KW pulley boost psi

voodoo50

Well-Known Member
68
48
Hey all, I was wondering if anyone on here with a Kraftwerks Supercharger kit knows how much boost the different pulleys produce. The options I've seen are 120mm, 115mm, 110mm. Anyone here know boost specifications for each? I personally have the 115mm pulley on my Rotrex. Thanks in advance.:escaper:
 

JonnyRotten

Well-Known Member
1,673
771
Mississauga, Ontario, Canada
Vehicle Model
Civic Si
Body Style
coupe
Hey all, I was wondering if anyone on here with a Kraftwerks Supercharger kit knows how much boost the different pulleys produce. The options I've seen are 120mm, 115mm, 110mm. Anyone here know boost specifications for each? I personally have the 115mm pulley on my Rotrex. Thanks in advance.:escaper:
What does the stock SC come with?
I'm surprised that KW doesn't have all the boost numbers for the different size pulleys.
 

voodoo50

Well-Known Member
68
48
So after looking over the Kraftwerks website this is what I was able to gather:
The kit for the 06-11 Civic Si and the 12-15 Civic Si come with the same size Rotrex unit. Its the C30-94 unit. The website advertises that the 120 mm pulley produces 10.8 psi. It shows the 110 mm pulley as producing 10 psi. KEEP IN MIND THERE ARE DIFFERENT SIZE ROTREX SUPERCHARGERS. EXAMPLE, THE S2000 USES THE C38-81 UNIT WITH A 70MM PULLEY PUSHING 11.2 PSI. THEY ALSO LIST A 100 MM PULLEY PUSHING 12.5 PSI. THEY SHOW A 90 MM PULLEY PUSHING 13 PSI.


I have been tuning with Vit and he told me that my 115 mm pulley has been pushing around 9 psi. We are still tuning but that was the psi reading he gave me. I sure hope that isn't all this SC is going to produce!! lol
 
Last edited:

voodoo50

Well-Known Member
68
48
Ill be running 110mm pulley . Does anyone how much boost it produce ?
According to the Kraftwerks website... if you have the Rotrex C30-94 unit with the 110 mm pulley, it is producing 10 psi. I would call Kraftwerks and ask them directly.
 

Dennis Rockholt

9k Alll Day
1,952
869
Franklin, TN
Vehicle Model
370Z Fairlady aka "Nismo"
Body Style
Coupe
Ugh S2k with KW kit? :eek::eek:
 

KramVTFG4

Well-Known Member
3
3
From what i've seen on a few builds the 110mm is pushing around 12-13psi..granted some are on E85 gas but that seems to be the general consensus for PSI also depends on your elevation that will make it flucuate what you're seeing.
 

ripply

Well-Known Member
207
379
My car with the 120mm pulley sees anywhere from 9.6-10psi up top depending on the weather. The 110mm pulley should put you around 12-13psi
 

twister8008

Well-Known Member
860
480
Omaha, NE, but I am a Wisconsinite
Vehicle Model
Civic SI
Body Style
Coupe
Ok, I spoke at length with TJ from Kraftwerks about pulleys and such. He told me the pulleys do not make the kit less reliable unless you "Drive it like an idiot. In that case you can fry the supercharger with a 120mm pulley as well.

Here's the breakdown:
120mm - 9-10 psi depending on tune. Rev limit on the kit is 8400rpm
Ok, I spoke at length with TJ from Kraftwerks about pulleys and such. He told me the pulleys do not make the kit less reliable unless you "Drive it like an idiot. In that case you can fry the supercharger with a 120mm pulley as well.

Each 5mm decrease in pulley size increases boost by 1-1.5 PSI
115mm - 8050 rpm
110mm - 7700 rpm
105mm - 7350 rpm

What I ask, is for people to share their belt lengths if they are riding with these pulleys. This will help people in the future. Thanks!
 
Top