OMS

[follet46]

I have started a simple F1000 style ground up design and build I have had some input from Apex, however i would like some experienced views and help.

i am not sure how to put this what i am looking for is,

a balanced view. not just to point out all the faults or prove i am wrong, but to help and include a drawing of what is wrong and a drawing of how to make it work, not just words


So i am chasing some help with rims and tires


the design and built frame are well along

http://www.apexspeed.com/forums/album.php?albumid=391

[S Lathrop]

What tires are you going to use and can you get data for those tires? Tires are the key to what follows.

In the US we mostly use FC tires. With a FB it is easy to over build the aero package and design something that exceeds the potential of the tires.

The other mistake is to under design the chassis. FB will perform very close to FA and as such you need to have a very stiff chassis. The best way to model this is to anchor the rear suspension and torque the car through the front suspension. To simplify things I only use the lower a-arm and a push rod to the chassis at the bell crank location. Use 750 foot pounds per degree as a load. As a comparison, a Swift 08 FA chassis is something like 13,000 ft #/per degree. You won't get close to that number but you don't want to be in the 2000 to 3000 range either.

I would look at a F3 car and copy that aero package as a starting point.

You should use 150 mph as the top speed you might see.

[follet46]

"What tires are you going to use and can you get data for those tires?"


Yes you bring up a serious point, tires I have read you run 7” and 9” I think
I am still open to final tire choice

I found these on eBay beautiful 13 x 7's old ford pattern i think

[S Lathrop]

"What tires are you going to use and can you get data for those tires?"


Yes you bring up a serious point, tires I have read you run 7” and 9” I think
I am still open to final tire choice

We run tires that were designed for 6 and 8 inch rims. They are designed for F2000. By putting them on 7 and 9 inch rims, we get the extra structural support to use them on F1000. The fact that the tires were designed and developed for a 1200 pound car also is in our favor because we only weigh 1000 pounds.

The tires designed for 8 and 10 inch rims are designed around cars that weigh closer 1500 # and as such weigh a lot more. Not good with low torque engines.

I have two completely different wing packages for the F2000 and F1000 versions of my cars. The F1000 uses the medium down force wing setup because the higher speeds the car is capable of results in the same down force levels.

We also run relatively wide track cars. The rules have a maximum width and we build right to that limit. As such, we can get all the down force we need with conventional, low nose, cars. The goal here is to minimize cross sectional area of the car at the front axle center line. The space between the bottom of the nose and the ground is not clean, no drag air space. You can think of the frontal area of the front of the car as the area bounded by the top, sides and the ground at the axle center line. The low nose gives you more options for front suspension geometry. The better your mechanical grip, the less wing you will need and the faster streight line speed you can expect. High nose cars came about because of narrow track rules.

So you need to settle the tire issue first then every thing else will fall into place.

[aims20]

Steve,

Did you obtain Tire data from Hoosier or through testing? Did they have data for the 7 and 9 inch rims?

[S Lathrop]

Steve,

Did you obtain Tire data from Hoosier or through testing? Did they have data for the 7 and 9 inch rims?

For the F1000 tires we are using Hoosier bias ply, FC tires. The tires were not much different from the Goodyear tires I used for FC and FSV before that. Hoosier recommended using these tires on 7 and 9 inch rims. The tires do not give close to the same performance on 6 and 8 inch rims.

My guess is that the tires have a limit of something around 400 lbs lateral force regardless of how much you push the tire into the ground. It may be higher but there is definitely a limit and the limit is within the capability of the car exceeding.

The other big issue you will have is getting all the power to the ground. We started with an open diff and got the car as good as we could. We are using a variation of the Viarloc differential and it seems to be very good.

We figured this out by testing the car.

[aims20]

My guess is that the tires have a limit of something around 400 lbs lateral force regardless of how much you push the tire into the ground. It may be higher but there is definitely a limit and the limit is within the capability of the car exceeding.

That's a pretty profound statement to a young engineer like me. Granted I haven't taken part in too many tire experiments. I know coefficient of friction will drop off as Normal load is increased but I didn't think the effect was that drastic. Its been pretty stuck in my mind that downforce was *mostly* proportional to lateral force. Is that something you've seen across most tires or just the Hoosiers?

