Camden vs. Nelson

Looking to install a supercharger on my S5 NA.
Super charger options: Camden or Nelson
- Pro n Cons of each?
- Horsepower and Torque power of each?
- Installations difficulty of each?
- Smog legal? (I doubt it but I think I heard the nelson runs on a stock motor)
- MPG of each? (Just curious)

Project Car of installing Supercharger:
1991 Rx7 N/A 5speed
- stock MT
- alum. RB flywheel
- 4:33 LSD diff
- stock clutch (but might have to upgrade it)
- cone air filter
- RB true-duals exhaust system
- koyo alum. Radiator
- electric fan
- stock 460cc injectors
- street port engine
- pineapple insert sleeves

ECU: stock
- looking to install Rtek 2.0
- changing secondary injectors to 550cc w/Rtek

Suspension:
- enkei front-17x8.5 rear-18x9.5
- RA-1 tires
- coilovers


Looking for what to add or remove/change on my RX7 if added one of these Superchargers. Would like to keep stock MT, 460cc primary, 550cc secondary. But who knows if that’s capable with a supercharger.

I heard Turbo gives more power for NA than Supercharger, but I’m going to run my car in Autocross and would think the supercharger will give me the torque and quicker response over the turbo. Not road racing, drag nor drifting.

Thanks

 

I donno if this may help, but it deals with superchargers...

https://www.rx7club.com/showthread.p...t=supercharger

https://www.rx7club.com/showthread.p...t=supercharger

Search

Hope I helped.

 

I'll take a look at it.
thanks lonetlan

 

https://www.rx7club.com/showthread.p...n+supercharger

All that I found of worth to your need.

 

I'm not going to speak about the quality of each kit but I will address the superchargers themselves.

The Camden is a roots blower. There is tons of info on roots blowers out there. While the roots blower is the least efficient form of superchargers, the Camden unit is the least efficient type of roots blower. It doesn't get much more old fashioned and crude than that. It uses straight 2 lobe rotors. This is the oldest style of roots blower and there have been many efficiency gains with roots blowers since this style first came out. Basically the Camden unit internally is almost what roots blowers were 100 years ago. Not many people are willing to use 100 year old technology on something far more modern than that.

The Nelson/Paxton kits used a centrifugal supercharger. As with the roots there is also tons of info on this particular style out there. A centrifugal is generally a more efficient form of supercharging than a roots blower but again this particular supercharger is just about the oldest form of centrifugal. This old unit used a very crude compressor wheel with straight fins. They weren't very efficient and by todays standards even their max volumetric efficiency was off the low end of today's charts. The drive system in these units was also very crude. They weren't gears or even chains or belts but rather a friction drive. The name alone is alarming. In place of gears, they used what are basically just steel ***** that are tightly packed against another one. It is the very tight friction of these that rotates the compressor when the pulley is turned. They are so inefficient that even spinning one of them by hand is a difficult chore. Combine a very inefficient drive system with an inefficient compressor wheel and it makes for a poor design. I actually find it amazing that this particular unit could make 210 rwhp on a 2nd gen with nothing more than a rising rate fuel pressure regulator at about 6 lbs of boost. A modern supercharger should be quite nice by comparison.

When you realize that these 2 superchargers are the stone age of their particular supercharger designs and that these are the most common ever seen on rotaries, it is no wonder why so many rotary owns have a negative opinion of supercharging in general. All arguments aside with turbos, these 2 particular superchargers are about the least efficient ways possible to boost a rotary. Even compared to practically any other superchargers. You won't find a kit for any of them though. I personally would rather stay n/a than to have those archaic pieces on my car. It's like installing Model T engine performance parts on your brand new 21st century ride.

 

Interesting thought rotarygod. Just looking my option and doing some research and supercharge does seem a lil fun for an N/A.
thanks.

 

If it is supercharged, it is no longer naturally aspirated...

 

I think its because there isn't anywhere to post about superchargers. I bet it would of been better to be in the Turbo section.

 

He wants to upgrade an n/a. Seems like the right place to me. Besides, if you even mention the word supercharger in the turbo section, it'll get torn to shreds with negative comments and in the end will have been a waste of time.

 

I have a Vortec V5G that I always intended to install on my '90 n/a. It won't make 400 hp but it isn't sized to. I bought it with the intention of only getting about 250 rwhp out of it and had no reason to buy one that had far more potential than I would ever use. It could probably do 300 or so which isn't bad in a light car. I never got around to it and am now married with too many other things going on. If you are interested in it let me know. You'll need to build the mounting bracket for it though. I was going to install it with no intercooler running 8 lbs of boost and using only water injection to control detonation. Of course I was going to use a new ecu as well. I wanted simple yet faster than stock. I didn't want to go crazy to get it though. My goals were realistic and modest rather than overly expensive and unattainable within my budget.

