1985GSL

iTrader: (4)

what is better turbo or super charger post your experiences with each and say which is better.

brandon davis

iTrader: (3)

turbo boost is better i think nothing like 20+lbs of boost.

cdrad51

Good thread, I'm interested too since 2005 will be the year of forced induction for me!

steve84GS TII

Superchargers are good for boosting the lowend and midrange.The mounting options arent great and are not conducive to intercooling.But you dont need to do any plumbing on the exhaust and there isnt a thermal issue since there isnt any extra exhaust components radiating heat.Centrifugal superchargers offer more topend power and are easier to mount since you dont have to put them directly on the intake manifold.However,they still rob horsepower from the engine to work,like all superchargers.
If the right size turbo is selected,it offeres more flexibility than a blower.It can build boost in the lowend and still make great power all the way to redline.Without sapping any HP from the engine.Intercooling is easy with the turbo's "remote" mounting and pipe style plumbing.But the plumbing can be complex,with oil,water and charge pipes turning into a mess really quick.

Car manufactures like superchargers because of the simplicity and durability.Turbos affect cold start emissions with their heavy cast iron components hindering catylist light off.But turbos offer more power making ability across the RPM range with cost and complexity being the downside.Mazda always preferred turbos because of the rotaries natural high CFM airflow and hot exhaust.It was only natural to go turbo,even though the supercharger would have produced better lowend,something the rotary lacks.On the N/A engines,Mazda developed its variable intake tuning and aux port system to boost torque in the lowend(basically a precurser to VTEC,it works the same way)

If you want predictable,linear power and you arent planning on making a bunch more mods,the blower is great.Itll give you pull at almost any RPM,and its simple to install.But tuning is required since there are no factory supercharged rotaries.
Turbos are better suited to the HP junkie, and you have the advantage of Mazda's experience and development with the TII engine.It makes drop-in easy and theres no tuning involved if you run the factory EFI.You just have to live with a little more lag and a lot more heat.

calvinpaul

iTrader: (2)

So the question is has anyone here ever mounted a supercharger in conjunction with a turbo, so as to boost the low end and the high end? Or is it just not worth the money/time/effort?

sweetege

In my opinion if you were to do that it would have to have the same amount of boost at all rpm's and you would have to do a lot of crap like right air flow and fuel management and stuff, it is probably possible but in my opinion it isnt worth itget a super than port it good high with port with added torque from super that will be my setup next year... (evil grin hehe...)

steve84GS TII

Compound supercharging is nothing new,its been used for a long time,most noteably on 2 stroke diesels.The blowers positive displacement fed the engine at low speeds and startup,then the turbo takes over at speeds.
Its not a bad setup on a gasoline car engine,it eliminates lag.But its complex,and the blower is still robbing hp from the engine.Turbo technology has progressed to the point where lag isnt as much of a problem.Ballbearings and computor designed manifold have made nitrous spoolup and large/small twinturbo setups mostly obselete.If you fork out enough $$ for a good turbo(GT series is one),youll get a very responsive turbo that boosts like a blower,but will hold on all the way to redline.

Hyper4mance2k

iTrader: (40)

back pressure used to turn the turbo saps power from the engine..... and when a supercharger is off boost you can run a good by pass valve and it only uses 1/3 of a hp, which is less a powerloss at cruise than and turbo can claim... Even seen a n/a or turbo funny car or top fuel car. I havent!!

Directfreak

iTrader: (2)

Boy, this is a really, really old arguement that has been done to death here, in many threads.

Please look those up before bringing up an old argument. Most people don't PERSONALLY know Jack Schitt about either setups, but are willing to spew information previously posted by others as if it was in FIRSTHAND knowledge.

Hyper4mance2k

iTrader: (40)

Hope you're not referning to me. I've been working with supercharged cars for over 8 years... And have a Huge knowlege base when it comes to turbos. I'm More of a supercharger fan so I'm more apt to argue in favor for it. Frankly when it comes down to it there are positive and negitive aspects for both turbocharged and supercharged applications. When it comes down to it they're really both equal andit all comes down to personal taste. And the fact everyone and their mom can turbo a car nowadays. So its become much more practial way of doing it. Since there is sucha large resource for knowlege for it. So basicly do this pick one you like more and then find out the best way to build it for your application. Because both superchargers, and turbochargers can acopmlish your goals.

sweetege

i dont know how much you can get a turbo for but an Eaton M90 is 300 bucks. cheap if you ask me thats the way i'm going. but lets please dont get into this argument again. cause it all depends on how much money you have and which you like better. it's called personal opinion not facts we here do'nt care about facts we care about is it fun was it hard to get or put in or how much was it not well this mag says blah blah blah. so anyway go with whatever you have the money for.

perfect_circle

https://www.rx7club.com/1st-gen-archive-71/engine-turbo-supercharger-82404/

fourth one down in the archive, didnt even have to search. goodluck

DAVID GRIMES

I see from your profile that you know about both ( at least from an ownership standpoint ). And you're right, it's the same old $ vs $... and which will boost the most... and which puts the least stress ... and whether to lag or not... yada yada yada.