[follet46]

could someone help with a airfoil shape and cord length for a front and rear wing

i am trying get around re inventing the wheel

[S Lathrop]

could someone help with a airfoil shape and cord length for a front and rear wing

i am trying get around re inventing the wheel

Try 10 to 12 inches front and the same for the rear. Add a slider ( A gurney with the part that mates to the wing surface about 4" long and the flap 1/4). You then slide that part back and forth to vary down force. Set the wing close to 0 cord angle, no more than a few degrees either way. If you want to have fun try a Clark Y airfoil.

The profile is not all that critical. Some airfoil from an airplane that flys about 130 kts should work just fine. I use a mid 70's March Indy car rear wing profile and no flaps for the front wings.

Reynard was using the same airfoil and cord on the front and rear of his FC in the mid '80's when I started getting serious about wings. I went to a shop in town and they had the tooling for the March rear wing and it was the same cord as the Reynard. I just build it in several cord lengths.

For the rear wing you can't go wrong copying a Dallara F3 rear wing from the last decade.

[R. Pare]

Cool NACA airfoil shape generator that I just found:

http://airfoiltools.com/airfoil/naca4digit

http://people.clarkson.edu/~pmarzocc...l%20series.pdf

http://aerospace.illinois.edu/m-seli..._database.html

Tons of data available on line if you look.

[follet46]

Yes there is a lot of data information designs and a wealth of knowledge out there

I just want to save time on something that would off been designed to death by now


It seems the people who know keep there cards close to there chest i get that

thank you for the Links i will follow them up

[R. Pare]

If I remember correctly, there is one particular NACA profile number that most race car wings are based on - some exact, some slightly modified. Maybe someone who remembers the number will be kind enough to divulge it.

[griceiv]

the eppler e423 is probably your best bet for a non-proprietary high downforce airfoil, but probably not the lowest drag solution. Selig S1223 is also a decent choice.

http://aerospace.illinois.edu/m-seli...plots/e423.gif
http://aerospace.illinois.edu/m-seli...lots/s1223.gif

Flying foam can cut you come foam cores for a reasonable price, if you want to do a DIY job.
https://www.flyingfoam.com/

[Marty Nygard]

I used the Eppler on my old home built DSR. Seemed to work fine but I had no alternate profiles to compare it to. I do know that before I stiffened it up I was getting about six inches of droop at the wing tips at the end of the main straight at Gateway. That was more deflection than I could get by standing in the center of the wing when supported at the tips.
There was also an old Race Car Engineering magazine article about aero that featured the Eppler and included a chart with lift and drag coefficients as a function of both angle of attack and gurney lip size. I might be able to find it and send you a copy if you PM me.
Marty

[follet46]

http://www.apexspeed.com/forums/albu...pictureid=3792
http://www.apexspeed.com/forums/albu...pictureid=3793

It is a start on the rear wing

would someone have a idea on angle of attack needed for this style of wing and how many degrees of adjustment

[provamo]

just listening

[Christopher Crowe]

-- was once the basic wing profile for race car use. No huge downforce drop-off in yaw; designed for subsonic aircraft operating in the low 120 knot range. Light Cessnas use this profile; Gurney used it as his basic profile back in the day (and the wind hasn't changed much since then).

Good link to the 2412's data as well as similar NACA designs:

http://airfoiltools.com/airfoil/deta...il=naca2412-il

Chris

[follet46]

thanks for that link i made a attempt at using the profile and looks good

i was thinking about finding a computation program that might run the package

and see how the drawing actually performs


http://www.apexspeed.com/forums/albu...pictureid=3794

[ianashdown]

If you check out the FIA regs for F3 the wing profiles are provided with coordinates. They are spec in F3

Ian

[follet46]

Thank you for that tip i will follow it up

[J Leonard]

I always liked the nose and front wing on the 1993/4 Williams F1 car.

