Hondaclub-belgium.be

$1 schreef:$2k ga in een keer zoveel mogelijk nieuwe bouten en moeren kopen ook, ik heb de Hondaprijzen eens bekeken en vind dit toch wel vrij gestoord (6 à 10€/bout, en je hebt er zo'n 20-tal nodig voor de voorste draagarmen alleen...)
dit vind ik er toch over (zeker voor sommige bouten, waar niet eens veel kracht op komt te staan). Iemand enig idee waar ik gelijkaardige bouten kan bestellen ? voor de echt belangrijke bouten ga ik wel bij Honda, maar volgens mij hoeven ze niet allemaal zo duur te zijn.

ik veronderstel dat , als ik graad 10.8 bouten neem, gerust kan zijn ?

$1 schreef:$2

$1 schreef:$2k ga in een keer zoveel mogelijk nieuwe bouten en moeren kopen ook, ik heb de Hondaprijzen eens bekeken en vind dit toch wel vrij gestoord (6 à 10€/bout, en je hebt er zo'n 20-tal nodig voor de voorste draagarmen alleen...)
dit vind ik er toch over (zeker voor sommige bouten, waar niet eens veel kracht op komt te staan). Iemand enig idee waar ik gelijkaardige bouten kan bestellen ? voor de echt belangrijke bouten ga ik wel bij Honda, maar volgens mij hoeven ze niet allemaal zo duur te zijn.

ik veronderstel dat , als ik graad 10.8 bouten neem, gerust kan zijn ?

Wat is er mis met de originele bout zolang deze niet beschadigd is? Dat je de rubbers zou vervangen bij het opfrissen van je onderstel lijkt me niet meer als normaal. Maar dat je originele, intacte, niet krom/kapotte draad/afgeslepen/doorboorde originele bouten zou vervangen door andere bouten, welke meerwaarde geeft dit? Alle bouten eens tegen een slijpsteen houden (met zo'n kuisborstel weliswaar) kan wonderen doen me dunkt .

Schiet me niet af als ik het nu compleet fout heb

$1 schreef:$2ostby Turtle » Thu Feb 09, 2006 11:45 pm
The rear suspension on the DC2 (and a lot of other Honda's) is quite special.

The trailing arm bush is designed so the wheel can move backward or forward - that's why there's so much play in it.

The trailing arm is controlled by 3 arms. Simplifying slightly:

The lower control arm takes the main side loads.
The upper control arm controls camber.
The front control arm controls toe.

The special bit comes in when you brake. When you're braking, the tyre as it grips wants to move slower than the car currently is. That pulls the wheel backwards compared to the car.

Now, the trailing arm bush is specifically designed to allow the wheel to move back like this under braking. You're probably thinking that's useless and bonkers. Not so. Look at the lower control arm, and the front control arm. When the trailing arm moves back, it's held by both of those arms which limit where it can move. The front control arm is a lot shorter than the lower control arm. So when the trailing arm moves backward under the braking load, the front arm will angle more than the lower arm simply because it's shorter. That means the front of the trailing arm has to move inwards. Adding toe in.

To put it simpler, the trailing arm bush is designed to be soft so that the arm moves back under braking, causing the front control arm to pull the front of the trailing arm in, adding toe in, stabalising the back end under braking.

Even more clever is the way the amount of toe it added is purely related to how far back the wheel is pulled, which is related to how hard you're breaking and how much grip that wheel has. So if one wheel loses grip compared to the other, the toe of the two wheels will differ, helping stabalise the rear end. Really cool, and clever.

Honda has several patents on it.

If you put a much harder bushing in place of the standard trailing arm bush, you stop the backward movement under braking which stops the toe change under braking. Whether you want that or not, is up to you. But if you do it, you should consider what toe to run at the back as it's effectively static after the bush change. You can set the car up to work well either way - I'm just making the point that removing this cool toe change under braking behaviour without considering the overall handling effects isn't necessarily a good thing for everyone. I've certainly seen enough people who've probably been saved from a spin by the standard behaviour when they end up braking too deep into a corner to consider it worthless.

Just thought people might find that of interest... handling is a lot more subtle that you'd think



-Brian.

$1 schreef:$2ront is a different ballgame. Sadly, while I'm happily post some things I can't post all my knowledge up for free, so I'll leave you pondering the front. It's a lot more complex, and also affects traction... since so many people are getting competitive with Honda's now (witness the number of 1/4 mile peeps now), I'm not going to give any clues about the front for free.

The rear always seems so poorly understood I reckoned it worth a detailed post. Of course, the really interesting Honda rear suspension is on the EK9 - that some other tricks on top.