But I am seriously thinking about getting a SC from Dan Atkins next Spring.
Unfortunately, I would like to know and read more about the subject specifically for the RX-7, but ONLY from those with knowledge from experience. That seems to be too much to ask. There's way too much "this is superior to that" ( premix or not... direct fire or stock ignition... etc ) and less actual information on how any one thing actually works.

That's why I have a particular respect for some of the forum members that simply post their experiences of what they did and their results. Jeff20b, Rx7carl, Sterling, DanAtkins, 680RWHP, and many others.

85rotarypower

This is a little off topic, but seeing Sterling's name there made me think of what he's posted recently. But I realized that he probably hasn't posted for a good month and a half. Where is he?? I always liked his views on things.

EDIT, Nevermind. Looks like he just hasn't posted in the 1st gen section too much. Looks like he's busy getting pissed off at people in the lounge and difference of opinion sections.

hornbm

I have driven plenty7 of FD's and I was lucky enough to drive dan atkins supercharged first gen. The camden supercharger setups are out of this world. If you havent ever had the chance to drive a supercharged rotary, its something to be experienced. My preference was made up right there on that drive.

My current weber N/A setup is on the verge of breaking 14's on a stock port. Can you just imagine what a superchager + weber would do? The question is hooking the power up.

Atkins rotary's current flag ship car, is a supercharged fuel injected ported 13B beast, but will spin the tires up to third gear. Supercharging gives power instantly, which makes wheel spin a big problem on street tires

gonzz

Nothing like the Turbo!!!

Directfreak

iTrader: (2)

I wasn't - I was referring to the thread starter, hence my statement:

Which was pleasantly brought up by:

Although - I do have to point a few things out. You stated

The back presure HP lost on a Turbo is NOTHING compared to Parasitic HP Loss a supercharger has across the whole RPM band, - especially at High RPM.

Technology has changed significantly, and Turbo's offer practically ZERO Lag compared to the old school days. I have a "large" turbo and and have full boost by 3500 RPM, and have built several lbs of boost by 2000 RPM. Imagine a Ball bearing Turbo - even less "lag". Steve84GS stated it well.

Proper Turbo sizing is the key to either Zero Lag, or High RPM CFM Flow. A Large exhaust housing on the Turbo (as the Aussie's like) will have very little backpressure too, nothing that you can even notice.

As far as the Supercharger "By Pass" that you are claiming - tell me which Supercharger has one that you can use on your Rotary. The "By-Pass" is almost always incorporated into the intake manifold - which you can't use if
you are trying to make it fit onto a little rotary.

Atkins S/C doesn't have a bypass, and that is a dedicated kit for use with the Rotary. So you will ALWAYS have Parasitic loss, and the extra heat generated.

The power and "wheelspin" that car (Code Blue's?) generated is nice, because it has instant torque. But... What's the point of all the torque to get passed .250 seconds later by a Turbo Rotary. Not knocking on their setups, but I think the most they have put out is in the neigborhood of 200 rwhp, and that's with all the bolt ons, and Fuel injection. I don't know about you, but my car on only the wastegate spring (9psi) puts out over 270 hp - BIG Difference. Not to mention running more boost. (which incidently, can be changed with the flick of a switch or the twist of a ****). Not having to change a Pulley is another Big Turbo Plus.

Also Funny Cars or Top Fuel cars are NOT ALLOWED to have Turbos. That's why. Look at NOPI (NDRA- Sport compact). Tell me which Race Team has a supercharger. That is a more realistic comparison, since the Rotary is allowed to run there as well.

I like the idea of a S/C on a Rotary, if you have already spent the money on every other bolt on available, since the S/C will only enhance them better. That way your previous investments in Mods doesn't go to waste. Maybe 200 rwhp is enough for the average RX-7 enthusiast. But every new car out there, and soccer mom with an SUV can still give you a run for your money with only 200 rwhp.

