R³ Hybrid Technology Solutions conversion process explained

[Persanity]

*I constantly edit my posts*

Hello Everybody,

Let me first start by stating that the aim of this thread is for the pure technical discussion for the electric engineering principles behind the Oshkosh ProPulse system, the technology in it that allows it to not use a battery systems as well as the inefficiencies of that system. Flywheel based energy recovery systems and their use in battery powered electric vehicles as well as more traditional hybrids then what I want to offer.

The company R³ Hybrid Technology Solutions will (hopefully) provide.
A complete turnkey, modular, universal, DIY hybrid solution with a ICE-electric drive that doesn't use massively expensive or massively heavy batteries.

The working concept for my system comes from many aspects of different technology currently available in hybrid vehicles across many industries. My system brings together existing methods of increasing efficiency for ICE, not just increasing efficiency for ICE-electric transmission hybrids, to create a unique fuel-electric transmission solution for converting passenger vehicles.

I'd like for this threads purpose to be about the discussion of how I can better achieve that goal.

We have the basic principles of a hybrid down and we know the ProPulse system is real, After all I think joker is driving one in Batman TDKR.

Lets not worry too much about overall vehicle efficiency but the efficiency of the ICE and generator combo. We can start thinking specific efficiency numbers later when I have a prototype, lets put our heads together.

I developed this system for myself because I drive 300-500, or more, miles in any given day and can't do a DIY pure electric conversion because I make short stops all day long on the overall roundtrip. I can't ever know ahead of time if I'd have the ability to charge up at a store, and if I did for how long, so the real world limitations of batteries in pure EV application are a very very real issue for people like me. The DIY hybrid conversion kit(s) available now for purchase and installation on vehicles are not appealing to me personally, Thus why I entered my concept into the MassChallenge. Because they will help me get industry contacts to further develop my idea,concept & prototype into a vehicle at no cost to me, if I win.

So Yeah, This is a concept but based on real world technology and personal research and experiments. I have made traction by doing tests on a Prius transaxle and running the generator from different sources to generate power. Limitation is heat with what I have to work with currently.

First the basic conversion process and conversion concepts. By taking a lesson right from the page of any car maker and using stamped replacement panels in out conversions, we can basically do anything we want to any vehicle while retaining original outward appearance of the vehicle. One similar idea or proof of concept is auto restoration products. You can build a entire new car from stamped aftermarket parts, shouldn't be too hard to replace key vehicle panels to change important aspects of the vehicle being converted to a hybrid drive system. Second, aftermarket niche communities like exist around the mini-trucking world are a good example of changing components of a vehicle to give different functionality while, mostly, keeping the vehicle appearing stock. By utilizing a independent front and rear suspension system in all our conversions regardless of what specific vehicle is being converted we have a system that can maintain proper ride height while still being tunable for increased performance handling. Our conversions can be FWD, RWD, AWD, or 4WD because we use independent suspensions. One idea I have been toying with is replacing the floor in non uni-body vehicles with a uni-body type floor made with stamped structural components based on uni-body structural details taken from the worlds safest uni-body car, no idea what vehicle that'd be just yet, with high crash test rating. Lower overall vehicle weight is achieved by getting rid of the full frame on non uni-body designs, like the mini-trucks do with custom "dune buggy" tubular frames. Using stamped parts to replace vehicle stamped parts is better then having a tubular frame because you can rapid prototype in a computer with stamped parts.

The concepts for the drivetrain solution I want to develop for private vehicle owners is primarily based around the Oshkosh ProPulse hybrid powertrain system. By taking all the best parts of a ProPulse hybrid vehicle that doesn't use batteries to store electrical power and adding additional elements from different industry energy recovery techniques, aspects of the system come together to allow the generator and ICE to maintain a constant
RPM in relation to each other even under full generator load for more efficient power generation in the same physical space. By oversizing components correctly we avoid running any one system at peak power. What makes the constant rpm relationship possible is having the engine decoupled from the road & gas pedal through the use of a computer controlled double clutch flywheel compensated pulsed alternator. There are also additional elements in the engine to generator system such as a device similar to the Toyota PSD (power split device), even though it doesn't split power, and a compound planetary gear set. That engine to generator system is what makes us unique and what gives us an edge over competition while still being powerful and fuel efficient. Please feel free to ask any questions, except what the flow of power is from engine to generator through the components I listed.
Thank you to everybody that has contributed to the threads I've post here the past few days.
Aaron Coach
Founder
R³ Hybrid Technology Solutions.