The toe change is in, not out (the shorter front arm pulling the trailing arm in as it moves back), but yes, it does automatically stabalise the rear under different grip levels. At least it does when you have the combination of bushes. If you're really curious, start with US patent 5,005,856 - that's for a slightly more advanced version of the same system... and dates from 1989

-Brian.

$1 schreef:$2pherical bearings do offer the ultimate in terms of geometry control, but with tradeoffs in initial and running costs. (Note: "rose joints" are a brand name - like Hoover for vacuum cleaners. I try to use spherical bearings as I generally used NMB and Aurora bearings rather the Rose!).

Whether or not that tradeoff makes sense varies for different uses - both for the car and the bush/bearing.

To make an informed decision as to which is most appropriate for what you want you needs to understand how the different options work and therefore what the tradeoffs are. Please ignore the rear trailing arm bush for this discussion (search instead). That's has a very unusual range of jobs to do which require special consideration.

Standard bushes follow a design called "metallastic" bushes. You have an outer metal shell, an inner shell and a rubber compound joining them. The outer metal housing is usually a press fit in the suspension arm. The metal inner is clamped to the other arm by the bolt. Then the rubber provides the movement - the metal parts stay fixed to their respective suspension parts. The rubber part has two conflicting jobs to do. It has to locate the metal inner relative to the outer - control the geometry. It also has to support the movement. So on the one hand it wants to be as hard as possible to keep the geometry perfect. But on the other hand it can't be that hard or the suspension won't move. Also the harder the rubber the harsher the ride - the more vibration etc that's transmitted. The Mugen bushes use a harder grade of rubber as they're less concerned with vibration and more concerned with maintaining proper geometry. However even the Mugen bushes aren't really that hard as they still have to support the movement of the arm. Metallastic bushes are popular OEM equipment since with no moving parts they need no maintaining, just occasional replacement plus by tuning the hardness they allow the harshness/sportiness to be easily tweaked.

Poly bushes work differently. With a poly bush the metal inner is still clamped to one arm. However rather than being fixed, the metal inner rotates in the poly bush itself. On initial examination this looks a lot better than a metallastic bush. The poly can be a lot harder as it's not having to twist as the suspension moves so in should be able to maintain better geometry. However there are two catches. Firstly since the poly is acting as a bearing surface over time the poly and to a lesser extent the metal inner wear. Secondly most of the suspension joints on the average car are not simple hinge joints. They support twisting as well as turning. To support twist the poly has to be soft enough to compress (or the suspension starts to bind as the energy trying to move the suspension has to compress the poly). The wear issue is often ignored - unless you take a suspension joint apart you often cannot see the wear so many people swear their poly bushes never wore at all. The twist is the more serious problem. Most of the bushes on cars need to support twist to a greater or lesser degree so when replaced with poly you have to compromise with the hardness of the poly. So as a metallastic bush replacement poly can only give it's best results on suspension where the joints are pure hinge joints so no twist support is needed. Where twist is needed (most of the Honda bushes...) it's still somewhat compromised. The wear issue isn't a huge one as poly bushes are relative cheap and the easiest to change for maintainenc. (The initial replacement with removal of the original metallastic bush being the hard part).

Spherical bearings are a metal ball with a hole that acts as the inner, with an outer housing. The metal ball is supported directly in the outer housing (sometimes using a PTFE or other liner for self lubrication). The inner ball can both rotate and twist freely while the centre of the ball stays in the same place relative to the outer housing. Since the inner ball isn't moving, rather it's just rotating, it offers perfect geometry control. That's generally what you want for handling (sometimes you use complicance to your advantage, but I digress....). So that's a huge plus. There are however, downsides. Firstly in common with poly bushes the parts are moving relative to each other and hence they wear. Secondly, spherical bearings need adapting to replace the original bearings - usually a housing to fit in the wishbone, plus side spacers to adapt the ball to fit where the bush inner went. Thirdly due to their metal parts and exposed nature they're vulnerable to corrosion. You can seal the housings to varying degrees to reduce that, but it's something to be aware of on a car that does road miles. As to the housings, there are two normal ways of retaining the bearings. The cheaper, race way is to stake the bearing in place. With staking once the bearing is in place a press is used to fold part of the housing over to retain the bearing. Once done, you can't change the bearing without replacing the housing. The other method is to use a circlip to retain the bearing - then you can remove the circlip and replace the bearing easily when needed. Adding circlip groves adds to the machining cost though - so expect such housings to cost more.

So which is best?

For racing spherical bearings. They're actually banned in a lot of categories for cost grounds, but where they're legal most top cars will use them. The handling benefits from being able to maintain designed geometry far outweight the costs of checking and replacing the bearings, plus the harshness isn't an issue.

