Anyone here tried one of the Rotrex s/c? Sounds like it woukd be perfect for the S2k, runs at higher rpm so more gains at lower and mid end compared to other s/c, doesn't make much noise, etc.

 

It's just a normal centrifugal supercharger. Vortech and Comptech are the same type (centrifugal), and I would imagine have the same characteristics.

 

Rotrex s/c use fixed ratio planetary rollers instead of gear driven centrifugal, which are more efficient with less noise. I believe this also allows for higher rpms and faster spool up of the s/c which means more power at the lower and mid ranges which all S2k owners are looking for. I might not be wording this correctly but I think you know what I mean.

 

From my understanding, Peter jackson of Jackson Racing and Skunk2 created (Kraftwerks. The product that is in release soon is their Rotrex kit for the s2000.

 

Ahh OK "self-adjusting planet geometry". Now I see the difference between the two.

 

Think we have heard the rotrex should be different many times enough now.
Is there anyone that can actually show some valuable data that will compare a rotrex with lets say a comptech or vortech?

 

Do a google search and start reading, they have data of better response at lower and mid range because of faster spool up ( higher rpm ) of s/c, lower noise. I know spool up is a term usually associated with turbo's but you know what I mean.

 

Never heard of it.

 

Yes ive done alittle bit of reading but its almost always the same things being mentioned, like it spools faster etc. I would really like to see comparable graphs or numbers to another centrifugal SC.

 

Do more reading, better low and mid power!!!!!!!!!

 

Yes yes thats also part of the usal information it all comes together, but still I have not found any real measures for HOW big the difference is. I would like some visual graph or some sheet with numbers that shows the distance to other sc's.

 

http://www.vtec.net/articles/ Here do some more reading, they have graphs somewhere, geeez.

 

if you can read compressor maps or flow charts here ya go.
http://www.rotrex.com/pdfs/Rotrex_Te...Range_V4.0.pdf

 

Nice info, im not experienced with Superchargers so any side by side tests would be intresting. Anyone know of such tests?
The Rotrex looks like a planetary gear to me.

 

i was hoping the kraftwerks kit would challenge comptech/vortech for supercharger market share based not only on performance but also on price. although comptech/vortech give decent gains, they are a tad overpriced.

i thought kraftwerks would've cornered the market by offering a cheaper kit (maybe at $4,000) but their kit is even more costly than everybody elses at $6495 for the base kit. now i'm not even going to consider them.

 

Anyone seen any pricing on the SOT hotside kit yet?

 

i'm under the impression that the sot/brp kit isn't quite out yet (just the four testers). i'd guess 'round five grand or so.

 

If i remember correctly, I saw some info about the shipping date for the preordered kits were postponed from early march to 26th of march, wich would mean tomorrow.

Havent investigated this any further, but it sure should be intresting to see what that supercharger kit can do.
I am very confident it will be "better" than the standard centrifugal SCs just because it has a much more brilliant design in my eyes. There are basically 2 parts of this SC where compressor rpms are converted to be greater than engine rpms. First is the beltpulleys ofcourse and second is the way it is designed as a planetary gear. Should be more like a turbo. At least my common sence says that

Still too pricy for my taste when I can sort out my own turbo kit for maybe 4000 bucks.

 

the base kit isnt 6500 bucks, thats the high grade kit that comes with new injectors, and hondata reflash. The 6500 kit tho does make about 300+ whp and is very much quiter and has a lot more torque. The only this i heard that you need to buy is a better clutch. I want to get this one but i am worried about the tranny and the drive train in general. Anyone got any thoughts for me?

 

I know a couple guys that have just installed it... 327hp & 213 torque with a really flat curve; boost starting at 2200rpm vs 6 grand..

Don't know if you can see this but they're getting ready for the 1 lap across America race (our Lotus 7s have S2000 motors in them)

http://www.usa7s.com/aspnetforum/Def...sts&t=2142&p=4

 

That's for the Rotrex, right? If so, which kit is it?

 

yea if i get a kit this will be the one that i end up buying

 

I just know it's the new rotrex supercharger and it's on a S2000 motor. Obviously the rest of the components are custom for the Lotus 7 engine bay (tight!). Notice it's down low on the driver's side....
I'm sure the kit for your car will be similar in performance but come with bolt up parts for your car.
This car did spend a considerable time on the dyno to make it ready for the race (reliability and performance). They actually have 2 tunes; one for premium gas and the other for the E85 stuff (which actually runs cooler). They had a Vortech last year but wanted the power to come on at lower RPMs.

 

Yup, seems rotrex or turbo are the ways to go for that.

 

I hardly think any turbo would be the way to go for lower rpm engagement. Any supercharger is belt driven, so it's running along w/ the motor at all times. If you want more/better/faster/harsher engagement, up the boost. or build your bottom end with some mild like stage 2 cams etc.

 

Turbos can be sized to spin up at low rpms, they just have to small. To get wide power band generally 2 are used. I had a Renault Fuego Turbo which was perfectly designed. It had a single turbo which started boosting at 2500 rpm all the way to redline at 8000 rpm. For the S the task is harder.

And I was wondering why roots blowers aren't used instead of centrifugal super chargers.

Jonathan

 

wow very informative thread, I'm in the market for this upgrade but I'm still contemplating on going turbo charger or supercharger.

keep it coming guys.

thanks
__________________
fire it up Pulse Star Plugs

 

We have run both Votech and Rotrex on our Ultralite S2K (mentioned above) in the One Lap and on the streets/tracks around the US. I have to say that I really like the Rotrex unit. Its quite and does exactly what its says it will do. We had allot of durability issues with the Vortech. It did not hold up well to the track abuse. The Rotrex has not failed one time. It allowed us to seize third overall in the One Lap in 08. After the One Lap we put it on the Dyno at Wheel to Wheel in Detroit and found that we were running 381 hp insteed of 327 hp @ 11 psi. Our new motor that Kenny Tran (Jotech) is helping us with will run closer to 18 to 20 psi (rotrex C38 hoping for somewhere between 550 to 600 at the rear wheels. This will give us a HP to weight ratio of 2.6 lbs to 1 HP. (1600lbs/600hp) If you would like more info follow these links.
http://organicracing.com/blog/ or to see the build http://www.usa7s.com/vb/showthread.php?t=2107

Cheers...
7evin
If it can't Kill you it Ain't a Sport

 

God they sound great youtube as a vid