Currently, just like electric car conversions, hybrid conversion have been tested and work fine with off-the-shelf components. That is not to say that new technology will not advance the concept. There is always room for improvement. Thats what we hope to do. Improve current technology to the point it is not cost prohibitive to do these advanced battery-less systems. Currently, they are only offered for commercial use or used in hybrid race cars.

 

[TylerDurden]

Suggestion: format the above monograph into more reader-friendly paragraphs. One concept per paragraph.

Good ideas need coherent communication. It takes time, effort and patience.


Edit: removed formatting example.

 

[Persanity]

I tried to put everything relevant out there so, yeah, it is definitely a little jumbled. One other thing that may or may not be relevant is Im not the one who will be building these DIY systems. Im the designer, even though the system is based on existing technology, it needs to be "engineered " and tested. Extensively. I hope to proceed to round 2 and get help from MassChallenge advisors to get OEM's to donate equipment for testing and have a fabrication or welding shop make the associated systems for mounting in a vehicle.
Thanks for your time.
Aaron Coach
Founder
R³ HTS

 

[bigmoose]

OK, it takes a bunch... but I have reached my limit. We are not going to have a proliferation of R³ threads here. I do not know what you are trying to achieve, but there are a ton of posts with limited technical content.

I am going to lock this thread, and you can PM me A SHORT answer ONLY stating if you want this thread combined with your original thread in general discussion http://endless-sphere.com/forums/viewtopic.php?f=1&t=38520&p=562304#p562304 or that thread combined here.

It would not be a good thing to send a long response. This thread, or that thread will suffice.

Perhaps you should find Trevor, he seems aligned with your goals and objectives.

 

[bigmoose]

In agreement with the author, we are going to lock the other two threads and re-open this thread for technical discussion. I will leave it to the author to edit his own posts to edit and/or remove material that is not germane.

 

[wheelbender6]

Compared to what I see on the ICE forums, the outline of your concept looked pretty good. Your hybrid kit sounds a bit pricey. Have you considered also offering a lower cost, simpler entry level hybrid kit? it could be similar to those used by Honda, which are basically an electric assisted ICE that never runs on trons alone. The Honda mounts an electric motor on the flywheel, but it seems that the same could be accomplished with an electric motor thats is connected through the accessory drive belts. I heard that Buick may soon offer belt driven electric power assist. I have no credentials in discussing hybrid propulsion. I'm just a shade tree tinkerer that is interested in hybrid propulsion.

 

[Persanity]

Once the design I have is 100% sound I can decide if its more prudent to provide kits or a conversion service. I would love to offer both eventually for DIYers and non-DIYers alike.

 

[fechter]

OK, here is a link to Oshkosh that explains some of the system they use:
http://www.armyrecognition.com/us_a...nical_data_sheet_specifications_pictures.html
Check out the video lower on the page.

 

[Persanity]

Thanks for the link fechter!

This is about the system itself. http://www.oshkoshdefense.com/propulse

The goal of my project is to take the existing technology in use by Oshkosh in their ProPulse system & apply it to a universal DIY hybrid conversion system.

By taking the batteries out of the equation, I can keep the costs and weight of my conversions way down in comparison to existing hybrid conversions.

This allows me to provide "extra" features, like independent front and rear suspension, as a standard feature in my conversion system.

It seems like the industries with the financial and technological backing available to them to bring this technology to passenger vehicles

only want to use it for commercial applications. Some automakers ARE using this technology, but only in racing cars and extremely high end hybrids.

I want to make it available to the average Joe for as cheap as possible.

Aaron Coach
Founder
R³ Hybrid Technology Solutions

"Just because I can't fabricate doesn't mean I can't innovate."

 

[coldfusion594]

You got my vote!

Good luck with your future endeavors I hope your plan works

Karl

 

[REdiculous]

Even their small ProPulse system has a (roughly) 100HP diesel genset...

I'd put a battery bank back into the design so you can cut that diesel down. I don't see how it would make sense to remove the original engine so I could put in another of similar size and a bunch of electrical goodies and a large electric motor.....for slightly better range, maybe, and less performance.

