zero boost lag idea...

[gotboost$]

well guys the lighbulb went off in my head Saturday as i was talking about the air pre-spool idea with my bud Jason as we were woring on his Turbo SHO


I read a thread a couple weeks ago about a guy who thought he could use compressed air pushed through a jut to pre spool up the turbo to reduce or eliminate boost lag. The biggest problem with this idea is the weight of the equipment needed to hold enough air to make it worth it would far outweigh ( no pun intended) any gains.

I had a not so similar idea. Most turbo's are water and/or oil cooled around their jackets. I thought it would be awesome if i could engineer a third turbine connected to the same shared shaft as the other 2 to up inside the water jacket. Attached to the same shaft as the other two turbines (exhaust side and o2 side). this third wheel would be driven by a water jet aimed at it. Using the water pump system already installed on the car. another path would to use this system with very aggressive turbine with a clutch system... much like a backwards torque converter where once the water turbine reaches a certain rpm (in tune with engine rpm) it disenguages and allows the main exhaust turbine to do all of the work.

Which got me to thinking. you could have +1 (or more!) psi constantly if the turbine and jet were tuned correctly, providing zero turbo lag no matter how large the turbo (within reason). And on full drag equipped cars they could run ultra high output water pumps and possibly electric helper motors running off of the battery, controlled by a simple rpm activated switch.

I think i'm gonna run with this guys, it's worth tryin to R&D it anways.

I'm gonna try to draw up the idea/system in a simple CAD program and run it by a few manufacturers or private tuners. Please let me know any input you have. good or bad as it will help greatly.


thanks

adam

 

[souprat]

so you wanna drive the turbo with a high pressure spayer to spool it. how much water pressure is it gonna take to turn the turbo at 100.000rpm? thats gonna take one mondo waterpump, and what drives the waterpump? the engine. so you would suffer some power losses to drive the waterpump. and then is your whole cooling system gonna run at the higher pressure? you'd need to have some strong hoses to withstand the pressure. then once you dis-engage the sprayer is that extra water wheel gona cause any air resistance/turbulance as it spins with the turbo? cuz that would slow it all down. i think the answer to zero lag turbos is ether a suprecharger or a
VAT-N turbo. turbos with a variable a/r ratio have been shown to spool twice as fast as a regular similarly sized turbo, and there is no need for a wastegate.

 

[Supra Blues]

This first question to answer is:

How much flow is in the cooling jackets of the turbo?

Then, the next question is:

How fast with said flow turn this new turbine wheel and is that flow fast enough and forceful enough to spin the turbo turbines to make any difference?

Its a great idea, but sounds way too complicated, ecspecially when you add in the workings of clutch system to the new turbine wheel system.

 

[Adjuster]

Compressed air is easy to get. Just add a small electric compressor and tank setup. It runs only when the tank pressure has been depleted. (Pressure switch)

It would be running when your not boosting, so there is little drag on your motor. (just alternator)

Also it's easy to setup using existing air solinoids, and pressure controls. (IE, only blows on the exhaust wheel when your TPS is past 80% and manifold pressure is less than say 2psi.)

By blowing on the exhaust side, your not confusing the amount of metered air going into the motor. (Also any water, or other crap in the air would not cause problems.)

The air bag suspension guys have the compressor/tank issues already resolved for you, so there is no development time to waste either.

Big question is, can you design a stainless steel nozzle, that is able to direct all of the compressed air at the right angle to effectively spin up the turbo quick enough to make it worth the time? (It would take 100+psi, and some substantial CFM of flow to work, but it's not impossible.)

 

[DrakeMK3]

The idea is interesting, however, the water-powered idea would probably not be feasable. The water pump flows coolant according to rpm, so you wouldn't really have any noticable power from idle up to where the turbo would normally spool anyway. Of course, there are also the cooling problems to your engine now that an obstacle has been added to the course of the coolant flow. It sounds waaaaay too complex of a problem to gain something minimal, but the compressed air idea has a small chance.

 

[Adjuster]

Let's put this another way.
If you want a gear driven setup, your going to need a motor right? (Assuming you can build a high speed clutch that will not cause shaft problems with the turbo balance and other issues like machining the CHRA to accept all this stuff.)

Where can you find a simple "motor" that is small, lightweight, simple to use, has few moving parts and would be safe to run around heat and fuel? It would also need to spin up near 20,000rpm if possible.

