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Hi everyone,

I would like to show you the project my friend and I are working on since few month. We are in mechanical engineering and this is our final project. We design and make all the calculation for all the part shown on the model. We check the suspension and all the frame on a finite element software to be sure to have a safety factor over 5/3 everwhere. The suspension dynamic were checked with 7 degree of freedom model. We also made the calculation for the estimated performance:

0-100 km/h = 3,6 sec
100-0 km/h = 31,6 meter
Weight = 636 kg
And a lot more.

P.S. Sorry for my bad english, i'm french canadian.

Here's some picture!




Rear suspension

Suspension avant


Rear brake




Feel free to comment and ask question!!

First off Welcome aboard!

Myself I'm intrigued by your pull rod front suspension. In my opinion, there's several benefits and few handicaps.
Plus I think that you should shake up the status quo every once in a while.
I wouldn't mount the turbo that low, no need to design in the complexity of a scavenging pump and having a minimalist exhaust decreases turbo lag.

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"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett

What's the calculated F/R weight distribution with a driver on board?

_________________
Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

Welcome. Ever tough of using an ej20 or ej25 instead out of a wrx? You could bring the center of gravity at the crank level. A locost design can't really accommodate the width of the engine but you surely can with this. Cut the back tranny of the remove the AWD system, you'd get a can with even torque distribution since the axle are the same length. Check project 818 from factory 5, that could give you some idea.

Bonne chance et ton project a l'air vraiment cool.

ps the old jdm ej20 twin turbo are really cheap since they can't be transplanted in any USDM Subaru, only sand buggy can use those.

CofG will definitely benefit ... i did a similar design on this TTBB truggy ;


lowering two heavy turbos, thick wall SS headers , wastegate + other plumbing makes a huge difference
however, scavenging was easy on the already dry sump Brodix block

coool renderings ... love the pull rod as well ... however, the steep LCA angle seems rather radical to me

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- Stephan -

It looks good, but it seems that getting in and out would be exceedingly difficult.

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mobilito ergo sum
I drive therefore I am

I can explain it to you,
but I can't understand it for you.

Top tube seems too high. Put people in the car. Top tube is neck or jaw height.

Copy the At-om more closely. Its proportions are better than your design. Your frame is too tall which makes the wheels look too small.

I'm wondering why the front lower suspension arm is at such an angle? Modern formula cars are like that because the chassis pickup points are high for aerodynamic down force reasons and that's not going on with your chassis. It looks like you will get a lot (technical term) of lateral tire movement with any suspension travel.

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John - Slow and Steady. . . Well slow anyway
Build Loghttp://www.locostusa.com/forums/viewtopic.php?f=35&t=6245

Add my vote to redesigning a bit to make it easier to get in and out of.

Otherwise, good luck on the project!

Thank you for your reply !

First of all, the 3d model for the engine is not the good one. I simply take a 4 cylinder model I had and made some modification to represent the 4G63T. When we will buy the engine we will be able to draw it and place the turbo at the right place. We take this engine over the subaru because it's easier and cheaper to get here.

The step angle of the front suspension is for rise the roll center near the center of gravity. The car will roll a lot less than if the roll center is far from the center of gravity.



For the weight distribution we estimate it at 35% at the front an 65% at the rear. The image below show the distribution in function of the acceleration. When the car accelerate, the most of the weight are on the rear tire, but at braking, the distribution are very close.



The car look very high mainly because of the perspective view. The fact I'm 6'4" doesn't help either. The seat aren't accurate I think, because when we put a dummy in the car, the head are very close to the top. Here the comparison with others cars.



The accessibility can definitely be improve, we didn't start to think of the ergonomic sooo..

It looks to me like you will end up with a large track width change and a rather severe negative camber roll on during compression using that front suspension..
You could do some research and look at sand rails to calculate suspension behavior, you've done a rather good representation of a typical front suspension from one.

(example pic's can be found here) http://alumicraft.info/prerunner/dualsport/

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"There are times when a broken tool is better than a sound one, or a twisted personality more useful than a whole one.
For instance, a whole beer bottle isn't half the weapon that half a beer bottle is ..." Randall Garrett

Yeah, no it doesn't, the waist is stupidly high ..

Always nice to see you show up here to relieve me of my position as the "Grump"
But I politely agree that there seems to be some strange things about this design, like the height of the entire top rail. Suspension pickup points are a bit wacky. If your CoG is THAT high then you should do some redesigning maybe. Seems everything in the car is too tall which has made your CoG just way too high.
Also, the concept of matching your CoG and your RC in height is a theoretical example of how they work with each other. Matching them is not usually the best design.
Also. looks like your RC may be higher in the front then in the rear, which will give you a "Pushy" car.

Looks like your Front RC is about here??

Not grumpy, just economical with getting to the point!

the frame is not too tall ....

its just the tires that are too small



seriously; i do agree that the frame proportions are very "offroad-ish" ... i really dont see the need for a high beltline like that in a street car

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- Stephan -