 

[Persanity]

My system USES the original engine in the conversion, keeps the costs down. BUT it makes it a flex fuel engine.
Meaning this conversion service or DIY kit could include a engine rebuild potentially. If I wrote bio-diesel instead of bio-fuel I apologize.

Im still developing the exact system that is going to connect the ICE to the generator but I intend for the combustion engine to run constantly at the lowest possible fuel efficient power producing RPM that a engine can be run and still produce enough power, to the end that its efficient by itself.

Then by a unique conceptual (but based on current automotive technology) transmission between engine and generator, the generator will always be at a constant power output speed independent of engine rpm and variable generator draw. Within reason obviously.

Its like running a electric motor at 150% power rating without coolant. You can do it, but not forever. The whole thing is designed to smooth out rotational speeds to maintain two independent RPMs on a variable draw system without bogging the engine down. This isn't free energy or over unity, it can't be maintained indefinitely, but for climbing hills and acceleration from a stop(with the gas engine having been off btw) its an amazing design.

From watching videos of the HMTTT with ProPulse you can hear the engine revving under load because of increased demand from generator.
If you never rev the engine beyond initial start up then its more fuel efficient. They say there system can be 50% more fuel efficient in those big trucks.
Not sure the light duty ones, either way it creates a practical solution where there was none before for myself and others like me.
Aaron Coach
Founder

 

[REdiculous]

There's still too much hand-waiving for me to take this seriously.

I thought the idea was to save weight by not having batteries? Your idea adds weight and you have to have the original engine running in order to go anywhere. I don't see a market for that...

Slower acceleration. Lower top speed, most likely. Heavier vehicle for sure. Better range, maybe.

You can't have the engine idling when you need 50+kw *right now*. The engine will take some time to spool up, and when it's not making its continuously-rated power, it's running inefficiently....a big engine putting out a few hundred watts is wasting a ton of power just to overcome the friction in the engine...

This is one of those things ... I just don't see it ... spending money to add weight and complexity for a minor gain, if you're lucky and it works.

 

[Hillhater]

.... By utilizing a independent front and rear suspension system in all our conversions regardless of what specific vehicle is being converted we have a system that can maintain proper ride height while still being tunable for increased performance handling....

Assuming you are aiming for a mass , daily driver/commuter type market... most modern vehicles ( trucks & vans excepted) .. are designed with independent suspension as a fundamental feature.
I suggest you focus on your drivetrain package .

.... One idea I have been toying with is replacing the floor in non uni-body vehicles with a uni-body type floor made with stamped structural components based on uni-body structural details taken from the worlds safest uni-body car, no idea what vehicle that'd be just yet, with high crash test rating.....

Sorry but, by definition a "unibody" design depends on the totality of the body structure for its strength...door pillars, window surrounds, roof panel etc, etc. You CANNOT just take the floor pan design from a unibody and use it under a set of body panels.
..BIG Fail !
I suggest you focus on your drivetrain package .

.... Lower overall vehicle weight is achieved by getting rid of the full frame on non uni-body designs, like the mini-trucks do with custom "dune buggy" tubular frames. Using stamped parts to replace vehicle stamped parts is better then having a tubular frame because you can rapid prototype in a computer with stamped parts......

Are you aware of the tooling and manufacturing set up costs to produce "stamped parts" ?.
..you would require huge volumes of any one design for this approach to become economical...even assuming you could produce an effective design without expensive prototypes and testing with minimal redesign/re tooling costs.
I suggest you focus on your drivetrain package .

You seem to have a pre occupation with rigid chassis, rigid axle, heavy vehicles. .. IE:- commercial Trucks & Vans ! ..why ??
If you really.... "want to make it available to the average Joe for as cheap as possible".... you need to familiarise yourself with the type of vehicles "average Joe" drives ...and...... focus on your drivetrain package . !

 

[Persanity]

The idea is to increase fuel efficiency of a existing vehicle by turning it into a parallel hybrid with no mechanical connection to the road.

Just like the Oshkosh vehicles with ProPulse previously linked to.

Swapping a transmission for a generator and a regular differential for a differential with an electric motor built into it to get rid of the drive shaft, in the case of a RWD,AWD, or 4WD vehicle anyway, would maintain the original weight.

It certainly would be lighter then current hybrid options that have all that stuff AND batteries too.
Super capacitors for regenerative brakes would barely add weight to a vehicle.

