Prodrive Uprights

[said]

Hello Fellas

Its been a while since my last post...

I bring this project of mine to you guys, been looking for information on the group a uprights for my race car, they are SO expensive, so i decided to make mine!

take a look!

This where the parts i was looking to make



Closer look



Totally different from OEM




I started drawing on 3D

this is the bearing holder



Bearing will be the same as a e28 rear, big boy...

Welded piece:



Hello Parts!




Bearing Holders





Steering arm holder (incomplete)






Well.. thanks for watching!

[rennteknik]

very cool!!

I saw your request for drawings over at s14power, do you intend to sell yours?

[said]

i might.. i want to see how mine come together, test them, then i can see if i can sell them, this are a cool upgrade, of course, the new design, made from magnesium or aluminum is cooler, but its just too much money for the same result..

ill keep posting!

[Ironhead]

Very, very cool!

Good to see people still doing things with these cars besides polishing them with a diaper and tracking sale prices.

[said]

thanks!! this has been a hell of a job.. but im about to finish it!! ill post some progress soon!

thanks for the nice words!

[said]

COMING TOGETHER!!!

[Wonder BOY]

Hi Said,
As I noted on M3 Tech Forum, nice looking but way too heavy. Your unsprung weight will be enormous. Make your parts from aluminum for the next version. Like my brother said: Prototypes are like waffles, you usually through away the first few . Sad but true.
/Walter Boggs

[Wonder BOY]

Hi Said,
As I noted on M3 Tech forum, looks good but too heavy. Your unsprung weight will be enormous. Make your next version from aluminum. As my brother said: Prototypes are like waffles, usually you through the first few away. Sad but true.
/Walter Boggs

[said]

Hi walter

thanks for the input
i had rough dimensions from a prodrive original piece, this person gave me measurements of the lower cube alone, and the total including welded sides, the difference between both was 6mm total, so this means they used a 3mm sheet for the job for the sides and face.

Im using same 3 mm but from chromoly, lighter and stronger than steel.

Sure, aluminum will be a great choice, in fact, many of today uprights are made from aluminum, e39, porsche 996, 997, and many other cars. They are fabricated in 1 piece, in fact, the last version of uprights are made from alloys i think, or maybe aluminum, Conrad have a great product on his website, but again, its too expensive because of the process it takes for reproducing them.

i can't do that, I've only done 4 pieces for my cars, machining aluminum, welding will be super expensive, plus i feel safer using a stronger piece, as the aluminum uprights tend to crack and sometimes break! Also, i am near the limit in minimum weight for my class, so no problem there! plus i can rally with this with no problem!

anyway, thanks for your input!


greetings from peru!

[Wonder BOY]

Hi Said,
In fact Chrome Moly is a type of steel. It is designated 4130. Mild steel is called A-36. It is not lighter for the same dimension piece. It is stronger but somewhat harder to weld. The weight difference will occur in one of the worst possible locations, i.e. the so called unsprung weight, increasing the mass of your suspension, making it less able to respond to changing road conditions quickly. If you want to add weight to a race car the best place to do so is in the center of mass. That location provides the least harm to handling characteristics.
By the way, you use the same machining process for aluminum as steel. It is just faster, much easier, and does not require carbide tooling. Also the components do not have to be welded, they can be bolted together.
/Walter Boggs

[LeeVuong]

HI Said

Those are wonderfull. Thanks for sharing. As a few have mentionned, those might be a bit heavy. And I will add that you can cut production time by 10 if making them as a single piece aluminum part. No need to make jigs. No need to weld etc. And it would be much lighter too. But hey, you have made your first prototype and from these drawing, you can now push the process a bit more. If I were you, I would ditch tnose e28 hubds/bearings. Simply use modern BMW bearings such as the ones from the e90 (and others). They make the design and production so easier.

[said]

my buddy lee!

thanks for writing!

well, i know production can be cut, but really, i am not making money with these, my intentions are not to sell them, if someone wants a piece, i can help them, but only a few will occur..

about the bearings... i thought of that too.. in fact, i bought a couple of Used e90 to see them..

here is the problem.

1. As i have a race car, i am using studs, so when the bearing fails, i will need to remove studs and re-press them on the new bearing hub.. NOT! hahaha
2. Using a single piece bearing is much easier to replace, i can buy this in any bearing store here in peru.
3. The bearing is 10 times tougher than the hub/bearing type, its a 42x80x42 bearing from a e28 rear.
4. Having the bearing go into a bearing holder, and this piece inside the welded piece, makes much less leverage on the entire unit. the e90, e39 bearings are just bolted, and nothing goes inside the welded piece, just 5 or 6 mm, vs. 20mm from the other design.

those hubs you see are not from e28, they are from e39, i took th big nut out, and lathe the inner race from the hub, making it pressable with the e28 bearing, that way i only change bearings, this is though for a endurance race, where if something fails, i can solve it quickly in pits.

my next challenge is making the brake caliper spacer, this one is with offset!

be prepared for some advice!

again, thanks for writing

[said]

Hi Said,
In fact Chrome Moly is a type of steel. It is designated 4130. Mild steel is called A-36. It is not lighter for the same dimension piece. It is stronger but somewhat harder to weld. The weight difference will occur in one of the worst possible locations, i.e. the so called unsprung weight, increasing the mass of your suspension, making it less able to respond to changing road conditions quickly. If you want to add weight to a race car the best place to do so is in the center of mass. That location provides the least harm to handling characteristics.
By the way, you use the same machining process for aluminum as steel. It is just faster, much easier, and does not require carbide tooling. Also the components do not have to be welded, they can be bolted together.
/Walter Boggs

Yes, you are right... i totally agree with the unsprung weight and center mass stuff..

Here in peru, strong aluminum is super expensive, twice as expensive as steel, i would NEVER made bolted components of this type, just imagine something coming off...

a solid piece like lee suggested might be a good way to do it... but hey, if prodrive did it this way, having aluminum on their materials.. why change it?

i am really looking to have something reliable, strong and durable. I know i will never have a problem with cracks, etc

Maybe in the future i can thing on something from aluminum.. like these?

[Wonder BOY]

Hi Said,
You are already planing to bolt on the steering arm to the bottom of your strut, right? As well as bolting your wheel bearings in place, right? And you have never seen a welded joint develop cracks, right? Hmm... You must be an amazing welder if you are so sure of your technique with 4130, a notoriously difficult type of steel to weld. I understand your reluctance to change your plan at this point in the process. All I am saying is: give it some serious thought and ask some knowledgable people before you spend more time building what is undeniably an ambitious pile of work. By the way Just how much would a piece of 6061 or 7075 aluminum cost in Peru? It must be close to the total National Debt, or am I mistaken again? They are quite a bit easier to machine than 4130. If you make it from one piece like you show in your pictures there are no parts to fall off. By the way your welds look serviceable but far from perfect. I think you are being a little over confident. Any way, it's your car and you will do whatever you want. Good Luck, man.
/Walter Boggs

[said]

Of course i will bolt them, thats the way they are hold on the prodrive version. I just prefer to do it with steel, seems safer. And yes, the welder who is doing this job, is an amazing welder, with years of experience doing race cars, parts, etc. He surely have the technique with 4130. Those welds you see are just spot welds, i think you must first wait for the finished piece before judging... just a suggestion

we don't have 6061 or 7075 here in Peru, we have something called Alumold, which is similar. believe me, it is VERY expensive here.

I appreciate your advice on doing them from aluminum, but just the material itself will cost the same as the whole finished piece, believe it or not.

I will post the final weight to see if its overweighted as you say it will.