Id like everyone's input on what cooling will be needed?
I say a monster cooler for the traction fluid, and a larger radiator. Id also feel a larger oil cooler wouldnt hurt either. Of course a big ass twin inlet intercooler will be needed also.
Im guessing this setup will put mid 500s to the tire happily. Nice part is he will be able to calm it down by going with larger pulleys, 110, 120 mm etc. and the blowers will be even happier not having to work as hard.
Say 16 psi and meth inj once sorted,, can you say..

 

Would it be better to have a monster cooler for the traction fluid, or just to keep each rotrex with separate reservoirs/coolers? Or is that what you were going to do anyway?

I don't think you'd want it going in series from one blower to the next as it would already be heated up. Unless you could put a cooler in between the two superchargers and just run one reservoir...

How has it been done on twin rotrexed cars before?

 

Another thought I had reading this thread.

In case your bracket doesn't work, I have noticed that the Rotex dealer in UK mounts the blower in a similar style to a VT or CT blower (in the area where the airbox is). I don't know if possible, but you might could mount one in that location and one in the orginal KW location. Just food for thought

Good luck with the build

 

There are a lot of factors there!
Take it back a stage to simple pyshics using the Universal Gas law.
P1xV1/T1=P2xV2/T2
From this you can see as pressure changes so does volume and temperature.
You cannot compress air with out generating heat. This is one reason you cannot simply add the pressures together as HORSEPOWER did.
In compressing air (or any gas!) ~80% of the input energy is turned to heat.
Hence the need for intercoolers.
Typically it becomes too inefficeient compressing any higher than 40 psi with out cooling the air before compressing again.
In an industrial application multiple compressors are manifolded side by side to increase flow at a fixed pressure.
I would suggest you run the blowers in the same arrangement through one intercooler.
This will have the added benefit of keeping the install simple and the weight down.
You will need to make sure both run at the same pressure though.
The intercooler is there to increase the density of the air at the lowest possible pressure drop, so the bigger the better, with paying a massive weight penalty.
There is a fine balance especially on a car that has to lug it all around
Plus pressure drop over the cooler is expontential so increases massively as you hit the limit of flow through it.

After heat pressure losses over the air route are the next biggest issue.
Keep the route as direct as possible, keep the surfaces smooth, keep the restrictions over things like intercoolers and throttle bodies as low as possible. This is the another reason you cannot simply add pressures as HORSEPOWER did.
BTW have you considered the massive increase in flow through the throttle body and inlet manifold?

So in summary with them in parallel through one intercooler you would get double the volume at the same pressure of one blower less the presure drop over the cooler.

HTH

BTW HORSEPOWER is the UK dealer for Rotrex

 

Mine were both intercooled and Methonal cooled. IC between blowers and meth after second one. It was experimental, done on behalf of Rotrex. You are very right about the heat. Unfortunately it wasn't tested to a final conclusion. But I have a friend in Europe who is running like this with relatively low boost per stage and seeing 2 bar guage and very good power on his S2k. My single stage ic kit is only seeing a rise in temp by 10 deg under hard full bore throttle so if the first stage is under control the second stage shouldn't be to difficult.
Regarding boost through throttle body etc, there are some high boost turbo's around running big power through std throttle and manifold. From my work so far I know that there is a bias in flow to different cylinders with the std manifold and ideally it needs replacing, which I intend to do.
It's great to experiment and I wish everyone success.

 

I am curious about the length of piping going into the single intercooler. Lets assume that we use a front mount IC. Obviously the blower on the drivers side will have a longer pipe before the intercooler. How will that effect the airflow?

I was thinking that if it is beneficial for both blowers to have similar length piping. One may be able to fabricate a V mount Intercooler setup with the dual feed for the intercoolers coming from below one on each side and the outlet for the IC could simply go to the TB from the top. That would look pretty sick too.

 

If you want a highly responsive track car, why not combine a C38 and the Roots SC kit... The Roots blower would take car of the bottom end, and the C38 would give you the top end. Instead of putting two SC's with identical efficiencies in the car...

Just my $.02.

John

 

Very good point. I think with the volume of air in the manifold a custom plenum manifold that equally disperses air into all four cylinders will be useful. I will have Larry at ENDYN fab the manifold, he currently has altered my manifold already but with the addition of the second blower the plenum will need to be enlarged. We will see what he says, I know he recommends an enlarged plenum for 89mm bore and oversized valves. Im not sure about 87 and standard valves. Ideally it would be sick to get the 89mm block to accommodate an increase in flow through the head! That might be the NEXT step. For now I want to get this on a stock bottom without the complication of too many variables.

GMK, I like that idea of equal distance between the FMIC and the blowers. After the brackets are perfected we can then route the IC piping.

As far as the c38 debate, this idea was beat to death months ago back in the snake charmer days. The c38 is in theory too large for either side of the block and not ideal for the s2000 powerband. This isnt my personal opinion im just relaying feedback given to me by others. I think if bigger was better KW would have used 2 c38's on the RSX, and not one of each. After Owning the c30 and witnessing its Low end throttle on demand I dont think I would want to make any sacrifices for top end power!

 

simple answer.... the idea of TWINS excites me!!!! haha

 

here is the oil cooler that will most likely be used in conjunction with a PWR 55mm radiator!! OJR has recommended me this radiator This oil cooler is a step above the KW c43 cooler.