Toyota has sold over 3 Million hybrids, not sure in total or just us, but that means there is a beyond a doubt a market for hybrids.

Have you heard of the companies ALTe or XL Hybrids?

They do what I want to do without removing anything and adding all the electric stuff, complicating the entire vehicle as its not meant to be there.
They do it with batteries and barely decrease fuel consumption.

As with any electric vehicle there is instant power from stand still. Picture the engine and generator as a 100% constant power output battery that can deliver the maximum amount of power the motor can ever use at one given moment .

I actually can run a engine like that. Thats the idea behind the concept of this drivetrain. Its is the unique aspect of this project that you won't find anywhere else.

By reusing parts from other applications Its not expensive at all. Certainly if I were to have the funds to go buy everything I need on ebay it would be cheaper then a budget motorcycle conversion in raw parts cost.

I want to provide a well engineered full conversion solution more then I want to provide sub systems of the conversion solution.

This is why Im competing in a startup accelerator program. I need money for engineers. But my principle is 100% sound. Think compensated alternator.
Aaron Coach
Founder
R³ HTS

 

[Persanity]

.... One idea I have been toying with is replacing the floor in non uni-body vehicles with a uni-body type floor made with stamped structural components based on uni-body structural details taken from the worlds safest uni-body car, no idea what vehicle that'd be just yet, with high crash test rating.....

Sorry but, by definition a "unibody" design depends on the totality of the body structure for its strength...door pillars, window surrounds, roof panel etc, etc. You CANNOT just take the floor pan design from a unibody and use it under a set of body panels.
..BIG Fail !
I suggest you focus on your drivetrain package .

Not to argue....

Based on the definition of a uni-body design I could do exactly that.

Do you think a S10 truck cab isn't designed exactly like a uni-body? Except without stamped frame rail in the floor of course.

If you made a new stamping of a S10 floor designed to have the uni-body body frame rails built into it, braced the inner body and roof, then took the original floor out and replaced it with the new uni-body floor the cab would be just as ridged as a uni-body car. Car and truck bodies aren't made in one piece, uni-body or not.

.... Lower overall vehicle weight is achieved by getting rid of the full frame on non uni-body designs, like the mini-trucks do with custom "dune buggy" tubular frames. Using stamped parts to replace vehicle stamped parts is better then having a tubular frame because you can rapid prototype in a computer with stamped parts......

Are you aware of the tooling and manufacturing set up costs to produce "stamped parts" ?.
..you would require huge volumes of any one design for this approach to become economical...even assuming you could produce an effective design without expensive prototypes and testing with minimal redesign/re tooling costs.
I suggest you focus on your drivetrain package .

You seem to have a pre occupation with rigid chassis, rigid axle, heavy vehicles. .. IE:- commercial Trucks & Vans ! ..why ??
If you really.... "want to make it available to the average Joe for as cheap as possible".... you need to familiarise yourself with the type of vehicles "average Joe" drives ...and...... focus on your drivetrain package . !

Yes, I am aware of the massive costs involved. I have developed a new stamping process/type of stamping machine for rapid prototyping of full sized car parts. I have a small non-computer controlled prototype of a much larger computer controlled machine I desperately need to get patented. One more reason I am in involved in a start-up accelerator program.

All my conversions would most certainly not have rigid axles. They would be 4 wheel constant variable axles with motorized differential, like the rear wheels of a Toyota Highlander only AWD.

 

[REdiculous]

As with any electric vehicle there is instant power from stand still. Picture the engine and generator as a 100% constant power output battery that can deliver the maximum amount of power the motor can ever use at one given moment .

I actually can run a engine like that. Thats the idea behind the concept of this drivetrain. Its is the unique aspect of this project that you won't find anywhere else.

How is there instant power from a stand still?

Newer generators auto-throttle based on electrical demand. Is that what you're talking about, or do you have a magic flywheel in there?...

I'm still lost - I don't see the advantage of this system. Why carry a 100+ HP engine if it's idle most of the time?..

 

[bigmoose]

Persanity do you understand the imputed liability issues with the things you are proposing? If not, get a lawyer friend so that you do not waste your lifetime...

 

[Hillhater]

Do you think a S10 truck cab isn't designed exactly like a uni-body? Except without stamped frame rail in the floor of course.......

