Sway Bars on a CG V6 Accord

[amato2]

Ok guys i have a whiteline sway bar at the rear of my car atm, its great handling is so so cool.

But i want to make the car handle more direct, if you know what i mean atm there is no body roll and stuff but the steering feels a little vague well not direct so to speak.

So i am thinking what if i put the Whiteline front sway bar on do you think that would help alot would it make the car handle more direct, i have Koni yellows on the car and they are set a half stiff on the rear and fully soft on the front.

i am also planning to upgrade the wheels too atm there stock looking to buy some 18's before christmas

[JohnL]

Ok guys i have a whiteline sway bar at the rear of my car atm, its great handling is so so cool.

But i want to make the car handle more direct, if you know what i mean atm there is no body roll and stuff but the steering feels a little vague well not direct so to speak.

So i am thinking what if i put the Whiteline front sway bar on do you think that would help alot would it make the car handle more direct, i have Koni yellows on the car and they are set a half stiff on the rear and fully soft on the front.

i am also planning to upgrade the wheels too atm there stock looking to buy some 18's before christmas
There are quite a lot of things you can do that will have an effect on making the handling more “direct” (i.e. improve steering response), and trying to cover ground this has unintentionally ended up being yet another long and rambling post! Please preface all following comments with ‘IMO’, others may disagree with some of it.

Adding a stiffer front ARB will most probably improve steering response, but as to whether you should fit one, well maybe, but probably not. If you increase front roll stiffness by adding the stiffer front bar (or increasing front spring rate for that matter) you run the very real risk of increasing under-steer, i.e. the steering response and turn-in may well improve, but then be quickly followed by under-steer. Only if the rear roll stiffness were already so high that the car tended toward chronic over-steer might fitting a stiffer front ARB be likely to be the right thing to do. So what else can you try, heaps of things!

Damper stiffness is very important to steering response. Have you tried the Konis stiffer or even at full stiff yet? (I like mine very stiff, but others may find it a little harsh). Stiffening the dampers (in bump and / or rebound) will speed up the rate of weight transfer, and thus increase steering response. Note that not only is damper stiffness itself important, but also how stiffly the damper is connected to the chassis and to the spring, so increasing damper bushing stiffness is also a very good thing, particularly at the initiation of any steering input (where any ‘vagueness’ in the bushings will impede the ‘sharp’ onset of weight transfer through the damper).

I know the Koni recommendation is set to full soft and use the adjustment just to compensate for wear, my advice is to ignore this advice! The Koni yellows ('Sport') are really quite soft and a bit mushy at 'full soft', significantly but not greatly stiffer at 'half stiff', and very much stiffer at 'full stiff' (i.e. the adjustment rate is not linear, getting substantially more sensitive to adjustment as you approach full stiff).

I've been told (by the Koni importer) that when setting yellows to full stiff, that the valve may close off (or nearly) possibly making the damper almost rigid. They suggest (if you want the stiffest setting) adjusting to full stiff, then backing it off just a tad (just enough to feel the valve move very slightly). Adjustment is easy (at least on the front, the rears may need to be removed to adjust, depending on the car), so you might as well try it, if you don't like it then you can back it off easily enough. If you do find that you like the front dampers stiffer then it might also be worth considering increasing the rear rate as well (a pain if you need to take them out to do so!), as the rear damper stiffness will also affect steering response.

Decreasing the aspect ratio of your tyres should in theory increase steering response, but not necessarily if the new lower profile tyres have a relatively soft sidewall compared to your existing tyres (which is relatively unlikely if you go to a significantly lower profile). Selecting new tyres with stiffer sidewalls will help (whether you change aspect or not), probably a lot depending on how stiff or soft the sidewalls on your existing tyres may be. Increasing tyre pressure significantly will tend to increase response, but might cause other problems above a certain point that will vary depending on the tyre, experimentation is required.

Increasing pressure substantially might or might not increase wear, and may increase response but at the expense of reducing outright grip, or grip over bumpy surfaces, though it may not (it just depends on ‘how long the string’ actually is). Both front and rear pressures will affect response. The tyre is ‘safe’ up to the max inflation on the side wall, but this may be too high for comfort (harsh), and may decrease outright grip etc as above. All these factors may differ significantly in degree from tyre to tyre (brand / model / size / profile / rim width to which fitted).

Avoid going to a wider tyre if you are not also increasing rim width, as this will tend to decrease response by making the sidewall behave effectively as if it were softer. In fact if you were to keep the same tyres and fit them to wider rims you ought to gain an increase in response because the wider rim will ‘stretch’ the sidewalls and make them behave effectively as if they were stiffer. If you intend purchasing a new rim / tyre combo then it’s likely you’ll be better off increasing rim width even if you don’t increase tread width.

