Twincharged idea # 1

[joshg123]

Now that my red car is up and running, i will put a clutch in it, crack the 400atw Do some laptimes, take it down the 1/4 and then ill be over it. My interest is more in the fabrication/engineering/making things that 'shouldnt be like that' work. (hence the toyota driveline etc)

I will be then focusing on my new chassis, plans are a probably a bit optimistic but i already have a good base chassis being it seam welded and homologated caged. People say im stupid for doing another one, but what else am i going to buy...... an evo?

A couple of the 'must haves' for my new chassis is twincharger, something ive always wanted to do.

Parts/ecu/engine strength/budget is really not my concern. My concern is on how to set it up. Basing alot of my research on the Bee*R twincharged s15 i wish to run a Ogura Clutch TX15 or equivalent Supercharger and then run a T04z turbocharger. This should see me make a reliable 450-500whp, something the motor wont sneeze at. Just for it to be competitive at superlap, it needs to be responsive.

Here is a proposed pluming idea, alot of the twincharged cars ive seen ran the turbo into the supercharger intake and then the supercharger mounted on top of the intake plenum. This i will struggle with as my engine sits a fair way back in the bay. And i also see the supercharger as a restriction there.

Can the engineers/fluid dynamics gurus suggest a better way, or would this way work. As i intend to clutch the supercharger to take it off once the turbo reaches a boost level higher than the supercharger produces

http://i6.photobucket.com/albums/y220/joshg123/TWINCHARGEDIDEA1.jpg

Explaining that 'bypass valve/derestrictor valve' is tricky. It would be setup so when the supercharger turns off, it opens and allows good airflow to the turbo intake, when the supercharger is on, it is closed and the supercharger feeds through the intake of the turbo and then on the conventional path through intake piping.

I see that as the supercharger helping the turbo spin up, as its the big power maker and the one that will be used most often. So spool and low end power will both be increased

Cheers

Josh

[Nemi]

waste of time just adds complexity and more heat into the system.

Go buy an Evo MR job done.

[joshg123]

The point is i dont want to buy an evo

[Alt_F4]

Seen this thread? May be useful...
http://www.performanceforums.com/forums/showthread.php?t=67207968

[monk_13]

I remember seeing a Rolla with a similar setup years ago, although from memory I dont think the charger had a clutch on it. Trying to remember back, turbo was setup as per normal, as was the supercharger, and they both forced air into a common chamber with a valve setup on the turbos pipework, so that the super charged air isnt forcing the turbo backwards, then once the same boost levels were reached, valve opens and turbo takes over... Based around the old HKS kit maybe??

[joshg123]

Seen this thread? May be useful...
http://www.performanceforums.com/forums/showthread.php?t=67207968

No i havent, thanks for the link....

[upgarage]

and this is better than an appropriately sized turbo how?

[Alt_F4]

and this is better than an appropriately sized turbo how?
More power from a larger turbo, while maintaining good low down grunt of an equiv. smaller turbo.

[joshg123]

and this is better than an appropriately sized turbo how?

Im not asking the pros and cons, im asking the best way to do it.

I know a good sized turbo gives good results, heck my 3037 is an awesome turbo to drive on.

I want to do something different, if it doesnt work, ill change it.

[Whittie260]

If you can clutch it that should work. only thing i would think is what happens when the turbo is cut from being supplied with xx psi air inlet to having to suck its own air? Going to cause pressure drop issues??

Thought about Maybe running the supercharger into the exhaust side of the turbo to help it spool with perhaps just a simple plain old non return valve?? The supercharger pushes air into the exhaust turbine to help spool and then once equilibrium is reached in the exhaust it clutches and you have an NRV to keep the air running in the right direction (not backwards into the supercharger)...

Honestly not thought about it for hours like you probably have, but might be worth a bit of thought.

**EDIT**

Actually, having said that, what sort of drag are you going to get on the motor with a supercharger not clutched??? If the turbo is pulling more air than the supercharger can supply, then it will pull air through the inlet (once opened) but if you keep the supercharger running (not clutched) then the turbo will be helping to pull air through the supercharger. But considering the supercharger is being driven by the motor, perhaps the turbo has to work less hard to suck air though an intake AND supercharger than through an intake alone.... this would save the extra weight and complexity of running a clutch on the super charger.....

