Like I said only one person has listened to me and he is a lot faster now. Y'all can choose what you want.
Like I said only one person has listened to me and he is a lot faster now. Y'all can choose what you want.
Aaron don't forget 950 is noticeably soft compared to what I had. I went from a 1200 down to a 950, a 250# drop is significant. I don't think it's the end all, IMO I need to go too soft before finding what I really like. I think the biggest shocker is that it doesn't oversteer like crazy with 325 out back.
Remember where I said above that the 4th gens like a 3 to 3.5:1 front/rear spring ratio? Well w/ the 950/325's you are at a 2.9:1 ratio. Right on track. Combined w/ soft bars, you may be close. I ran 850's and 275 for a year or so. Car was OK, but not consistent from track to track. Biggest issue was standing starts. I would just get killed due to rear tire spin. No weight transfer. Softer springs allow the weight to shift. You need this to happen.Originally Posted by Supercharged111
The F/R rate ratio is a guide as some guys like a lose car and some can't drive one that way. Lose is fast, but is hell on rear tires. makes the front work very well though as they can do more stopping and less of the turning. Remember, brakes and throttle are for turning too.
I agree w/ Aaron to a point. You can go too soft. Since roll rate stiffness is limited by the sway bars, you must add some spring rate to compensate for that. If softer was better no matter what, we all would be running OEM spring rates. Trust me, I've run 5 years on a 550/175 rate set-up w/ 315's on all 4 corners w/ a previous 4th gen. My CMC car is way faster w/ 200 less HP.
Set-up is a puzzle. The pieces of the puzzle are springs, sway bars, camber, caster. Mess w/ one and all need adjusting.
One way to tell is all the puzzle pieces are fitting well is to look at tire temps across the face as well as air pressures of the tires front to rear. If your F/R pressures are different by more than 5lbs, you need a set-up change. If your tire temps across the face of the tire are off by more and 10 degree steps (ex: outside220, middle205, inside220 = too low air pressure) you need a set-up change.
You should be using the tires equally across the face. This gives you even tire temps (10 degree total spread should be the goal). My tire pressures are normally 2 or so different at most from front to rear. I may even have a difference of 1 or 2 from left to right.
#1 -Know why your making a change, #2 - predict what that change will give you. #3- If you get something different, question #1. #4 - If you get what you expected, was it more or less than what you need. #5 - Go back to #1.
So you have the rate ratio range (3 to 3.5:1) as a guide. Are you in that zone?
How are your tire temps across the face?
How are your air pressures from tire to tire?
Is the car faster now than before?
Also, never use tire wear as a guide to set-up. I need to flip my tire between each event to get full life out of them.
After I sell my CMC car this yr I'll reveal some numbers on my car but until then I have to remain quiet haha.
Tire temps continue to haunt me. I even read an article recently that said what you said, it's great feedback that tells you exactly what's going on. I couldn't tell you my tire temps, I don't yet have a probe.
Is the car faster? Hard to say. With the illegal spacers, yes, but when I max out track width legally it may get pushy again. I got my ass handed to me at HPR, so relative to the field no I wasn't faster than before but there were a lot of variables. On my most recent track day, I ran as fast in 95 degree heat as I did in May when it was 75, but the track wasn't being heated by cars last weekend (about 8 turned out total) so how hot was the track really? I had plenty of open laps in May once the field spread out too. I know the car makes less juice in the heat, but on my last run I was able to hit the rev limit every single lap between T3 and T4. I've never done that before, ever. I was also able to hit the limiter in 4th just before the brake marker every single time and I couldn't do that before either. The car gives indications that it's faster, but it isn't putting up the lap times and I was driving the wheels off of it compared to May. I was more consistent and picked up a lot of speed in parts of the track I felt I was lacking in back in May.
#4: I got what I wanted on that spacer change, but it makes me wonder if there isn't more to be had?
On another note, I think I may have artificially stiffened the front when I raised it and the roll center.
Is the car inconsistent or is the driver? Track surface could have been different too?
I also think you are overthinking all of this. Set the rates to something you like. Then buy the right shocks that can help you make finite adjustments at the track to change the setup to the conditions. Beyond that. Get tons of seat time. With that seat time, you will get a better feel for the car and can make small changes as YOU get faster.
Good luck!
Ah, fugg it.
Yah you have to get a lot of practice in to understand what you feel under the car. No point in changing a bunch of stuff until you know what you are changing.
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