RR guys running C5 Z06 wheels
01-23-2019, 11:04 PM
#22
Been putting more thought into this as I read your comments carefully and it's starting to sink in. While I don't have the measurements going back, prior to the rear end swap, I was running a 1.5" hubcentric adapter to get the 18x10.5 rears to clear and no spacer on the 17x9.5" fronts. I'm now running a 14mm spacer on the rear and I believe everything else in the equation remains the same. Hence, whatever my measurement was before (I presume I was wider in the rear), my current measurement on the rear is now a good 1.9" (roughly) less than what it was. I haven't tinkered with this before, however I'm guessing that would be a significant shift in the balance.
I'll measure it out to get a precise measurement, however what front vs. rear track width delta do you aim for? This discussion may be providing some very valuable insight into how I might be able to improve my cars manners on track.
I'll measure it out to get a precise measurement, however what front vs. rear track width delta do you aim for? This discussion may be providing some very valuable insight into how I might be able to improve my cars manners on track.
Last edited by Midnight02; 01-23-2019 at 11:13 PM.
01-23-2019, 11:48 PM
#23
I don't know what to chalk it up to either because the shift in wheel rate is very insignificant. My scrub up front is 1/4" max as measured years ago. It's actually negative without a spacer unless I really screwed up. Most want 1/4"-1/2" delta with 1/2" generally being more preferrable. Go too narrow and the car is good to 9/10ths then tries inexplicable to kill you. That said, we all run similar shocks and tend to have a front to rear spring ratio of 3.5-4:1. Somehow I've managed to make my car go with a 4:1 ratio and only 1/8" delta in F/R widths. By all accounts it should plow like a dumptruck, but somehow it works well. I suspect I've adjusted my driving style and setup to accomodate this, the car tolerates early throttle application very well and once you're on the throttle, the car is rotating and moving out. That said, to some extent it does require that throttle so every once in a while I'm stuck in no mans' land but I make it work.
I should caveat those deltas with the fact that they work at 260whp, 3250-3300# post race weight, and spring rates in the 700-900/2XX range on Toyo RR 275/40/17 tires.
I should caveat those deltas with the fact that they work at 260whp, 3250-3300# post race weight, and spring rates in the 700-900/2XX range on Toyo RR 275/40/17 tires.
Last edited by Supercharged111; 01-24-2019 at 12:04 AM.
03-18-2019, 01:09 PM
#24
So I finally got back out on track after the winter and took the spacers off the front so the F/R tracks were the same width and the difference felt great! The car felt flatter in the turns and was more stable especially on turn in. I realized it was taking longer to take a set where I just had to toss it and let the rear raise up and I had to grit my teeth and be ready to catch it but after the change, its just ready to roll into the turn without the drama. Thanks for the advice!
03-20-2019, 10:21 AM
#26
Haha didn't think that! I've looked over your build thread, still want to go back and read more, but I believed you know your stuff. I just didn't even know my track widths were that different until this thread started and I went out and measured, and even then didn't think it would make that much of a difference. Either way that's what I love about these discussions, always trying to learn something new.