Remember, that if the turbo is sucking air then the exhaust (pistons pushing upwards) have to power the turbo. But if the super charger is helping push the turbo then the exhaust (compressible) isn't pushing the turbo, but the supercharger (running off the crank. ie, expanding gasses pushing down on the pistons) is pushing the turbo

End of the day, As i have been told many times, KISS... Keep It Simple Stupid

[joshg123]

If you can clutch it that should work. only thing i would think is what happens when the turbo is cut from being supplied with xx psi air inlet to having to suck its own air? Going to cause pressure drop issues??

Thought about Maybe running the supercharger into the exhaust side of the turbo to help it spool with perhaps just a simple plain old non return valve?? The supercharger pushes air into the exhaust turbine to help spool and then once equilibrium is reached in the exhaust it clutches and you have an NRV to keep the air running in the right direction (not backwards into the supercharger)...

Honestly not thought about it for hours like you probably have, but might be worth a bit of thought.

**EDIT**

Actually, having said that, what sort of drag are you going to get on the motor with a supercharger not clutched??? If the turbo is pulling more air than the supercharger can supply, then it will pull air through the inlet (once opened) but if you keep the supercharger running (not clutched) then the turbo will be helping to pull air through the supercharger. But considering the supercharger is being driven by the motor, perhaps the turbo has to work less hard to suck air though an intake AND supercharger than through an intake alone.... this would save the extra weight and complexity of running a clutch on the super charger.....

Remember, that if the turbo is sucking air then the exhaust (pistons pushing upwards) have to power the turbo. But if the super charger is helping push the turbo then the exhaust (compressible) isn't pushing the turbo, but the supercharger (running off the crank. ie, expanding gasses pushing down on the pistons) is pushing the turbo

End of the day, As i have been told many times, KISS... Keep It Simple Stupid

I thought about that pressure drop issue, i think i could run the turbocharger on its own to begin with, find out when that hits the boost the supercharger is going to lose efficiency at. Say 1 bar, so when the autronic sees 1.1bar it de-clutches the supercharger, and opens the intake for the turbo. Because with the pulleys the supercharger is only ever going to make a certain boost pressure at a certain rev range.

Or you could do it rpm based, and work out that the superchargers power curve drops off at 5000rpm. , then work it so you size your turbo so it makes more pressure than the supercharger at 4750, basically what a gt35/t04z would on my engine. So if i had fairly conservative duration cams, i could have a power band from 3500-9000 if its sized correctly

I dont have the displacement to mess about with 'correct turbo choice' like you have on a rb26 etc... so i have think outside the box.

[Whittie260]

I wasn't reffering to the engine side of the compression system, rather the turbine side of the turbo.

When you clutch the supercharger you are asking a WHOLE lot more effort from the turbo. Will this cause any upsets with the system? ie, the exhaust might not be able to supply the force to spin the turbo, which will drop turbo pressure, which will drop exhaust pressure, which will drop turbo pressure, and so on and so forth till you reach equilibrium (same, or higher, rpm than same boost on turbo only motor). The RPM switch sounds like it would work, but if you are running on pressure sensors, you are going to get a drop in intake pressure when you switch the system and this could cause the electronics to switch the supercharger back on. This could have a cascade effect and you could have issues controlling the pressure of the system.

However, with an RPM thing, if you test with the two pressure mechanisms separately you are not going to get a true reading. If the supercharger is running stand alone on the motor, on boost, you have a WHOLE heap more air flow through the system than if only the turbo was on the motor and was off boost for the same rpm... If the supercharger is pushing more air through, this will spool the turbo faster, causing boost earlier, which will cause issues if you try and swap with an RPM indication....

End of the day, it will be a complicated control system and i am not sure that testing each pressurising system separately is going to work.


I Hope this makes sense to you, it makes sense in my head....

[Whittie260]

Have you managed to find any references of someone else running a clutched supercharger/turbo combo on a motor? For control-ability i think you might need to run the supercharger at all times and control turbo pressure so that it is the same, on boost with inlet gate open, as the supercharger at all RPM's...