NO they are not. The designers of an S10 cab do not have to consider structural loading. That is confined to the chassis members. That is the whole point of rail chassis design,..to take strength (weight) out of body sections where it is not needed.

...If you made a new stamping of a S10 floor designed to have the uni-body body frame rails built into it, braced the inner body and roof, then took the original floor out and replaced it with the new uni-body floor the cab would be just as ridged as a uni-body car.......

You need to look into this more ...A LOT more. !

.... I have developed a new stamping process/type of stamping machine for rapid prototyping of full sized car parts. I have a small non-computer controlled prototype of a much larger computer controlled machine I desperately need to get patented. ........

you need to decide which of your undeveloped ideas you want to focus on first

...All my conversions would most certainly not have rigid axles. They would be 4 wheel constant variable axles with motorized differential, like the rear wheels of a Toyota Highlander only AWD.

There you go again with your 4x4 truck thought train.
What happened to average joe and his FWD commuter hatchback ?

 

[Persanity]

Do you think a S10 truck cab isn't designed exactly like a uni-body? Except without stamped frame rail in the floor of course.......

NO they are not. The designers of an S10 cab do not have to consider structural loading. That is confined to the chassis members. That is the whole point of rail chassis design,..to take strength (weight) out of body sections where it is not needed.

...If you made a new stamping of a S10 floor designed to have the uni-body body frame rails built into it, braced the inner body and roof, then took the original floor out and replaced it with the new uni-body floor the cab would be just as ridged as a uni-body car.......

You need to look into this more ...A LOT more. !

Have you dismantled entire cars panel by panel for scrap metal?

Uni-body or truck cab, they are designed exactly the same.

A number of smaller panels comes together to make a bigger structure with rigid elements to increase structural integrity.

Uni-body designs have more structural elements in more places then non-uni-body designs, that and that alone is the only difference there is. If you disagree with that basic truth then please go watch videos on how the two are made.

IF and I do mean IF I where to go that route, the replacement parts would be designed in a computer. They would be structurally load tested and it would not just be the floor of the vehicle replaced. The the A pillars of the windows and b pillars on the doors would all be reinforced. Like if you added a roll cage, but done with stamped part meant to fit the vehicle the way a replacement panel would when doing bodywork.

...All my conversions would most certainly not have rigid axles. They would be 4 wheel constant variable axles with motorized differential, like the rear wheels of a Toyota Highlander only AWD.

There you go again with your 4x4 truck thought train.
What happened to average joe and his FWD commuter hatchback ?

Well that is simple. He gets a differential motor in the front of the vehicle instead of the rear.

As somebody not disciplined entirely in any one given area I have a unique view from many different areas of knowledge.

I don't claim to know everything about everything but I know a lot about enough to invent and innovate.

Aaron Coach

 

[Persanity]

You see the sub frame that the motor is mounted on?
Every car has some variation of that.
You see how the suspension is part of that sub frame?
Think along those lines for mounting my system to the car but with universal linkage for mounting in any passenger car.
The differential motor replaces the transmission in FWD & RWD conversions, its just in a different location based on original drive train or customers desire. There is no reason a FWD cant be RWD or RWD a FWD. Of course for universal fit, why not make all conversions AWD?

Another thing about the uni-body stuff.

All cars are built on certain architecture.

Like the F-body cars are Camaro,Firebird and Trans-am. They share a floor pan with the G-body cars if I'm not mistaken.
http://en.wikipedia.org/wiki/List_of_GM_platforms

These cars are so much more universal then most people realize.

The PT cruiser has the floor pan of a Dodge neon.


It wouldn't be hard to create a uni-body platform to convert light duty trucks like the s-10 to a uni-body design.
The mini-truck people use very minimal square tubing to make frames for their conversions to a mini-truck from a full size truck.

My background isn't EV stuff, its DIY auto repair and artistic design (And plan-o-gram design and implementation but that not really relevant to this stuff). There are plenty of artists that design or redesign a car and have others do the fabrication.

My artist is kinetic sculptures. I combined those principles and my automotive experience with my DIY repair knowledge and with my desire to be green and go electric with my inability to use an EV because of how much I drive in a day to form the system I enter in the MassChallenge I am describing here.

Aaron Coach.

