I do not think Ti is allowed for the control arms, but is allowed for certain components such as springs etc. The rules still restrict certain components to be made of a specific alloy.Quote:
Originally Posted by AMSS
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I do not think Ti is allowed for the control arms, but is allowed for certain components such as springs etc. The rules still restrict certain components to be made of a specific alloy.Quote:
Originally Posted by AMSS
Ti is not allowed unless it is basically a sub-component of a catalogue part. Suspension components are not part of that.
Mg also not allowed other than the wheels.
How would the FIA be able to tell what material is being used without some destructive testing? Seems like it would be easy to hide, particularly bits that are hard to get to, e.g. buried deep in the engine.
They wouldn't, but they sometimes act on tips and that's when they know exactly what to go look for.
In case of the engine, it is disassembled to the last bolt and nut and each and every part is inspected and characterised in the homologation. And it can be checked to this level of detail at any point if requested. Same for suspension or any other parts worth using exotic material on, all are physically handled and any obvious ones would stand out to experienced inspectors.
But more to the point, if you think about it, it's the "obvious" major items where one can gain the most advantage by using fancy materials, so it's not hard to have in mind already the usual suspects. Saving fractions of grams by using Ti bolts in some hidden location, for example, is out of scope of WRC in my opinion (not yet anyway). If the rest of the car is so perfect that you're delving into such minute detail, then you should be winning the championship anyway.
They can simply weigh it. A part that is said to be steel, but is made of titanium will have a different weight.Quote:
Originally Posted by sonnybobiche
I don`t think they use Mg wheels however as there`s a minimum weight on the wheels, 8,6 kg (if it`s still the same s it used to be).Quote:
Originally Posted by Mrpengski
I don't know if anyone is using it, but it's allowed.
I'm pretty sure many teams use magnesium rims. At least many R5 teams use them. They are not super light as anyway there is minimum weight, but they are much stronger than alu.
How have the new 2017 WRC cars affected tyre wear? Martin Holmes speaks to tyre consultant George Black to get the low-down.
https://rallysportmag.com/feature-wo...r-tyre-update/
Thanks to the crack journalists that cover the WRC, we literally just found out that there is another new regulation for this year: onboard tyre pressure monitoring.
Heard that on the radio today too.Quote:
Originally Posted by sonnybobiche
Seriously, if WRC could get the technical journalism that F1 has... It is literally the only aspect of F1 that is better.
Was just watching a stage start and started to wonder, what changes in the engine mapping between road mode and stage mode to give such a different sound to the engine?
its a completely different map ,very mild that don't stress the engine.Quote:
Originally Posted by TyPat107
Have to agree with this; but not only F1; the GT/LMP Sportscars technical journalism is streets ahead as well.Quote:
Originally Posted by itix
They obviously think WRC fans aren't particularly interested in that side of the sport - or they themselves aren qualified to write about it.
My opinion (and I'm not expert at all):
1. M-Sport Ford Fiesta WRC - Tehnical best car at the moment, handling maybe not.
2. Hyundai i20 Coupe WRC - Suspension worst of all (just a little impacts & huge damage) but fast car.
3. Toyota Yaris WRC - Tehnical problems still (Latvala's car), maybe best handling.
4. Citroen C3 WRC - Bumpy conditions = disaster. Dominant car on tarmac.
Hyundai
Attachment 1404
The biggest difference in sound comes from the anti-lag system or ALS. Here, you can hear it activate on some cars before they rev up. https://www.youtube.com/watch?v=a5SjKyP3Wk0Quote:
Originally Posted by TyPat107
Citroen is fast on tarmac, hard to handle on gravelQuote:
Originally Posted by ESTR
Toyota is fast on very fast roads (gravel or tarmac)
Hyundai is seems to be the best overall but they struggled a lot in Finland with the big jumps.
Ford is quite equal on all surfaces.
As far as reliability, I think Ford has had the least issues, but I'd have to make a list to be sure
For me.Quote:
Originally Posted by AnttiL
FORD - Has developed into the best overall package at the minute, engine seems very strong.
HYUNDAI - Still pretty strong overall, but but a few cracks appearing (no pun intended). Understeer in high traction, weakness of castings to impacts.
TOYOTA - Best chassis, but the team is still learning event to event and the car isn't always on point at the beginning. Reliability still an issue.
CITROEN - Inconsistent, the best on smooth, high traction. Watching the live TV it is clear as day, it just turns a tighter line than the others and can be driven within itself. On low traction, bumpy surfaces its all over the place. Suspension seems the worst of all. I guess we will see in Wales/Australia if the recent testing has made some gains.
