Ohlins FSAE Double Barrel Shock

[lporter]

The word on the street is that Ohlins is going to release a FSAE version of the Cane Creek double barrel shock within the next month or two. I spoke with Malcolm from Cane Creek and Curtis from Ohlins today and the new shock will be 200mm eye to eye with a 57mm stroke and 8mm rod ends. They will still be 4 way adjustable, however the valving will be FSAE specific. All other dimension should be the same as the old double barrel and they will be available from Motorsports Spares in Indy for about $600 each.

[BenB]

It would be nice if they offered this with a bigger piston.

[Conor]

or a bigger discount.. $600ea? yikes.

[ad]

Originally posted by Conor:
or a bigger discount.. $600ea? yikes.

you could get the st44s for that price!

[lporter]

True, but smallest eye to eye length for an st44 is over 9" and it's only a 2 way adjustable damper.

[mtg]

Originally posted by ad:
you could get the st44s for that price!

That's like saying "why get the double cheeseburger for $1, when you can get the regular cheeseburger for $1??"

[exFSAE]

or a bigger discount.. $600ea? yikes.

Only $50 more than the DB1...

[MikeDutsa]

Watch it running those expensive shocks, We were told in the cost presentation ('06 west) that using $600 st44's was "not in the spirit of the competition". let alone the fact that you have 10% of your cost ceiling tied up in shocks alone.

[exFSAE]

Watch it running those expensive shocks, We were told in the cost presentation ('06 west) that using $600 st44's was "not in the spirit of the competition". let alone the fact that you have 10% of your cost ceiling tied up in shocks alone.

Thats funny, that quality suspension components aren't in the spirit of the competition.. but outsourced carbon tubs (with cost report car price of $13k...), heaps of titanium and CF, etc, are all in the 'spirit' of building the affordable 'weekend autocrosser'?

More reason why the cost presentation is a load of BS.

[BenB]

Whatever your thoughts are on the price you got to give to both Ohlins and Crane Creek for finally developing a damper that is geared toward FSAE. Before your only choices were running the mountain bike shocks that normally will have horrible characteristics if left stock or full size car dampers that way overkill for a FSAE cars.

[Pete M]

ST-44s are hardly the best shock that money can buy and they're seriously beefy too. We've done well in cost the last couple of years, including 06 west, and we had ST-44s on the car. Maybe you just got a weird judge?

Our engines cost us in the region 2-3 grand australian (we get ripped off). I see no problem spending about that much or even a bit more on good dampers. They're pretty critical to the car's performance.

[Derf]

While at FS, I saw some dampers on Chalmer's car that looked to be a job done by Ohlins based upon the double barrel. Is this by any chance related to the solution that they're going to make available to all teams? We were pretty happy with the DB last year, but any extra support by the manufacturers enhances and raises the level of the competition. If anyone from Chalmers would mind responding about the dampers on your car it would be appreciated.

[John Grego]

I heard that Kansas also had their shocks rebuilt but I don't know if they were done by Ohlin or someone else. Maybe they have some insight. Chalmers told me that they had theirs done by Ohlin and they were sporting black Cane Creeks with shiny blue reservoirs.

Any pictures or links for these new shocks?

[flavorPacket]

Originally posted by BenB:
your only choices were running the mountain bike shocks that normally will have horrible characteristics if left stock or full size car dampers that way overkill for a FSAE cars.

or you could build your own...

[Roger]

Originally posted by exFSAE:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Watch it running those expensive shocks, We were told in the cost presentation ('06 west) that using $600 st44's was "not in the spirit of the competition". let alone the fact that you have 10% of your cost ceiling tied up in shocks alone.

Thats funny, that quality suspension components aren't in the spirit of the competition.. but outsourced carbon tubs (with cost report car price of $13k...), heaps of titanium and CF, etc, are all in the 'spirit' of building the affordable 'weekend autocrosser'?

More reason why the cost presentation is a load of BS. </div></BLOCKQUOTE>

The best way to come out ahead on the cost report is to manufacture as many components as you can and provide good documentation on it. When you purchase such expensive shocks, and do the same across the board in other areas, its easy to drive up the cost.

Although, I don't know why so many people buy such expensive components, when such a small portion of the cars even finish the endurance event! =)

[Osth]

While at FS, I saw some dampers on Chalmer's car that looked to be a job done by Ohlins based upon the double barrel. Is this by any chance related to the solution that they're going to make available to all teams? We were pretty happy with the DB last year, but any extra support by the manufacturers enhances and raises the level of the competition. If anyone from Chalmers would mind responding about the dampers on your car it would be appreciated.


Yep, we have been using the modified DB dampers for our two last cars and from what I understand the adjustability and characteristics of the dampers is quite good, but I don't really think that we have gotten their full potential out quite yet as we have not had the time to play around with the settings enough yet(too bad when you pay that much in the CR, right?).

