I have been Recently considering the Forced induction path for my FC and have been looking into superchargers. Other than the Camden kit I can't find anything so I was wondering if anyone had a SC kit on there car and would be willing to talk to me about their setups. I am talking about fuel solutions ECU flashing the whole nine yards.
Also I am sure this has been covered but im not just looking for a manufacturer im looking for feedback and Ideas.

Thanks

 

I have the camden kit and when I first got it I had an FD fuel pump and a SAFC II and some bigger secondaries but can't remember the size right now, I have to ask the guy I got the kit from. You can't make the power like a turbo but it's nice to have it right away, no spool up. I drove home about 500 miles and love it all even though it was 100+ degrees outside and no AC and it only had the 6 psi pulley on it. Now I'm in the middle of installing a stand alone and an autonomics TB, four 72 lb injectors and an 11psi pulley.

 

im about to put mine one and after i break in the car with it on, i plan on going to a 12 psi pully, a megasquirt, and i already have water/meth injection to keep temps down and a walbro, i also have a light weight steel flywheel. it cost alot of money to setup i can tell you that. with a standalone bigger injectors and 12 psi im hopeing to get around 250hp if not more.

 

i was reading a mag at the grocery store, sport comapct car or something similar, they did a side by side comparison of turbos and supercharger kits. said the supercharger was more expensive and less HP...

 

The supercharger gives instant power though and only gets stronger as your rpms increase. Camden is the only full kit that I am aware of that is still in production for the RX7. They recently came out with the EFI supercharger. It ran a little hot, but I don't think my car was set up correctly before I had to have the motor torn apart.

Paxton use to make a kit for the RX-7 but they are no longer in production. These were great, but their fatal flaw was the gearing in them spun the supercharger past its max due to the RX-7's high rpm abilities and killed the supercharger.

What type of driving will you be doing? If autocrossing, a supercharger is great as its instant predictable power during the lower rpm runs, unlike the big turbos that you would need for great horsepower. If you are able to keep the car in the rpm range that the turbo loves, then a turbo would be the better choice.

And the final question is $$$$$. Its been stated over and over on this site that the turbo is the best bang for the overall buck. Not only are there more parts, more experience out there for a turbo, but the parts themselves are cheaper.

Good luck on your choice. We can always use more SCRX-7's.

 

If you want instant and predictable power, why not install a properly sized turbocharger instead? A high compression 6 port engine spools a stock turbo instantly. Moving to something of similar size with a modern design (ie. GT28) will give you boost as soon as you crack the throttle, but won't make gobs of power. Of course, neither will a supercharger.

 

well since everyone is convinced that big turbo is the only way to go, (thanks FnF), not many are taking the time to size turbos for their specific application. they assume the bigger the better. We see a lot of BIG turbo Supras around here, most of them are the laggiest cars you've ever seen... and most arent even that impressive when the monster turbo finally kicks in.

 

The Camden kit is the only supercharger kit currently offered for the FC. With the current mass availibility of cheap JSpec TII engines, trendiness of high boost levels, and fast spool rates of modern ball-bearing turbos, there really isn't much market for Roots or centrifugal superchargers. We may see Lysholm supercharger kits in the near future if the cost of their manufacture continues to decline with advances in machining technology.

The whole nine yards would include a standalone EMS because the original EMS is horribly outdated regardless of how you flash it. If you are interested in superchargers, I recommend that you get a copy of Corky Bell's "Supercharged!" book from which I quote: "No one can go fast on a fuel system that is not calibrated correctly, and no fuel system in existence can be calibrated as accurately as modern electronic fuel injection. For this reason, EFI is the only fuel delivery system discussed in this book."

Yes, but a supercharger's boost is directly tied to engine rpm, which gives the car a more positive feel vs. the disconnected feel of a turbocharger. Also, the article may be a bit biased because sport compact cars (and rotary-powered cars) are usually light and tend to have high-rpm engines, which favors turbocharging since they are never raced at low rpms and don't require a lot of low-end torque to get them moving.

Not exactly. See pic:

 

Is that only using a 7lb pulley? Suppose you run a 12lb pulley? Interesting graph, where did you find it?

 

Running more boost with the camden becomes counter-productive as you increase heat measureably! I don't suggest anything over 10 lbs and I definitely recommend water injection as a must have.

 

I drew it myself because a lot of people who do not have a strong background in this type of thing tend to have difficulty understanding the difference between supercharger types. The lines are simply generalized representations, but I think they portray the main idea. However, keep in mind that you are just looking at boost on that chart, which does NOT necessarily relate to torque or horsepower.

In most cases, if the supercharger was properly matched to the engine with a 7lb pulley, changing to a 12lb pulley chews up the supercharger and/or fries the engine. If you want 12lb of boost, then start with a 12lb supercharger. Additionally, the Roots type (Eaton, Camden, etc.) is intended for low boost / high volume operation and performs poorly at higher boost levels.

 

didnt paxton make a limited run of S/C for the FC

 

First of all Boost is not linearly related to jack ****. The rpms at which the SC turns and thus the amount of air pumped, does.

"Boost" is the relation of mass of air moved vs the restriction the engine/intake present to that flow of air. Obviously you need some restriction or you will run a 1:1 pressure ratio (aka, no boost) and most compressors are actually a little more efficient with a little backpressure.

At any rate, That graph is basically "bupkus" as Adam Savage would put it, but the whole thing about how Centrifugals keep going up is very much true.

