edub

Maybe we have a different definition of tinkering, regardless, I would rather learn how to do something and understand how it works myself, hence the post.

Do you turn your car over to a shop and just let them do what they do?

edub

http://forums.pelicanparts.com/porsc...ing-rates.html

That thread took an eerily similar direction as this one is. The desire to understand the quantitative change a swaybar makes is a good question in my opinion - I would want to know the effective rate as well.

winders

Feel free to reinvent the wheel if you want.....these cars are not new and plenty of people already have experience setting them up to be more track oriented. You could get a great starting point and tinker from there or you can try and figure everything out yourself and take a lot longer to get the right place.

You don't need motion ratios and frequency numbers to tinker with the car. In fact, I would argue you probably don't have the tools to properly use that information to setup the car. Hell, I bet only the Factory has the information and tools needed to properly model the 718 GT4 street car. You don't need that information to tune the car anyway. If you know what the car is telling you as a driver, you can make the changes necessary to make the car better. Do you have enough experience to driving to know what the car is telling you? If you don't, having the motion ratios and frequency numbers are not going to be of much use anyway.

My car? The person that built it 12 years ago gave me a car with a known "good" setup. I drove it for 3 or 4 years changing nothing but tire pressures and sway bar settings. Once I learned how to drive, I started changing the car. In the last 8 years the car has been massively changed and I have done all of the development work on the chassis.That would include tires, tire pressures, alignment, dampers, springs, sway bars, ride height, rake, etc. All on my own.....I did outsource welding, engine, and gearbox work because I am smart enough to know that professionals are a lot better than I ever could be.

edub

That's literally why I'm asking these questions, so I can learn to do dev work on my own. In the meantime I can drive the car while collecting data on how it's setup so that when I'm ready, I can make changes and test my theories.

No one said I'm going to reinvent a wheel, or setup a car better than the factory. Those are not my goals or presumptions.

Cory M

The disconnect here is that racers are trying to provide practical information that can be implemented in the short term. The OP is interested in science project primarily for learning and eventually long-term improvement.

I don't think you're going to find all of the information you're after posted on the internet. Most enthusiasts aren't digging that deep and wouldn't know what to do with the numbers if they had them. It's not the kind of stuff an OEM or shop is going to share freely. You're likely going to have to take some measurements, make some calculations, and some assumptions, to get what you're after. Some things, like CG, aren't too hard to measure.

flatsics

https://rennlist.com/forums/gt4-spyd...ing-rates.html

https://tarett.com/products/gt4-spri...ade-kit-gt4suk

stownsen914

OP - if you are interested in digging into data and doing some modeling, you can try a suspension modeling program like susprog. I used it years ago to do some suspension redesign. I'm sure there are other programs now to choose from. Susprog is targeted at designing and fabricating suspension, but it can be fun to model an existing suspension setup to see what it's doing. You'll probably have to do some legwork getting the measurements to plug in. For those more interested in the end result (a good handling track car), you might be just as well off choosing components based on recommendations as I'd guess for a platform like yours that information shouldn't be hard to come by, but data may help influence decision making. Enjoy the journey if you wind up pursuing it!

edub

Yes I am interested. There are quite a few suspension model programs out there, and even better there are simulators I can run against my own data using different models. I've been spending a bit of time figuring out what sorts of data is present in the car (my post on EXLAP for example), I'm not as optimistic now, but am hopeful to utilize the built in suspension potentiometers to measure chassis roll and strut velocity. EXLAP seems limited to 10Hz which isn't good, but the potentiometers I can measure manually at a high rate. I just suspect their operating range won't give me enough resolution to really determine what the suspension is doing but it's still early days...(thread).

Ubermensch

edub, I went down a similar path and enjoyed reading and learning from this classic:
The theory, math, and practical examples are well connected, and you can easily take the measurements you need to build your own simple models and tinker with the concepts. If you're just doing this to learn and to explore then I wouldn't get too wrapped up in the accuracy and precision of your measurements. Get them in the right ballpark and move on so you can focus on what you're trying to learn.

NaroEscape

My suggestion also is post this question in the Data Acquisition …. Sub forum. All the data guys hang out there and are not (usually) so judgmental as they are here.

edub

https://rennlist.com/forums/718-gts-...ion-ratio.html

TLDR

Method 1 - measuring suspension pickup points - Rear Motion Ratio was 0.78

Method 2 - measuring damper movement - Rear Motion Ratio was 0.75

Didn't measure the front yet

Montaver

You could talk to someone like Dundon who developed a kit, or a good race shop that installs a lot of this stuff to get a baseline before you buy hardware. My shop built me an MCS 2WR kit with proven rates for a ride frequency that is still street able, with corner balance, ride height, rake etc already dialed in. I can then have fun fine tuning it at the track knowing a lot of the variables are already in a good place. Sounds like you want to go further down the rabbit hole than that though, so curious to hear how you get on!