S/c Rb20det?

[Softy]

ok i have did a search but didnt find what i was looking for.

does anyone know of any place that makes a s/c kit for a RB20DET?

i got a 2530/pfc/cam injectors etc atm but its lacking soming and considering goin down the S/C route so i can get more low down grunt.

any opinions/ ideas/ knowlege welcome

thinkin about gettin the toyota 6cyl s/c and slapping it on with a pulley kit,but i dont know what sort of power ill make.

[Waldo]

wats an s/c kit

[Miller the hoon]

Super charger kit

[Softy]

also i think i worded it wrong....

i wanna get rid of the turbo all together and have just a S/C

[Miller the hoon]

Sprintx in wa do a few i dont no if the do 1 for the sr

would toyota fit i wonder mr2 1.6

james

Edited December 8, 2005 by Miller the hoon

[Scribble]

Maybe use the SC14 charger. I noticed one at cash convertors for $480

http://calaisturbo.com.au/showthread.php?t...percharged+rb30 this thread over at calais turbo is a good read if your keen on venturing down this path. It's done on an RB30 but im sure wouldnt be too much to adapt to an RB20.

Enjoy

[Cubes]

If you want to make decent power (200+rwkw) with s/c you either

1. spend big $$ on a real super charger

2. twin charge (as mcstocky has/is)

3. don't do it at all and drop a 2.5/3ltr in it.

[CEF11E]

the supercharger won't make the power you want. if your current setup seems laggy (2530) on a rb20.

buy a rb25de, use the bottomend and head but all your sensors, pfc, fuel rail, injectors, turbo. basically everything even youe cams from the 20 in the 25.

you can pick up a rb25de for like $900. and you should be able to get 250rwkw with much less lag.

A good supercharger will cost at least 2g plus 1g worth of fabrication....

"there is no replacement for displacement"

sorry my dad allways says that to me

[1400r]

we've got a few 4agze little s/c here at work softy what about running one of these as well as your 2530? or talk to Terry about stroking your motor to 2.3lt or 2.4lt he has already got some gtr rods coming just needs to get a crank.

even better offer to buy the motor out of the white ceffy's thats coming over its already a 2.3lt?

[CEF11E]

twincharging would be cool...

I drove a twincharged mr2 20V frankenstien.

1.6 litre bottom end, 20 valve head, hiflowed ct26 turbo, 4agze supercharger.

the cool thing about it was at 1000rpm the supecharger would kick in and you felt like you were hitting full boost, just when you thought it would level out, then the turbo hit full boost at 4500 and christ! hang on...

Scared the shit outta me. the car weighed bout 900kg and put out 189rwkw

twincharging the rb20 would give you great bottomend/midrange.

the plumbing would be a bit of a headache tho:)

[ebola]

I don't understand... how can a supercharger be laggy?

I thought that the SC superchargers were screw types - fixed displacement. that is, boost from zero.

and even variable displacement superchargers are more predictable than turbos. rpm = boost, no matter what load.

I have thought about (and no more than thought) a small fixed displacement supercharger before the turbo (rb20) in order to provide a little more power off turbo boost - and switch it off automatically when the revs get high (magnetic clutch).

Except that I don't know what kind of draw through the supercharger would have when the turbo is pulling three times the amount of air.

I figure it would be able to spool the turbo quicker too - pre-turbo boost = more air in = more air out = more exhaust.

hmm... I think its time to search for supercharger turbo....

EDIT:

perhaps I should read more carefully. lag with *current* setup.

But I'm still interested. I'd like to see what can ge done with a pre-turbo super charger.

Edited December 9, 2005 by ebola

[1400r]

who said it was laggy?

[StockyMcStock]

if any of you guys are serious about twincharging, i can explain a few things and how best to go about it.

i don't think softy is keen on the idea, moreso wants to try a straight blower setup. for the RB20 i'd use either an SC-14 overdriven to 14,000rpm or if you could afford it, an Eaton M90 twisted-vane three lobe twin rotor roots blower. the eaton *may* be slight overkill but better to oversize than undersize.

[SideWaysChef]

if any of you guys are serious about twincharging, i can explain a few things and how best to go about it.

i don't think softy is keen on the idea, moreso wants to try a straight blower setup. for the RB20 i'd use either an SC-14 overdriven to 14,000rpm or if you could afford it, an Eaton M90 twisted-vane three lobe twin rotor roots blower. the eaton *may* be slight overkill but better to oversize than undersize.

<{POST_SNAPBACK}>

I am totally keen on doing a twin charge set up on my rb20

it sucks having no power before 3K

my brother works at toyota wreck so was thinking of grabbing one off a 4agze or something similair

was going to set it up before the turbo but was thinking i might need to remove the aircon or something to make room for it

[StockyMcStock]

if you're "totally keen" here's a basic overview:

1) Find a place to put the blower

2) mount it, and drive it. This is very hard. Expect a number of destroyed belts before you perfect it all. the mounts must be perfectly rigid and perfectly aligned to the drive belt.

