4k Superchargeing

[DearmanKE]

Ok

 

I'm trying to work out how to setup an sc12 on my 4k, Blow through setup, useing something like a weber carby, but the questions are not about fuel setup

 

i have several questions some might be abit confuseing so bear with me

 

1. Would it be possible to have a switch that will limit the boost level, much like the ecu does on a 4agze, but maybe setup with intake manifold vacuum connected to a relay connected to the clutch of the charger, just the question is there a relay that uses vacuum to tell when something should be switched on/off

 

2. if the supercharger is disengaged, then how will the carby get airflow, is there a gate or something that can be setup to open to allow air when the clutch is disengaged on the charger, i noticed on the outlet of the charger there is a smaller second outlet attached to the main one. if this could be open and closed when disengaged and engaged respectivly then this would releive pressure at high RPM where boost would be limited by the answer to question 1.

 

cheers

Alex.

[OniBerserker]

I'm pretty sure the sc12 has an electric clutch,you should be able to hook it up to some kind of pressure switch.

I'm pretty sure the supercharger continues to spin passing air through it, just not under load.

 

but i could be wrong...

Edited October 22, 2008 by OniBerserker

[maxyboy55]

1. Would it be possible to have a switch that will limit the boost level

 

 

2. if the supercharger is disengaged, then how will the carby get airflow, is there a gate or something that can be setup to open to allow air when the clutch is disengaged on the charger, i noticed on the outlet of the charger there is a smaller second outlet attached to the main one. if this could be open and closed when disengaged and engaged respectivly then this would releive pressure at high RPM where boost would be limited by the answer to question 1.

 

1.yes, its called a wastegate, operated by vacuum or you could get a boost controller that alters the boost level with a wastegate

2.the motor will still suck air through the supercharger when the clutch is not engaged, i.e. the lobes will move at their own speed relative to how much the engine is sucking

Edited October 22, 2008 by maxyboy55

[DearmanKE]

so would a blow thorugh setup useing a wastegate to release buildup of pressure when the throttle is off, and to limit boost work?

[maxyboy55]

so would a blow thorugh setup useing a wastegate to release buildup of pressure when the throttle is off, and to limit boost work?

 

yeah i think so, my dad's doing a similar setup with his boat (sc14 on a wrx motor!) and hes mounting his wastegate between the intercooler and the throttle body-(same thing as mounting it between the charger and inlet manifold) and he's using a boost controller to change the amount of vacuum supplied to the wastegate so yeah i think it'd work the same with a blow off valve instead of the wastegate(less expensive but not as strong)

 

max

[DearmanKE]

hmm cool,

 

bit different for me because instead of throttle body it goes to the carby and the carby can't be over-pressurised, which is where a blow off valve owuld work, or wastegate, so the boost controller measures the pressure and when it reachs a certain level it sends a vacuum signal to the wastegate to open up, and close when pressure dies down?

[maxyboy55]

hmm cool,

 

so the boost controller measures the pressure and when it reachs a certain level it sends a vacuum signal to the wastegate to open up, and close when pressure dies down?

 

well, the supercharger is always pumping out the same amount of boost unlike a turbo and yeah the boost controller either uses vacuum to operate the wastegate or it can use the pressure from the supercharger itself to operate the wastegate and it alters the amount the wastegate is open for how much boost you program it for,

 

one more thing, why do you want the carby on the pressure side?

i reakon that it's much better on the suction side because it has an intercooling effect and much easier to plumb, but thats my opinion :laff:

[kickn5k]

Ok

 

I'm trying to work out how to setup an sc12 on my 4k, Blow through setup, useing something like a weber carby, but the questions are not about fuel setup

 

1. Would it be possible to have a switch that will limit the boost level, much like the ecu does on a 4agze, but maybe setup with intake manifold vacuum connected to a relay connected to the clutch of the charger, just the question is there a relay that uses vacuum to tell when something should be switched on/off

 

cheers

Alex.

How much boost do you whant to run?

I don't see this as such a good idea as the over/underdrive of the sc controls the boost pressure(pulley ratio)

why spin the S/C hard and vent the boost out when you can put a smaller pulley on the crank or bigger on the S/C.

But thats just my opinion.

I have nearly finnished doing a blow through efi setup on my 5K. i have converted the sc12 pulley to v-belt as i had a aircon pulley on my balancer already , i modified a sigma aircon pump pulley and bolted that to the sc12 center hub.

on a test run on the weekend it made 4 - 4.5 psi depending in the gear i was in. but i may have a leak or two as i havent finnished off the plumbing properlly yet.

One BIG draw back with a blow through setup is the need for a blow off valve which after two laps around the block vented out gave me the s*&ts big time so ill run it back in before the S/C.

Good luck with it all, its worth all the stress for sure even on 4psi i had a masive grin on my face.

 

stu.

Edited October 22, 2008 by kickn5k

[DearmanKE]

maxy: the faster the supercharger spins the more boost it will create, theres is not as much of a range as with a turbo, but SC's still produce more boost at higher rpm, i have got a stock ABV, may be able to use that as a wastegate.still have not decided which way to go, may still go suck through,

 

kickn5k: hey mate, i want to run about 5psi, yes i know about the different sized pulleys, I'm still unsure of pulleys sizes to use, but when the throttle is closed on a carby, the pressure is going to buildup and it needs to be vented. thats what my questions are about.

so you made 4-4.5 with a stock ac v belt pulley and a sigma aircon pump pulley, could u measure the diameter of the sigma pulley, this could be a way to go for me, asi have a stock aircon cracnk pulley to. I'm still going to get pulleys to have the right boost amount, but yeah i need to vent the boost when the throttle closes or is half closed, else bang goes the carby.

Edited October 22, 2008 by Shizotimang

[DearmanKE]

blow off valve which after two laps around the block vented out gave me the s*&ts big time so ill run it back in before the S/C.

 

what u mean vented out after 2 laps?

 

shouldnt it vent on deceleration? throttle closed?

 

elaborate i don't get what ya mean lol

 

and yeah i can't wait for the silly grin on my face when i finally have a boosted corolla haha

[SLO-030]

just mount the carb inside an enclosure like taz rx has done. that way there is equal pressure on the inside and outside of the carb.

[Killerolla]

I remember seeing a carby that was from the states that was self adjusting for the amount of boost being pumped through and i pretty sure it could handle over 20psi. First self tuning carby that i had seen ill try and find out a bit more about it. But i think that would be the best way to ad a supercharger.

[5kpanelvan]

hi i had SC14 on a 5k with mild cam i was useing a jaguar SU carb on my setup and it was boosting to 10 psi and made 108 rwkw

 

 

ill try find some pics of setup

Edited October 28, 2008 by 5kpanelvan

[Budowski]

hi i had SC14 on a 5k with mild cam i was useing a jaguar SU carb on my setup and it was boosting to 10 psi and made 108 rwkw

 

 

ill try find some pics of setup

sounds awesome wouldnt mind checking this out

[camerondownunder88]

Hi,

Kickn5K Just curious did you happen to use my how to fit a sigma aircon pulley to a SC12/14 blower article on here? As I have a SC14 with that pulley I used on that post on my blower if yours is the same pulley that is what I can expect then.

 

Also my sigma pulley has 2 belt grooves for a V belt does yours?

 

And 5kpanelvan what size is that "big" Jag SU you used and also what tunning was needed for it to all go on the car when it was on was the SU just right for the K motor?

 

 

Cheers

Cameron