The downside is that ride ‘harshness’ will tend to increase somewhat, which is why most car manufacturers tend to err on the side of narrower rims for a given tyre width. Never fit rims that are wider than the max rim width recommended by the tyre manufacturer. Going to a substantially wider tread will most probably increase response and may well be OK on smooth roads, but if you drive on uneven / bumpy roads you might regret it (increased erratic torque steer and tram-lining over undulations / bumps, related to ‘effective’ scrub radius changes as the centre of average loading traverses across the tread face, more so with wider tyre).

Stiffening the upper damper mounts by replacing the stock rubber bushes with stiffer poly bushes will increase response (as will ‘compressing’ the existing standard rubber bushes with additional spacer washers placed under the existing bush retaining washer, but don’t crush the bushes to death!). The effect of this on response is somewhat similar to increasing chassis stiffness, though not identical. If your car has Mac struts then I'd consider pillowball style strut mounts to get rid of the stock soft rubber upper strut mount. This should also provide some adjustment to increase caster (and camber) angle.

Replace all rubber ARB bushes with stiffer polyurethane items, as this will make the ARB begin to act significantly earlier as the chassis starts to roll, increasing weight transfer earlier which will improve response. Anything that removes bush compliance in the suspension will tend to be beneficial in some degree, so poly bushes everywhere can’t hurt, other than increasing harshness somewhat.

A slight increase in front toe-out should help, but may decrease straight line stability and increase tyre wear (especially with more camber angle as well).

Increasing neg camber (front) may increase response, and will assist front grip in tighter corners because it helps to counteract outside wheel pos camber gain due to body roll, a problem that is worse with Mac struts (than double wishbones), and worse still if the car is lowered. With Mac struts, if you lower the ride height a lot then neg camber gain with upward suspension deflection lessens (not good). If you lower the car so much that the control arms become angled upward from the chassis to lower ball joints, then it’s theoretically possible for the car to actually gain pos camber with upward suspension deflection (instead of neg), which is the exact opposite of the ideal! You wouldn't really want much more than about 1.5° static neg camber on a road car.

Because increasing caster angle also increases the ‘trail’, increasing caster significantly will definitely improve response, on-centre feel, straight line tracking, and is also beneficial for steered camber angles because it causes the steered outside wheel to gain neg camber as the wheel is turned and the inside wheel to gain pos camber (both good in tighter corners when more steering input is used because it helps keep both contact patches more ‘square’ to the road as body roll occurs, and it will occur to a significant degree even with high roll stiffness).

You want as much caster as you can get, it's almost impossible to have too much (within what is reasonably achievable without creating mechanical problems), but there will be an increase in steering 'weight', though this is generally a good thing that adds to steering feel.

Without PS a lot of caster makes the steering onerously heavy, but with the almost universal fitment of PS many manufacturers are increasingly using substantially higher caster angles than even a few years ago, 10° from the factory is not outrageous these days (and some racing cars may use a lot more, which is why so many race cars retain or fit PS).

Caster can be increased (somewhat) by fitting a pillowball style upper mount that allows such adjustment, but can also be adjusted by shortening the ‘radius rod’ attached to the lower control arm (thus 'pulling' the bottom of the suspension forward relative to the top of the suspension).

Caster should only be substantially increased if you know what you’re doing, if you go too far you may create problems with; bump steer (depending on how you do it), suspension arm pivot bush angularity (might cause premature bush failure), the angularity of ARB linkages (tough on the linkage and it’s bushes), and possibly drive shaft ‘plunge’ (‘pulling’ the suspension forward at the bottom may cause the driveshaft to shorten a little, so the drive shaft could conceivably ‘bottom out’ as normal suspension motion causes the drive shaft to change ‘length’).

Higher spring rates will probably help, though most likely not as much as increased damper rates unless the spring rate increase is quite large. This is also a factor when increasing tyre pressure, i.e. the tyre has it’s own vertical ‘spring rate’ and is part of the overall springing being a ‘spring’ in series with the coil spring. Higher pressure increases the tyre’s ‘spring rate’ so increasing overall spring rate.

Strut braces also work to increase steering response (as will anything that increases chassis stiffness, and the chassis can never be too stiff!). Both front and rear braces make a difference. I have front and rear home made strut bars, and taking them out makes an obvious difference to response and general handling.

Anything that stiffens the chassis is by definition good, and the rear is often the softest part of the chassis. E.g. I have a home made ‘X’ style tubular brace fitted to my CB7 that fits behind the seat in the aperture that Honda provides to allow long cargo to be passed into the passenger compartment, and this definitely helps response and handling, as I found out the other day when I removed it in order to carry a long load in the car. Taking it out made the car feel relatively soggy in the rear end, impaired steering response and increased under-steer. This ‘void’ in the chassis structure is only there to allow long cargo to be carried (i.e. it’s an invention of the marketing department), and actually detracts significantly from chassis integrity.

