Merli's R32 Track Bitch

[dazmo]

I can tell you that the Mspeed car does not use any of the factory pickup points for the suspension and also has a full compliment of custom suspension arms that would correct roll centre etc. not to sure about the drive shaft angle though. The underside of the Mspeed car is a work of art having poked my head under it and had a good look at it and taken a few pics at last years Rev speed Tskuba la battle time attack event. I do believe that Mark and Russ might have borrowed a few ideas from that car for their new R34GTR. The amount of work that has gone into it is phenominal and i believe that a lot of the suspension was designed by ex super gt mechanics.

[phunky_monkey]

This is obviously the opposite of what we want. So we want air to flow quicker under the car then over the top. The pressure on the upper surface of the car where the flow is moving faster is lower than the pressure on the lower surface, giving you lift like a wing.

Excuse my ignorance, but if this is the basic theory, then what would be so bad about having a flat undertray on a road based track car, with some NACA ducts underneath to aid cooling, like the S14 I posted? Seems like a relatively cheap and simple way of increasing the speed of airflow under the car, and reducing turbulence?

[bigmikespec]

I can tell you that the Mspeed car does not use any of the factory pickup points for the suspension and also has a full compliment of custom suspension arms that would correct roll centre etc. not to sure about the drive shaft angle though. The underside of the Mspeed car is a work of art having poked my head under it and had a good look at it and taken a few pics at last years Rev speed Tskuba la battle time attack event. I do believe that Mark and Russ might have borrowed a few ideas from that car for their new R34GTR. The amount of work that has gone into it is phenominal and i believe that a lot of the suspension was designed by ex super gt mechanics.

Are those photos somewhere for you to share? That would be fantastic to see in the flesh, lucky you. Imagine having some ex V8 Supercar engineers messing around helping some Australian TA teams!

[JUN`R32]

would be very keen on that carbon/kevlar undertray

ohh man, hot hot hot

If you decide to manufacture and sell, pm me

id b very interested !!!

[XXXV]

Very Smick cannot wait to see it in action

[Roy]

Excuse my ignorance, but if this is the basic theory, then what would be so bad about having a flat undertray on a road based track car, with some NACA ducts underneath to aid cooling, like the S14 I posted? Seems like a relatively cheap and simple way of increasing the speed of airflow under the car, and reducing turbulence?

It is a good start, but there is a difference between flat and smooth. You need smooth and not necassarily flat, ie parallel to the ground.

[Beer Baron]

Are those photos somewhere for you to share? That would be fantastic to see in the flesh, lucky you. Imagine having some ex V8 Supercar engineers messing around helping some Australian TA teams!

you rang?

here is a couple for teasers. I didn't make last years superlap but I did go in 07 and it was there then. great car and yes it has some re-designed suspension to enable it to have such a low ride height. it is literally touching the ground a fair bit. if anything the suspension set-up on Marks R34 is even better.

I only have a couple of my pics on my work PC. Daz might have some better ones he can post and things might have moved on since 07? i'm not sure.

[Beer Baron]

now back to merli's build. I have 2 teaser pics. but merli will have some even better ones to come...

and this is the phrase I'm having tattooed onto my butt. It's my favourite old time japanese saying, from our friends at Trust.

[Merli]

SPY SHOTS!!!! OMGWTFBBQ!!11

[Beer Baron]

teehe. Be it or high end, it never stop igniting your combustion!!!

it's how I live.

[AtomicBomberMan]

I dont think the M-speed car is allowed to race anymore. is that true? Mark berry brought it up in conversatioin a few weeks back that M-speed had to sell off all their stuff, because they did not meet the rules of the class. I cant remember what it was. I'll try to find out.

Merli, great build mate. The spy pics are definitely hinting that you have a lot more up your sleeve! More spy pics please BB!

Edited June 5, 2009 by AtomicBomberMan

[Beer Baron]

not quite. they had to sell their products to the public. previously m-speed was just a workshop that built their own time attack cars for the owner. as most of the events they enter are for tuning shops the other shops were not happy that m-speed did not build customer cars, nor tune or manufacture tuning parts for sale. they have not been banned. but they did decide to start selling some of their products to the public to keep people happy.

[dazmo]

Sorry my mistake Richard it was 07 that i took the pics i have of the Mspeed car as well. Though it seems we got shots of the exact same things only i think your shots are of a bit better quality than mine (mine were taken in hast (awe) on my phone) i will have a hunt around and see if i have any covering some of the stuff that is not in your pics.