They sell these all day long. They are called die grinders, and run off compressed air.... Just incorporate the same design of the die grinder into your turbo model, and there you have your air assisted turbo spool device. (Don't know how much drag this would add, but it would work.)

I still think the nozzle idea is better blowing on the exhaust wheel, it's simple, and would be effective. It also could be fitted to any turbo on the planet, and the air pump/tank combo's are made everywhere too.

Keep thinking about it, this is a good idea, and I'm supprised nobody with a large turbo on a small motor has done this yet.

Just a FYI, compressed air blown over the wheels is how they balance turbo's when they are made. (CHRA is assembled, and the exhaust and compressor housings are left off. The unit is mounted in a machine, and the tech attaches the oil supply to the CHRA. Then uses compressed air to spin up the turbo while the machine calculates the amount of imbalance. The tech then removes material with a die grinder to finely balance the turbo. From what I've been told, they get the wheels going about 20,000+ during this process.

Do NOT try this without oil in the CHRA however, it will screw up your bearings very quickly at these shaft speeds. (That would be a danger in having this system, if it failed, and blew air into your turbo while the engine was not running, it could ruin the bearings.)

 

[gotboost$]

so you wanna drive the turbo with a high pressure spayer to spool it. how much water pressure is it gonna take to turn the turbo at 100.000rpm? thats gonna take one mondo waterpump, and what drives the waterpump? the engine. so you would suffer some power losses to drive the waterpump. and then is your whole cooling system gonna run at the higher pressure? you'd need to have some strong hoses to withstand the pressure. then once you dis-engage the sprayer is that extra water wheel gona cause any air resistance/turbulance as it spins with the turbo? cuz that would slow it all down. i think the answer to zero lag turbos is ether a suprecharger or a
VAT-N turbo. turbos with a variable a/r ratio have been shown to spool twice as fast as a regular similarly sized turbo, and there is no need for a wastegate.

Yes drive it with a high pressure sprayer.'

It doesnt' have to spin @ 100,000 rpm to produce 1lb of boost. Not sure waht the exact figure is yet but i know 100,000 rpm is thrown around as an "as fast as" or "as much as" figure.

Yes the water pump would be where it is coming from. Plan is to use a in-line electric pump to double or triple the pressure. = minimal drive train loss (you're water pump is running at the same level anyways reguardless). Any drain would be from the alternator.

High pressure hoses are a must

Whole cooling system would not have to run at the pressure coming out of the water jet. Or even as much as the additional electric pump will produce.
Can always use a pressure regulator on the run back line to the cooling system after the 3rd turbine.

If the water turbine is disengaged from the shaft the other two are spinning on it would not affect them. It would only affect the rate of the water wheel spinning.. which reasonable would increase if the water jet is still hitting it while it doesn't have the dead weight of the rest of the shaft and the other 2 turbines to carry/spin.

Variable turbine turbos are awesome but none are readily availble yet and use complicated computer systems that are vehichle specific correct? I know ford or chevy was engineering them for some of their turbo deisels.

 

[gotboost$]

Big question is, can you design a stainless steel nozzle, that is able to direct all of the compressed air at the right angle to effectively spin up the turbo quick enough to make it worth the time? (It would take 100+psi, and some substantial CFM of flow to work, but it's not impossible.)

Exactly! The nozzle design would be key. But you would only be able to use it maybe a few seconds (10 maybe??) every couple of minutes.

Also the weight of water would carry a lot more force at the same psi than air would because of it's weight and such

thanks

adam

 

[gotboost$]

The water pump flows coolant according to rpm, so you wouldn't really have any noticable power from idle up to where the turbo would normally spool anyway. Of course, there are also the cooling problems to your engine now that an obstacle has been added to the course of the coolant flow. It sounds waaaaay too complex of a problem to gain something minimal, but the compressed air idea has a small chance.