AgreedQuote:
Originally Posted by doubled1978
Ford seems to be overall the easiest package with good reliability and no direct weaknesses in handling though it doesn`t shine either in any certain area it seems (or maybe slow technical gravel they have the best grip..), basically a championship winning car
Hyundai was the fastest car beginning of the season but seems Toyota and Ford have slightly pulled away, seems to have a strong engine.
Toyota seems to have a fast car with the best aerodynamics, maybe struggle a bit with the suspension on slow technical gravel and technical reliability needs improvement.
Citroen fastest on tarmac, gravel still a big question mark (bearing in mind Meeke had a very good starting position on Friday)
Regarding the gearbox issue that Tänak had. How big difference it is running with gravel gearbox instead of tarmac one on tarmac rally ? Is it a big disadvantage or not?
Probably just different gear ratios? It didn't seem to slow him down that much...Quote:
Originally Posted by EstWRC
Looking back now, Hyundai seems to have a big history this season with suspension/steering failures from relatively minor collisions
Monte Carlo Neuville
Sweden Neuville
Argentina Sordo (fixed on the road)
Sardegna Paddon
Finland Paddon (hit the same stone as Tänak, who got away with just a puncture)
Finland Paddon (2nd day)
Germany Neuville
Spain Sordo
Spain Mikkelsen
Spain Neuville
The only other similar issues that come to mind are Østberg's suspension failures in Argentina and Sardegna, but I haven't watched the onboards to know how if he goes off or not, but I got the impression that his team has a weaker part or a part not changed as often as M-Sport. Lappi knocked the suspension in Poland but the most damage was to the engine (the same as Latvala in Spain?). Hänninen also did something similar in Finland but they were able to keep it together to service and didn't even slow down that much.
IMO nobody of us can say how big handicap it is. Probably the main issue is that the center and front differentials are one unit with the gearbox (I think they are). At least front one is mechanical and since You can't open it You have to drive with wrong ramps in it. That means You have to change maps of the center one to somehow cope with it, i.e. it for sure isn't optimal.Quote:
Originally Posted by EstWRC
Thanks like always mirek!
that's exactly the problem,the diffs ramps and preloads,than the shorter gravel gear ratios.Gravel diffs are more ''tight''Quote:
Originally Posted by Mirek
considering that,Tanaks pace was excellent vs Ogier.
The time lost on high speed sections with lower gravel rations could be a big factor too.
Tanak did an amazing job.
A few images of the Yaris suspension set-up.
The control arms and subframes are works of art. Formed and welded components which are lightweight yet extremely strong.
Attachment 1414
Attachment 1415
Attachment 1416
Going back to the Hyundai upright failures and looking at them from structural point of view rather than drivers' errors, I was wondering where do the rules stand on MMC (metal matrix composites)? I haven't got the time to check, but won't be surprised if they are banned. Maybe Mrpengski can let us know.
I am only saying this to exclude the possibility that the usage of this low strain to failure high notch sensitive, but light and stiff material is the culprit, given that the failures occurred around the lower joint threaded area with the thread acting as a "notch".
Excluding this, I assume the uprights are machined from forged billets, then shot peened for better fatigue resistance, giving the surface its matt appearence.
The other option is that the uprights are made from extruded aluminium billet (or even worse, cast billet - very hard to believe), which will give lower structural properties.
Next questio is what kind of ali alloy as some of the high performance structural aluminium alloys can be low strain to failure high notch sensitive.
Final point - is Hyundai's structural "rock touch" load case, that the suspension components are designed to, severe enough to cope with the events encountered on the side of the road? It is a very fine balancing act between ending with not too heavy components and not too weak components.
The question is: HOW DO THAT HYUNDAI of Neuville survive Argentina?? Germany and spain total disaster
The matte appearance from hard anodizing, not shot peening.
Not sure about Hyundai, but the Toyota hubs are forged monoblock body hubs (similar to AP uses for calipers). The other teams could possibly using billet hubs if not forged. Nobody would use cast alloy. MMC could be a possibility since a lot of the Manu's are using Pankl comoponents for suspension hubs, uprights etc and they use MMC for other racing forms. I'm not sure if MMC is allowed for WRC.
https://www.pankl.com/en/racing/driv...nology-design/
https://www.pankl.com/en/racing/drivetrain/products/
ESTR - very simple - the suspension did not see loads exceeding its envelope :)
racerx1979 - I would be very surprised if the colour comes from hard anodizing rather than shot peening. Structural ali alloys do not hard anodize well and any hard anodizing significantly reduces the fatigue properties, while hardly really contributing to making the alloy that hard, while shot peening increases significantly the fatigue properties, which is critical for a suspension upright.