[follet46]

could someone help with recommending a good clutch to use

and what to do to make it strong

[Bill Elder]

Bit late! For a similar vintage gsxr, billet basket - and I think a change of springs from a dodgy memory were the upgrades.....and a TL1000 hydraulic slave conversion. I do recall aftermarket plates were rubbish at the time, maybe that's improved?

Standing starts will no doubt increase required clutch maintenance.

[follet46]

could someone help with a little info on the difference

between the fit off headers off a gsxr 1000 07 08 to a 03

can they be used

thanks apex i was sent these in the mail, very nice great fit

[sportech]

I don't know about the 03 engine but the difference between the 06 and 07 GSXR engines is that the port diameter is .160" larger in the later engine. Also, the bolt flange is wider and the port spacing is slightly different. With slip on collectors and port adapters it can be done if you know ahead of the header build. Why would you want to give up the HP advantage of a late model engine?

Dave

[follet46]

i have a 03 engine and have been looking for a header exhaust system

i came across a new 07 S/S std system that i could modify

thank you for the info

[follet46]

could someone help with specs and measurements

on BBS and or Oz rims so i can machine the drive pins and design for typical mounting and offset numbers


just a run of the mill rim set up

are the specs different from a 8" and 10" set to 7" and 9" wide set


I am chasing a set BBS or Oz rims or something similar i would like 7 and 9 but anything close will do

the uprights and hubs leave a little room to maneuver

[follet46]

could someone tell me why you can or can not run brake lines through a arms

[S Lathrop]

Go for it. No reason not to. Just do it right.

[follet46]

could someone help with

the low profile bearing how dose it hold the bearing in place

could some draw it and where can this style of bearing be purchased

[S Lathrop]

The a-arm has a metal insert built into the arm. That is the circular part with the 4 small holes. The bearing is staked into the metal insert the same way bearings are staked into rod ends. You can see the staking grove as one of the several circles around the ball.

[follet46]

I do not get it

or how i can machine one what are the tolerances is it a interference fit

[Mike B]

http://www.aurorabearing.com/pdf/technical-data.pdf

Scroll to page 14 to see how these bearings are staked. It also gives dimensions for the housing and chamfer if you want to machine your own housings.

[S Lathrop]

I do not get it

or how i can machine one what are the tolerances is it a interference fit

http://www.aurorabearing.com/product-catalogs.html

Down load the product catalogue at the top of the web page. You are looking for the PNB series bearings. The procedures for mounting the bearings are on page 76 and 77.

Using staked bearings is very common. I use them any place I can instead of using a rod end. In fact, I only use rod ends when I have to make a link adjustable. Otherwise it is a staked bearing.

Below is the outer end of the steering link that I use. It was necessary because with a front steer suspension, getting a lot of steering angle necessitated that I reduce the size of the link near the steering arm clevis and upright. The cost of making outer end is offset by the time savings in closing air foil tubing around a round boss for the rod end. This outer end requires that I just split the airfoil tubing along the major axis , flatten the tube on to the bearing holder and weld. The other method is to machine a ring where the ID is machined to stake the bearing and you weld the ring into airfoil tubing that is flattened to the width of the ring. Again this is a big cost savings in making suspension links. Making the rings is no more expensive that a threaded boss. Also the bearings are a lot less than rod ends.

[follet46]

ok thanks for that

having a look at it now

I had purchase the bearing and cup from mcgillmotorsports in England but the profile

just was high

the interference fit bearings seem to run into 11 thou has anyone mix and matched there

bearing choice and style fitment

[provamo]

just following this thread

[follet46]

could someone describe this bearing and holder

sizes and machining specs

i wish to replicate this one

[DanW]

I do not get it

or how i can machine one what are the tolerances is it a interference fit

Its usually a press fit. The bearing is either staked with a punch or a snap ring groove is machined and an internal circlip fitted.

http://secure.chassisshop.com/partlist/6454/

http://camburg.com/all-products/fabr.../uniball-kits/

You may find something local in OZ too.

Good luck!

Regards,
Dan

[provamo]

GREAT REFERENCE! DanW

used to work in a shop where they were turned "by hand" on belt driven lathes in the early eighties LOL

[follet46]

the diff is nearly complete could someone give me a idea what weight

a helical diff set up would weigh in at