Johnny T's Superchargerd Ke55

[Rolla__Boy]

He hasn't got a boost gauge though, I would say he is just using the figure I told him it was running on my 5K, Once he gets a boost gauge we will know. He should have one anyways, to keep an eye on things

[johnny t]

oh 10psi geez what and it didnt do ne damage?? i want mine to run that! yeah well when i got it looked at b4 i put the sc set up on the mechanic said that it was almost over cammed ill get a boost guage hopefully this week.. because mine is 60 thou over i didnt think that it woulda made much diff between a 4k and 5k?but I'm no expert!

 

how can i get it to run more boost now?? when i put my foot down bout half way or so it sorta takes a lil bit to get going like the power is sorta delayed would cam overlap cause this? johnny t

[Rolla__Boy]

Put thicker oil in the carby.

 

And to make it run more boost, put a bigger pulley on the crank, or a smaller pulley on the SC

[johnny t]

yeah but how can u get so much more boost in ur 4k with the same set up??? i dnt understand that ... its got dex 3 in it that redy colour oil... apparently thats good shit... yeah my thermo is held on by string cause thats all i hads at the time and i wanted it goin so i bodged her up at doesnt move..ill get anotherone that fits properly when i get round to it!

Edited September 4, 2006 by johnny t

[johnny t]

also rolla boi how do u no how much boost ur running with the pully size like can u work it out or u put it on and see?? and how much psi do u rekon id be able to run without damaging the engine..so it doesnt die later on

[Rolla__Boy]

I got more boost in the 4K, because there is physically less space in the cylinders than the 5K....And I used normal engine oil in the carby and it was great.

 

You will have to try a pulley and see, I don't know any measurements for certain boost.

 

And it depends on the tuning, how you drive it etc as to how much boost you can run. There is no possible way for me to predict how long your engine will last.

 

If you pulled the SC off it and had it badly tuned and drove it hard it wouldn't last either.

 

So keep it tuned, drive it sensibly, keep fresh oil and filters on it, and it should be fine

[johnny t]

oh right yeah ill get a boost gauge in the next couple of days..and let u no what its running yeah i understand the fact the 5k has more volume to fill than a 4k but ur 4k and my 4k should be around the same shouldnt it??

[johnny t]

rolla boi how do u drain the oil outa my carby?? cause i might see if it runs beta with engine oil.. but its not very responsive either a few of my mates say its from the oil bein to thick? is that right?

[Rolla__Boy]

I was using thin oil first, and it had no response. It was like a huge flatspot til like 4 grand. Then I put engine oil in it, and it was VERY responsive

[johnny t]

yeah my flat spot is untill like 2 grand or so ill try engine oil soon but can u please tell me how to drain the oil outa the carby

[johnny t]

where can i get a bigger pully from??

[roids70]

nice ride man! i might be down near margate or snug in the next couple of months i might give you a pm when I'm coming down

 

Cheers Sean

[Rolla__Boy]

I have no idea how to drain the oil.

 

It uses heaps of oil anyway, I had to fill it each week

[kryton brown]

Use these calculations to work out pulley sizes..

 

When fitting a supercharger, you should match the swept volume of the supercharger to the size of the engine. If the choice is made carefully, problems from overboosting and the required paraphenalia to solve these problems will be minimised.

The supercharger will also be kept in its safe operating speed with correct selection.

 

To choose a setup you need to know :-

1. Engine capacity

2. Maximum engine speed you will be using.

3. Boost level desired

 

I am setting out the calcs needed for a 1200cc engine in the steps below.

 

FIRST CALCULATION (Engine Litres/min @ 0 Psi )

Multiply engine capacity (in litres) times maximum engine Rpm. E.g. 1.2 litres x 6000 rpm = 7200 litres/minute. Divide this figure by two as engine only fills every second stroke. (7200/2 = 3600 litres/min.

This is the engines air requirements in litres/minute at 0 Psi boost.

 

SECOND CALCULATION (boost ratio)

Add the boost pressure desired (7 Psi) for the engine to 14.7 Psi (atmospheric pressure).

(7 psi boost desired +14.7 =21.7 psi)

Divide this answer by 14.7 and this gives the boost pressure ratio. (21.7/14.7=1.476) This is the boost pressure ratio above atmospheric pressure.

 

THIRD CALCULATION (Actual air requirements @ desired boost)

 

Multiply the boost ratio by the litres/minute obtained for 0 Psi and you get the actual air requirements in Litres/min for the engine at that boost. In our example this is 3600 litres/min X 1.476 = 5313.6 litres/min for 7Psi boost.

 

To decide on the correct size of supercharger you need to know :-

1. The swept volume per revolution of the supercharger. (Eaton M62 1 litre/rev, SC14 from a 1G-GZE 1.5 litres/rev, SC12- 1.2 L/rev)

2. The maximum continuous safe operating speed for the supercharger. (Eaton M62 14000 rpm continuous, Toyota SC14 12000 rpm??)

3. The maximum pressure that can be safely produced by the supercharger continuously. (Eaton M62 12 psi, SC14 10Psi??? teflon on rotors melts??)

 

CALCULATION (Supercharger rotor speed)

Divide the desired air flow (5313.6 L/min) by the swept volume of the supercharger (SC14 from the 1G-GZE is 1.5 litres per revolution). This will tell you the maximum speed the supercharger rotors must be run at to produce the volume required.

5313.6/1.5 litres = 3542.4 rpm for the SC14.

5313.6/1 litre = 5313.6 rpm Eaton M62

 

CALCULATION (Pulley size ratio)

Divide the rotor Rpm by maximum desired engine rpm to get the drive ratio of the pulleys. For an SC14 on a 1200 @ 7psi boost the desired supercharger pulley ratio is

3542.4 /6000 rpm = 0.5904.

 

EXAMPLE OF CHANGE OF DRIVE RATIO

If the 1200 cc engines supercharger pulley ratio is increased to 0.75 using the 1.5 ltr/rev SC14 charger, the volume of air produced when running to 6000 would be 6000 x 0.75 x 1.5 litres =6750 litres/min

 

Boost produced would be 6750 litres/3600 litres (at 0 boost) =1.875 boost ratio For Psi boost ((1.875 x 14.7) - 14.7)=12.86 Psi.

 

if using an SC12 just substitute 1.2litres/minute instead of the 1.5litres/minute for SC14..

if you want to get even more technical the sc14 is actually 1.42litres/min! and even more so use the exact displacement of your engine eg. 3T-c is 1770cc..

 

Hope this helps.

[Des]

1 vote to pin that post at the top of the page. :(