Quote:
Originally Posted by bNks334
Definitely disappointed in the RS3's.
A 6k/16k setup is actually not over-steer biased at all. It is actually slightly under-steer biased, but is fairly neutral and it drives that way. Effective wheel rates are close to 309/285 (1.99/1.95hz) which is why I also deleted the front sway altogether.
Putting power down hasn't seemed to be effected that much at all. I feel like the car handles much better now that I am no longer dragging around the rear suspension. With 6k/12k and a big front bar I felt like the car plowed like crazy on turn in. The suspension was still rolling even after the front tires had turned in and taken set. The stiff front and soft rear setup just wasn't working for me. I felt like I had to drift the car around the course to get it to turn (slow in fast out).
The extra weight on the outside front tire (less squat with the stiffer rear springs) seems to allow me to drive the car around corners more, albeit with a much more careful left foot on the gas peddle. The car goes where I point it. Having 500wtq makes up for needing to wait a split second longer to get back on power on exit. I appreciate being able to toss the car into corners at higher speeds though. The outside REAR wheel seems to be doing MORE for me now instead of the suspension just rolling over... basically cross weight remains neutral during roll.
I was surprised by how nimble a corvette can be on a tight autocross course. If only I could afford one for warm weather driving lol.
I don't think I'll ever de-mod my 135i just to be class competitive in autocross. My first event was a thrill, but the novelty has worn off already. Something about standing around for 6 hours to drive for 4 minutes doesn't do "it" for me. Not to mention the cost/value isn't there either. Latest even was pretty far away requiring bridge tolls, gas, and an entry fee of $90. People only got 5 runs. It's hard to even learn a course in 5 runs lol.
It's pretty awesome to see what people are doing with the 128i. Mine made 214/210 with light mods before I moved to the 135i. I might've been happy had I gotten headers and tune for 23xwhp. In a lot of ways 128i tuning knowledge exceeds what n55 tuners have experimented with.
I thought you were talking about how you plan to setup the FRS LOL That setup would actually make a lot of sense on an FRS.
For the 1-series, I needed over 2* camber to fit my 17x9 setup so I can see how that is a good reason to run more camber. The 27mm bar and 450/850 rates are where a good amount of people are at with there 1-series setups. 850 rear spring is 15k. Not far off at all from my 16k (896 lb/in). The front spring and bar is where I get lost. Your front wheel rate is going to be 153% stiffer than your rear wheel rate. The 27mm bar on top of that is going to effectively add another couple hundred lbs of spring rate. Your cross weight under load is way out...
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Since I'm finally getting around to reading this.
Even with stiff roll rates (such as those created by a 27mm front bar with a 1:1 motion ratio, and 450lb wheel rates), you still need > 3 camber to keep optimum front tire grip. 450lb seems to be about the happy place for front spring (I had tested between 400-600 in 2016). Much less spring rate and you are going to run into travel problems up front at anything resembling optimal ride heights / compromised geometry.
So, that gets around to the rear. It gains a lot more camber in bump, so that part is nice, and you don't need nearly as much static camber (2.2-2.5). However, having gone as high as 1200lb springs in the back, you run into two pretty substantial problems. 1. Ride compliance, and 2. weight transfer on throttle. If you're trying to get all of your roll rate done back there in spring, the car makes quite a bit of power for its rear grip. So it will much more easily overload the tires. I've got a clutch diff, a 20mm rear bar, and 850lb springs. The car still has excellent bump compliance, but won't run into the issue where one has to still be rather careful driving the rear of the car on power w/high lateral loads.
Having been down the road of operating on textbook theory many times myself over the years, ultimately, the clock is what matters most. I want as much compliance out of the rear of a car as I can for the car to still turn. It'll ride better on the street (and over bumps / surface irregularities on course, which exist a LOT on the east coast), and allow for much more aggressive throttle use without "digital" weight transfer. Kyle and I had talked a bunch about this early on in my development of the car originally, and I'd tried REALLY hard to go the textbook route with high rear spring rates and not much rear bar. It was a far disaster. 400/1200 might have worked from a balance perspective laterally, but it would have been HORRIFIC to drive on the street, and hard to drive aggressively.