Bob78rx7

Hello, My name is Bob and I'm new to these forums. I have a yellow early 79 Mazda RX-7 (It only had a left rearview mirror, and hood popping rod is on the right side) with a 13B fully ported, free-flowing exhaust, 4-Barrel Carb, and racing transmission, clutch, suspension.

My question is: Do any of you use superchargers and if you do is it belt driven or electric powered?

(Attached picture is NOT a picture but actually a Japenese 78 that looks very similar)

edwin-82/rx7

iTrader: (1)

www.camdensuperchargers.com

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iTrader: (1)

We have a Camden Supercharger.

If you want to see it ? look in my Sig.

Bob78rx7

Thank You edwin although there is one problem with those Camden Superchargers. It said fuel injected, and talked about 2nd gens. I use a Carburated Engine and Even though I am using a 2nd gen engine I'm quite sure I have the stock ECU for 1st gen.
If anyone can give me any more info on superchargers for rx-7s and electric superchargers in general.

One more thing, How do I get my attached pictures to display or at least a link?

nick1

although i know almost nothing about superchargers, i do know that you can run a camden with a carb'd engine

nick1

you'll get your answers once the right people see this thread. don't worry. also, just so you know, there is always a big huge debate or should i say "scrap" on just about every thread that mentions superchargers regarding whether turbo, or chargers are better, so be warned.........

trochoid

iTrader: (6)

To attach pics, go to the advanced, skip the post quick reply.

If you are talking about the eBay electric superchargers, many of those are marine bilge vents.

What are your hp goals? A bridgeported 13b 4-port with high compression rotors can get you to 250, maybe more.

BlackFireRX7

electrically powered superchager...can you say inefficient??

thats like getting in your car and driving around the block just to go across the street!

Bob78rx7

My car will be about 240-250 peak hp once the engine is broken in but for now it only has a few hundred miles on it. I also don't want a bridgeport because this is a street car (not streetracer) I'm going to be driving this to work and stuff so I don't want something that will decrease reliabilty or cost alot to drive.

And about the electric Supercharger I would make it toggle switch operated for a nice little 15 sec. boost or so. Kind of like nos. Also i would get a much powerful alternator and a seperate battery that would got to the Supercharger and to my sound system when I'm not boosting (think LOUD ). It would be a street leagal (I think)nos that I don't have to refill. But what I just said is all I know so I would like to find out more. I'm also thinking of installing an intercooler but would it work when I don't have the supercharger boosting?

Thanks for the attachment help trochoid, the picture was too big.

64mgb

iTrader: (1)

What I want to know is where you found a 1978 RX-7??

jrs10

As for switching on and off an electric SC (Which I think are POS anyway) how would you handle the fuel enrichment that would be required so you don't go lean under boost?

jrs10

Of course, my previous comment (regarding enrichment) would only apply on something that can provide boost. (from what I understand... those electric SCs can provide a higher CFM, but almost nothing for pressure... so you really aren't gaining anything that a free flowing intake can't give you.

What you really should do, is spend the time and money right, get yerself either a TCU or a SC, and properly build your induction system. Plus, when you do it right, you could run a standalone ECU for fuel management and ignition if you desire... which when tuned correctly can give you better driveability, better fuel economy and so on.

Remember the the name of the game is volumetric efficiency you may be able to flow a high CFM, but without any reasonable amount of pressurization (boost) to fill the combustion chamber with more air, you won't see much, if any, performance enhancement. (except for the lighter wallet from buying a electric supercharger)


---edited for spelling errors.---

BlackFireRX7

You need Kiker's button!!!!!

look here

seriously though, if you want nitrous then install nitrous...

For a variety of reasons (some listed above) it would be in no way worth it!!

Kinda reminds me of my buddy that put a heat sink fan in the intake duct of his 89 Grand Prix with a 2.8L...

DAVID GRIMES

BlackfireRx7, That is so cool how you linked these threads with hyperlinks. Jumping back and forth is like deja vu and all. Wow. Thanks.

Bob78rx7

I have thought about it and most of you are right. In order for this to work it would be too expensive and complicated. And I don't actually need nos or a nos-like boost. I do want a button like his that does something cool like a cloud of smoke or rearward spraying washer jets. I do have a more free-flowing intake than stock but I don't think it is completely free-flowing.

Is SC a Supercharger? and TCU a Turbo? I don't know much about ECUs or chipping cars. Although, I would like to get into it. I just don't know how I would program my car's chip to get the best performance, or how to install one (I bet it tells you how). My next question is would an intercooler be helpful if I didn't have boost (ie. turbo or supercharger)?

