It took one hour. I used to be a mechanic and have all the tools
but my garage is unorganized.

The pins on the verticle link just spin when backing off the bolt.
I used a thin channel lock to hold the pin from turning.
The space between the link and the bar is small to get
a hold of the pin, I had
trouble finding a pliers that will fit in there. There is a very
small size vice grip available but I couldn't find mine.

I had to remove the rear wheels. It takes 13 and 14mm
wrenches and sockets. I think the slots in the brackets are
too large for the bolt heads, I will install some flat washers
under the bracket bolts next time I am under the car.

Otherwise very nice quality piece.

Tim

 

There is a 5mm hex in the end of the end link bolt..you can pop an alan wrench in there to keep it from turning. I also installed the flat washers they are necessary IMO. INstead of taking the wheels off I just unbolted the rear air difuser(hollow plastic) and let it hang down. Gave me all the wiggle room I needed. So what do you think abou tthe performance now that you have it installed? I find it to be noticeably different when really pushing the car.

 

i just put my car on jack stands and did it. took about 20 minutes. i would have been able to fit under there if it werent for my pro kit drop

 

geez now you tell me, I didn't see the hex, that would be much
better. I removed the wheels to pull the bar out one side.
I've read some things on these boards about the rear bar
but never heard about the hex before.

The handling is alot different. I hung it out in some exit ramps
today and felt the rear coming around. I'll need a little more time
on familiar roads to quantify the difference, it appears to be ovesteering now and may not be neutral.
Oversteer in a front drive car? something different to get
used to.

This car really needs to be lower, that's my next modification.
I'm going to do the comptech springs.

What do you do with Competch dry transfer decal that came
with the bar? Will it hold up on outside glass?
I expected this would be for inside glass apply.
I was going to put it on my rear quarter window.

 

I don't know if it's quite oversteer but the understeer is definitely gone.. i'd say completely neutral to mild oversteer. I find that if you push it hard you'll get all four wheels sliding. Maybe that is due to the poor tires though and when you get some better rubber some understeer might come back. I also have the comptech springs and rear camber kit in my living room...doing the install this week

 

I had a little more practice with the new rear bar today,
it is definitely better.

I'm very interested, let us know about the comptech springs.
That is my next mod, I am thinking comptech springs because
they rar the least drop available.

 

That was my thinking too. I want to tighten up the gap but still look stock-like and keep the ride decent.

 

Is comptech making different sizes for these sway bars? or is there only one (21 mm? .. or is it 22mm? I cant remember)

It sounds like there may be a bit too much tendancy to oversteer with just the 21mm sway bar ..which kinds makes me think that the limits on the car may actually have decreased.

Ideally what I would want is neutral, with very slight understeer at the absolute limit. So perhaps a 20mm or even 19mm would be better. But I'm not sure if anyone makes one yet.

The other option is put in the 21mm and then to stiffen up the front bar as well, which will help balance it out.

 

comptech is 23mm rear. There is no way it's decreasing the cornering ability of the car. It tracks flatter and more stable with better turn in. What's happening is what all cars try and do, maximize the potential of the tires on it.

 

why only the rear bar? i haven't seen anyone purchase the front one....as far as i knew, i thought the front one would provide better performance because the tsx is front wheel drive. or is it just because of the price difference?

 

my guess is that it sbecause the front bar is bigger than rear in stock form, plus the front end has additional stabilization in strut tower brace. so a bigger rear bar will have a more dramatic effect than a bigger front bar.

 

why only the rear bar? i haven't seen anyone purchase the front one....as far as i knew, i thought the front one would provide better performance because the tsx is front wheel drive. or is it just because of the price difference?


Sway bar fundamentals:
a sway bar or bigger sway bar reduces the conering force
at that end of the vehicle.

The tire traction force is linear to the load. When you go into
a turn, weight transfers to the outside wheels, increasing
the traction force available from the outside tires. The
traction force of a tire is the weight times the coefficient of
friction.

A front engine car has natural oversteer. The weight up
front makes the front tire's traction force much higher
relative to the rear, front tires stick and rears slide. So they add
a big front sway bar to reduce the net traction force up front.
The front bar makes the front traction worse, to match the back.

They actually want to induce too much understeer ( front slips )
because it is safest for mom and pop to handle understeer.
Usually braking or letting off the power is intuitive and safest
for mom and pop drivers to pull out of understeer.

Performance drivers might want less understeer or even some
oversteer. So you add a rear bar or increase the rear bar size to make the rear traction worse and induce more oversteer.

