Hi everyone,

I've been reading this message board for a while and I think it is time to be a little more active.

The past few years I have been reading alot about kitcars and it wasn't until a few months back that I discovered Ron Champion's book and read it twice now already.

Finding Alan's MR project inspired me even more, I really like the MR concept but I wanted to make something totally by myself and since I have not done this before I did not want to take up the task. So I kept my focus on the Locost.

But last week I was discussing all this with a friend of mine who has similar wishes. Just like me he is an RX7 fan and he has been wanting to make a 787B replica for some time. We started discussing the ideas.

I've been busy on the design of the spaceframe and body of the car and am hoping I can post some 3D pictures here soon and get some help. The book has convinced me I can do this with my knowladge and the help of some friends but since I have never designed a spaceframe before suggestions will be very welcome.

General specs so far:
- Mazda 13B n/a rotary engine (RX7-FC)
- Porsche 914 transaxle (provided I can find one for an acceptable price
- Suspension, steering, etc. from the donor RX7-FC
- 1.6 meters wide, 3.4 meters long (much smaller then the 787B, I don't want a replica:-) but it will be that sort of look).

My biggest concern is if I can make the spaceframe work and not make it to small (I'm not the smallest guy around:-) and that I need the RX7 donor car registration to be applicable to the new car.

Thanks for advise and help, I hope to make some new friends here:-)


[Edited on 31/12/02 by BasOlij]

Hi Bas, Welcome to the madhouse.....

To be honest I'm not familiar with the 787B......why not start posting some pictures and your ideas into the archive....as soon as you have registered (like now) you can start posting...it creates your section automatically...

There are plenty of us on here who will look stuff over and give our opinions...

Looking forward to seeing your ideas...

Alan

Hi Alan,

Seems that I indeed have come to the right place. As soon as I have my basic design worked out I will certainly post some pics here.

The Mazda 787B was the 4 rotor GT car that won the Le Mans in 1991. Just like in superbikes, rally and now the GT class rotor cars where banned.

http://www.2751engineering.com/787.html

Ah yes, very nice indeed

Sounds like a great project...I'll be watching with great interest.

Good luck, and see you around.

Oh, forgot to say if you can use a ring-gear flipped VW type 1 IRS transaxle then I'm sure that Kennedy engineering (here in the US) do an adapter for the RX engine.

You probably knew already though

Hi Alan,

Thanks, already knew about that. Some of the american RX7 guys have put their 12A's and 13Bs into those VW bugs and already informed me of that. I will go that route if I can't find an exceptable priced 914 transaxle.

The only problem with the bug's axle is that it's a 4 speed and the gearing is a little long for the 13B. The 914 is a 5 speed:-)

A dutch friend of mine is pondering about putting a 12A into his bug aswell, maybe see what his experience with that is and go for the cheaper bug transaxle:-)

Okay, this is a very early stage render. The spaceframe is far from completed and the body work is not yet rendered so it's hard to see what the final idea is but it will be close to a GT car like the 787B. Haven't desided if it will be a open roof or not.

The engine box is just a guess of what the 13B with transaxle should be, I don't have accurate messurements.

I will probably shift things around before I am happy with the frame and there are still many crossmembers and triangle constructions to be added. Also in some places I have to much:-)

Radiator will be up front. At the back and side of the passenger compartment some airdams will be created to cool the engine further. Also the oil cooler will be mounted somewhere there. I haven't desided on the fuel tank, best guess is somewhere in the back, only place there is room so will have to be something good (/strong/safe).
Rescued attachment MR_frame03.jpg

Hello Bas, and welcome too. I think though, you are on the wrong forum, only for the reason, I can't see your project being Locost!
Only joking, it's a very interesting looking project. I know absolutely nothing about rotaries, apart from the funny noise they make, so I too will be following this one closely.
Have you considered the possibility of using a 5 speed Renault transaxle? I've used a few in the past, and have even converted them to LSD. Coincidently, some of the Peugeot pickups had a ZF slippy diff in them, which more or less drops straight into the Renault transaxle.

Hi Rorty,

I have no idea what sort of price tag this is going to have but I'm going to try to go as low as possible without compromising safety. So going for single donor if possible (only transaxle can't come from an RX7). I can probably get most parts I need from my old RX7 that got wrecked last year (not my fault:-( ).