This would avoid back-flow into the supercharger (avoid working the engine to keep supercharger pressure up) and allow for a smooth transition between the supercharger and the turbo.

If you research twin turbo set-ups and swap the small turbo for a supercharger i think that is what you are up against. I have heard of people doing home-made twin turbo systems, and that is hard enough, let alone running superchargers too...

[adrenalin]

What blower are you going to run ? and what type ?

Seems to be an awesome idea if it will fit in the bay.

[cplagz]

Josh, have a look into the Lancia Delta Integrales, I know there are a few around the hillclimb circuits that are twincharged, they might give you some ideas.

I say go for it though - twincharging is awesome. If it doesn't work, try for twin sequential turbos :P

[DanWA]

There is a full buildup of stockmctock's twincharged vl on calaisturbo.com.au including some vids on how quick it spools with the blower.

[joshg123]

What blower are you going to run ? and what type ?

Seems to be an awesome idea if it will fit in the bay.

Ogura Clutch TX12 or 15 depending on how the calculations work.

Reason, they all come with clutches.

I could use a vortech but they are more suited to big v8's, i dont know if thats what i need

Yeah ive been searching about the nissan march and lancia, both twin charged. However as i said, most of the cars ive seen have the blower directly on the intake manifold, perhaps fine for 2-300hp, i want to hit the 500hp mark.... Hence the question regarding having the charger between the intake valve and the turbo may become a restriction rather than a help, even if its not clutched

[cplagz]

Kenne Bell do twin chargers on Mustangs pushing out 600hp IIRC.

[Lonewolf]

might want to look at the the rotrex too..
http://www.supercharger-experience.com/

They have a couple of sized models, but not sure if they are able to be clutched off.

[Saf]

Im with Whittey on this, the part where here says KISS.

I know you want to do something "unique" and i understand that, and appreciate it. The problem with doing radical mods by ways of a unique manner on the forced aspiration side usually (more like almost always) means one of two things. Failure, or hurdles and in-abilities to achieve the desired full result, ie total project effeciency is down.

Quickly, if you want to twincharge, id parallel charge it. The SC is parasitically driven (crank), turbos are exhaust waste driven, hence both will constantly be working. Definition of working is pressure and volume of air flow.

By running them parallel, you acelerate from idle, the SC spins up and forces air volume then pressure to get the engine going, thus making heat (power) and waste gas, thus spinning up the turbo. The SC down low will pressurise the intercooler, and some air will want to u-turn back into the exducer of the turbo (surge the compressor) but it wont just pour out of the inducer and towards the air filter ... because the turbo by now is getting the turbine spinning, and yes the ccompressor will be surging, but it will hold a majority of gas back.

As the turbo spins up, the the percentage of surge will go down at what point the air will be stationary, and then flow towards the IC.

At this point the turbo will flow more volume and more pressure towards the SC, but the sc your using will have a mechanical valve so to speak, via spinning rotors/screws back towards the incoming air (from the underside).

Only prroblem with that is some rotors like to use teflon seals, and these will not like the boost pressure being hurled at it.

This way both are thier own identity, and are not subject to working off each other what may cause a restriction.

Like i said, its good that your thinking outside of the circle. I have in the past acquired three different heads ill port and setup in 3 very different ways, and have a couple different cam sets, and then for shits and giggles, re-did the intake manifold 3 times and in the end felt perhaps 1/100th of a F1 team, but was very fufilling to know for sure the ways and why i had done that. I like those kind of mods more, im doing the same for my CA18 to go into my Skyline, but your i guess on the same mindset with a different take on how your going about it. Credit mate.

[joshg123]

The way i put it Saf, is anyone can do something simple. Most on here wouldnt undertake such a project, because its 'too hard' or too time consuming. Everyone said that when i put the gt4 driveline in my 323. I did that, now you look back at it and say, wasn't THAT hard, just needed thinking and trial and error. Now i can do as many heli's as i want and push for big power. Something i could never achieve on the mazda box. Ill carry this experience and setup through to the new chassis.

I consider. 'Too hard' a load of wank, 'Too hard' just requires more brain time, more planning and more trial and error.

