super charging 18RGEU

[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

[75Ta22LT]

A bloke I do quite a bit of work on my cars with, was running an sc14 on a 2.6L rodeo (damn u holden/isuzu!). He had mounted it straight off the factory A/C mounts and by changing pully's got it on there fine.

With 10 pounds boost, copper head gasket, standard internals, 2 1/2' exhaust coming off lukey extractors. He dyno'd it and ended up with just under 220bhp.

We grabbed a shit old top mount intercooler off a 3sgte celica wreck, mounted that just prior to the inlet manifold. Took it back to the dyno, the engine took 14 pounds at the same temp that it was sitting on previously at 10 pounds. Made 263bhp.
-Point being: BUY A INTERCOOLER!!!!!

3 months late, engine went bang, REALLY badly. We examined the supercharger and one of the rotor's had sheared off quite a bit of metal, which in turn had found its way into the delicate parts of the engine - completely rooting it....

Of course this is due to Stu revving a shit old engine out to 8000rpm all day long under heavy boost.

BUT, I believe if the S/C hadn't been under such load we wouldv'e got a lot more life out of it!

As Jon said, don't spin the S/C to fast, or the rotor coating WILL dissapate, leaving you with metal on metal goodness.

[dale30]

A bloke I do quite a bit of work on my cars with, was running an sc14 on a 2.6L rodeo (damn u holden/isuzu!). He had mounted it straight off the factory A/C mounts and by changing pully's got it on there fine.

With 10 pounds boost, copper head gasket, standard internals, 2 1/2' exhaust coming off lukey extractors. He dyno'd it and ended up with just under 220bhp.

We grabbed a shit old top mount intercooler off a 3sgte celica wreck, mounted that just prior to the inlet manifold. Took it back to the dyno, the engine took 14 pounds at the same temp that it was sitting on previously at 10 pounds. Made 263bhp.
-Point being: BUY A INTERCOOLER!!!!!

3 months late, engine went bang, REALLY badly. We examined the supercharger and one of the rotor's had sheared off quite a bit of metal, which in turn had found its way into the delicate parts of the engine - completely rooting it....

Of course this is due to Stu revving a shit old engine out to 8000rpm all day long under heavy boost.

BUT, I believe if the S/C hadn't been under such load we wouldv'e got a lot more life out of it!

As Jon said, don't spin the S/C to fast, or the rotor coating WILL dissapate, leaving you with metal on metal goodness.

Point taken.!!!!

Dont think pumping fuel through the inter cooler would be a good idea though.

ive never run methanol through a s/c before but it runs so cold it normally freezes up the manifold so i would be hoping for the same thing.

[jonra23]

To evporate 1 kg of methanol will absorb the same heat require to increase the temperature of 1 litre of water by 245 degrees C so will pull quite a bit of heat out of your system.

regards
jon

[dale30]

To evporate 1 kg of methanol will absorb the same heat require to increase the temperature of 1 litre of water by 245 degrees C so will pull quite a bit of heat out of your system.

regards
jon

Dont know where you guys come up with these facts..lol

All i know is frozen manifold = very dense air/fuel mixture = hp...and no overheating problems.

regards dale

still like to know if 88270 8.3:1 will take 12 psi boost happily.?

[Screamn_Sleeka]

1G-GTE's are 8.5:1, and everyone safely raise the boost on the stock turbos to 15 psi.
Id say 12 psi on 8.3:1 is still cruzn.

(1GGZE's are 8.0:1 though...)

[dale30]

Ive been building and racing 6cyl and V8's for 30 years but these things are all new to me so please be patient with my dumb questions.

How do i tell what my supercharger is sc12/14 ? No real markings but i believe it came of a 1JJ something.

[jonra23]

.............length.......... width....... height........ weight........ displacement
SC14.....311mm ......148mm ....254mm ........11.9kg ........1420cc
SC12.....249mm ......148mm.... 254mm ........10.8kg ........1200cc


regards
jon

[dale30]

.............length.......... width....... height........ weight........ displacement
SC14.....311mm ......148mm ....254mm ........11.9kg ........1420cc
SC12.....249mm ......148mm.... 254mm ........10.8kg ........1200cc


regards
jon

Thanks
I better break out the trusty tape measure. So much for an old bloke to learn.!

[dale30]

What fuel do people usually run in turbo and s/c 18rgs.??

[thechuckster]

95RON or better - as mentioned elsewhere, they are prone to ping/detonate when highly strung.