Renault transaxle would be nice, I have one of those in my Delorean I think. My biggest concern is mating it to the rotary. There is a widely used adapter for the VW/914 transaxle which I know is good. For a renault transaxle I'd be looking at having someone create a one off for me $$$.

The reason for chosing the rotary is pure love for the technology. There are lighter engines out there that produce more hp. But none the less it's a special thing since it uses rotors instead of pistons which means the engine is simpler and vibrates less. It's a 1.3 liter twin rotor that produces 150bhp stock. The turbo'ed version from the FC deliveres 200bhp stock (early versions 180) and from the FD (bit over budget for me) delivers 250bhp stock (the new RX-8 delivers that without a turbo:-)).
Engines are very tuneable. Only downside is that they use more fuel then piston engines but I hope the end result of this project will be much lighter.

I am not happy with it yet but this is the basic idea for the body work....

It's hard to get the shape right in 3D, probably when I need to make the real molds I can get it much nicer. Awell we are far from that stage yet:-)
Rescued attachment MR_frame05.jpg

Hi again Bas....

I agree about curvy shapes being hard to do in 3d....

What software are you using?

Looks like you are on the right track so far.

HI Alan,

Using 3DS Max for this so it is pure modeling, no calcs whatsover for the structure. Did some final tweaks and I am pretty happy with the end result. Only needs a nice spoiler. Also I couldn't get the doors completely right, I'll have to figure that one out when building it.

The Limbo doors are just for fun, I have no idea yet what mechanism I am going to put in place for the doors.

Gonne continue now on finishing the space frame and the on to suspention and all that.

One thing that I am very interested in knowing, what have you guys have done concerning windows? For a GT look like this I don't think I can get a window from a normal sedan or something. I'll have to do something custom.


Rescued attachment MR_frame07.jpg

Hello Bas, that is looking impressive mate....

I know it is early stages, but looking at the render for the frame skeleton I would be looking at introducing more triangulation in the cabin area, maybe diagonals in the floorpan area and in between the upper and lower chassis members along the sides. I think you could be losing a lot of rigidity without it.

Regards, Stu.

Hi Stu,

There are 3 triangles now and they are for the cooling mount and stuff:-)

I haven't gotten around to that yet but don't worry, I'm definatelly going to add enough of them:-)

I wanted to make the body first so I could adjust the frame proportions first. It's such a hassle to change diagonal bars in 3D constantly so I am saving that for last:-)

Ahhhh, I see.....
Looking foward to the next installment
Keep up the good work Bas!!!

Hey Stu,

well the nice thing about having the day off is that you tend to do alot of work:-) So here's one more picture. But I think I'll call it quits now:-)

Put most of the diagonal bars in now.

Anyone got any pointers for me so far? Have I made any obvious design faults? I'm still not sure if the car is big enough, but I want to keep it as small as is realistic:-)
Rescued attachment MR_frame08.jpg

Hello Bas,
as you can see I have registerd too. Now we can discuss some more over here aswell For the other people : my name is Bart, I live in Belgium, and I'm the friend Bas mentioned. So, yep, I'm the one who'd like an exact replica of the 787B...
I think your work is coming along nicely, wish I was that good with a PC...
You could take a look at the KUDZU-Mazda, from LM. It's an open MR car, might be intresting to you. Unfortuneatly, the link I have for that one doesn't seem to work anymore.
The Autoexe WR might be intresting to you too.

Hey Bart,

That autoexe is a beauty!

If you finish those drawings for your 787 I'd be happy to put them into my PC and get you some renders from it:-)

Hi Bas,
got holidays until the 21st, so should have some time to finish the drawings
I will let you know, ok?

The only other suggestion that Iwould perhaps look at doing myself would be the introduction of a transmission tunnel (so to speak) in the centre of the chassis from front to rear of the cabin area, which I think would add greatly to the overall strength of the chassis. It will also double up as a handy place to mount gear levers, handbrakes etc, and to run various pipes and wires through.....

Or you just havent got round to adding it yet, ignore me.