Also found this picture of our car taken by the nice guys at the Helsinki team:
CFS07 front damper (http://www.formula.stadia.fi/FS2007/album/1/slides/IMG_4909.html)



or you could build your own...


Has that been done by any other team in previous years? I'm not in to the dampers my self as you can tell by the not so informative answer above but it seems to be a difficult task as there must be a lot of really high precision machining needed for that... And it seems like one of the things they highlighted at (the crappy "You suck, read the rules...") design review at Silverstone earlier this year, where they were saying that making your own brake calipers and cylinders is just stupid when there is such a large market for off-the-shelf parts.

[LU-Bolton]

I would have to agree with Osth on this one. I understand why some teams would build their own shocks. Custom lengths, control of the overall size and damping characteristics, etc. I can think of a few teams that I believe have done it in the past: ETS, Penn State, UWA.

I don't think it's in the best interest of 99% of the teams though. Most teams will do a better job improving their event score by driving more than by spending the hundreds of hours it would take to design and build dampers from scratch. But then again maybe your team has 5 or so good engineers who understand dampers that can spend their year building custom dampers. My team never had that. http://fsae.com/groupee_common/emoticons/icon_smile.gif

Aaron Cassebeer

[flavorPacket]

Osth,

Cornell, Michigan, PSU, ETS have all made custom dampers, though ETS's use some production parts IIRC. And I have never had trouble convincing a judge that building dampers was the right decision, primarily because there is NO market for off-the-shelf dampers for FSAE. If there was such a product, I'd buy it today and spend my time chasing girls instead.


Aaron,

As the suspension leader (and by leader I mean only member) for a team that has built their own shocks (and will do so again), I can assure you that we do not have 5 people working just on dampers. Here, the suspension group comprises me and one helper who's just getting his feet wet.

I agree that building custom dampers probably takes up resources that could be put somewhere else to score more competition points, but I don't do FSAE solely to win the competition (not even mostly). I'm here to learn and to get a sweet job, two goals which are easily accomplished when you build your own dampers. Plus, you have to consider the secondary benefits of developing custom dampers. It is very likely that, in the process, your team will have to build some very sophisticated models for both the damper and vehicle, which will improve all aspects of your car's handling and will also help you in design.

[JR @ CFS]

Originally posted by LU-Bolton:


I don't think it's in the best interest of 99% of the teams though.
Aaron Cassebeer

I think this is the main arguement. I understand that making your own may lead to better job prospects and improve you as an engineer and of course, with intricate knowledge gained from research, you can probably convince most judges for your choice. But for the rest of us out there, I think this is a pretty good idea.

Ohlins adapt the dampers specifically for our application and provide everything at cost price. Why do we get this, because they are practically next door to us at Chalmers. Why don't we design our own...well, there is that reason of course, but also that we have a brand new team every single year with little to no carryover in certain aspects. Additional to this, everything we build is made inhouse in our own machine shop by students who have probably never been in a workshop before. We do not like to hand things out to machining companies because 1- we don't have the budget for that and 2- the hands on machining element is a cruitial part of our course and doing this defeats the purpose.

At the competition, the cost and design judges as far as I can recall, liked our choice once we gave our reasoning. The cost judge raced cars himself and said it was one of the first things he looked at when purchasing a vehicle.

I think it is up to each team and individual member to align their choices with their goals set out for the year. The Ohlins dampers met the criteria of our goal statement.

[flavorPacket]

jonnie,

I agree with you completely. As I said, if I could buy a damper designed and built by professionals that provided the curve I'm looking for and was of the right size, I'd buy it in a heartbeat, regardless of cost.

PS our dampers cost out to less than 100/each in the cost report

[Christopher Catto]

interesting views here. you guys are spot on regarding all the pros and cons.

regarding cost and spirit of the comp, I would say that most prospective buyers would go for a car that does not have very highly expensive components even if it is a bit slower. then the rich guys, well they buy what they want really... so Titanium is gonna make you lighter but how many 460 Modenas or F3 cars do you see with Titanium everything??

as for making your own, true, you are not paying profit to Ohlins or whoever. BUT, I would say this:

1) make sure what you set out to make is relatively simple and known technology. dampers are but some of the more intricate details are down to precise machining which many unis may not have or down to company specific stuff which is not visible or known to most engineers). so your dampers may perform better in your opinion and obviously since they are designed for your purpose.