MMC wise, I will have to dig into the rules and find out if it is allowed (bear in mind it is not allowed for uprights in F1 after 2009), unless someone with inside knowledge is able to comment what the rules say. Anyway, I would be very worried if I had to use MMC for suspension uprights on a rally car.
I know for a fact the TGR hubs are hard anodized after being cryo treated. Shot peening sometimes contaminates the surface.
Some of the other manu's hubs may be shot peened before being hard anodized, but they are not shot peened and then left uncoated. The images of the Toyota hubs I pictured above are hard anodized. Also, shot peening is fairly old-tech in the motorsport world. Laser peening is used companies such as Pankl and Arrow.
Shot peening of Al alloys is commonly performed on aircraft parts to be hard anodized. The shot peening induces residual compressive stresses to compensate for the decrease in fatigue life due to the relatively brittle anodic coating. Common applications are hydraulic cylinders and pistons. All shot peening residues are chemically removed prior to anodizing. – MIL-S-13165C, paragraph 3.3.10.2; MIL-P-81985, paragraph 3.5.2.1. Nitric acid-based solutions are used.
Some great reads if you're into Metallurgy.
Effect of Shot Peening Variables on Fatigue of Aluminum Forgings,” Metal Progress, v. 120, No.2, p. 33-35 (1981) and
Hard Anodic Coatings on Aluminum Alloys: Evaluation and Control of Porosity,” Metal Finishing, p. 19-24 (December 1992).
And another study from long ago which shows the benefits of shot peening and anodized coatings.
If you don't feel like reading the whole thing go to page 19.
http://dtic.mil/dtic/tr/fulltext/u2/a108869.pdf
All good reads, thanks racerx1979.
For clarity I should point out that race car suspension component design is part of my daily job.
In general anodizing (either of the hard or decorative kind) is not a great practice for highly stressed suspension components and can do more harm than good for reasons already stated.
Also talking about billets, all machined uprights start from some sort of billet, which in itself can be forged (best for strength), extruded (most common) and cast (worst for strength). For obvious reasons the first two options are preferred for suspension components.
I also work on chassis components focusing on motorsport for over 12 years :). We use SolidWorks, CREO and Ansys for FEA.
I agree that most "highly" stressed components such as lower control arms are made of T45 or 4130 are not anodized because they are not made of aluminum :).
But we are talking about hubs here which are machined from 7075 and then anodized. Some lower control arms are also anodized depending on the application and loads. Scroll down to see the Evo X R4 arms which came in red anodized for the left side and blue anodized for the right side. Typical old school wrc style components.
Ever seen Ohlins, Proflex or EXT shock bodies and reservoirs?
They are always anodized if aluminum and almost always nickel plated if steel. That's the titanium color you usually see.
Just like this AP caliper
https://www.essexparts.com/cp8350-tr...-left-anodized
And some more info from Brembo talking about hard anodized calipers and showing the same gold color. Anytime you see this color its hard anodized.
https://www.youtube.com/watch?time_c...&v=VQdAnQ8GZlA
Sometimes its a clear anodize and the aluminum will have a shiny polished look. Take a look at the components on Miko's old car. Tons of anodized parts (goldish and titanium components) and note the shiny hub. If this was shot peened it would have a dull finish. It's actually clear anodized after being polished.
Attachment 1417
Another hard anodized Subaru WRC machined hub.
Attachment 1418
Attachment 1419
http://www.racetuners.com/shop/index...roducts_id=449
When using steel the components are nickel plated as shown here.
http://rallycarsforsale.net/ads/bran...s-impreza-wrc/
Evo X R4 lower wishbone in red anodize.
http://www.mml-sports.com/index.php/...rm-assembly-lh
Evo X uprights hard anodized.
https://www.brypar.com/shop/prime-r/...front-upright/
Thanks racerx1979, I am happy to leave it at this.
Went through the rules (or what is publicly available) and can't see a ban on MMC. Actually, as is usual, the rules are very badly written talking about where "composite material" is allowed, evidently only considering resin (or similarly) based composites here, but without clearly defining what constitutes "composite material" and as such leaves the door open for protests if a team decides to explore the use of MMC, although these can sometimes be more pain than gain.
IMO it's more precisely described in homologation regulations.