BlackFireRX7

When air is compressed (such as with supercharger or turbo) it heats up. This makes the aircharge less dense and will make the air/fuel mixture less stable which can cause detonation. To get away from the detonation you have to run even less ignition advance and/or less boost. An intercooler disipates this heat, which allows the air to become denser still and allows you to actually run more boost and/or ignition advance.

to answer your question: On a normally aspirated engine the air has not been heated so it does not need to be cooled by such means. Some people pack ice around their intakes manifolds/carbs/intake tracks...a good "cold air" intake works too. just make sure its not one of those dorky *** ricer "K and N" intakes that is really a hot air intake! lol

If you clouldn't tell I am a piston guy by nature....can someone confirm my spiel about detonation as far as its relation to rotaries?

Bob78rx7

So is a cold air intake different than an intercooler on a naturally aspirated engine? i thought they were basically the same. And what is ricer about K&N? My friend loves them.

jrs10

Okay... there is no intercoolers on a NA motor... Intercoolers cool compressed air... there is no compression that occurs with the air prior to entering a NA engine... so no need for an intercooler. Most intercoolers are air to air... meaning that you take the hot air coming from the TCU (turbo charger unit) or the SC (super charger) which may be very hot, and cool it using the ambient air.

So with that... you can take 200F air temperature and cool it to ~80F on a 70 degree day... you are passing the heat to the air around the intercooler. It works very similar to a radiator.

The other kind of intercooler would be water to air. Cooling the air charge with cool water. Since water can absorb much more heat than air (its denser than air--so it has a higher thermal efficiency) it is able to cool the air very well, but also requires much more hardware to run.

The only type of intercooler that could work (but don't work as I'll explain) on a NA motor would be a water to air... (an air to air would do absolutely nothing.) But of course, the water to air IC (intercooler) would create a flow restriction on the intake, since you are relying on the motor's vacuum to pull air. The forced induction on a boosted motor will overcome the restrictions.

Now... As for a cold air intake... If you are pulling air from under the hood, you are going to be getting lots of hot air. A cold air intake simply gets the air from a cool location, usually underneath the front bumper. As you probably know, cooler air results in a denser charge, which when tuned correctly, will give you more HP. Cold air intakes also have their drawbacks as well... for example, if you drive in the rain, and get water splashed up to the intake, you have a chance of sucking in water, and hydrolocking the motor.

I don't consider K&N to be "ricer"... though it is a very common bolt on, that doesn't do a whole heck of a lot... just don't expect 30HP gains from an air filter... as a matter of fact, many newer cars with hot-wire MAF (Mass Air Flow sensor) experience a loss of power running a oiled-gauze style filter, because people over-oil them and coat the MAF sensor in oil.

797

an electric supercharger is a joke, they'll give you like 2 horsepower. Yes an intercooler will help a forced induction engine, it cools the air down. You should do some searches on some of these things, theres a lot of good info on nitrous and supercharging, and turbocharging the rotary.

BlackFireRX7

I am refering to the "cold air" intakes that ricer kids love that are really hot air intakes because they are cheap and just pull air from the engine compartment...

the reason KnN is in quotations is because most of the cheap ones are imitations

KnN is a great product!! I plan on one for my Camaro (if I ever get around to building an airbox) and my Rx7

anthrax

In your first post you said that this car is Carbed, but then in subsiquent posts you said that you had a stock G1 ECU, and then go on to talk about "chipping" your car.

Now unless I missed something, Carbed cars don't have ECUs that is one of the beatuiful things about carberation no electronic control.

That means that there is no chip for "chipping".

Any way on these cars TC seems to be the way the wind blows around here. There are a number of different ways to achieve this like a TII engin and drive train swap, or turbo your exisiting engin.

This forum can be a great resource.

Good Luck

A

Bob78rx7

Thanks for all the info and help.

kenn_chan

the 1st gens have a small box that resides in the passenger compartment, many people think that this is a ECU when the see it for the first time, and mistakenly call it that, i would assume for the sake of the discussion that that is what he is reffering to.

you do not need forced induciton for an intercooler to work. its just that on an NA the restrictions to the intake outweight the gains of cooling the air charge. you do not neccesarrily need an intercooler if you are turboing or supercharging it just allows you to make more power as you can tune to a higher level without predetonation and of course cooler air = more o2 per lbs so it makes more power naturally.