Hi Stu,

You are very right indeed:-) I'm still fiddling with that idea, I need to run the cooling pipes to the front somehow and a gear changer might come in handy when you get above 20kmph:-)

Thanks:-)

Bas, you'll have to excuse the time delay with my replies, as I'm on the other side of the world.
You're correct about the Delorean having the Renault transaxle, it's mated to the Renault/Volvo V6. I'm very familiar with the Delorean. Before I moved down here 11 years ago, a friend in N. Ireland worked for Delorean, and I drove his.
I think you'll find that the 914 trans is scarcer than the Renault trans, with a commensurate price tag!
If you can find the data for the transaxle, I'm quite happy to design an adaptor plate to suit. I can convert it to G-code too, for direct input into a CNC mill or router, which would be a very economical way of doing it.
The last one i did, was a couple of years ago, and cost about AUD$125 for the aluminium, and AUD$160 to machine it, so roughly UKP100.00.

Hi Rorty,

Whow its a small world afterall:-)

Hmm, I'm afraid this whole adapter stuff is pretty new to me so I'm a bit unsure what data you exactly need. But it does sounds pretty good, Kenedy engineering asks 400 USD for the Mazda <-> Porsche adapter plate. If you can make me an adapter plate to fit it to a renault I'd be very happy.

Anyways, I'll put this on my list of options, when I get to the point where I have the engine and I'm looking to buy the transaxle I'll make my final choice and be sure to contact you.

Thanks alot, sounds very promising! The renault transaxle is in abundance here so it would be a very smart choice for me:-)

Hey Bas, get a decent transaxle, so I can buy a copy of that adapter-plate
Well, I'm not sure how much HP the Renault one could take, but I guess it'd be more then a VW or 914, so...
Still, could it cope with aprox. 500+hp from my dream engine on the long run?
BTW, still working on the chassis drawings...

Bart,

I know the transaxle in the Delorean can handle 200hp easily (except my autotran, it has a max of 160). I know there are people out there who go even higher, some of the turbos go over the 200 mark with the stock tranny. Michiel has just rebuild his PRV-6 and I think it is around 250hp and goes fine. Ed is thinking of a 300+ hp Delorean at the moment.

I'll ask them what the max rate is for the stock renault transaxle, if it is not enough there are still plenty of options. The PRV-6 is used in MANY cars and there are many trannies that fit on it so in theory they should all be able to attach to a 13B with the same adapter.

Owh, here is a nice fact btw. The tranny runs the right way for our intended layout but the wrong way around for the Delorean (Delorean is tranny first, then engine). The result is that they reversed the gears on the tranny so it runs the wrong way internally. As a result they couldn't use the speedometer connection on the car (it is in a desperatly wrong place also) and as a result the Delorean has a REAL crappy cable attached to the left front wheel to messure speed:-)

So you'll have to get rid of the delorean and buy a 787B from me
Speedometer will be rather crappy in my design too, cause hardly have place in that car to put a driver in, let alone useless stuff like speedometers
I think this 787B will be a car for people like me: 1m75 tall, 60kg heavy, so just able to sqeeze in there...
Anyway, the Renault transaxle should work, and if not I get a motorsport version. Something that will hold 700+hp, and cost the price of a decent car Well, guess not...
Just a thought, but doesn't a 944 have the gearbox at the rear? Like a transaxle, only it's not bolted to the engine? Might take a look at that... You also migt try Hurley Engineering, the have put Mazda Rotaries into FWD NSU RO80, so obviously must have needed a transaxle too...

The 944 is an option, so is a 924, both should be able to handle the hp. But I am not sure what that will do space wise.

Also I think the Renault transaxle + adapter is the most economic friendly option. The transaxles are widely available. There are plenty to be found in cars that no longer get through the MoT and the likes that you can buy for almost nothing.

For a 944 transaxle your sure to pay several hundred euro's, the 914 transaxle goes past 1000 euro.

Hi Bas,
That looks like an interesting project. I have always been a fan of GTP cars and especially like the mazda. Have you seen the following site:

http://www3.telus.net/962

The guy makes replicas of Porsche 962's.

Renault transaxles are used a lot in Ford GT40 replicas. I know of a number of people running this axle with 400hp engines. Take a look at www.gt40s.com there is quite a lot of info on tranaxles there.

Good look with the project and keep us updated.

Paul

that porsche link is exactly the one I was talking about in the e-mails, Bas...
I think you can find some ideas there.
Do keep in mind though what I said earlier by e-mail: you can not use the engine as a structural part, as is done with the Porsche. This is because of the nature of the rotary. The long bolts that keep the engine together would never be able to cope with the stress.
The suspension setup on that Porsche is more or less what I want on my replica, but as you know that's all still in a very early stage...

