I am 19 yrs old and i'm a newbee sorry i f my grammar isn't rigth either i am terrible at english.

I am planning to buy an fc and i want to modified its engine to run faster , i was reading this article about natural aspireted engine, it said that it work like a turbo charge but unlike turbo charge no lag time and it continues to give boost to the engine.This interest me and went of to research yet i dont have a definet answer how it work or how it to be fitted to the fc . I am relly greatlful if you can give me some pointers and some advise in this matter.

 

I think you're kind of mixed up with your terms.

Naturally aspirated (abbreviated n/a) is like the basic engine. Then you have two choices to increase HP through boost...

turbo - uses the car's exhaust to spin up a turbine, which will compress the air. Turbos have turbo lag, which means it doesn't spool up (and therefore not giving you that extra power) until, say 3000 rpm.

supercharger - runs off belts and doesn't have that turbo lag, like you said

With the camden supercharger kit, I think I've read people can get up to 180-200 HP. The stock turbo already creates 180-200 HP and can be modded to maybe 400 HP with a compressor upgrade. Just stuff off the top of my head. For more info on superchargers, you can always use that search button at the top and type in "supercharger."

https://www.rx7club.com/search.php?searchid=625683


quote from evil aviator (much more knowledgeable than me):

There are really only two advantages to a belt-driven supercharger on an RX-7:
1) It's different.
2) The "feel" of the car is more positive because boost is directly related to engine rpm.

Other than that, a turbocharger setup is usually less expensive, offers a wider boost profile, will yield more power for a given boost level than roots or lysholm superchargers, is less prone to detonate than roots or lysholm superchargers, is easier to intercool than a roots supercharger, and will create boost faster than a centrifugal supercharger. A modern ball bearing and/or sequenced turbo will also create boost at about the same point as a roots or lysholm supercharger.

False supercharger "facts':
1) They create instant boost.
2) They give the engine more torque than a turbocharger would.
3) They are less expensive, less complicated, and easier to install than a turbocharger.

 

ATI blower chargers and roots chargers cost a ******* fortune compared to garret turbos. So thats totally true. Instant boost is completley possible with a roots charger.

Personally, the only good supercharger is a blower type and not the roots. Roots cannot be intercooled, and is for low boost applications. Although a blower type has a slightly longer delay, not much, it can be intercooled and has far more potential.

 

A roots CAN be intercooled. They can also run 15+psi if it's setup properly.

 

don't top fuel rail drag cars run roots type superchargers? the ones with the 4 inch wide supercharger belt. Does a supercharged engine feel like an n/a but with more power? or does it boost up all of a sudden like my turbo II?

 

it's more evenly distributed throught the rpm range.

 

From what I understand, every FC in your country comes with a turbocharger. Keep it that way.

The advertising you reference is probably from a vendor trying to sell a supercharger kit to people who own cars that do not have a turbo. Since your FC will have a turbo, there is no reason to spend $3,000 to $8,000 AUD on a supercharger kit that makes the same (or less) boost.

Absolutely, but it is a much larger undertaking than intercooling a supercharger that has an internal compression ratio.

Show me one that runs 15+ psi on super unleaded pump gas. I would especially like to see a kit that is advertised to perform at this level.

Dragsters use Roots blowers when the racing rules do not allow a better form of forced induction. High octane race fuel such as alcohol is less prone to detonation and pre-ignition, so higher boost levels are possible than would be on a street car.

There are three main types of belt-driven superchargers. The Roots and Lysholm types begin to produce boost quickly, reach peak boost about as fast as a quick-spooling turbo, and pretty much hold that peak boost level until redline. A centrifugal supercharger is quite different, as it produces more boost with more rpm (for example, it may feel like it produces 2psi for every 1,000rpm, even though this isn't exactly correct in technical terms). The main thing to understand about the turbo vs. supercharger feel is that a turbo spools on its own which makes it feel disconnected or mushy, while a supercharger is tied directly to the engine which gives it more of a positive mechanical feel.

 

To gingenhen thanks for clearing that up , now i know i got those two term mix up and i know what n/a engine is all about and what is it do .I also understand what is different between turbo charge and super charge an what benefit rx7 engine and its performance .Thanks for the advise all of you guys cya next time .

 

To gingenhen thanks for clearing that up , now i know i got those two term mix up and i know what n/a engine is all about and what is it do .I also understand what is different between turbo charge and super charge an what benefit rx7 engine and its performance .Thanks for the advise all of you guys cya next time .

 

Aviator: The GTP guys do it pretty often, even my crappy setup was running 13 without much trouble. The stock blowers suck complete *** though above 10, ported and with better plenums/etc they're commonly in the 15psi range.

 

You mean with a Magnuson S-model Eaton supercharger?

 

Evil Aviator:

"stock" Eaton blowers equiped on Ford super coupes run 13psi on premium from what I read on their forums. I would suppose that 2 more psi would just require a pulley and the adequate fuel and ignition modifications....

 

That's correct, with the MP plenum and outlet there are quite a few people on the sccoa that are around 15psi. Any generation of the m90s (though the 1st models are a pain in the ***....) can

 

That's what I figured. It is hard to find a Roots supercharger kit that is intended to run over 12psi boost because most people with an engineering background that would allow them to design a kit would realize that boosting past this level is not the brightest thing to do. While the M90 is capable of 15psi boost, I don't think you would find anybody other than street racers and ghetto mechanics doing this to a street car.

From an interview with Jerry Magnuson:
"Jerry also offered some additional performance observations to dispel old roots falsehoods. Spinning a blower harder may get more boost, but that doesn't automatically mean more power. In the case of the Eaton, it's not a high pressure device. As he explains, it's pretty good at 11 or 12 lbs of boost, but it's dynamic a 8 lbs. The basic principle is high volume, low pressure. When you start moving out of that area, you're defeating the purpose of a roots blower."
Reference: http://www.sccoa.com/articles/blowerbuild.html

I think you will find that consistent with what I have been saying for quite some time.

Anyway, my disagreement with your quote of "They can also run 15+psi if it's setup properly" is that when set up properly, a Roots blower will not run anywhere near 15psi. A 15psi Roots blower is a ghetto mod IMO because it is well outside of the intended boost range, and a proper 15psi boost setup would use a different form of supercharging. While I do see many uses for a Roots blower, supercharging a gasoline engine at 15psi boost isn't one of them.

See the Magnuson quote above.

 

Good post Evil

 

Thanks, I hope the Roots supercharger application is a little more clear now.

 

With the quicker spool up, would a supercharger be more benificial than a turbo for autoX?

 

I have seen supercharged cars perform very well in autocross events. I think it has more to do with the supercharger being tied directly to the engine than it does with a quicker spool-up. Balance is very important in autocross, and it is much easier for a driver to control the power of a supercharged engine than it is a turbocharged engine, especially if the turbo is producing a lot of boost. Also, a supercharger doesn't necessarily have a quicker spool-up, or at least as far as boost vs rpm is concerned. A centrifugal supercharger doesn't even reach full boost until about engine redline, but still seems to work well in autocross events.

 

erm roots blower not only can just be intercooled, the boost is always there unlike the cent blower that needs to spin up to the sky before full boost...

 

Ok, now I get what you're saying. And I do quite agree with what you're saying. There's a point on a roots blower where AE and VE don't make up for the air/power you're gaining, however, like I was saying, with a modified blower it's been shown that forcing it out of it's efficiency can still be beneficial if done 'properly' (such as intercooling/etc), though it is definatly out of the 'proper' usage of the charger I would agree.