I am by no means a suspension guru, but always trying to learn. A post in the SPL prototype thread (listed below) got me thinking.

https://my350z.com/forum/brakes-and-suspension/230829-some-new-spl-stuff-sneak-peak.html

How many different types of devices/upgrades are there for the Z? I'm not talking about brands or models, just genericly speaking. Maybe this is something we can add to the ever-growing FAQ, along with the function of each. Yes, I have read the FAQ stickies and didn't see these mentioned. Anyway, here's a go at a simple list. Anyone who wants explanations... we'll get to that next.

Up front!
- Strut tower bar
- Sway bar
- Springs
- Shocks
- Coilovers
- Control Arms
- Camber Plates
- Toe Arms?
- Connecting Rods?
- End Links?

In the rear!
- Lower strut bar (by spare tire)?
- sway bar
- springs
- shocks
- coilovers
- camber plates
- control arms
- toe arms
- connecting rods
- end links

Let me know what I missed!

 

What you missed are all the rubber bushings [inside suspension arms] and spring seats.

Important to remember that suspension is just what it says "to suspend the body and really nothing more".

90% of the performance comes from tires and the other 10% from the suspension. Really difficult to change even 3% of the performance by modifying suspension.

 

I beg to differ. Suspension makes HUGE difference in performance. It is the most important upgrade of any production-based race car.

We build and race T1, AutoX, and World Challenge Vipers for the most part at Naykid Racing.

We also have a 1987 BMW 325i. It probably makes about 200hp at the flywheel off the 2.5l straight six. Its only 4 seconds off the 500hp Moton equipped T1 Vipers here at PIR. Its faster than anything in T2 (350z, STi, Evo). The BMW is a suspension monster. It turns faster, its more predictable, and our drivers have more fun in it than the Vipers. How? Light weight, rigid chassis, and most importantly, suspension tuning.

Drive a stock Z and a Z with a quality aftermarket suspension tune. The difference is night and day.

-Also- In the front & rear, you can buy aftermarket adjustable A-arms from Cusco or JIC. Tanabe or GT Spec sub frame braces are also available.

 

Wow! 3% huh... I think it's quite a bit more than that! Suspension changes the whole dynamics of the cars drivability on the street, drag strip, autocross, hp racing, many try to combine street and ___. I know with autocross and hp racing a lower stance and eliminating roll/sway enables better cornering while accelerating and braking.

I had a 2k Celica I wanted to setup for autocross that I bought a few new suspension parts but got the coilovers 2nd hand under the impression they were setup for my purpose, wrong! I think they were setup for a drag strip because the spring rates were F'ed for corners; teh azz end seem to always kick out, but digs/straight lines it hooked up well.

Made the cars performance more like 50% worse! I replaced them with springs I ordered new and got the results I expected, digs were not as hooked up but corners were much safer as well as it didn't jar you on long trips.

 

Okay so to add to the list we have...

Up front!
- Strut tower bar
- Sway bar (aka Anti-roll bar)
- Springs
- Shocks
- Coilovers
- Control Arms
- Camber Plates
- Toe Arms
- Connecting Rods
- End Links
- Bushings
- Spring Seats
- A Arms
- Sub-frame Brace (similar to sway bar with more connecting points)


In the rear!
- Lower strut bar (by spare tire)?
- sway bar
- springs
- shocks
- coilovers
- camber plates
- control arms
- toe arms
- connecting rods
- end links
- Bushings
- Spring Seats
- A Arms
- Sub-frame Brace (similar to sway bar with more connecting points)


That about cover it?

 

I am speaking of MEASURED performance on a skid pad or lap time.
The Tirerack has a few MEASURED tests from adding bigger sway bars and or various lowering stifer springs on BMW............they actually improved things by less than 3% but I was being generous.

You can change the steering feel and the roll coupling ratios [body roll] but these will do little to change the ability of the tires.

You can redesign a street car for a special purpose but that effects ride quality faster than the performance goes up [ratio wise].

 

although many peeps have replied, i will too, adding to my low number of posts. i think suspension is very important. i put (coilovers, front and rear strut bars, front and rear sway bars, rear lower tie bar, and JIC endlinks) on my 98 civic coupe, and it handled great.

handling and cornering are two very different things. i could swerve from side to side violently in that car going 60mph and never hear a peep from the tires. i flew off a 10 foot cliff going 55mph going up a mountain road and the car landed flat and no damage except for a radiator mount.

when i got the Z after that car... i didnt feel as stable. i can loose the rear end going 15mph in 2nd gear with like less than 50% throttle input. but the Z is rear drive and the civic not.

the most important things are CORRECT ride height, ive heard the Z does very well with a 1" drop. if you add some sway bars, it should feel like riding on rails.

also weight is big. if i could have my civic back, but somehow with RWD, i would keep that car forever.

 

rough image...

 

I'm very curious as to what Q45 is saying. Are you claiming that on a skidpad, stock suspension vs full aftermarket parts and tuning will yield less than 3% difference in G's?

I would think there is a significant difference aided by suspension. Although it's true it can't do much to improve traction with the tyres because that's determined mainly by it's manufacturers, but because it affects the way drivers interact with the car, it is worth significantly more than the 3% difference you stated. I would think it makes a huge change in laptimes because the way the suspension responds allows the driver to keep the tyres at their maximum traction for longer. Skidpad ratings won't be too different though I agree.

Sorry for my long ramble guys, would just like to have a few things cleared up

ChiShi

 

Tirerack tests show the lap time changes...........calculate the percentages, yourself.

They are trying to sell these aftermarket parts [to you] so they try to portray them in the best light.

Most people don't even realize that a stiffer sway bar on one end actually reduces the traction on those tires compared to a weaker bar.
Excess [greater than negative 0.75] camber increases braking distances.

I agree that some mods improve the driver feel so they can drive nearer the edge, however a professional race car driver can usually outdrive any typical street racer in a stock version assumming identical tires. A professional might beat them with oem tires vs their $4,000 worth of mods and tires.

I am not against mods per se*, just that modders need to undertand the physics involved so they do cost effective things [proper sway bars and adjustable shocks].............the softest fastest wearing lightest tires money can buy on the smallest wheels that will fit the brakes, etc.

Nascar still used 15" tires.........sure they are very special but still 15".

Manufacturers go to all the trouble to redesign a suspension to save 2 pounds and people frustrate the process with heavy wheels and tires.

* My car is slightly lowered, has shock tower strut bar, and different sway bars, different shocks, and camber adjusts to return to oem numbers.

Tires are always the weakest link.