A word (or two) about strut braces; get good ones, if not then don’t bother (forget Ebay!). If you can cut and weld you can make your own, probably better than many of the commercial ones available. The bar itself needs to be straight and either a decent OD and / or thick walled (for stiffness in tension and compression without ‘bowing’). If a straight bar is not possible it needs to be very stiff (i.e. even larger OD and thicker wall). However, a lot of strut braces I've seen while having a decent enough bar are very flimsy at the bracket where they attach to the top of the strut tower, and therefore next to useless.

The attachment brackets are very important and need to be well designed and made from decently thickly dimensioned material (i.e. thick not thin steel as is so common). If the brackets are not robust then they will flex and the brace cannot do what it's designed to do, no matter how stiff / rigid the actual bracing bar may be. I suspect this is the reason why a lot of people confidently state that a strut brace makes no or little difference while others swear by them, i.e. some people are using rubbish strut braces with flimsy attachment brackets…

So long as it’s well designed and made it doesn't matter whether the strut brace is a one piece unit (welded construction) or a bolt together three piece (bar and two attachment brackets). Also, with a bolted together unit, it doesn't really matter whether the ends of the bar are attached to each bracket with one or two bolts (some people seem to think two bolts makes the strut brace stiffer, but it doesn't, at least not to any significant degree and not in the 'direction' in which forces actually work in the strut brace).

Strut braces work to transfer forces side to side in tension and compression through the bar, and don't (can't) effectively deal with any vertical forces, and don't provide any appreciable added vertical stiffness, i.e. they cannot prevent one side of the chassis (or portion thereof) deflecting 'up' relative to the other, regardless of whether they are welded together or how many bolts are used to connect the bits and pieces.

Strut braces only act in compression and tension, not in ‘bend’ as would be required to resist vertical deflections in the chassis. To act in bend (i.e. to effectively resist a bending moment) the brace would need to be a substantial girder or an elaborate triangulated / braced structure that has a very high ‘beam’ strength, and none do. Without an effective brace in position, a vertical force applied at the top of the spring / damper will attempt to deflect the chassis upward or downward at that corner, but because of the innate vertical chassis stiffness much of this force is re-directed laterally (less stiff direction for the chassis), and it’s this portion of the loading that is resisted in compression or tension by the strut brace.

Enough? Plenty to go on with I think!

[amato2]

Your a champion mate, you have basically answered all my questions too. I have plenty to go on now and read up on too.

I used to have a 91 4ws as my daily awesome car i used to love driving that thing everywhere but its gone ahwell.

But thanks for that info will hunt around now for some parts and do some adjecting on the Konis too that for sure

Thanks mate

[SiReal]

I think its time to do a photoshoot my friend. haha

[amato2]

Yeah thats a definate, I need to fully polish ma car and then i am very very ready sounds like fun

Somebody reversed into my front driver door too so i need to get that fixed before i think about foto shoots

[JohnL]

Well I hope it helps more than confuses! Keep in mind that you don't have to do everything to make a big difference, just a few changes will help a lot, so long as they are the right ones. Some changes will make a big difference on their own, others will be subtle (though if you add a few subtle things together and you can end up with a big sum affect).

You've already done one of the best things you can do and that's fit really good dampers, but you need to tweak them to get the best from them. Fitting a nice stiff rear ARB is also one of the best things you can do, but even better if the bushes are poly (note that not all polyurethane is the same, it comes in degrees of hardness, from nearly as soft as rubber to much harder).

If I was where you are now, I think my next move would be either strut bars or altering geometry, in particular getting some more caster on the car. If you want to change caster but you don't know exactly what you're doing (or have mate to help who you're certain knows what he's doing) then I would strongly reccomend getting professional advice, but be careful, not all 'proffesional' advice is equal...

If you're looking at new tyres then remember sidewall stiffness, but also, as a general rule of thumb the tread blocks should be larger rather than smaller. Larger blocks are more stable than small ones and will 'squirm' less, tending to give better responsiveness. All else being equal, if the rubber is soft the blocks will squirm more than with harder rubber, harder rubber tending to be more responsive but less grippy. Whether you are willing to trade some grip for some response is up to you, though I don't mean to imply that a soft tyre will ipso facto lack responsiveness.

Of course smaller blocks are likely to be better in the wet, as will tread with wider grooves. Fewer and narrower grooves will tend to be better in the dry, if for no other reason than fewer and narrower grooves will mean more rubber in road contact. It's all a compromise.