity of the sound) with utterly astonishing specification and performance for its time, but ultimately a heroic failure (under funded in post war struggling British economy).

I would love to see one of the pistons. I bet I could make a nifty keychain out of it

Bore and stroke = 49.5mm by 47.8 mm, so you probaly could, or egg cups...

[deevergote]

Deever, read more carefully, that's a V16 (sixteen), not a 12.

Did you download the sound file? Copy it to CD and play it loud on a good stereo, and if you play it at the real DB (probably impossible...) your ears will bleed. It's an amazing sounding motor (not just volume, which was very very loud, but the complexity of the sound) with utterly astonishing specification and performance for its time, but ultimately a heroic failure (under funded in post war struggling British economy).



Bore and stroke = 49.5mm by 47.8 mm, so you probaly could, or egg cups...

Whoops! Yeah, I went looking for pictures of it and realized it. I guess my overworked brain couldn't fathom so many cylinders in a 1.5L!

I want to burn it to a CD and play it in my car I'll tell people my Fit is heavily modified...

[The-Gr8-Ox]

that supercharged v16 sounds sweeeet looks like a beauty too!

[Renjiking13]

the only thing about superchargers is that you are constantly in boost. plus they are not that good on 4 cylinder engines. for example look at the new cobalt coming out. it is no longer supercharged it is running a turbo. turbos are better.

[The-Gr8-Ox]

the only thing about superchargers is that you are constantly in boost. plus they are not that good on 4 cylinder engines. for example look at the new cobalt coming out. it is no longer supercharged it is running a turbo. turbos are better.

i dissagree,

superchargers are just fine for our cars, the lame excuse of "superchargers are constantly in boost" has no merit. boost goes up when rpm goes up, and superchargers like say the jrsc for the h22 is putting at most 15psi or tad more at full throttle with the high boost kit, in idle or around 2-3k you might be putting somewhere in the neighborhood of 5-8 psi. the carb legal kit only does 5-6 psi max, that will not harm the motor at all.

your psi is lower than a turbo, and a turbo can be more harmful than the supercharger.

lets stick to superchargers and leave turbos out of it, this isn't thread dedicated to which is best, but can we do it, and what is available

[johnl]

your psi is lower than a turbo, and a turbo can be more harmful than the supercharger.

Superchargers ('blowers') can boost at more or less any psi you want, e.g. BRM V16 boost = 70psi (with the most powerful incarnation of the engine).

The nice thing about most positive displacement supercharger set ups is the boost pressure can be much the same from low to high rpm, making for a flat torque curve from low to high rpm, which isn't so easy with turbo chargers or centrigugal blowers (both non-positive displacement).

One of the problems for the BRM V16 was that the torque curve was very much a product of blower rpm, rising very steeply with engine rpm. The car suffered greatly from losing traction, and once wheelspin started the engine rpm jumped and power sharply increased even more, making it harder and harder for the driver to regain traction (I once read a drive report where the rear tyres were described as "existing in a state of wheelspin").

If you listen carefully to the BRM recording, you can hear that the driver isn't really 'on it', but I wouldn't blame him (Stirling Moss refused to race the BRM because he considered its power characteristics dangereous...).

[deevergote]

your psi is lower than a turbo, and a turbo can be more harmful than the supercharger.

You can bleed off boost from a turbo at any PSI you want with a wastegate. Turbos can be intercooled, which makes for lower intake temperatures. Heat is a MAJOR cause for engine wear and failure. It is difficult and very expensive to intercool a positive displacement blower, and the effects are usually not as drastic as with an intercooled turbo setup. The only real way a supercharger is safer than a turbo is that you absolutely can not accidentally overboost with a supercharger. A turbo's wastegate can fail. The supercharger will only spin as fast as the engine will spin it. To overboost a supercharged engine, you'd need to over-rev... and that would probably blow the motor first.

Turbos are more versatile. There are more options for parts and more options for installation. Ultimately, though, it is the effect that determines which is superior. If instant throttle response and a fairly flat torque curve are important (such as with an autocross car), a supercharger is very useful.

And there's no problem with superchargers on smaller 4 cylinder engines. The Cobalt wasn't changed to turbo because the supercharger was an inferior piece of equipment. It was changed because the market showed that the demand was for turbo sport compacts (the SRT-4 and Mazdaspeed3 outsold the Cobalt SS significantly)

[EJX_Michael]

I'll bet it didn't, but I'll also bet it didn't work...

You would win the second one... It wasn't getting enough fuel to move, it would just stall when pushing the gas pedal. We didnt want to drill the jets out on the carb though...

Just a little fun to see if it would work... Which it didn't... I should have stated that in my original post...