For serious track day use it's not quite so clear cut. There are strong advantages to replacing a few of the bushes with spherical bearings. Replacing the right couple of bushes gives most of the handling gains of replacing them all without adding drastically to the maintenance or the harshness of the car. For the other bushes either harder metallastic or poly bushes can work. Metallastic bushes require a press and suitable tooling to change the bushes initially, but require changing far less often (they do go eventually). So higher initial costs. Poly is much easier for the DIY mechanic to do and maintain plus tends to be a bit cheaper. So for the DIY inclined it's worth considering. If you understand what job each bush is doing it's very possible to mix and match - exploiting the properties of poly where it doesn't have to twist as much so can be very hard without problems and metallastic where the poly bush would have to be relative soft and therefore poor at geometry control.

Personally I have two cars. One uses spherical bearings almost everywhere (actually used a couple of metallastic bushes still). It's setup to be able to use slick tyres properly though and not to do a lot of road miles.

My second car which while very focussed is a road car that's also capable of track days uses metallastic bushes.

I also look after a car that's a fun road car and track car - that uses a mixture of metallastic and poly bushes. Plus a range of race cars - ever one of them which can use spherical bearings for it's series uses at least some.

For the original poster my suggestion if you're planning on sticking to a mixture of road and track use with such a focused car then I'd change to a mixture of spherical bearings where they have the most benefit, with metallastic or poly elsewhere (the choice on which mainly depending on whether you want the lower workload of keeping the metallastic bushes or not). If the important spherical bearings currently use staked housings I'd change to circlip ones for easier bearing changes.

Final note on costs. There's something of a myth that spherical bearings cost a fortune as they're expensive to replace. If you're using friendly housings the bearings can be replaced easily. As an example bearing cost, the two largest ones I use on any of the cars I work on are Com14 size - load rated at 31tons (when you're dealing with shock loadings and slick tyres you get to the point where you need that!). A pair of them as needed for the car costs £42 for NMB bearings and last for a seasons racing (so more than a years track days for most people).

I'm not going to post which bushes to replace with spherical bearings for the best cost/benefit - I do earn some of my living designing suspension setups and setting up cars so have to drawn the line on what knowledge I give away for free. But I will say with the description I've posted on the pros/cons of different approaches there's enough information to figure it out. I have also posted a little on what works where on the rear previously (search!).

Finally, I've said it before but the trailing arm bush is a very special case. I've posted on the tradeoffs with that before.

-Brian.

$1 schreef:$2k heb er ook hardrace inzitten welliswaar niet op ne dc2 maar op ne EJ9.
Het verschil is goed te merken ,let er op als ge de draagarmen terug installeerd dat ge dan uw rubbers pas aandraait als de draagarmen onder spanning staan.
Gaan uw nieuw rubbers ook wa langer mee.Je kan gewoon de krik zetten onder de voorste onderste draagarm en omhoogkrikken tot de auto net van de grond af komt en dan aandraaien.(Indien je geen put ter beschikking hebt)

Ivm de trailing arm bussen heb ik hier 4 exemplaren liggen:
Mugen ,Hardrace,oem honda ITR/CIVIC en OEM honda MB6 aerodeck.

De mugens die zogezegt harder zijn als oem zijn ... gewoon even hard als nieuw oem bussen.
Heb ze getest met een gewicht eraan en daar is geen verschil in te zien.
De hardrace bussen zijn in mijn ogen ook te stijf voor op straat, op circuit kan ik nog wel inkomen.
De OEM MB6 Aerodeck zijn iets stijver als de OEM ITR/Civic bussen ,en geven een iets beter gevoel.
Of dit daadwerkelijk beter rijdt is een ander zaak.

Ik zou gewoon nieuw oem trailing arm rubbers steken of eventueel de mugens ,al zie ik niet direct een voordeel ervan.
Kheb ook ITR 98 spec achterste camber armen steken ,geven meer ruimte vanachter bij de velgen .

De beste verandering was veruit de voorste bovenste draagarmen links en rechts omwisselen voor meer Caster.
Ga je van stock 1°40' naar het max van stock 2°40'.
Stuurt pakken beter in, veel directer .Voor een Type-r denk ik dat je hier dan beter vanaf blijft ,omdat alles al perfect is gemaakt van fabriek met de vering en swaybars enz
waardoor je wss overstuur gaat krijgen .

$1 schreef:$2acht tot die van een eg er gewoon hetzelfde uitzagen,niet vergeten tot een eg/itr anderser vastzit als een ek