michaelnyden

From my understanding as explained to me by a vendor on here, the C38 can spin to maximum of 90K rpm. The kit comes with a 90 or 100mm pulley and has these options as upgrades from Kraftwerks:

AP1 Comes with 128mm Crank + 100mm S/C Pulley for 9150Rpm Redline @ 12.5psi
Option 1. AP1 128mm Crank + 95mm S/C Pulley for 8900Rpm Redline @ Approx 14.5Psi
Option 2. AP1 128mm Crank + 90mm S/C Pulley for 8450Rpm Redline @Approx 16.5Psi


AP2 Comes with 128mm Crank + 90mm S/C Pulley for 8200Rpm Redline @ 13psi
Option 1. AP2 128mm Crank + 85mm S/C Pulley for 8000Rpm Redline @ Approx 14.5Psi
Option 2. AP2 128mm Crank + 80mm S/C Pulley for 7600Rpm Redline @Approx 16.5Psi

So obviously at these designated redlines, the blower is at ~90K RPM. At what PSI/pulley do you think it would be wise to upgrade to their larger BOV option? I assume if stilal taking the AP1 to the fctory 9K redline, the 8900 (95mm pulley) would still be safe? Can a math guru help me out with the calculations on blower/impeller speed? Maybe we can make a chart of input shaft, engine rpm, and impeller speed. The drive ratio on the C38 is 1:7.5

0bsolete

Here is the equation for the C38 blowers

((crank pulley)/(blower pulley)) x (drive ratio) x (redline) = (impeller speed)

Memo6453

419whp & 277tq on the -81 blower on an '07 with 60mm test pipe n exhaust. . Only issues was missing 2 of 4 banjo oil bolts. CJ next day aired them for me. Fingers crossed on no early issues.

Waiting on CJ to get back to me on the 32mm billet bov included with kit. Seems to flutter more than other kits my tuner had recently done. The 32mm might be too small for the setup.

Only put about 75 miles on it since boost. But damn those 75miles were great!!!


-Mike

S2000ABQ

I recently purchased a used kw v2 kit with 90mm pulley from another board member and installed my blower, plate, and intercooler today. I had a few questions that weren't resolved in the manual so I would much appreciate any help.

1) I have not yet installed my injectors, fuel pump, or EMS. If I disconnect the intake tubing from the intercooler path can I start and run the car to verify my install? I would imagine I'd get a bit of air blowing out from the intercooler I just wanna make sure I wont hurt any of the components and I would like to make certain my install is solid prior to getting the fuel side finished and getting the car to my tuner.

2) The kit was used so I've emptied the cooler and tank and bought new SX150. The instructions state to fill the reservoir up 3/4 of the way and then start the car with no coils connected. Reading other threads and Rotrexs' manual they state the compressed air method is much safer, so I will be doing that. Does filling the tank 3/4 still apply? The rotrex technical handbook states to fill oil to the maximum mark on the dipstick and then loosen the banjo bolt at the inlet side and apply no more than 15psi. When the oil starts to come out it is properly primed. Then top back up to max level and turn on the engine and look into the tank to view oil movement. Then there's a dance you have to do of topping the fluid off quickly to keep the oil at the max indicator on the dipstick. Is there any needed advice here? I feel like I got it, just seems like kind of a pain in the ass. It also states that to properly check the oil level I need to keep the car at 2-3k rpms while I check the dip, much like an automatic transmission.

3) The bypass valve vacuum line needs to T into the FPR line, I am not certain of the orientation of the bypass valve in relation to the hot side of the intercoolers piping and the inlet filter's elbow. The bypass valve has a piston and spring inside, does the piston top face the piping to the intercooler or should it face the elbow where the inlet filter is attached to.

Thanks in advance for the help!

NINJA EDIT:

I read through Habits' thread and got alot of info. I was also able to answer my third question. It would appear that the billet kw recirc valve is possibly undersized for the c38 type chargers the previous owner of my kit was venting to atmosphere with the piston head facing the intercooler piping. There was a cap mounted onto a small section of pipe coming from the inlet elbow.

Another EDIT:

Didn't get a response from anyone so I figured I'd just do it. With just the blower and intercooler and oil cooler attached I started the vehicle. This was with my EMS, injectors, and Fuel pump not yet installed. I first filled to the max line, used an air hose and rag to put 10-12psi of compressed air until it leaked from the inlet side of the blower. Then topped the fluid back up to the max fill line on the dipstick. With the dipstick removed I started the vehicle and at idle is slowly drank the oil. I just kept adding an oz of fluid every so often to keep the reservoir from completely emptying. I then left it slightly overfilled while I disconnected each inlet and outlet hose to verify I had fluid movement. Kept engine at ~2500 rpms and filled to max full.

First startup after filling up the reservoir
First Startup Kraftwerks ApJuan

leo520

i got my kit a while ago
i order the c38 91 blower kit
n i saw the part number on the blower is 142079

can someone tell me where to check if its c38 91 or not?
thx

06S2k07Si

Use the measurements at the bottom of the C38 technical document... You should be able to tell by that...

http://www.rotrex.com/Home/Technolog...Technical_Data

Habitforming

Pretty sure that's a serial number

leo520

thank u.
my car is in the shop insatalling the kit now

do i need to inform my installer just to incase some problems or just let them handle the job?
thx

Memo6453

have they installed the kit before? if so, id let them be. If not, maybe bring up the points everyone has agreed on to help with the install. re-read Habits thread just incase. Good luck man... in for numbers!!! Car is a blast to drive!



-Mike

johnzal

so i got my kit with -91 and 95mm pulley..
my question is will my exedy clutch ( oem replacement ) be enough.
it only has about 5k miles if that, i was not thinking about supercharging when i bought it more then a year ago