Yes the water pump flows coolent according to rpm, but with a electric pump design you're water pump would flow just like normal. The point is to have zero turbo lag. so the secondary water pump would run under the normal rpm range of the turbo

example: you're factory turbo hits full boost # 3,000rpm. You're turbo starts making boost at 2,300 rpm. With an electric water pump system the motor would come on at either the flick of a switch and cut out at 2,300-2,500 rpm where the exhaust turbine takes over.

or

The pump motor could run constantly from right at idle to 2,500 rpm where it disenguages and lets the exhaust run the turbines. giving you 1-2 lb of boost through the idle-2,500 rpm. thats roughly 15hp/tq per psi depending on you're motor correct? so having 30 more hp/lb of tq would be hella worth it to me

yes you're engine is running into an additional obsticle, but when the water wheel is disenguaged from the main shaft it would spin like a mother fu#$)r.

my idea was to have a main coolent entry like is already on the turbo and a secondary entry for the high pressure coolent nozzle. the main entry would be aimed to run over the turbine anyway assisting even more.

yaa it sounds complex, but imagine running a 700+ horsepower turbo without lag :love:

imagine you're care is already making 500-700hp. Obviously you have a badass turbo on it that barely fits in the engine bay. You're range of 500-700HP is 4,500rpm to redline 6,200 appx. its fun as hell to drive and fast as a mo fo.

Now you have a water jet system and are able to extend that range from 4,500-6,200rpm to 2,500-6,200 rpm. and you're running 8-9's in the 1/4.

wow, that gives me a hard on just thinking about it... :aigo:

its gonna take a while to engineer and do the R&D, but is it worth it to be hangin with a F50, or Saleen S70 in you're MK3? or just about any turbo car?

i think so... maybe i'm just a dreamer... :icon_conf

 

[figgie]

yaa it sounds complex, but imagine running a 700+ horsepower turbo without lag :love:

:icon_conf

ain't happening. Think about it. a 2jz mottor trying to push a GT42 turbo doesn't start going until it hits 4000 rpm..

the 2jz/7m motor is 3L displacement meaning every two revolutions it pumps out 3 LITERS of air.

so we divide 4000 rpm /2 and get 2000 rpm and multiply this by 3L. that equals to 6000L of air that is pumping out every MINUTE and that barely gets a GT42 spinning! Unless you carry a 500 gallon tank with a pump that can flow lots of water at high pressure. Sorry. Not happening.

 

[americanjebus]

the idea i've always had for getting rid of turbo lag is use the slow exhaust flow from low rpms and use like a gear between the exhaust turbine and impella, as it is now its just 1 rotation of exhaust wheel = 1 rotation of intake, with a gear in the mix and some sort of simple clutch mechanism that will make it 1 rotation at exhaust and 3 revolutions on intake and then kick it off to 1-1 after a certain rpm the lag would be reduced, i know the exhaust flow from low rpms would be really weak and barely be able to push the wheel arround but doesnt the wheel already spin at low rpms, with the gear system providing you dont add too much resistance through the gears the exhaust gasses should be able to make the intake side pump slightly faster.

wild idea that hasnt had too many factors thought of but a simple gear seams lighter than an air tank or a series of high pressure pumps and hoses allong with a secondary coolant supply.

 

[Shawndude]

wild idea that hasnt had too many factors thought of but a simple gear seams lighter than an air tank or a series of high pressure pumps and hoses allong with a secondary coolant supply.

Lol, you design a "simple" gear and clutch system that works at 120+ thousand RPM, and doesn't add much weight to the original turbines, and the world will beat a path to your door.

Just use a 25 hp shot of nitrous guys. You will not outsmart engineers who have been working on this problem for 40+ years now. Sorry, but without extensive knowledge to back up some of these crazy ideas, that's all they are........crazy ideas.

 

[Dirgle]

Some of you guys are talking about a having 1-2 PSI of boost at idle. Assuming this was even possible you would have to redesign every system in the car that runs on vacuum, especially the brake booster. You would really need to figure out something fancy because 1-2 PSI isn't going to do much in the power assist area.

 

[7mgte3sgte]

we could always go the Nissan route Super charged and Turbo charged set it up where u use the super charger at low boos times like taking off so instant response then for higher speeds and gears the turbo chargers

 

[garrettrowe]

we could always go the Nissan route Super charged and Turbo charged set it up where u use the super charger at low boos times like taking off so instant response then for higher speeds and gears the turbo chargers

Yup - whatever power you're going to make from the pre-spool device is going to be pulling as much power as it would take to spin a supercharger from the motor anyway via the water pump or alternator, so you might as well throw a supercharger on there since they're ready-made and relativley cheap.

 

[Adjuster]

Compressed air, possibly might work, using water to force a "3rd" impeller inside of the CHRA?

Don't see that happening any time soon. (Unless you have a custom cast CHRA made up for this turbo.

