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New mid engined project.
Tudor (Ted) Miron - 21/11/03 at 11:28 AM

Well after some thinking and negotiating with various manufacturers I finaly realised that I have to build my oun car
Here's a very initial picture. It will change massively. (my buddy Dennis is helping me with body design)
Car is modelled with Solid Works 2004,Suspension is designed with ADAMS/Car, CFD analyses with CFDRC, Chassis FEA with MSC.Mark.
This forum is a great source of information and motivation - thanx guys! I'm sure that I'll get a lot of help from you guys nad I'm allways happy to offer help from my side.

Ted

PS: Please be kind to that pic. it's very initial and out of date actually. CFD analises forces a lot of changes to sidepods area etc., etc.

Edit: Somewhy I can't see my oun picture . So I added it to Photo Archive just in case.

[Edited on 21/11/03 by Tudor (Ted) Miron] Rescued attachment dp2.jpg
Rescued attachment dp2.jpg


gsand - 21/11/03 at 12:05 PM

Nice body work design. I like the shape of the sides, but i'm not sure about those twin cockpits

Any details on drivetrain?


Tudor (Ted) Miron - 21/11/03 at 12:30 PM

Thanks Gsand,
Unfortunately this dual cocpit will have to be abandoned for practicality reasons. Geing in and out of the car would be a bit tricky this way. It's not a pure race car (unfortunately) so a lot of things are compromised. I'm sad about those cockpits because they worked very well aerodinamicaly.
Drivetrain. It will be bike engined. Now designed around Busa (what an innovation ) I'm looking at various diff options. Particularely "your new" idea (sorry mate just kidding ) of using a car diff was under consideration. Main problem is weight distribution. Weight is optimised for 1 persone/driver only. With LHD and engine on left side it's not very good. RHD will be good thought. I'm looking at various Qaife units as well. ATM it's modeled around Quife CD axle unit (QBA2R1), Powertech sistem is not completely abandoned as well.

Ted

[Edited on 21/11/03 by Tudor (Ted) Miron]


gsand - 21/11/03 at 01:07 PM

quote:
Originally posted by Tudor (Ted) Miron
Drivetrain. It will be bike engined. Now designed around Busa (what an innovation ) I'm looking at various diff options. Particularely "your new" idea (sorry mate just kidding ) of using a car diff was under consideration. Main problem is weight distribution. Weight is optimised for 1 persone/driver only. With LHD and engine on left side it's not very good. RHD will be good thought. I'm looking at various Qaife units as well. ATM it's modeled around Quife CD axle unit (QBA2R1), Powertech sistem is not completely abandoned as well.

Ted

[Edited on 21/11/03 by Tudor (Ted) Miron]


mm, i thought it was an alright idea... o well.

If you are using a car diff and independant rear suspension you could position the motor and diff basically anwhere along the engine bay, just to compensate for the driver weight.

Regards, Glenn..


Alan B - 21/11/03 at 01:17 PM

Aha...a development of the DP1...looks promising...good luck guys...

Will it still be 4WD?


pbura - 21/11/03 at 01:29 PM

That IS a nice design, Ted, and very original.

You're planning to sell these, right? If your contacts and likely initial customer base are oriented towards racing, I would resolve any compromises and go that route, with even a single-seat option. This car would appeal more to racers, I think, with the low ground clearance and no windscreen. Sort of like a LMP or a MK GT.

Just my 2 kopecks

Pyotr


sgraber - 21/11/03 at 02:22 PM

Very nice design! I like the concept as a whole. Good work.

My question regarding the diff. Continuing the idea of longitudinal bike engine coupled to the diff directly or via coupling... What drawbacks are there to offsetting the diff severely to the right side of the car? A shorter halfshaft on the right, longer on the left. Resulting in the engine being placed closer to the centerline of the car? As I look at a FWD drivetrain, and this is exactly what most every fwd (and transverse RWD) car do right now. The only drawback that I can see would be greater angular movement of the right-hand CV's and more twisting (windup)possibly of the LHD shaft.

Graber


Tudor (Ted) Miron - 21/11/03 at 02:43 PM

Thanks guys.
Glenn - I didn't mean it's a bad idea - not at all. You mean using unequal length shafts?
thank you Alan Yeah in body design it's a development of DP1 concept. At list now. This is a V1. I think it will change a lot still. We don't really want them to be identical. Actually I think that after resent CFD studies DP1 is going to change in some areas as well. It showed VERY promising results btw!
Technicaly it's different. It's much less innovative. Traditional I would say. RWD and 1.6 track/wheelbase ratio. True two seater... It will be simple bat all key areas will be designed to perfection - chassis, suspension, aero. (At list I'll try my very best)
Suspension is my love and with access to ADAMS/Car (makes Mitchells WinGeo look like calculator compare to P4) it's possible to get in the ball park in shorter time. (I'm very lucky to have help/consultation from very top racing level)
It will be 3 versions in 1 car Road , road/track and track/very little (VERY GOOD) road .