 

[Hillhater]

There is no reason a FWD cant be RWD or RWD a FWD. Of course for universal fit, why not make all conversions AWD?

possibly because of added complexity, higher cost, lower efficiency, reduced passenger & luggage space...to name a few.

...I don't claim to know everything about everything but I know a lot about enough to invent and innovate.
Aaron Coach

" a little knowledge can be a dangerous thing " !
I dont see much invention or innovation here,..just wishful dreaming and poorly researched thinking. !
Carry on as you wish my friend. you have a long / hard/ frustrating / expensive ..learning experience ahead of you.
And do let us know how your application is recieved. :wink:

 

[REdiculous]

It wouldn't be hard to create a uni-body platform to convert light duty trucks like the s-10 to a uni-body design.

My stepdad totally wrecked my S10 a couple days ago and I still wouldn't let you near it. There's no reason to mess with the body, floor boards or cab. My truck is totally hosed but the cab is the same shape/size as it was before the wreck.."like new".

The S10 would be a good platform to play with, because they really are "light industrial" trucks, but there's no way I'd change the structure or try to make it better. It'd be a fat waste of time/effort/money.

What you need is a drop-in replacement for the engine. Keep the manual transmission...don't convert automatics...make it easier on yourself.

 

[Persanity]

I am sorry you don't understand what I'm trying to achieve.

All the concept are sound. Spend a little doing research into kit cars and mini-trucks.

There are no new concepts here, other then the engine to generator components, besides putting it all into one package for turnkey hybrid conversions.

If these type of hybrids didn't save money then the military wouldn't use them in environments where its logistically too expensive to convoy large amounts of fuel.

UPS, USPS, Coca-Cola, Fed-Ex all are converting their fleets to hybrid drive because these systems save money in start stop delivery situations.

I'm glad that 90% of people can use pure EV 90% of the time. I am not one of those people.

A parallel hybrid with an electric transmission that has a properly sized ICE/generator combo has better power density then any battery.

The Toyota 80KW/150KW differential motor (I forget exact power output) is about the same size as a normal differential.
They make ideal motors for my conversion system. Again keeping inline with reuse. repurpose. retrofit.

Why would having front and rear drive motors decrease passenger compartment size or be less efficient?

Two motors would be better. You can run higher voltage into each at lower amps for same overall output.
At a lower motor temperature too because the conversion of electricity into motion is distributed between two motors for less heat losses in the motor winding.

Right?

That is how I understood the reasoning behind why Toyota uses two motors instead of a traditional differential for 4WD/AWD in the hybrid Highlander.

Luckily I'll have to access to the resources of MIT students through the MassChallenge accelerator do the actual CAD and
engineering work. So I won't be spending any money myself except to go up to Cambridge Massachusetts from Watertown Connecticut.

Anyway, The technology from this system if it was being commercially produced would translate over to pure EV too.

There would be no reason that a kit purchaser couldn't built a pure EV with it. Just don't purchase a generator system and buy your own battery system.

Aaron Coach.

It wouldn't be hard to create a uni-body platform to convert light duty trucks like the s-10 to a uni-body design.

My stepdad totally wrecked my S10 a couple days ago and I still wouldn't let you near it. There's no reason to mess with the body, floor boards or cab. My truck is totally hosed but the cab is the same shape/size as it was before the wreck.."like new".

The S10 would be a good platform to play with, because they really are "light industrial" trucks, but there's no way I'd change the structure or try to make it better. It'd be a fat waste of time/effort/money.

What you need is a drop-in replacement for the engine. Keep the manual transmission...don't convert automatics...make it easier on yourself.

Sorry your step-dad crashed your truck, That really sucks.
Incase it hasn't been clear I'm not doing these conversions myself. My company will be. I'll hire the right people for the job.

I am a designer, not an engineer, of this system. Does it have bugs? Distinct possibility.

My business may be in the start up stage, but this is happening. Its not a crazy dream.

I have no definitive plans for the chassis for my conversion yet. I just want it to be as universal and modular as possible for the largest possible usage across car platforms.

The prototype will be some type of a chassis that in some way will adapt a S10 cab to a alternative under carriage design.

Probably a tubular roll cage like frame.

 

[TylerDurden]

Its not a crazy dream...

Of course it is.





But plenty of crazy shit makes money - although, I'm not sure there are enough people in this country willing to pay what this conversion will cost.