Chassis fabrication and suspension

[Toyzda]

Profi,
A 4 link will still be an improvement to any live rear end. The binding happens whilst the links stop the roll steer over bumps and cornering. Any live rear end setup is a comprimise in a track car.

Abuilder,
I do not see the need for so many holes. Some of the positions available in this design would cause huge amounts of tramp and roll steer. This would be horrible in any case, road, drag or track. My point is the holes do not need to be so plentiful at both front and rear ends, so you cannot adjust (tune) the car straight into a wall! Also the suggestion that this car's builder is cortina savvy would indicate he should know what the perfect setup is with that diff and that length link arms. You can only control how much the diff moves (for and aft) and anti-squat when tuning the arms with a 4 link, and nothing more.

Although your car seems to be more thought out, but why do you need so many holes on the chassis mount of 4 link. For a track car this is too many,you would never need the ones in the middle. I donot try to launch 1500hp cars, so i dont know about that. Most likely different needs.

[msadyno]

locked bird cages abuilder...... same deal. Anyway good on the sporty corti guy for having a crack. To have a "chuckle" at someones design you don't agree with is a bit arrogant when the same person could throw it back at you with your 30 year experience welds.

The end of the day who gives a stuff when they go like a shower of s*%t , massive handfull to drive and leave a grin from ear to ear for days. These things are built as a stress reliever for the day to day rubish most people have to deal with and if it's not 100% perfect.......... who cares ! As long as the owner gets satisfaction from it.

[Abuilder]

locked bird cages abuilder...... same deal. Anyway good on the sporty corti guy for having a crack. To have a "chuckle" at someones design you don't agree with is a bit arrogant when the same person could throw it back at you with your 30 year experience welds.

The end of the day who gives a stuff when they go like a shower of s*%t , massive handfull to drive and leave a grin from ear to ear for days. These things are built as a stress reliever for the day to day rubish most people have to deal with and if it's not 100% perfect.......... who cares ! As long as the owner gets satisfaction from it.

Msadyno, shows how much you know. He bought a kit and fitted it. He never designed it. It is not that I don’t agree with the design, the design is fine. It is a standard street/strip 4 link. Who ever put that set-up in did it wrong and being arrogant has nothing to do with it. It’s done wrong and that is all there is to it. The bracket is fitted to the wrong side of the diff end of story. Plus when it comes to putting in a 4 link like that the principle is the same no matter what car.

So in your eyes you don’t mind paying good money for something to be done wrong as long as you get satisfaction. So you are saying it does not matter if it does not perform at a 100% 60% will be good enough or maybe even 50% is alright in your eyes as long as you get your buzz. But wouldn’t the buzz be even better if it was performing at 100%.

And by the way 4 link and 4 bar are quite different.

Are you trying to question my welding ability? I would put my welds up against anyone’s.


Toyzda, to explain the full ins and outs of a 4 link you just couldn’t do it on a forum. I can assure you that in drag racing those holes get used. You can tune a lot more with a 4 link than the 3 items that you mention. On any given day, tracks are different, drivers are different, cars react different even the weather can come into play so the adjustment is needed. Remember though, I am talking drag racing 4 links not circuit racing 3 or 4 bar setups. As for the guy being cortina savvy, I have already answered this question once “when it comes to putting in a 4 link like that the principle is the same no matter what car”.

I will happily discuss 4 links with anyone, but they are complicated and too hard to explain on a forum.

[Toyzda]

4 links are not complicated at all. They are quite easy. On there own they cannot do anything else but control tramp, roll steer and squat. It is a fair point about meeting track and driver needs, but the function of the 4 link can never change. If incorrectly installed you will only change it effictiveness.

I also am not out to argue or critisize, but I don't see how a 4 link can control anything else. If someone else does not agree, then they know something I don't. I do not use 4 link rear end in my car, so I am unaffected.

This should be a place for sharing knowledge, not forcing people to listen

M

[Abuilder]

Hey I am not arguing and I am trying to share my knowledge. If you don't mind me asking, what is your experience with drag race 4 Link as you do say that you don't have one.