2) if possible try to make your own stuff if they fit a packaging space and a performance envelope. if they are simpler than off the shelf parts and you can prove their performance is on par then this is an advantage. basically, like dont use stuff thats too complex for your car. 4 way adjustable is gonna make your car very tunable but I dont know many drivers who instinctively buy a car with such adjustability. this can go with adjustable diffs, adjustable traction control maps, adjustable Ackermann (Loughborough), adjustable rear steering (like Skyline). Jesus, shouldnt engineers be working on making stuff easier and with less need to adjust? Can we make a car go fast without needing to test months and months like in F1?

3) if you are making simple stuff then the costing is simple. if you are making complex stuff then I am sorry but I would prolly never believe your costing sheet. i dont believe 99% of the costing sheets because nobody is ever pessimistic. coming from a company that makes sportscars in low volume I know that every single stupid detail can bump the price up. FSAE costing has to be simplified to help us all out from the pile of paperwork. so, sure 600 for each damper is quite high, but I am not gonna believe that some Uni has custom dampers for even 400 bucks because FSAE just dont really count any R&D and background work. For your dampers you are paying engineers to be on the phone with you, availability of parts, quality control.

So if the judge tells you that the dampers are steep. Tell him that in the time it would have taken you guys to machine the stuff (outsourcing is accepted in the rules but really the spirit is to have the car built by students in order to learn stuff and not just outright win) you went to knock on the door for sponsorship and learned about how to run a team efficiently. I ve been there, designing wheel centres, fuel tanks etc but I think it should stop when you get to dampers and callipers unless you wish to put it forward as a project for guys to learn and get a job in industry. I think doing projects on this is in fact a very good idea just kind of complex to fit in with your need for the team to move on and tune stuff, not just make it.

[flavorPacket]

Chris,

All good stuff, but please understand that I only said that the dampers cost $100 each in the cost report. In real life, it cost closer to 8-10 times that, perhaps 20 if you count R&D time and talking with experts. Also, we manufactured everything we could, but obviously there are some things that require specialist work.

*edited for spelling

[LU-Bolton]

If my team had the resources yours does, then I agree I would have maybe at least thought about designing parts such as master cylinders, calipers, and dampers. I never had the flexibility to be able to go off and specifically attempt to master one component of an FSAE vehicle. I know I would have learned a lot as I'm sure you have. Instead, I was not only Team Leader, but also Suspension, and Chassis Team Leader my senior year. As you know, this kind of responsibility can be quite taxing. However, it gave me the understanding on how to be in charge and improve the efficiency of the operation.

The reason you choose to design dampers and I think it's inefficient is that we are different types of people. I think about it as the bottom line: will designing this damper get the car to where it needs to be at the end of the year? Usually my answer is no. However, I must admit one of the greatest advances for Lehigh FSAE was having a dedicated analytical-type person help us out on the suspension team.

It takes all kinds! I love this stuff. Great to hear your perspective flavorPacket.

Aaron Cassebeer

[flavorPacket]

Aaron,

I'm surprised that you survived a year like that! And please don't get the wrong idea, our dampers are far from 'mastered'. Hell, we had to run Fox's on the front at east for skidpad because we were rebuilding ours in a hotel sink!

[Dan Lentsch]

any word on when the Ohlins will become avalible / where to get them from?

and an awnser to my own Question once again, November 1st, $595.00, and www.motorsportsspares.com (http://www.motorsportsspares.com)

[SLracer]

Just a note to any teams wanting these they are only currently planned to make 125 or so of these shocks. They are also offering a spring package for $175 of 16 springs a set in 150, 175, 200 and 225 I believe. Talk to Scotty at motorsportsspares for more details.

[lporter]

Just got ours in today, mother of god are they gorgeous. Motorsports Spares was very helpful, they answered all my calls and sent me Roehrig dyno files for all the settings they have tested (opened via the free software available on REI's website). They look identical to the original double barrel, I'll post pics when I get a chance.

[Fyhr]

We got ours a few days ago too, got one lying next to me. Still have to study some more but we'll have a model done soon.

Don't know if one already exists at the share lib since its down though.

Here's what i've got so far:
http://www.luracing.m.lth.se/wiki/uploads/e/e2/Damper_21013.jpg

And here's what they look like in person:
http://www.luracing.m.lth.se/wiki/uploads/3/37/Doublebarrel.jpg

[lokuputha]

Originally posted by Fyhr:
We got ours a few days ago too, got one lying next to me. Still have to study some more but we'll have a model done soon.

Don't know if one already exists at the share lib since its down though.

Here's what i've got so far:
http://www.luracing.m.lth.se/wiki/uploads/e/e2/Damper_21013.jpg

And here's what they look like in person:
http://www.luracing.m.lth.se/wiki/uploads/3/37/Doublebarrel.jpg

thats model looks great, you should add it to the CAD Library http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Fyhr]

Right, made the last few fixes, proper placement of the spring retainer plate, correct number of teeth on the spring pretension plate and submitted them to the library.