Great stuff Paul! That GT40 site has got some great info on these sortof things.

I wonder if anyone did a GT40 with a 20B in it:-)

What is that LMP you are working on? I still wonder how people will react when you drive a GT car onto the driveway:-)

Tonight I hope to have some time to do some more updates, all these sites have given me some clues on how to make my design much better so I'll be changing some things.

One more site for the rest of the interested here:

http://www.sakermotorsport.nl

owh, Bart don't worry, the frame is the structure, the engine just the propulsion, this is my first go at designing my own car so I want to keep it straight forward:-)

Bas,
My project is an open cockpit LMP style car similar to a Radical SR3. It will be powered by a Suzuki Hayabusa (eventually either bored and stroked to 1500cc or with a turbo). I am about a week away from finishing the first version of my website describing the project. I will post info here when its done.

On the subject of rotary engines the following US produced CSR may be of interest to you:

http://www.diasio.com/

Take a look at the D962R

Hmm looking forward to your site:-)

That rotary car seems pretty cool. Not to special though, pretty much what we are trying to do. Bit more expensive though, although if Bart goes ahead with his 787B project that wont be cheap either:-)

Interesting they put a bridgeported 12A in there, not very street legal:-)

Bas, some people even have street legal peripheral engines... Depends on state laws. I might consider PP fo the 787B. If I ever build it... cause it will be a very long term project. If everything goes well I might give it a try next year.
BTW: everything is legal, just don't get caught

Very true Bart,

Anyways, I wasn't to happy with the body, it just didn't look right, so I've been looking at the pictures of similar car and desided to redo the body. Some small changes to the frame and a new body. Not finished yet but looking alot better then before!
Rescued attachment MR_frame09.jpg

Damn, keep putting 2002 in the pictures:-)

This is one where you can see the altered frame design (and yes, I haven't done some of the things yet I was going to put in:-))
Rescued attachment MR_frame10.jpg

Very nice work, but don't forget to drill holes in the floor to get rid of the rain now you lost the roof... It looks really different now, more race, less street. Cool job. I'm stuck now, cause I only have a low-budget software so I cannot model the body, nor refine the chassis. This is what I have up to now. Maybe you can remodel it in real 3D software someday. And add the nice body... (aswell as some decent Volk wheels too )
Rescued attachment 787Bscreenshot.jpg

Hey Bart,

Looking good! I wonder though, how are you going to place the air ducts? Seems there are some bars in the way? Could be wrong though, hard to see without the body

I designed on top of the model drawings I've send you earlier, and used them as a background. Therfor airducts should be ok. The sidepots are made smaller , so the actual bodywork will/would have some air in between there. So some place for airducts. Only the lower left one will slightly interfear with the sidepot-bar. So a small cut-out and a painted frame would hide that. That was the most challenging part by the way, making sure I could use all the airducts... A scale model will show if my calculations are ok...

Oops, turned out I made a critical design error, if I had build everything like this I would not have fit in the car:-)

BIG oops. Just made everything to low. Also the radius of my tires was a little to low. Adjusted everything so a 17" and maybe even an 18" is possible. So far still basing everything on the 16" that comes with the RX7. Tire size is currently 205 wide, design should allow up to 250 to be used perfectly.

I've adjusted almost everything to more realistic messurements. As a result the car is now 1m70 wide and 3m50 long, ground clearence is still 10cm. The highest body point for the 'cabrio' is 65cm (75 above ground). With the top on the highest point will be just over 100cm (110 above ground).

Haven't adjusted everything so there are still some things missing and some faults.
Rescued attachment MR_frame10_11.jpg

BTW,

has anyone got any suggestions about naming this project?

Wasn't 15" the wheel size for FC's? Anyway, don't really know a name... You could call it "porsche-eater" or "PSMNA" for Pistons Make Nice Ashtrays Haha, that's the rotary nut in me... Anyway, kep me (and the others) informed on the progress you make.

Hey Bart,

Both 15" and 16" where available. We had 16" on our FC that we ran on the Nurburgring. I think only the later turbo's came standard with those 16" rimms.