3) Piping. The cold air pickup is on the inlet of the turbo, just as normal. the turbo OUTLET feeds into the blower INLET. the blower OUTLET then feeds through your intercooler, on the other side of the intercooler you position your bypass gate (another whole topic). between the bypass gate and the throttle body, you then place your AFM if you have chosen to run one still.

the basic premise is that the roots blower will give straight up boost right off idle, pulling air in through the (combined) inlet of the turbo. this low rpm boost creates much greater exhaust gas flow, much earlier than normal. this spools your turbo much earlier, which now PUSHES air into the blower inlet. the delta pressure across the blower goes up a bit, as it becomes more efficient with positive inlet pressure. say it's giving you 10psi, and the turbo pushes 9psi into it, then you might come up with 20psi at the plenum.

advantages:

massive torque spread.

no lag.

power delivery is much easier to control than a big single turbo setup, everything is linear instead of all-or-nothing top end power.

you can run a GIANT turbine a/r and wheel, with no lag, as the blower can help spool up a much larger than normal turbo, much quicker.

this means your exhaust back pressure goes down heavily, which increases top-end power further.

if everything is sized correctly, you can achieve inlet pressure > exhaust back pressure. again, huge gains in top-end power.

disadvantages:

packaging, and driving the blower. this can be difficult, but you can make it work with a bit of know-how and testing.

if you were doing it to an RB20, i'd get an SC-14 blower (make sure you get the one off the 1g-gze, NOT the one off the 4AG-ZE) and get it running on the engine first. then fit your turbo and pipe it all up. turbo selection is critical, you basically want it much larger than you normally would, especially in the turbine stage. perhaps a GT35/40 .86 or 1.06 rear if you were shooting for 10psi/10psi boost spread. half-half is a good place to aim here.

as a guide, my setup is an RB30DET with 8.3 CR, i have an Eaton M90 blower which i will set up to provide 6-7psi. the turbo i chose was a full house GT40 with a 1.34 rear housing and 84mm rear wheel, which is rather large. it would be fairly silly on the engine on it's own, boost up around 4500rpm i would imagine.

the other thing to think of is compressor stage surge line, you will generally want the largest A/R on the compressor that you can, so that it can provide big airflow at low pressure without being beyond the surge line. mine is a .72 A/R compressor.

[Softy]

nice write up man.

ok i have pretty much decided to scrap the s/c idea.

thinkin about slappin a 2510 on it and a re-tune.

will be more then happy with 190rwkw and a much more responsive bottom end hopefull PFC/Poncams etc that i have already help this.

or another thought i had,cams give more top end right? and lose bottom end.....so maybe thats my problem.

the cams killing my bottom end? but then again,poncams anit really that big

[Cubes]

The 2510 will hardly spool earlier than the 2530.

Keep the 2530, Speak to Chris32 about his 2510, thats making 190rwkw but early in the rpm ~6000rpm or something due to the lack of exhaust flow, it noses over pretty hard.

I don't think the 2510 is really that good on the rb20. Stick with the 2530, wait until the rb20 pops and throw a set of rb25/26 rods and crank through it then crank up the boost.

Edited December 10, 2005 by Cubes

[ebola]

nice one, StockyMcStock

but I have a question for you (and everyone else, as well).

I had figured that if would be more efficient to have the blower before the turbo, not after (yes, I did read your post).

I had figured on the supercharger being a liability once the turbo kicked in.

I'll take your word for it. but what do you reckon would happen if it was the other way around? supercharger, then turbo?

so many questions. so little time

[Cubes]

The blower flows less than the turbo as a result it will pose an inlet restriction to the turbo. So no, its not more efficient.

[StockyMcStock]

spot on. it would work to start with, but as soon as turbo airflow became greater than the blower's possible airflow at any rpm, it would restrict and be useless.

remember that a roots blower is just a big vacuum pump, it is purely mechanical in nature. so it takes a gulp of air, and moves it to the other side of the cartridge. do it quick enough, and you get a pressure difference across the thing. increasing the number of air molecules in each gulp of air by adding pressure to the inlet side is an easy way of making it move more air.

think of the setup this way: the turbo is only there to increase the possible amount of air that the blower moves, by forcing more in at the inlet side.

edit: addon -

a lot of people figure the only way to twincharge is to use a complex system of valves and shit to switch the two airstreams over at the correct point. this is a silly way of doing it because you negate the effect of having inlet pressure much greater than exhaust back pressure. this is one of the primary reasons it works so damn well, but if you switch your blower off in the high RPM and the turbo only is working, your back pressure is exactly the same as it would have been with just a single turbo setup. (granted, you have a giant exhaust housing so the in-ex pressures are probably still pretty good)

Edited December 10, 2005 by StockyMcStock