Sounds like the SOS kit is the one then and as I was reading..I take it, it's not Carb Legal since it got updated? Also is the CT kit and SOS about the same kit or different setup?

 

It has never been Carb legal. Comptech or Vortec is only options for supercharger

 

You can just pay someone or revert partially back to stock if you're worried about SMOG checks. I've gone partially back to stock with my SOS kit for California SMOG checks. I've done it three times and it only takes about four hours. You can just leave the heat exchanger on the car.

 

You have to factor in total cost/budget for the project, the kind of powerband you want, etc.

 

Kraftwerks actually has great customer service as well. We've installed their kits on multiple customer cars and had a lot of positive feedback on these. We've seen their kits be reliable, make good power gains, and not cost an arm and a leg. Sales pitch or not, there are a lot of great things to say about the Kraftwerks kits.

Kraftwerks does offer smaller pulleys for the C38-81 and most of their standard superchargers for those looking to push more PSI.

 

Kraftwerks you can go one pulley size down only without lowering engine redline. You can also upgrade to 91 blower for a couple more psi. Not quite maxed out stock but close too. It also puts out more boost than either the stock sos kits as it seems to make about 15-16 psi stock kit.

 

Summary of all of the above and other threads:

There are two major supercharger kit suppliers in the US. These are SOS with the Paxton blowers and an aftercooler, and Kraftwerks with the Rotrex blowers and an intercooler. The TTS kit from the UK is similar to the Kraftwerks kit. The older Comtech and Vortech kits are similar to the SOS kit.

The SOS and Kraftwerks kits are both quality kits and are pretty straight forward to install.

Many posters who spent several thousand dollars on a kit defend their choice and a few attack the other one. Disclosure: I bought the Kraftwerks kit.

The SOS kit comes in various configurations from lower HP to higher HP up to about 500 hp using E85. The KW kit comes in a standard form that makes a little over 400 hp. You can special order larger KW pulleys to reduce the boost. The KW kits also make up to about 500 hp using E85.

The KW kit is a bit less expensive than the SOS kit. The TTS kit is currently more expensive (probably largely due to exchange rates).

The SOS kit uses Paxton blowers which have a lot more gear noise than the Rotrex blowers in the KW kit. Some like the "supercharger sound" that the Paxton blowers make. I personally don't and this was a factor in my choice.

The aftercooler in the SOS kit provides less pressure drop from the compressor to the manifold than the intercooler. The Rotrex compressors are more efficient than the Paxton compressors and the end result is that the SOS kits with small pulleys and aftercoolers and the KW kits with the intercooler put about the same power. The Rotrex systems seem to put out more power for the same boost level than the Paxton based kits. This tends to verify that the Paxton blowers absorb more engine power to compress the air than the Rotrex blowers.

The aftercooler uses water to cool the air. Water holds a lot of heat energy and this water acts like a heat storage tank. For street driving or drag racing this water does not heat up much before it has a chance to cool off again. Thus, it makes a very good cooling device for these purposes. On track the water heats up and becomes less effective at cooling the charge air. The intercooler does not have this heat storage device and its effectiveness remains more constant on track.

The TTS race kit is very similar to the KW kit with the C38-91 option but uses larger piping so it is more efficient and puts out a bit more power than the KW kit.

While the KW (and TTS) kits out of the box are nearly maxed out because they spin the blower near its limit, these kits are putting out about 420 whp with the C38-81 and 460 whp with the C38-91 blower respectively on 93 octane pump gas. They make 400+ whp with 91 octane out of the box.

The SOS kits come with larger pulleys out of the box and make less power, however, they can be upgraded with different blowers and pulleys to make similar power as the KW kits.

For much above 500 whp, the SOS kit has the advantage.

I have done my best to summarize what I have read on these forums concerning these two kits and presented a comparison in an unbiased manner.

Bottom line is that they are both very good kits but take slightly different approaches to creating power.

 

Nice!! That's good to know I will definitely do that I hate the fact California has Strict emissions back in Alaska no Smog/emissions. My budget is no higher or close to 8k. Has anyone ran or is it possible to run that intercooler setup for SOS or that upgraded heat exchanger will do the job? Thanks for the replies, the knowledge and info!!

 

Yeah, I know of the no smog in AK. I used to live there when I was in the military. I wouldn't bother with an intercooler. The upgraded heat exchanger works fine.

 

Between the KW and the SOS, which one is easier to install and requires less modifications.