Think about the bar. As the outside spring is compressed in a turn, the bar is pushing the inside tire down. Transfering weight and load back to the inside wheels. It reduces the weight transfer to the outside tire and in the turn, a bar reduces the net conering force of the two tires at that end of the car.

If we pitch our TSX into a turn and the fronts are slipping we
can only hit the brake or let off the gas. So performance
drivers want a bigger rear bar to make the rears slip instead.
They really want it neutral so both front and rear to slip
the same but there are so many permutations of load, weight
transfer, lateral acceleration, we can never be neutral in every
turn geometry.

If more oversteer is present, rears are slipping, the driver
will then turn into the slide and apply more gas. Thus performance
drivers might want more oversteer where the compensation is more power, vs more understeer where the compensation is brakes.

Now what I notice is some turns, the rear of my car really comes
around with the comptech bar, it is slipping. I also sense more jacking at the rear end, from bar pushing the inside wheel down more.

I think the car needs to be lowered to use this bar. I'm not sure
the bar is an advantage right now. I'm not sure it's worse either,
I think it went from understeer to oversteer and is not right yet. The jacking was there before and may be worse now with this bar. Lowering will reduce the weight transfer, body roll, and movement in both front and rear springs and bars.

Tim

 

That was really helpful. Thanks.

 

very much so. thanks!!

 

tinky, let us know how the ride is after the comptech spring install...i'm very curious to know..thanks.

 

TSXTim -- i'm not a suspension expert but i have some questiosn about what you are saying.

Saying that a rear sway decreases traction in the rear which is what causes the car to rotate better is not really the case IMO. A anti sway bar reduces roll which unloads weight from the outside wheel and helps distribute it to the inner wheel. That means it distributes cornering forces more equally to the two rear wheels which is going to increase absolute traction in the rear. If what you were saying was true then lowering a car(which lowers center of gravity, decreases roll and distributers cornering forces to all the tires more equally) would also be 'decreasing traction'.

Now that i've said that i'm going to say that yes, a bigger rear does transfer more lateral grip and traction to the front. it does affect the handling balance, but this isn't at a loss of overall absolute grip. This is double good in a FWD setup because the front wheels also provide the motive force so maximising the lateral grip of the front helps you accelerate out of turns as well.

 

Been checking every day for news, what's up, how's the
springs ?

 

Sorry I made a mistatement.
When the outside spring is compressing and is raising the bar,
this is raising the inside wheel, and compressing the inside
spring. This reduces body roll, thus they are called anti sway bars.
They also stabilize ride where a input to just one wheel on a bump is somewhat transfered through the bar to the opposite side too.

By compressing the inside spring ( or effectively lifting the inside wheel) this is transfering load from the outside tire to inner spring, reducing the outside tire's load and cornering force, and reducing the net cornering force at that end of the car.

So the larger rear bar does not reduce understeer by improving front traction, it makes the car more neutral or increases
over stear by reducing the rear traction. Alternatively a smaller
front bar could be installed but then body roll would increase.
Ther is probably chassis torsional mechanics where changes in
the rear bar are translated to the front tires as well.

 

 

[QUOTE]Originally posted by TSXTim
[B]Sorry I made a mistatement.
When the outside spring is compressing and is raising the bar,
this is raising the inside wheel, and compressing the inside
spring. This reduces body roll, thus they are called anti sway bars.
They also stabilize ride where a input to just one wheel on a bump is somewhat transfered through the bar to the opposite side too.

# ride is marginally degraded since obstacle on one side is met with effectively higher spring rate as other side also forced to counteract the obstacle via the coupling of anti-roll bar. Only time there is no degrading is when both wheel meets same obstacle at the same time ie a speed hump

By compressing the inside spring ( or effectively lifting the inside wheel) this is transfering load from the outside tire to inner spring, reducing the outside tire's load and cornering force, and reducing the net cornering force at that end of the car.

# by compressing against inside wheel/spring, that compressed force is transferred to outside as inside spring would prefer to extend rather than be compressed. (both ends of bar try to move in unison with the direction of the greater force which is now acting on outer tyre. ie up but finds resistance of the inside spring which prefers to extend down. Bar bends in torsion)

# tractional force/grip of a tyre is not linear to increase in its load. Its return of traction/grip gets progressively worse with load. law of diminishing returns. Lighter static load gives better grip. Downforce without actual mass is even better. In this case only static load is considered. Racing cars are made lighter for this reason as well.

# a uncoupled independent rear axle(or front for that matter) has more total grip than one coupled with a anti-roll bar. The reason for this is: take the extreme example of a heavy bar enough to lift the inner wheel during cornering. The inside wheel obviously provides zero grip and the total grip coming from the rear is now only dependent on the outside tyre since entire rear load is now transfered via the bar to the outside. ie load doubles. BUT the grip returned for that doubling in load is not double, it is less than that. So total grip of rear axle with anti-roll bar is less than that of an uncoupled one.

# reason for degrading total rear grip is to obtain near neutral handling balance. Ironically by degrading total rear grip, a neutral handling car can go through corners faster and result in higher g-numbers as opposed to an understeering one.

Hope this helps !

AL

Yes I have fitted the Comptech rear bar to my CL7

 

Thanks for the informative info! What part of the world do you live in to be able to get a cl7?

 

I live in Singapore. The traffic is Right hand drive and is similar to Japan which is why we can get the CL7. We also have the 2.4 Type S which I reckon is your TSX.

AL

 

.

Hope this helps !

AL

Yes I have fitted the Comptech rear bar to my CL7 [/B][/QUOTE]



Once fitted with four Pirelli Pzero Nero I am very satified
with the comptech rear bar. The rear oversteer is only certain
conditions and is not difficult, it just takes some getting use
to the car being different. Overall I am much more confident
pushing it now.

We probably have some different views but not that different.

First, the traction force is linear with load. The law of friction force is force = coef of friction times the Normal force. The coef deminishes from static to sliding friction at breakaway. This is
why a car suddenly breaks loose. The
transition from static to sliding coef is a step change not gradual
and this is why oversteer can be dangerous for unskilled drivers.

As long as the center of gravity is above the roll axis, weight
is transfered to the outside tires. However the bar transfers part of the force that is compressing the outside spring back to the inside spring, both pulling the inside wheel up and holding the chassis down by the inside bracket - reducing body roll. The force transfered from the outside tire is then partially consumed
in resisting the roll couple. This is reducing the load on the outside tire by transfering this back to the inside spring and countering the roll couple. Therefore the traction force on the outside tire is reduced where F = u * N. u is the coef of friction.

Because there is less down force on the outside tire it is
developing less F.

There is confusion about breakaway. That is when the
tire's adhesion is exceeded and slides from the drop off in
coef of friction at the transition from static to sliding friction.
This is also a function of N. In this model the
tire is developing less F even when not sliding.

A lighter car does not go through turn faster than a heavier
car. There is not a mathematical model to support that.

If they both go through the same turn at the same speed
where the lateral acceration is the same, the lateral force
of centrifugal acceleration is different from the different masses where F = ma

The lighter car is developing less lateral force but it's
tires are developing less fraction force
from less normal force N, the heavier car has higher centrifugal force and higher traction forces from higher N. It's a wash.

If you observe a difference in light and a heavy car it is because
they are different cars with many different details, not because
they are the same cars with different weight.

If you had two models of exact same roll centers, suspension geometry, center of gravity, same tires ( the coef ) everything the
same except their size and weight scales, they would perform
identically provided every detail such as torgue and horsepower
were on the same scale. You have to have the same scale
horsepower for the heavier car to overcome the
friction losses from tires operated at higher N and higher
traction forces. It all has to be same scale and there is no
difference in mass making lighter cars go through turns faster.

Just watch the A division and B division cars in sports car racing,
the heavier A division cars go faster in turns as well as
straight lines.

 

a must read: "Race Car Dynamics" by William and Douglas Milliken. It is very clear in that book that I am not making this all up.

AL

 

The neuspeed rear bar is 19 mm, and the comptech is 23 mm.
What is the stock size rear bar?

I have read here that 23 may be a bit to much bar, and some have said it may cause some over steer.

So is the neuspeed bar going to give more of a neutral feel?
And not take so much from ride quality?

Has anyone tried the neuspeed rear bar?

 

Performance wise, it's actually beneficial to have a little oversteer at the limits in a FWD car. It's very unusual to have an FWD car oversteer at all but its a welcome change. Correcting from an oversteer is very easy with FWD, just steer in the direction you want to go and give it gas. You'll look like a pro!

 

a picture is worth a thousand words..... ------->

 

The stock bar is 14mm.
Neuspeed is 19mm
Comptech is 22mm

Oversteer tendency pronounced when using tyres with lower grip. Higher grip tyres can be chosen to add understeer and balance the handling.

Ride comfort still good with Comptech bar, only slight firmness. Rear dampers may not be enough to counter additional single-bump spring rate thanks to the stiffer bar.

As described, oversteer can be fun but only if you are looking for such antics.

AL

 

Yes, a car that is set up for oversteer won't be much fun on the streets. But if you do autox and use it as your street car some compromise will have to be made.

 

Yeah I've noticed this too when pushing the stock michelins at the limit. Oversteering fwd has to be the easiest combo to drive hard around