Then where are you going to get water under pressure to spin up the turbine? This is going to take some volume of water to do it right, and tha water has to be stored, or do you plan on using simple engine coolant.

 

[gotboost$]

Then where are you going to get water under pressure to spin up the turbine? This is going to take some volume of water to do it right, and tha water has to be stored, or do you plan on using simple engine coolant.

well think of a pressure washer... it only ouputs (liters per hour) as much as it can feed from the garden hose... like 7-10gph. (I used to pressure wash trucks for FedEx freight). But the output is under high pressure... so running a garden hose over a turbine wont do much of anything(like the primary coolent line into this design). But put that under a high pressure nozzle like that on a pressure washer, (this is what i planned on using for the prototype) then you are spinning that wheel at at least 4,000 rpm dont you think?

so for the question about reworking the vacume system, it wouldn't be necessary if you had a staged boost controller, (one that regulates boost per gear) so in 1st gear with the system on you can be at a dead stop and still make boost. How much boost would be variable depending on how big of a turbo you have on the car.

It all clicks to me. You would need an upgraded alternator and deep cell battery, but i already have those on my car.

Sounds like it will be a winter project but i think i'm gonna "borrow" the water pump from by dads big ass pressure washer ( needs rebuilt anyways). This thing is 5' tall and 4' wide. Its awesome... runs on kerocine.

keep the ideas and feedback coming guys... much appreciated

 

[gotboost$]

also, if anyone has any dead turbos they are not going to rebuild, I would like to buy them for this project. Hell if you give them to me i'll build you a system after I build mine ; )

 

[Adjuster]

That RB with the SC and twins is pretty nice.

Looks like a roots type blower, and those turbo's are not very small either. (Would be interested in seeing the power/dyno results from that motor.)

You could run some seriously low CR, and still be driveable on the street with monster top end power.

The pressure washer idea for pre-spool? I'm still not a supporter. Use air if you want, but water brings a whole new complexity to the system.

Just dealing with the extra air over your 02 sensor and into your cat will be problems galore. (It will heat up your cat quickly as you add the extra 02, and burn off the unburned fuel in trapped in your cat.)

If you need more spool, just get more PSI/CFM. (Like with two pumps/tanks and regulate them to 175psi. That is plenty to get a turbo spooled up quickly... LOL)

Better yet, just design a one way valve, close it, and pre-pressurize your upper IC pipe with 10lbs of "boost" from the tanks. You could close off a frame rail or two, and use them as extra air storage...

This could go on and on and on....... Lots of ideas. (The proven ones being used today actually work well however, others are either cost prohibitive, have durability issues, or cause a motor to fail emissions requirements.)

Just have to throw one more out here.
Design a huge version of a pressure regulator.
The regulator fits into your upper IC pipe.
It only allows your engine to see whatever the maximum boost pressure you determine is.
Excess boost from your turbo is routed to air tanks. (Could be built into your frame if you want.) That air is held in reserve by huge solinoid valves untill you ask for it and the turbo is off boost. Then it would be released into the intake, the one way valve would keep it from going to the turbo, and you have instant power...

Another benefit is no WG is needed, any excess boost pressure is just dirverted to your tanks, and stored for later use.....

All you need now is a computerized system to controll it all, and some dilithum crysytals for the warp core....

 

[figgie]

the idea i've always had for getting rid of turbo lag is use the slow exhaust flow from low rpms and use like a gear between the exhaust turbine and impella, as it is now its just 1 rotation of exhaust wheel = 1 rotation of intake, with a gear in the mix and some sort of simple clutch mechanism that will make it 1 rotation at exhaust and 3 revolutions on intake and then kick it off to 1-1 after a certain rpm the lag would be reduced, i know the exhaust flow from low rpms would be really weak and barely be able to push the wheel arround but doesnt the wheel already spin at low rpms, with the gear system providing you dont add too much resistance through the gears the exhaust gasses should be able to make the intake side pump slightly faster.

wild idea that hasnt had too many factors thought of but a simple gear seams lighter than an air tank or a series of high pressure pumps and hoses allong with a secondary coolant supply.

problem

nothing is free

imagine a bike 10 speed. What happens as you go into lower gears to try and go faster? The pedal effort is MUCH more. This idea will also do that so yes you can get a 1:3 ratio gear BUT how much more energy is going to be spent trying to spin the turbo faster now?