Merli you must be feeling like it is christmass over and over again with shiney new parts turning up regularly I have heard good things about the cusco sway bars and I can tell you from experiance that nothing beats the Ikea stuff me likey verry much.

[Boosted Zed]

Re aero I have read race car books, research heaps on the web, and spoken to motorsport engineers and carbon race car gurus on this subject. Also tried and tested and tuned on my car.

Re unnnndertrays. Full or if can only do partial under trays, even if only flat reduce drag and indirectly give down force, as the whole car becomes a wing indirectly. This is done by air moving smooth and fast under the car whilst slow over the top, having further to travel, and F1 cars gain 40% approx in down force from doing this. If have room to ad an air dam at front, and rear diffuser at rear even better. Both work on principal of air expanding causing a vacuum, I think is best way of explaining it or negative pressure which pulls the car down. Any angle over about 15% air separates and causes turbulence. The front under trays section needs to be flat then taper up at less than 15% to stop the air separating. IF it goes up then tapers back down it has no effect and I don’t think it works , in fact may just create turbulence. It would probably better just being flat. Proper air dams need to be flat at front then gradual rise less than 15% then be flat and continue under the car. Depending on space you can move this air dam further forward or back to tune desired down force. Add trip strips and rubber lips under the car around the front wheels reduces turbulence also and makes front air dam and rear diffuser work better, as air is cleaner and again faster under the car, reducing drag and making more down force indirectly.

This was my first attempt and not right as explained.

If over 15% then can use these small vortex generators to keep air attached and rear diffuser as in this case on my car works better. Also the angle of the rear diffuser director plates are at 3 degree angle to act like big vortex generators reducing turbulence as air separates from the car and reducing drag.

For more see link.

Aero

[fatz]

your car is already aerodynamic johnny

like a door chock

[Boosted Zed]

your car is already aerodynamic johnny

like a door chock

I was just talking to Andrew about our fats sort of behaving himself, and here he is like a champion.

My car is a wedge yes or as you call it a chock you nugget. Front end and bonnet is at an angle unlike GTR's, free down force. Zed also has more of a slope of the windscreen, which is lower by a few inches. Another reason to race a boat.

[fatz]

7 days till a track day im just building up my trash talk

[SimonR32]

Re unnnndertrays. Full or if can only do partial under trays, even if only flat reduce drag and indirectly give down force, as the whole car becomes a wing indirectly. This is done by air moving smooth and fast under the car whilst slow over the top

you have got yourself a little confused here!

cars (which generally have curved upper surfaces and flat under surfaces) act like a airfoil (wing)... but a airoil gives lift not downforce, so as your speed increases so does your lift!!! we then put on spoilers, rear diffusers, flat undertrays etc etc. to try and to try and create downforce. there are two ways of doing this, reducing the amount of lift (the best way but you will never get downforce by doing this only) and also by increasing negative lift (this works as well but puts more drag on a car than just reducing lift as you are increasing drag on the car twice, first with the original lift and then again when you create the negative lift to counteract the positive lift). All of that confusing enough? I'll try and lay it down a bit more...

the aim of a undertray is to increase the air velocity and thus reduce the pressure (like you said) under the car and let things like spoilers still create downforce (not the whole upper side of the car, this will still be creating lift)... the only way to create negative downforce under a car would be to have the undertray as a reverse wing... but because the car is close to the ground this would actually not work as the air would increase in pressure as the undertray gets closer to the due to the volume of space reducing and actually create lift (would actually create more lift the lower the car got)

a rear diffuser is designed to create lower pressure (a fixed amount of air travelling below the car at a constant temperature is then allowed a higher volume thus reducing the pressure) below say a rear wing creating negative lift and higher pressure will cause "downforce"

a front splitter creates a huge high pressure zone from the car travelling through air being trapped above it thus creating drag and negative lift

also remember you can't create lift or negative lift without creating drag, but if you have enough power to overcome the drag then the benefits outweigh (pardon the pun) the drawbacks. This is why we get to jetset around the world in planes

its just simple physics and gravity using , but it can get confusing

a understanding of pressure in direct relation to volume and Bernoulli's principle is a must

as roy said, its very hard to explain without face to face with diagrams and hand gestures... if you want i might be able to do a diagram some time to try and explain the pressures put on a car body!!!

[SimonR32]

Zed also has more of a slope of the windscreen, which is lower by a few inches. Another reason to race a boat.

actually i believe the z's windscreen is at lower slope (angle) than a gtr, which means it would create less drag but actually more lift

[SimonR32]

the people who designed this apparently own a wind tunnel its a good example of what to aim for

Edited June 6, 2009 by Cerbera