I have access to and can tig weld, grind, cut, work at the workshop all night if it requires it. Have access to lathe's, mills, cnc plasma cutters if i ask nicely. It will work, however i just need the techo's to advise the best way of plumbing it.

Your suggesting basically using each pressure source as its own one way valve so to speak? Ie the turbo spinning at low rpm is enough to force the superchargers displaced air through the cooler, and the supercharger spinning will stop the turbos displacement running back through the charger.

Obviously that setup will not be clutched then, hows the charger going to like 9000rpm? As if you de-clutch the supercharger, the air from the turbo is just going to go straight back through the charger and out its intake. It needs to stay spinning to do that.

Cheers for your input

Josh

[Saf]

Your suggesting basically using each pressure source as its own one way valve so to speak?

Obviously that setup will not be clutched then, hows the charger going to like 9000rpm?

Part a, correct. Part B, also correct. How its going to like it, i dont know. Depending on what type of charger and its design.

You do have another way. You could run a throttle body after the SC, on its outlet pipe. This you would de-spring so its loose, and run a stepper motor stright to it. The Autronic can control the way it would close, based on boost, from the turbocharger and the clutch on the SC unlocks (or breaks contact).

The problem you have here is a clutch switching on and off, so many times, every gear change ... i dont think it will last too long.

This way you have a mechanical valve that will eliminate the turbo backflushing the SC.

To iron out the transition of the SC flow (not boost) and turbo flow, in realtive figures to the wheels in power, you can step it, thus making the SC taper its flow off, so you dont get a spike of power at the wheels when turbo comes online. The SC can work 500rpms past the point of the turbo coming online, and once the stepper is shut (ie 0% flow) the SC clutch can shut off.

If you want to be simple and not step it, you can run the TB into a simple solenoid (or pneumatic air ram thats run via a solenoid, and feeds air from its own SC ... so so so simple and reliable) that simply closes the TB from 100% to 0% and at 0 the SC clutch dis-engages. If its done into the overlap of turbo pressure, and of course flow to make the engine work, you will get a smooth powerband.

This has a advantage. If its wet, slippery, or simply you want a little lag to get you going hard out of a turn, you lower the SC cutoff point, thus acquiring some lag.

Matter of fact if your turbo comes on at 5000rpm hard, you can run a rotary switch on the dash you could have ..

1 : Turbo (SC clutch off , TB closed)
2 : SC + Turbo 50% Duty (SC clutch off, TB closed at 2500rpm
3 : SC & Turbo (SC clutch off , TB closed at 5250rpm)

1 would make it very easy and sedate to drive, great on the street where it would run like a N/A. 2 would get you off the line, and in the event of a spin get you going , but be very driveable as it would leave a window of lag. And 3 would be all in, SC and turbo with a 250rpm overlap for smooth power delivery that would look would draw a dyno graph that looks like a ramp Robbie Madison would love to ride.

TB is the key IMHO.

[Whittie260]

When i said KISS i did not in any way imply that what you are doing should not be attemped on grounds of "too hard". Simply i meant you need to put some serious time into thinking about the setup and producing the simplest possible solution. Too many electronic controls, too many control valves, etc etc just add to complexion and can cause issue with reliability.

Basically, don't just jump on an idea, think about how to do it with less moving parts.

With your initial idea i still think the issue of when you switch the SC off and the turbo has to suck it's own gas is going to be the biggest problem.

[joshg123]

When i said KISS i did not in any way imply that what you are doing should not be attemped on grounds of "too hard". Simply i meant you need to put some serious time into thinking about the setup and producing the simplest possible solution. Too many electronic controls, too many control valves, etc etc just add to complexion and can cause issue with reliability.

Basically, don't just jump on an idea, think about how to do it with less moving parts.

With your initial idea i still think the issue of when you switch the SC off and the turbo has to suck it's own gas is going to be the biggest problem.

I wasnt implying it was you regarding the 'too hard' comment :), its all good i want it to be as simple as possible in operation also. Just that their is not much simple about this setup

Cheers Saf

Josh

[Turbo2.6L]

Plumbing SC into exhaust side of TC sounds like the best & simplest design in the thread so far. A TO4z with 2bar at 9000rpm should achieve 500 for you & the SC would help bring it on alot faster, maybe not as fast as your idea though...