If you're starting from scratch, I thnk you might as well work with a more flexible system that is much more upgradable, and easy to obtain the parts for - AKA Turbo.

I am not trying to **** anybody off, and I am not arguing for or against anything. I am stating some FACTS though. Everybody is entitled to make their own decision.

Just my 02 cents.

kapn krunch

id recomend that you read maximun boost by corky bell or a book called by street supercharging see what the diffs between the 2 are and decide wich way you want to go from there. those are both very informative books with lots of good information on both subjects in them

Hyper4mance2k

iTrader: (40)

Yo, directfreak very good points. If I was starting fron scratch I'd go turbo, But I hate to waste money so I'm prolly going Scharger Unless Robert can hook me up. I e-mailed him So maybe I'm going turbo afterall Gawd that would suck, or shall I say Blow. lol

Whizbang

if the turbo is so great then why do all of the top fuel drag cars run S/C's?

Asnwer: Turbo Lag.

I know a guy running 25 lbs of boost on his S/C and it being a lysholm style, it has a better effeiceny then any other S/C (80+%) and the it has a torque curve like a mac truck.

Directfreak

iTrader: (2)

CORRECT Answer: was already stated in my post above.

Sterling

Ooooohh I just love this arguement!
C'mon, let's argue 'bout it!
"Turbos suck ***, man!"
"Superchargers rob all the power they make and stress yer engine!"

David Grimes, I have not had a blown rotary, so's ya know. I proposed the idea about two years ago (maybe three) here of using an Eaton M90 on my stockport 12a. (Look it up. Lotsa good info.)
Here's what I have learned...

I have yet to slap that M90 on my little puppy, but whenever this old BS rears it's ugly head, I'm amazed at the knowitalls that wanna compare apples to oranges.

First of all, the Atkins blower...I met Dan. I like him, he's a great kid and not a malicious bone in his body. But his ole man bought the Camden from MazdaTrix, he didn't make it himself, and so I have no problem saying that that **** is older than Direct Freak!
Two lobes, straight, and I'm not even sure if there's a teflon apex seal. It requires plumbing for an oil line, utilizes no bypass valving and is not port-conducive to breathing in cooled charge.

The Eaton M90 is a tri-lobed helical rotor design and port-timed to get rid of that "Fuppp-Fuppp-Fuppp-Fuppp" pulsation, is lubrication-resevoired with a plug and can be orientated at any angle, and utilizes a bypass valve that while you're cruising is said by Eaton to leave the blower using 3 HP (THAT'S T H R E E ) to spin during cruising.
And Eaton guarantees, as an OEM part, their supercharger series for O N E H U N D R E D T H O U S A N D miles!

I only figured it was fair to mention that not all SCs are made equal, while turbos are pretty much one design.
2ndGenV8RX-7(Kenishi please forgive me for typing that) mentioned the Lysolm...the Eaton M series is about as close to a screw-type as most of our wallets will allow for.

Ehhh. Family takes priority, ya know how it is. Hopefully someday I'll be able to start my project. The plan is to make a kit with all the brackets and **** and sell it to you guys. Then you just need a blower and intercooler. Trying to make it so you can all boost your rotaries for UNDER $1500...12-15 psi max, and NO CHANGING PULLIES!!!
If it all works out, I'll have a manual over-ride for the by-pass valve that gets set into the dash.

"Dial-a-boost"

You people think I'm kidding.

IanS

iTrader: (4)

Since we are talking about it (well, you are) what would be a good sized S/C for a single rotor.

BEHOLD!!! The power of the 6A!!! muwahahaha

Sterling

I dunno. Eaton makes a couple real nice 1 litre blowers...one for the Mercedes Kompressor (Add a few bucks because it's for the Mercedes).
They have a nice high threshold, so running in a one:one will be great. You're not likely to be blowing out 8K RPM in a single-rotor anyhoo.

Look up "Magnuson" blowers. These guys take the barebones Eatons and port the intake and outputs so that they pulse less, etc. I have a hard time thinking they have any need to replace bearings (IE< I doubt that Eaton uses shitty bearings) but they gaurantee some of their blowers to some outrageous RPMS.

I say better to overboost and underdrive. Boost can be bled.
It's all speculation on my part.

Supper

Actually, I hope you are not kidding. The only thing that has kept me from not considering doing forced induction on my 12a is the costs vs. the benefits. Because, IMO, $2,000 + isn't worth putting boost on an engine that is allready fun to drive as it is. I would just get my tit in a ringer if I had boost.

That and I have the diesel truck to feed my boost addiction.