[Toyzda]

Sounds like you trying to start a pi$$ing match...

Instead of that please share with me what else a 4 link can control in suspension geometry apart from tramp, roll steer and squat. I am interested in why you keep barking at the postman.

[Abuilder]

It is you that is barking at me and trying to turn it into a pi$$ing match. All I asked is what is your experience. I have already told you mine.

If you believe that 4 Link is not that complicated then power to you.

You can make a car do a lot of marvelous things by tuning a 4 link. You can also make it do a lot of crappy things if you don't know what you are doing. It can control life in the front, lift in the rear, twist of the chassis, it can control squat in the rear, it can control squat in the front, you can control how much weight you want it to through, it can control torque steer, you can even change a drivers reaction times, you can quieten down an ill handling car, you can make a lazy car more aggressive. The list goes on. There are a good 1/2 dozen books written on the subject, I own most of them. You can even attend a week long school in the US just on tuning 4 link. There a guys who are paid mega dollars just to tune the rear setup in drag cars. There is even software written to help beginners and novices to help set up and tune their 4 link.

Would this all be in place if 4 link was really easy to set up and it did nothing else but tramp, roll steer and squat. Remember I am talking about drag racing 4 link not circuit track 4 bar.

[Corolla52]

Hi Abuilder

You say

"It’s done wrong and that is all there is to it. The bracket is fitted to the wrong side of the diff end of story."


Now I am very new to circuit racing and the Sports Sedan I have
has a 4 Link set up.
I am trying to learn about it [as well as alot of other things on the car].
What difference does it make to the position the bracket on the diff?

This is all new to me as I am coming form 15 years with Speedway.

Stefan

[Abuilder]

If you look at his pictures, it is a drag race setup and you wouldn't use it on a circuit car. The bracket has been fitted to the rear of the diff instead of the front. If you look at my pictures the bracket is on the font, the holes have to be in line vertically with the centre of the diff housing or just forward of it. The whole lot has to do with the leverage and the rotation around the centre of the axles. If you look closer at the other guys pictures his front brackets are actually upside down as well. Your front holes are cut on an ark so that you do not have any trouble adjusting it. Because his brackets are upside down his ark runs the wrong way so this will cause problems with adjustment. Also when you put the front brackets in there are a lot of calculations you have to do to make sure that the bottom holes are in the right spot. It all has to do with instant centres. It even comes down to the length of the bars can make a huge difference. It all comes down to the leverage and by putting the brackets in wrong it mucks it all up.

This is a very quick explanation. I hope it makes some sense to you.

[Toyzda]

It is you that is barking at me and trying to turn it into a pi$$ing match. All I asked is what is your experience. I have already told you mine.

If you believe that 4 Link is not that complicated then power to you.

You can make a car do a lot of marvelous things by tuning a 4 link. You can also make it do a lot of crappy things if you don't know what you are doing. It can control life in the front, lift in the rear, twist of the chassis, it can control squat in the rear, it can control squat in the front, you can control how much weight you want it to through, it can control torque steer, you can even change a drivers reaction times, you can quieten down an ill handling car, you can make a lazy car more aggressive. The list goes on. There are a good 1/2 dozen books written on the subject, I own most of them. You can even attend a week long school in the US just on tuning 4 link. There a guys who are paid mega dollars just to tune the rear setup in drag cars. There is even software written to help beginners and novices to help set up and tune their 4 link.

Would this all be in place if 4 link was really easy to set up and it did nothing else but tramp, roll steer and squat. Remember I am talking about drag racing 4 link not circuit track 4 bar.

We are obviously missing each others point. You, i believe are talking about tuning a 4 link. I am talking about its function in relation to the geometric affect on the axle.

Everything you mention above is tuning related, which is very complicated and hard to master for every type of suspension setup. I agree 100%.

However as far as geomtry goes, I believe i am correct. All the tuning you have mentioned can be altered by adjusting roll steer (to combat the effects of engine torque at launch and the transfer of load from the rear wheels back to the engine through the chassis) and squat (front end in relation to rear without changing spring/damper rates).


So, i assume we are both right.