Supercharger and Turbocharger

[02_silver_wagon]

I saw a picture on the internet a few weeks ago and I can't remember where I saw it. I was wondering if any of you have seen it. It was of an rb26dett with upgraded twins. The strange thing was there was a what looked to be eaton roots type supercharger off the side of the engine (under the turbo manifold) conected to the belts. The charged air from the twin turbos and supercharger went into a dual inlet intercooler and came out as a single cold pipe going into the intake manifold.

Have any of you seen this pic? If so please post it. What do you guys think about this? I have been thinking about it ever since, I don't think it would be that hard to do. Here is a site with supercharger info You can order a bypass actuator. All you would need would be a wastegate type valve to not let back presure on the compressor side when the supercharger was going and then when the turbo spooled up the supercharger would open its bypass actuator and then the 15-20 psi of the turbo would open the valve. I really don't think it would be that hard. Although im just daydreaming. Let me know what your thoughts are.

[mambastu]

Think it might be an Ogura supercharger from the design of the front housing.

[02_silver_wagon]

No thats not the picture I have seen, but it is the same idea. What do you guys think about the fesability of doing this, either on a rb or even with a build ka and a huge turbo like t78?

[mambastu]

I was originally going to 'twincharge' my CA18DET using an overdriven Toyota MR2 SC12 supercharger for lowend boost but a written off Skyline came up at the right price and I decided to go for an RB25DET in the end. I also figured that the RB25's longer block would make it easier to install a supercharger should I find the low end torque still wan't enough

The Toyota SC12 and larger SC14 superchargers are dirt cheap in Australia - around $350 AUS for a used unit.They have an electric clutch on them so they are ideal for this sort of application. You can switch them off when your turbo is delivering a reasonable amount of boost. I was going to use my GReddy E-manage to activate a relay to turn the supercharger on and off.

It would make an interesting project

[02_silver_wagon]

I don't have a skyline let alone a rb25det or rb26dett. I just thought to post it here because I saw it done on a skyline engine. I'm doing a ka24de-t buildup and it crossed my mind of something maybe I could do later on if I wanted to use a HUGE turbo like the HKS TO4R. With only 2.4 liters it probably wouldn't spool til 5700rpm (with compound forced induction I think it would cut down atleast some of the spool up time 500-1000rpm). I really think it is possible and wanted to hear what other knowledgeable people thought.

[02_silver_wagon]

Haha if found it.

[02_silver_wagon]

Are the sc12 and sc14 style superchargers from the Australian toyotas Ogura style or roots style superchargers?

[PROJECTRB240SX]

ITS THE SAME ENGINE, I THINK THAT WAS A COMPLETE CUSTOM JOB. I DON'T SEE WHY IT WOULDN'T WORK, AND THE TO4R ISN'T THAT BIG, HELL THERE IS A GUY HERE IN AZ WITH A T-56 IIRC THAT SPOOLS RATHER NICELY.

[02_silver_wagon]

Yes they are the same engine.

Actually a T56 isn't "that big" it flows a little more than the GT3037 as you can see here

Actually a T04R is big it is HKS third biggest turbo.

[TommyTheCat]

IWith only 2.4 liters it probably wouldn't spool til 5700rpm (with compound forced induction I think it would cut down atleast some of the spool up time 500-1000rpm).

There's where a divide comes in, whether you're actually spooling the turbos with the supercharger or using them seperatly like in the picture you showed. The only way the turbo (in your picture) spools faster is due to the increased power+gas from using the supercharger. And I think that the cut in spool time as a result could only be about 200-400rpm faster max.

But when you're driving the SC into the TC to actually decrease spool time you run into the (huge) problem of routing the air around the SC when the Turbo is actually engaged.

So cutting spool time is not the goal, the whole idea is having this boost down low where the turbo doesn't work. You get the SC from 0-4k?rpm and the turbo from 4.5k+ (or whatever it normally acheives).

[thephatone]

isnt supercharger suppose to be mounted on the intake side not the exhaust side? wierd...i dont get why its next to the exhaust side of the motor...interesting but cool i guess

why not just get a decent size turbo because we all arent going to run 1000hp with t78/t88s a good number to aim for is 500hp@wheels in my opinion, because 500hp@ wheels will do some serious damage to those in the Fords and Chevys, would a t60-2 do it? i think it would, 4 bangers can spool it up fine so 6 cyl would be a tad easier

[02_silver_wagon]

There's where a divide comes in, whether you're actually spooling the turbos with the supercharger or using them seperatly like in the picture you showed. The only way the turbo (in your picture) spools faster is due to the increased power+gas from using the supercharger. And I think that the cut in spool time as a result could only be about 200-400rpm faster max.

But when you're driving the SC into the TC to actually decrease spool time you run into the (huge) problem of routing the air around the SC when the Turbo is actually engaged.

So cutting spool time is not the goal, the whole idea is having this boost down low where the turbo doesn't work. You get the SC from 0-4k?rpm and the turbo from 4.5k+ (or whatever it normally acheives).

I don't know a whole lot about cars but what I gather is. Most superchargers increase horsepower 40-60% To get those numbers you need 40-60% more air, 40-60% more fuel, and have 40-60% more exhaust. I just think it would help spool up time quite a bit more that 200-400rpm. I don't think it will help spool times 40-60%. I was thinking maybe 1000rpm.

[TommyTheCat]

thephatone - The reason it's mounted to the exhaust side is for ease of routing into the intercooler.

And yeah, I'm not sure on truely how much of the increase exhaust gas will effect the spool time. It could be significant. *shrug*

[mambastu]

Are the sc12 and sc14 style superchargers from the Australian toyotas Ogura style or roots style superchargers?

The Toyota SC12 and SC14 superchargers are both 'roots-type' and they use teflon coated triple lobe rotors to improve their efficiency. Rumour has it that they were actually made by Ogura for Toyota. Looking at the Ogura range of superchargers they do look almost exactly the same so I wouldn't be surprised if they were.