[zeroyon]

I dude I know in holland is big on his super / turbo setups.... i know ... "isn't that weird !"

Has some really great results but I have never verified due to his location.

Esseintially uses the same setup as you have in your pic.

Uses fly by wire thottle body for the on / off valve and always uses a supercharger with an on/off clutch.

He has tried the setup with two throttle bodies but it didn't make much difference.

The biggest isssue you will have is the switch over point. Its all fine and dandy on WOT but at every other point in the map its a nightmare.

You will need somehting that can 3d map your cut over point to get a really drivable car.

[joshg123]

One thinks a sm4 could do this? Perhaps use one of the PWM outputs as you can build a 3d graph for boost control, you could build a map for the cross over and set your frequency as you see fit to match the fly by wire throttle, perhaps a BA falcon throttle body, fairly simple in design, easy to get a hold of and info a plenty.

[joshg123]

Edit,

Compound turbo looks like a much easier, cheaper and more achievable setup.

Engine can spin a gt30 to 20psi under 4k, so power band could be 4-9k or something, a awesome area imo.

Reliability would be up, engineering mishaps would be down. Just need to size the turbos correctly

[duste]

Edit,

Compound turbo looks like a much easier, cheaper and more achievable setup.

Engine can spin a gt30 to 20psi under 4k, so power band could be 4-9k or something, a awesome area imo.

Reliability would be up, engineering mishaps would be down. Just need to size the turbos correctly

I'm not one to say I told you so, but you know...I did tell you so. :P

Providing you're not in a super rush for getting this all sorted, I'll pick up that book of mine sometime this week - has some further information on staged/compound/sequential setups as well as all that formula shit I was telling you about.

[Kye]

Edit,

Compound turbo looks like a much easier, cheaper and more achievable setup.

Engine can spin a gt30 to 20psi under 4k, so power band could be 4-9k or something, a awesome area imo.

Reliability would be up, engineering mishaps would be down. Just need to size the turbos correctly

Speak to Tristan from WTFAuto, he been developing a setup like this for years and had it all working on his MR2. Was making bullshit power until he decided to turn the wick up even more and throw a leg out of bed.

[Whittie260]

Tristan has put the same setup in the MEZMERIZE (sp??) supra. It's on the dyno this week, chasing 500rwhp on standard internals and auto. Been for a spin in it and it spools from like 1500 through to redline at 7k!!!

They were even talking about doing an xr6t, so they should be able to put one on your car.

Not a cheap install tho...

[joshg123]

Ill do all the fab work myself man, thats my interest in it.

Ive been looking tonight, the basic theory is very easy to do.

[Lonewolf]

think your missing the point here, he wants to design and install his own system....

Compound turbocharging is cool, and would expect that working with the one media (exhaust gas) will make things a fair bit simpler. All in the sizing of the turbo's

[Azrian]

http://i144.photobucket.com/albums/r200/AK6T/Compoundturbosetup.jpg

There is quite a bit of fabing to do not to mention where to fit it.

Good luck anyway mate and have fun. Keep us up to date.

[mitchy]

http://i144.photobucket.com/albums/r200/AK6T/Compoundturbosetup.jpg

There is quite a bit of fabing to do not to mention where to fit it.

Good luck anyway mate and have fun. Keep us up to date.

hah! i wasn't the only one that took a screenshot from that video :P

[Azrian]

haha nope

[mitchy]

definately a very interesting setup.. would be great to see someone on here have a crack at it and see the pros/cons of it.

[joshg123]

Just doing my research atm, ill budget for a big build in 6 months or so..... With my radiator in the back, i think its fairly achievable

Cheers for everyones help on this

[Azrian]

Have you read this thread mate. Its quite interesting.

http://www.dsmtuners.com/forums/custom-fabrication/336541-my-compound-turbo-set-up.html

[Alt_F4]

Have you read this thread mate. Its quite interesting.

http://www.dsmtuners.com/forums/custom-fabrication/336541-my-compound-turbo-set-up.html


Spool-up goes like this:

10 psi @ 3264 RPM
20 psi @ 3720 RPM
30 psi @ 4058 RPM
40 psi @ 4518 RPM
Nuff said :eek3: