New Project - Chasis Stiffening Mods for Improved Handling

[defcon1]

My objective is simple...

To get the ceffy to take corners as well as any stock rear independent suspension vehicle, or at least, come bloody close to it...

The ceffy suffers from a host of problems caused by :

a) The rear torsion bar
b) The length of the wheelbase

Taking corners on stock suspension basically feels like a boat. Lowering springs like Eibach basically lower the centre of gravity and loads up the absorbers thereby making the suspension stiffer, but the effect is still far from desired.

Even on the Hotbits set I have, the handling is much better overall, but I have significantly compromised it's comfort.

Then, as the ceffy ages, and the metal shell degrades, you start getting all sorts of creaks and noises. Noise does not happen unless there is movement somewhere in the car. Because of the long wheelbase, every time you take a corner, the body flexes...resulting in bad weight transfer which lowers the efficiency of your absorbers and springs, irrespective of the type of absorbers adn springs you may be using, plus, creaks as the metal welding points flex.

So...my next mod will take care of all this. I expect to be able to handle corners almost like a beamer, and certainly much better than a stock A33. And, I will eliminate a heck of a lot of irritating noises. My absorbers and springs will be fully optimized, and I won't get sea-sick every time I go up Gentings...

The best part is...even on stock springs and suspension, your handling is going to be so good, you might decide not to spend that RM 3k+ on aftermarket coilovers or Titans...

Presenting........SUBFRAME CONNECTORS.

This is not new and has been installed in cars for a loooong time. Ultra Racing has been installing these in Perdanas and A31's. For drift cars, it is almost mandatory for a subframe connector stage II set to be installed.

There is no ready-made option available for the A32 and A33. However the principle is so simple, that any welder could fabricate one.

Subframe connectors work by stiffening up the chasis and limiting the amount of flex, which makes for more positive handling characteristics. Weight transfer is also optimized, and this will allow your suspension and springs to work the way they were meant to work.

I've called Ultra Racing, and yes, they can fabricate them for us. The price : RM 450 - 550.

BUT...this thing is so easy to do. So, why pay Ultra Racing for a few bits of metal welded together. I've been talking to Naray, and we think we may be able to get some commercial welders to do them for us.

All we need is material (Ong), welder (Naray), design (Me) and some way to lift the car on all 4 wheels (the suspension has to be loaded with the car's weight so that the body flexes into the shape it is usually in when driven before welding in the subframe connectors. An inspection bay would be best. Or, one of the old car-wash ramps but a low ramp, cos the car has to be horizontal when the welding takes place. A wheel allignment bay would also do...so maybe one Sunday at Lee's? I think I can interest him enough in the project for him to come and open his workshop doors one Sunday...

Comments please...

 

[dream.tent]

Interesting! Will the frame holds the chassis? I mean shouldn't it be at least comes with a tensioner? like always pulling the chassis inwards?

if it's just a bolt on, won't it flex along with the chassis? I'm just thinking out loud now...

i saw those frame for Altezza that bolts on and suppose to hold the engine bay and with the lower arm as those diffrent parts that needs some tie down.

But our chassis is already one big piece...maybe it will help but not sure will be significant? unless we can like tighten it after bolt on?

 

[Madrocky]

The function are similiar to anti-roll bar and sway bar... Correct me if i'm wrong..

 

[defcon1]

Interesting! Will the frame holds the chassis? I mean shouldn't it be at least comes with a tensioner? like always pulling the chassis inwards?

if it's just a bolt on, won't it flex along with the chassis? I'm just thinking out loud now...

i saw those frame for Altezza that bolts on and suppose to hold the engine bay and with the lower arm as those diffrent parts that needs some tie down.

But our chassis is already one big piece...maybe it will help but not sure will be significant? unless we can like tighten it after bolt on?

Yes. Designed properly, the frame will hold the chasis. We are thinking of changing the subframe connectors themselves (the two long lengths going from front to back) to square hollow bar...probably 2"x1.25". Not sure if this dimension exists, so we need Ong here.

Also, the thickness is important. It has to be rigid. There is no need for a tensioner since the frame is designed to hold the shape of the chasis rather than to pull it into shape, and it welds on, not bolts on. The idea is to stop the chasis from changing shape as the car moves and different forces are applied to it. Basically, the chasis is one multilayered skin of metal with just a frame holding it in shape. What we are doing is to stiffen that frame. Tensioning AFTER it is welded in WILL change the shape of the chasis as forces are applied to it. And knowing how kiasu I am, you can bet it will be strong enough.

The cross-members will be bolt on. The centre cross-member will incorporate a thick metal plate in the centre where the 4 diagonal cross-member can bolt on. Nuts will be welded into the frame to make it easy to bolt on and off. Bolts will be tensile steel self-locking bolts attached with very good spring washers.

And yes...there will be some degree of flex...BY DESIGN. If the frame does not flex at all, you will not be able to feel the moment just before the car loses traction or "buang".

Engine or gearbox subframe connectors are different. I have yet to design this, but I doubt that our car needs them. Our stock crossmember is already quite strong.

The function are similiar to anti-roll bar and sway bar... Correct me if i'm wrong..

Similar, but not the same. Anti-roll or sway bars...as the name implies...are designed to stop the left-right roll of the car especially when taking corners by redistributing force more efficiently from left to right or vice-versa. However, as most of our cars are lowered, the effect of an anti-roll bar will not be so distinct. Still, I do have a design for our Ceffy, and one day, we might get someone to make them for us. The bar needs to be precision bent and formed...so as I told Ong...a bodybuilder won't do...can bend, but not precise enough...

Ultra-Racing can make sway bars for us...and here, I would not suggest diy unless we have access to a proper machine shop with heating and quenching facilities. Installation is easy, and the parts needed to install are available at any hardware store for the rear sway bar. The front anti-roll bar will take some work...it's sitting under the engine and in a difficult position. Supported by the subframe connectors, it is my opinion that the front anti-roll bar is not an issue, though I would consider the rear sway bar.

The image shows a simple rear sway bar design for a cefiro/maxima. For some real improvements, I would set the bar itself directly in the middle of either the side or the bottom of the torsion bar, and attach it to the torsion bar through two D-bushings.

 

[edgar_raphael]

commercialised it and send it to Australia and NZ for our benefits :)

I'll be waiting.

 

[defcon1]

But Edgar...all you need to do is contact Whiteline in Oz. They can definitely build all the components you need...sub-frame connectors, rear anti-sway bar and front anti-roll bar.

I used to deal with a guy called Bob Tait...but I don't know if he is still there. It's been many years. Better than mailing 15 kgs of metal to you...

If you really have a problem there, it shouldn't be a problem to fabricate a set and send it. After all, dismantled, they are basically a set of seven straight lengths of metal...

By the way...where are you located?

 

[edgar_raphael]

South Australia.

You should know that labour are very expensive here. To put the car up on the hoist alone would cost me AUD$50, let alone leaving the car for them to do all the measurements and welding. And you have to pay for renting the place to park your car while they do the work for you.

Which is why we would rather source parts from another country which left us to do all the installations ourself, save us all the hassle and ridiculous charges.

 

[defcon1]

Hmmm...I understand. Well, let's see what we can do for you then... :)

It should not be difficult to fabricate a spare unit, but be aware...for the subframe connector to work properly, you need to have it welded in at 10 points. So, you will need to see a welder about it.

Sway bars and anti-roll bars are easier. Just need to dismantle the old one and bolt in the new...

 

[edgar_raphael]

Easy, we go to Bunnings, buy a welder machine (share amongs us) and do it ourself.

But what type of weld is needed? I think there are several different types of welds, there is TIG, MIG and etc.

I think you should ask the person who is doing the job for you to keep a data for the measurements and design. So that he can fabricate it anytime without having measure again from the car.

 

[defcon1]

I believe the preferred welding technique here is TIG welding, using a wire filler. And you are right. Data needs to be kept, but I will do it.

The fabricators here are basically...just fabricators. You tell them to weld, they weld. You tell them to cut, they cut. You tell them to join, and they join. The best way would be to make a prototype under a car, then make all the necessary measurements and produce a technical (or semi-technical) drawing from the data. I'm no engineer, but I think I can produce a competent diagram..

 

[weikee]

Welding the things into the car really need to take extra caution and also proper paint to do the job back. It will easily get rust on the welding area.

To make a strong frame, its best to use the Seamless metal tube used in racing cage, cause the metal are not like ordinary "tube" its not form by folding two end and make a round shape. Its not a must, but its good to use seamless, cause during flex the seam give way will not be there.

 

[honggas]

~Quoting DiGi, Fui-Yoh !!!

I got 2 question,

Question Numero Uno
since we're doing this mods, does it affect (err .. i dunno what they refer to, i think it is... ) 'crumple points' in event of accident?

Question Numero Dua
Does this mods compliment Strut Bars or we can make do without the front and rear strut bar altogether?

TQ

 

[defcon1]

~Quoting DiGi, Fui-Yoh !!!

I got 2 question,

Question Numero Uno
since we're doing this mods, does it affect (err .. i dunno what they refer to, i think it is... ) 'crumple points' in event of accident?

Answer Numero Uno
No, since the bars start behind the front wheel and terminate in front of the rear wheels.

Question Numero Dua
Does this mods compliment Strut Bars or we can make do without the front and rear strut bar altogether?TQ

Answer Numero Dua
This mod compliments Pillar Strut Bars, but will probably allow you to work with the stock Anti-roll Bar and do without an after-market Rear Sway Bar. It will also improve the efficiency of the stock suspension by maintaining the correct angle when cornering (lessening the amount of body/chasis flex) and facilitating accurate and fast transfer of weight between the four wheels.

 

[honggas]

Hmm ...

Sometime I do believe that Defcon is actually destined to create custom parts for Cefiro (and maybe for Ong's Triton too, if given the chance )

The actual time I was wondering on why aren't there many options for A32 to improve handling and there suddenly he pops-up

So ... when is this mod happening?

 

[ongteckweng]

honggas...u r right about my triton...it needs custom kit for the suspension!! the bodyroll is horrible n the suspension is just too soft...

 

[defcon1]

Uh-uh! Sorry, but am alergic to Tritons...the moment I touch one, I break out in rashes in all the most sensitive areas...

 

[ongteckweng]

Uh-uh! Sorry, but am alergic to Tritons...the moment I touch one, I break out in rashes in all the most sensitive areas...

dont worry....i wont even let u touch it...

 

[Cheong Mou Kei 4G9XT]

Defcon1 : erm...how much is da rear bar cost...?

 

[defcon1]

Hey Cheong,

Sorry, I don't sell the stuff. That photo was from the US where they make these bars for the Maxima...basically a cefiro with a different skin. In the US, they would cost anywhere from USD 109 - 169 for a non-adjustable bar. Trust me, there is no point to get an adjustable one.

The rear bar can be fabricated by Ultra Racing for the cefiro. Or, if you have a machine shop with the proper bending and quenching facilities, you could ask them to make you one.

Right now, I am more interested in the subframe connectors cos this may very well stiffen up the frame enough such that a rear sway bar may not be necessary.

Btw, a rear sway bar, coupled with a rear torsion bar may stiffen up the rear too much. It will function like a dream when the road was dry, but you have to be extra careful in the wet. The minor flexing of the chasis just before the rear of your car gives (or buang) is very important because it warns you that you are on the edge.

 

[Cheong Mou Kei 4G9XT]

i dunno but i still prefer antiroll bar.
now tok wat oso no use coz im gonna be sued for bankcrupcy soon