Anyway, on a rotary engine as inefficient as it is you need to REALLY focus on getting the most efficiency out of the compressor as you can, no matter what kind it is... thusly making centrifugals or twin screw aka "lysolm" superchargers the best idea.

Ideally a Lysolm would make up for the lack of low rpm power from a 13B, but rigging a way to intercool the air would be hard. A centrifugal is easier to run plumbing to a intercooler with, which is why I'd recommend that... as well as a properly set up exhaust (scavenge, dammit) and some porting.

But at any rate, you still won't get what a turbo gets... there is a reason people use turbos despite the lag.

 

I am looking into getting an intercooler for it so heat will not be an issue. The GTP uses a similar roots blower, and a company who makes intercoolers for them is looking at the bolt pattern of the RX7 intake to see if they can make it.

 

Wow this is alot more feedback than I expected. Well from what im being told at this point S/C is more on the lines of what I would wan't along with a good port job and a quick gasket match. After that 7lbs of boost - 10 lbs of boost is what I would be looking at and I would like to run it with a Centrifugal SC. Probably some 550 CC secondarys a walboro 255lph fuel pump custom fuel rail and probably a modified corksport FMIC system And just a HKS Fuel cut Defensor or E-manage. If I could afford it I would get a haltech but after the rest of this im not gonna have one red cent.

 

I know turbos are better in the long run but depending on what you do with the car is what you will buy. With a really good supercharger all you have to do is press the gas to get power.
If it tickles your fancy do a supercharged and turbocharged engine. Use a big turbo and the supercharger will compensate for the low rpms if you do it right.
(side note)
i got a working supercharger from a v1692 detroit. I think this is gonna be my next project. Its gonna take me hours just to figure out how to mount it in the car lol. I'm prolly gonna have to weld in a 1in adapter plate to the lim and maybe cut back some of the firewall.

lol

 

A centrifugal supercharger is the worst case for something like this. You will get hardly any boost at low RPM when you really need it.

A "gasket match" is going to be very little help.

You don't need an FCD on an NA as the NA ECU does not have fuel cut. To say "FCD or E-Manage" doesn't make much sense since the E-Manage is a tunable piggyback ECU, while an FCD just eliminates fuel cut on a turbo car without effecting the fuel flow.

A Walbro 255 is serious overkill.

There's no reason to use a custom fuel rail.

 

It will be interesting to see how this two speed centrifugal works out.

http://www.worldcarfans.com/tuners.c...d-supercharger

I'm fairly sure that the cost of the head unit will not make it attractive to 2nd Gen owners.

The size of the Rotrex unit seems ideal for a 2nd Gen, but again there is the cost factor of the head unit.

http://www.w2wpowertrain.com/c-64-ro...d-pullies.aspx

 

I had not meant to add FCD and I was tired but I have been looking at a few things since I got home and have decided on just a roots SC I am gonna order a Plenum from camden just to make things easier. And actually I think im gonna run a F-con instead of the E-manage. and wun it with a 8-10 lb pully.and 255lph would be overkill I will probably just use a 3rd gen Fuel pump. so what do you guys think? The rest will be the same.

 

I'm not sure what "bupkus" means, so would you please explain in technical terms? Feel free to post actual boost profiles to help explain.

More importantly, when does a race-driven RX-7 go below 3000rpm? Never.

Agreed.

I think the Rotrex head unit is priced just fine when compared to other superchargers. I would be interested to see how a C30-94 works on a 13B, although the compressor map shows it to be pretty much comparable to a conventional centrifugal compressor. As much as I like the AMM, I don't think it will be as much of a success with the sports car supercharger market as it will be in applications that place greater value on efficiency and smoothness. I am anticipating more sports car success with the plain Rotrex head unit unless the AMM addition is extremely inexpensive (which I doubt). Either way, I don't see much future in RX-7 supercharger kits.

Just in case you haven't found them, here are the main pages to Antonov and Rotrex:
http://www.antonovat.com
http://www.rotrex.com

See my sig. (No offense intended, just my own thoughts).

 

It's simply not worth the effort or the cost. If you care nothing of money, have at it. If you're afraid of lag, spend a week driving the car and you'll learn to avoid it for the most part. And the gains of a turbo by far will outweigh the 'no lag' benefit.

/i've tried em all!

 

I'm just looking at the instant power and it's goal is as a auto cross/weekend Drift Car, so instant power is to my benifit not to mention putting together a Turbo kit will cost more and at this time I cant handle the hassle of a drivetrain swap.

 

Just a slite curiosity, but how much horse power does a turbine generate in order to spin the compressor, or better yet how many watts is required to compress all that air.

 

Sorry, I forgot to address this. Yes.
http://www.geocities.com/boatseason/rx7.html
http://pbgarrott.tripod.com/Garrott.html

It depends on the supercharger model, rpm, and pressure ratio. Most manufacturers will give you this information. For an example, click on the various supercharger models here to see the charts:
http://www.magnusonproducts.com/models.htm

 

i don't think i'd go with an e-manage for the 7. it's a piggy back so it's still dependant on the factory ecu. it's parameters are limited also. and to tune it to compensate for the primary/secondary injectors being different sized at different rpm's is though on an e-mange. works fine for regular engines but i havn't heard too much good new with rx7's. go full standalone with a good tune it'll be the best money you'll spend. people spend hundreds of dollars for 15-30 hp increases anyway. might as well get the best performance out of your mods.