Pyotr it's a trackday car initialy could be adopted as pure racer fairly easy... thought it will be hard to adopt it as pure laxury.....

Thank you
Ted


Tudor (Ted) Miron - 21/11/03 at 02:50 PM

Graber - I agree that unequal shafts are not a BIG problem. Problem is to find a good (small and light) car diff...

Ted


sgraber - 21/11/03 at 03:02 PM

quote:
Originally posted by Tudor (Ted) Miron
Graber - I agree that unequal shafts are not a BIG problem. Problem is to find a good (small and light) car diff...

Ted


There are a number of AWD cars with light/small diffs. The problem is that they don't handle much power.

If the BEC front engine boys are using IRS diffs -- "INCLUDING" a driveshaft and 2 UJ's-- and their cars are very light, what are you going to need different than what they use?

Obviously The price you pay for ultimate lightness is money. In that case go with the quaife...

Graber


Tudor (Ted) Miron - 21/11/03 at 03:06 PM

You're absolutely right Graber. The real point here is cost. And it's a hard point.... I'd like it to be inexpencive but I want it to be as good as possible. We'll have to find a compromise

Ted

PS: I mentioned that it's designed around Quife CD axle unit (QBA2R1) at the moment, it's not final thought.

[Edited on 21/11/03 by Tudor (Ted) Miron]

[Edited on 21/11/03 by Tudor (Ted) Miron]


Noodle - 21/11/03 at 03:07 PM

quote:
Originally posted by sgraber
Very nice design! I like the concept as a whole. Good work.

My question regarding the diff. Continuing the idea of longitudinal bike engine coupled to the diff directly or via coupling... What drawbacks are there to offsetting the diff severely to the right side of the car? A shorter halfshaft on the right, longer on the left. Resulting in the engine being placed closer to the centerline of the car? As I look at a FWD drivetrain, and this is exactly what most every fwd (and transverse RWD) car do right now. The only drawback that I can see would be greater angular movement of the right-hand CV's and more twisting (windup)possibly of the LHD shaft.

Graber

In FWD cars, the different resistance in the materials (through differing lengths)contribute to torque steer.

Project that to a fixed toe situation with a RWD machine and things become better. I suppose there's a chance that one wheel could break traction before the other.

Still, the Sierra diffs were slightly offset and nobody moaned about them too much.

Cheers,

Neil.


sgraber - 21/11/03 at 03:59 PM

quote:
Originally posted by Noodle
quote:
Originally posted by sgraber
.... The only drawback that I can see would be greater angular movement of the right-hand CV's and more twisting (windup)possibly of the LHD shaft.


In FWD cars, the different resistance in the materials (through differing lengths)contribute to torque steer.

Project that to a fixed toe situation with a RWD machine and things become better. I suppose there's a chance that one wheel could break traction before the other.


Agreed re; My point about the windup of the half-shaft.

Although it's pure conjecture on my part -- the very fact that the rear wheels will not be steering should make the torque steer issue a moot-point. IMHO - You are more likely to loose traction from one wheel or the other due to road irregularities and weight loading due to cornering forces. Most road racers would experience initial maximum acceleration while the chassis is still in a semi-unstable position. Ie; coming out of a corner. I suppose if you were at the drag strip... ?

Does anyone here know for sure?

Still, I have never seen a mid-engine BEC with the differential offset massively to the right so as to place the engine on the centerline.

Come to think of it, in a LHD car, having the diff offset to the far right would balance against the weight of the driver quite nicely in the chassis.

Graber

PS - Did we hjack your thread Ted? or is this still a valid continuation of the subject?


sgraber - 21/11/03 at 04:18 PM

quote:
Originally posted by Tudor (Ted) Miron
You're absolutely right Graber. The real point here is cost. And it's a hard point.... I'd like it to be inexpencive but I want it to be as good as possible. We'll have to find a compromise



You apparently have top notch technical tools to help you solve many design issues facing you. And that is great for an extreme performance car such as what I imagine you are building. The question I would pose to you then is; How will you scientifically evaluate the price-performance ratio of a Quaife vs a car diff IRS?

Would it be safe to assume the Quaife is going to cost 10x that of an LSD irs? Will it weigh twice as much? Does the quaife have a reverse gear built-in? (You'll need to add that to a streetable car IRS.)