Okay, I extended the length of the car a little further. I think there will be plenty of room in the car now. I've also made the front part of the space frame a little wider. Gives me some more leg room:-) Hope I will not run into steering trouble.

I'm still not sure what to do with the back. I'm not happy with it yet. I want something that allows me to use a rear view mirror. I'm thinking of doing a roof you can remove, so make it sort of a cabrio alike thing for summer time. Suggestions are welcome here:-)

I'll see if I can extend the info on my website a little more soon. Right now there is almost no of this project so:-)

Bas, from the latest drawings I feel like your car looks a bit like the old Can Am racers. So those might be of intrest. Maybe you can take a look at some McLaren MK6 replica's for ideas. You could build an open car and have a hardtop for less nice weather. You can mount the mirror on the dash, or use a windshieldframe. Do remember that a full screen will mean wiper(s) and heating/demisting. A simple deflector would be easier, but less comfortable.

I don't mind figuring out the wiper thing and the heater thing. I'm thinking of building in a heater anyways because I will be using the car all year round.

I am worried about where to get a proper windshield in the first place:-)

Just take a look at excisting kitcars. Some of them will have something usefull. Once you decide the style of the body, just look at cars in that class, and make your design fit the windshield. That 'll be easier then the other way around.

Yeah but I don't know of any car that would have the kind of windshield I am looking for:-)

Here's the progress so far......
Rescued attachment MR_frame13.jpg

How about a windscreen of one of these?

(click here).......

Or even one of these?
Rescued attachment flying_saucer.jpg

Hi Stu,

A windscreen from one of those would be nice but I think they are tailer made for the GTR, thats gotta be expensive:-)

But definately one to keep in mind, thanks!

Rorty, If you can get me one of those I'll redesign my car to use one of those gravity inverters aswell:-)

Hey Everyone,

it's starting to look good! I think I'll stick with this design! Just need to start detailing it.

Will start working on a nice website for it soon since I am starting to bloat this thread with pictures:-)

Tell me what you think so far?
Rescued attachment MR_frame14.jpg

So it has a roof again...
I think it lloks pretty good, but I'd either lower the roof or make the wasteline higher. Just an idea...

I am thinking about raising the back a bit. The actual top I am not going to finish until I have a good idea how the size in real life is. The roof may be higher then needed but it might also be that the roof is to low.

Not sure what the best way will be to test it. I am thinking about building part of the car from wood 1:1 scale to find out. They had a sale on wood the other day at Gamma so it should be cheap enough to do. Then I can deside if it is to high or to low. Also the wood frame I could complete the body work on and use it as a counter mold.

But dunne know yet, seems like an awfull lot of extra work....

Okay now we are getting somewhere for real. Got the doors in (still need windows) and the frame is somewhat further developed now. Still need to fix some things at the engine compartment but other then that I think this is pretty much finished.
Rescued attachment MR_frame15_16.jpg

Looks good, but you might find it easier to get in the car with different doors. When you use doors like the 787B or Ultima they'll be less in the way. These sort of cars aren't easy to get in and out anyway, so you might want to get the best result on that topic.

Hey Bert,

I'm not to afraid of the doors. The way I designed them to open means there are totally clear of the opening.

I haven't completely figured out how to make them stay up, probably some gas struts or something.

Hey Guys,

Just a small update here, I had some very expensive repairs on the Delorean the past few months and things have changed.

I have desided to not take changes and I am going to go for a normal locost following the book and build it bit by bit as I have money and time available.

After that I may still get back to this project because this is really what I want to do but right now it would be irresponsible.

Anyways, with luck I should start working on a locost sometime during this summer. I probably will even go rotary:-)

Bas, sorry to hear the mid-engined project is on hold, but also glad you are still building something....and that the middy is still there in the background.

When I started mine I always wanted to build a "supercar"...kind of Ultima beater (and still do to be honest), but things like doors, windscreens, ventilation etc. always surfaced to slow me down.

Then, after building my buggy I found the Locost movement. The search was then on for suitable donors.....after what seemed like ages searching in vain (probably a month or so to be honest) I though why not do a similar budget style approach, but with a middy....

I could lose the doors, the screen and so on and have a "simple" build. The rest is history as they say...

Anyway, good luck...at least you'll be building something.

Hey Alan,

The difference is, you already build a number of things:-) I'll certainly go back to the midengined concept eventually, I just first want to build something where most of the questions are answered, following the book wherever I can, only deviating there where needed because I want to go single donor and have a different engine choice.

