super charging 18RGEU

[dale30]

Hi Guys
I have finally given up on the 18R and just bought an RGEU.88270 stock and original.
This is for a speedway car and will run between about 4000 and 7000 rpm, most at WOT so drivability isnt an issue just accelleration.

Torque is also not important as that just causes wheel spin in my sport.
Eventually i wouldlike to be getting about 200 at the flywheel.Budget at the moment is about $1.50.

The way i see it i have two choices.

If i can find a manifold i can put the solex's on. But with the crappy cams and and 8.3 comp im not sure how well it will go.

OR

8.3 should lend itself to supercharging.!!
I can get a s/c setup for a 2.6 sigma with 350 holley.with some modification i could replum it back into the efi manifold. S/C is setup to run 12psi.

Flywheel will be lightened before it goes in. not to much though.

I only have 4 weeks until next race meeting so have get it going then do more mods as budget allows. Cams would be first on the shopping list.

So there you have it, Im open to all suggestions.

Also dissy is probably no good to me without ecu so can i use my 18r dissy.? i read somewhere about using internals from 22re if true i can get one of those..What else do i need from 22re to make it work.??

[ed]

if its WOT and 7000-9000rpm - id just get a wellmatched trubro

[dale30]

Turbos are crappy on speedway, Throttle response is every thing as your feathering it around a corner.
7500 would be as high as i would need to go.Unless the motor would be happier up higher,I could change diff gears.

[Lambolica]

You can use an SC14 off a 1G and if you can find them an A/C mount to mount it on.

From there a little custom work to line up the pulleys would be about the most budget way to go.

[ed]

i dunno... on a speedway, given the sustained load and rpm, a turbo bang in its efficiency range would be pretty responsive (this coming from the #1 turbo hater of all times) look at those drifting clowns in their puncy cars, they achieve exceptional throttle response - the key is maintaining operating conditions

*says me who hates turbos and has never a driven speedway event

[dale30]

A turbo i would have to go and buy ...A supercharger i can get for nothing.
Superchargers dont need intercoolers either..more money.

Anyone know what sort of power 12psi into RGEU would make.???

[ed]

true true...

[pilot]

I have literally no experience with superchargers and a doubt showed up: does a supercharged heat up less the air charge than a turbocharger at the same pressure/flow?

I have seen superchargers using intercoolers but just in pictures. I´ve never really studied it nor seen it alive.

[dale30]

The heat from the exhaust side of the turbo is what causes it.

[pilot]

I don´t want to pollute this topic too much, but are you sure it is a noticeable source of heat for the air charge? I would have thought that if there is a difference it might be beacause of the difference in compressor type (centrifugal, positive displacement, etc).

[ed]

The heat from the exhaust side of the turbo is what causes it.

oh really?

[EldarO]

yeah...

















nah.

Eldar.O.

[Starfire]

The 18rg is fairly ping prone. At 8.3 with 12PSI I think you might have some trouble. If you lower the boost or drop the compression (thick head gasket anyone?) you might be better off.

Get an intercooler. Even a crappy one from a standard car is better than nothing and can be had quite cheaply. They make a massive difference.

Sean (bluewire) has experience in supercharging an 18rg. He did it to an RA40 Celica. I think his compression was particularly low though (around 6 to 1).

Cheers,
Terry

[dale30]

OK
If i run it on methanol that should overcome the pinging problem.

[RA35GT]

Heya mate,

The 18RGEU has a conventional reluctor dizzy, it does not need the ECU to work.



The Light Brown wire is an ignition 12V and yellow wire is the tacho wire.

[Black]

Hey, sounds liek your gonna have some real fun with this, im not too sure how much similarity there is between the 18R and 2tg but there is a step by step guide of how to supercharge a 2tgeu on the net. you will find this by searching

'Supercharging Toyotas 2TGEU by Tim Frost'

if you cannot find this i have it on file, just ask and i'll post it up or send it over for you,

Cheers Black

[Norbie]

The heat from the exhaust side of the turbo is what causes it.

This is incorrect. Compressing air (or indeed any gas) increases its temperature. This is equally the case for turbochargers and superchargers, given the same boost levels.

OTOH if you're running methanol you don't have to worry too much about that. I'm thinking the 8.3:1 compression ratio might be a little low for methanol though, unless you crank the boost up to buggery?

[jonra23]

Guessing that you are looking at a SC12 or SC14, from what i have read you dont want to turn them faster than about 11,000 rpm or they start to have trouble with the rotor coating.

As other have said you are going to get pretty mush the same temp rise with a supercharger as a turbo system at the same boost levels.

If you are running methanol and a SC12/14 without an intercooler inject/squirt some of the methanol in prior to the supercharger, it will do two things, makes the supercharger seal better and absorbs a fair bit of heat that the is created when the air is compressed, not advised running a fuel mixture through an intercooler though as a backfire could be ugly, straight water injection will help in that situation.

If you are going to run the throttle body post the supercharger to give better throttle response you will need to run a BOV else you will get a big pressure spike when you take your foot of the thottle.

regards
jon

[dale30]

I am going to run a 500 holly on top the supercharger so that will solve lots of probs.

Would still like to know how high comp ratio might go from 8.3 and 12 psi boost.Should be some sort of formula out there.

[jonra23]

Your theoretical compression ratio will be 15.07 =8.3*((14.7+12)/14.7)

This does not allow for losses because of the lower density heated air.

regards