I would love to create a low cost mid-engine BEC myself as my next project. Therefore I am very, very interested in your final choice and especially in following the thought processees you will use to make that decision.


ProjectLMP - 21/11/03 at 07:20 PM

Looks good ted. Look forward to seeing it progress.

On the unequal length drive shafts, the powertec unit used on the Radical SR3 results in one shaft being a lot longer than the other. Doesn't seem to be a problem for them. Also, I guess if you have a LSD (or torque biasing diff as used by the powertec unit) fitted then any variation in traction would be handled by that.

I like the idea of using a used car diff with a short propshaft like on the Coram LMP. This has got to be the most cost effective if you can find a light diff with the right final gearing. I think Coram (or whatever their called now) use an e36 BMW diff.


Tudor (Ted) Miron - 21/11/03 at 07:49 PM

Well it's not that clear for me...
Quaife SD unit :
+ build in reverse, fairly compact. ATB
- not THAT light 49Lb, expensive QBA2R1 @ £1420.00 GBP plus you need a good chain 100GBP.

Powertech(made by qaife for Radical) - all the above and no chain. Even more expencive.

All those allow easy packaging and good weight distribution (LHD)

Car diff:
+ Inexpencive if used.
- Needs LCD, heavy, requires unequal shafts for good wight distribution. Plus reverse box.
Good choice for RHD.

There's also a Taggart/Taylor chain drive diff - VERY light 17lb as used on DP1 - about same price as Powertech.

I can say that packaging (perfomance oriented) and price will be maijor factors.

Ted


Car


MikeR - 21/11/03 at 08:05 PM

I've just got to throw my two pen'th in to this.

I LOVE TWIN COCKPIT DESIGN.

Well i just thought i'd throw that in

Despire looking very sexy id be worried about how you'll make all those curves without it costing a fortune tho!

Oh, and from the other thread, i'm really interested how you do the diff as well..... If i can get to the library this weekend i'll be looking up the porsche transaxles from the 924's etc as they seem to go quite cheeply on ebay.


suparuss - 21/11/03 at 08:24 PM

i have looked into this a lot for my project, the powertech box doesnt need a chain, but it does have one inside it (i havent seen inside one but you can tell by the shape of the casing) its probably a good one but may be something to consider regarding relialilty. i eventually designed my own reverse gearbox that bolts straight to quaifes atb diff and looks very promising, which was reinforced when i found out radical were developing the same idea at the same time as me and quaife are building one now (im biding my time to do anything untill i find out if my patent gets granted)
some people might be getting fed up of me plugging this reverse box on here so ill leave it at that, but there are a couple of pictures of it in my photo archive, and it will be very light, and due its simplicty should be quite chep and very reliable (apart from the need of a chain to drive it) and ill explain further how it works if you are interested!



Russ.


Tudor (Ted) Miron - 21/11/03 at 10:23 PM

Powertec doesn't use chain:

http://www.quaife.co.uk/index2.htm

Ted


suparuss - 21/11/03 at 11:00 PM

looks like its got a chain in it to me, have seen quaifes site before and read everything on there about all their bike engine gearboxe and havent found anything to make me beleive other wise. unless it has 2 great big pinion gears in there


Ps- sorry if the pic belongs to anyone on here, cant remember where i got it from. was amonst hundereds of other car relted pics that i download cos they were interesting but i dont keep track of where from.

[Edited on 21/11/03 by suparuss] Rescued attachment Transaxle1.jpg
Rescued attachment Transaxle1.jpg


ProjectLMP - 21/11/03 at 11:41 PM

This picture is from my site. The powertec unit doesn't have a chain. There are a pair of gears inside. These can be changed to alter the gearing.

Ted, you will still have different length drive shafts with the powertec unit because it is offset to one side of the engine. So in this regard it isn't perfect from a weight distribution standpoint. Plus it has straight cut gears so is very noisy which may be a concern for a road car.

I wanted to stay as far away from chain drive as possible. They are messy, need regular replacement (every 2000 miles or so) are prone to breaking. Just talk to a few westfield XTR2 or radical prosport owners. For a race car they are good because of low weight and high efficiency but for a road car in my opinion just too much hassle.

[Edited on 22/11/03 by ProjectLMP]


Hugh Paterson - 22/11/03 at 10:15 AM

Ted.
Very nice, I look forward to watching the build of that, be interesting to see which diff u settle on.
Shug.


Tudor (Ted) Miron - 22/11/03 at 03:13 PM

Thanks guys.
I'll keep updating.

Ted


Tudor (Ted) Miron - 22/11/03 at 08:14 PM

Here's a picture of Busa and Quaife CD axel unit model.

Ted Rescued attachment drivetrain.jpg
Rescued attachment drivetrain.jpg