If I do that successfully, then I am ready to design something myself

Well Bas, even if you want to go Locost first, which I believe is a good idea for a first time builder (like you, or me ) anyway, you still could go mid-engined .
To most imoprtant thing to get a powerfull, sporty and entertaining car would be power to weight ratio. So the car must be kept lightweight. No roof, nor doors would make the build not only simpler, but also cheaper. And a lot is possible on the Seven-like chassis, looking at the caterham 21 (which of course is not a Locost at all) If you design the car to have the cockpit further up front you can put that rotary engine (remember: it is VERY compact) behind you, a bit in the style of the old Auto Unions...
My project hasn't even started, yet got cancelled again... After finding the Belgian MOT doesn't agree with 225/50/15 tires on my 1982 RX7, nor with the lowered suspension (still driveable, don't hit the streets or anything), I cannot see how the are going to allow a self build car.
It is possible, but right now, finding out the laws in Belgium, and how to make the best of them, is priority. If I can find a legal way to build and register a self-build Locost, I will go ahead. Otherway, I might just aswell move, I hate this over-regulated country! Need any train drivers in the UK?

Hey Bart,

Nah I'll go standard RWD first. Experience is what I need now:-)

I hope the APK and RDW laws in Holland stay the way they are for now. If I take to long building this car I may also run into the same problems as the European Union seems to be keen on making selfbuild cars an impossibility.

I have done a finite element analysis of several car chassis and I would suggest the following for your mid engined design.

The engine bay will need some diagonal braces. Take a look at tube R on the lowcost plans or at the Y brace on the Lotus 23 chassis for ideas. Two diagonals, one on each side of the engine bay are much better than one.

Don't use that bent tube on the outside of the chassis running from the passenger region to the engine bay. The bend is a bad idea as far as chassis stiffness is concerned.

The tunnel down the centre of the chassis probably does not contribute much. The lowcost chassis is certainly better if the tunnel tubes are replaced with a simple sheet steel welded tunnel with minimal internal bracing.

You may be better off, weight for weight, with a ladder frame. The massive superiority assumed for spaceframes is just hype. Most spaceframes are actually less stiff than a well designed ladder frame due to inadequate triangulation. With additional triangulation and some minor redesign it is possible to double the stiffness of the lowcost book chassis, reduce the number of tubes and reduce weight aswell.

I have written my analysis results, which cover several types of chassis, into a Word document which I could e-mail to you if you want.

Good luck with building your car.

I would be intrested in some chassis anylises, for future projects.
I'm planning a locost type car for the (rather) near future, to practice skills, but would like to build a more serious car after that, so any ideas are welcome (mid engined car, rotary powered, ...)

yeah I would like that analysis aswell, the MR project has been postponed for awhile but it always helps getting info

Send me a private message ok?

Hi there , my name is Paul.
I intend to daydream about building a small midengined car(thou i think it would be imposible to get it registred in germany) ((

but ...............one never knows ;o))

hope to learn a good deal from you ...

later Paul

Hi Paul,

Did you check out my site?

http://www.desicodesign.com/meerkat/

May be of some interest.

Alan

quote:

---

Originally posted by Deltonhall
(thou i think it would be imposible to get it registred in germany) ((

---

Hi Alan ,
thats the place I came here from..... :o))
realy great stuff.
My intetion would be to go very much smaller,something like honda S800 or Suzuki Cappuccino (just midengined)or a smart roadster.
my opinion is that you dont need a lot of horsepower to have fun.
but it seems hard to find a suitible donor.
I thought of using a bike engine,but how to make it reverese?
and after all it should not cost a lot because it īs all never going to see a road(legaly at last).
any thoughts welcome.... ;o))

later Paul

quote:

---

Originally posted by Deltonhall
My intention would be to go very much smaller,something like honda S800 or Suzuki Cappuccino (just midengined) or a smart roadster.
my opinion is that you dont need a lot of horsepower to have fun.

---

Just check some of the bike powered kit cars around these days. No problem at all to get a reverse! You keep using the bike gearbox for the forward gears (you even get sequential shift with them!) and a reverse gearbox extra. That really isn't an issue to worry about. Different models are available, so you'll just have to find the one that suits your concept/budget best.