 

Agreed.

 

Honestly after seeing the available options on the market I've decided to build my own supercharger kit. I wont bother going into the pros/cons of a supercharger vs a turbo, but for what I want a supercharger is the ideal path.

I'm basing my design around the eaton m90 from a ford Thunderbird. It has decent efficiency, many upgrade paths, are cheap and easy to buy used or new and importantly actually fits on top of the motor.

 

That supercharger is about mid technology in the roots world. It isn't the oldest and isn't the newest. It is better than the Camden design but there are still about 3 generations of roots blower improvements that are newer than it is. The problem with using the M90 is that it is a bit small so it isn't going to be terribly efficient. You may get 225 hp or so out of it but don't expect much more. Lower end power and drivability should be quite nice though. The M112 would be a better option but then you run into the issue of finding a way to make it fit on top of the engine. I used to have an M90 off of a Thunderbird and with it's long snout, even fitting it on top of the engine was an issue but doable if you are creative. I abandoned the idea to use it and then picked up a Vortec V5G instead. Sadly I'll probably never get around to installing it. I have too many other expenses and have been trying to build up my own (non car related) company so even time is short.

 

Wow.... sounds good

But, Rotarygod like you said im not trying to make major power, just some with more torque. Also i want it to be a daily driver too. Not a full on Race car. yes i do want this little power gain for AutoX.

True. no Supercahrge Section.

 

It will be an adequate daily driver if you do your best to build it right, and drive it respectfully.

 

Unless you're offering it for sale as a package, it's not a kit. Kits are things you buy.

(pet peeve)

I think this DOES belong in the rotary performance section. I didn't go to the Single Turbo section when I upgraded my 13BT to N/A status.

 

You can always convert it to a shorter snout housing, then it will fit.

 

I don't speak from experience but, I can't help thinking that the N/A drive-train which reportedly doesn't like a stock 13BT won't like a supercharged 13B any better. Especially since we're talking about a positive-displacement supercharger (low end torque) and activities such as autocross.

 

I think the supercharger is a little more forgiving on the transmissions as its a smoother transition of torque to it. Thats what kills transmission instant torque

 

I had the most up to date Nelson/Paxton system. It had the later Paxton charger and upgraded pulley. This made sure that the supercharger did not spin out of it's designed rpm level. The first pulleys were over spinning the supercharger and causing catastrophic failures. I don't really remember all this stuff now.

But anyway, with just the rising rate fuel pressure regulator and a K&N it made 225rwhp. The dyno chart was a dead straight 45 degree angle on hp. I will find the sheet if you really want this.

It was nice but the whole system felt like it struggled. I think it could have done another 25 hp if I had some sort of fuel management.

I spoke to the guy that bought the rights to the design. He said it produced 9-10 psi and would never produce anymore no matter what you did...that is it.

As for the drive train, mine was stock. I had no issue whatsoever. The stock trasmission and rear can handle 225rwhp for sure. Now if you are clutch dumping fan it might have issues...

 

Not that it has much relevance to this thread, but Ive really been wanting to do a twin-screw kenne belle charger on a 20B. 9-12psi and ~450whp with instant torque and response would be incredible.

 

Drivetrain strength information around here is really misleading. Many people act like just installing a turbo or supercharger is going to destroy the transmission or rear end. This just isn't the case. The strength issue comes into play when you are driving it really hard. The TII drivetrain can take more abuse but even it can be hurt and it doesn't take 500 hp to do it. I had a TII drivetrain in an 88 n/a and I ended up killing an afermarket TII clutch and took out a couple of syncros in it and I did it with less than 200 hp. What killed it was how hard I was driving it. Sure I would have killed the n/a drivetrain but it still happened. I could have driven very differently and made it live just fine, n/a drivetrain included. Hard launches off the line are what is really bad for it. You don't need to upgrade the whole drivetrain just to add boost. Just don't drive like it's a race car. As much as everyone wants one, it is impossible to have a race car that is streetable.

 

I was killing transmissions with stock 12A power. Then I started using Shockproof gear oil and all was well.

Now I'm killing transmissions with modified 13B (N/A) power. I just learned that Shockproof is only beneficial for the first five or six thousand miles, after which the calcium bits in it that provide the cushioning are depleted.

I went from a working, happy trans to having to hold my hand on the shifter in five 40-second runs. The bearings don't tolerate shock loads and will rapidly lose their ability to maintain end play. I change the units out before they eat the gears.

 

Well I've always figured clutch dumping is the main culprit (that and bigger, stickier tires), but still after reading through a number of N/A-to-Turbo threads over the years I guess it bothers me to see often and quickly they fail. That said, I'm not seeing how much abuse they receive on top of the miles they've accumulated before part X breaks.

 

From what I've seen, 3rd dies first, and CAN fail from a roll.