|
|
Post by thedubdude on Feb 4, 2022 17:07:15 GMT -6
Good afternoon everyone. Let me start off by saying I am building a 1977ish Nova (X Body) for my local half mile. Despite me growing up at the track, It is my first real racecar and need all the advice I can soak up. The class is Factory Stock (think Hobby stock) and is an entry level class.
The track (the PAS in SoCal) is a half mile oval. The corners have a decent banking and usually stays fairly tacky throughout the night. Rarely ever gets dry-slick or excessively muddy. The main usually kicks up quarter sized chunks that's close to soft modeling clay.
The car is a 1975-79 Nova and it has not been driven yet. Only has idled for cam break in and setting timing. Rules state no racing or adjustable shocks (KYB Gas-A-Just's are on the car now and legal), 235/70r15 DOT passenger tire and NO STAGGER. Spacers are ok. Wheels are 15x7 w/ a 3in backspace. Lowering springs are ok but no lowering blocks or adjustable shackles. Car should be "stock for make model and year" per the rules. Car currently has multi leaf rears, and 12in front coils. Spring rates are LR:225, RR:200, LF:800, RF:900 (no idea how this handles yet but I would prefer a balanced set up. Idk how far off base these rates are. Tire PSI is a blank slate also (we can run 1 beadlock on the RR.
I've dug through a lot of posts here and have a decent understanding of suspension geometry. The problem is that most people here are running metric cars so I know a lot of this can vary. Can anyone here shed some light on how I should have the car set up with regards to tire PSI, wheel spacers, spring rates, and camber. Any insight is GREATLY appreciated. Lmk if there are other details that is needed too. Thanks!
|
|
one8
Fourth Place
Posts: 52
|
Post by one8 on Mar 4, 2022 13:05:44 GMT -6
I would say your setup is pretty close. X cars and mid 70s A bodies don't need as much front spring as metrics. But it's hard to know without the weight percentages. I assume you can't run spring sliders on the rear either. Bilstein and Afco make excellent stock mount non-rebuildable shocks that most sanctioning bodies don't consider "racing" shocks. That'll help dial in the setup as well. Can you run ballast?
|
|
|
|
Post by thedubdude on Mar 14, 2022 15:19:57 GMT -6
I would say your setup is pretty close. X cars and mid 70s A bodies don't need as much front spring as metrics. But it's hard to know without the weight percentages. I assume you can't run spring sliders on the rear either. Bilstein and Afco make excellent stock mount non-rebuildable shocks that most sanctioning bodies don't consider "racing" shocks. That'll help dial in the setup as well. Can you run ballast? Thank you for the response. Its good to hear I'm in the ballpark. I don't believe I can use sliders and I still need to scale the car sadly. I also have 1000lbs and 1100lbs springs I can play with. Would that be too stiff for a leaf car? These are all the rules elaborate on.... "All parts must remain stock. b. No reinforcing of any parts of the suspension. c. No weightjackers. d. The word stock means stock! No racing parts. After Market non adjustable springs allowed. No spring buckets. No lowering blocks. e. Any stock OE replacement shocks with a value of $90 max per shock." |
|
one8
Fourth Place
Posts: 52
|
Post by one8 on Mar 21, 2022 11:42:34 GMT -6
If PAS is tacky and doesn't go dry slick, you may want to at least bring a #1000 spring for the RF. If you are tight in I would put a stiffer spring in. But only make small changes and 1 at a time. Try to keep the front spring split to #100 max. If it feels loose off I would lower the rear rates by #25. The Bilstein shocks are around $90 and they have a good selection to help you tune. But remember they list rebound first. Opposite of other shock companies. I would start with these tire pressures and adjust from here.
LF 24, RF 30, LR 26 and RR 28.
|
|
one8
Fourth Place
Posts: 52
|
Post by one8 on Mar 21, 2022 11:48:27 GMT -6
Fix a tight in condition first. If you find you are tight in/loose off usually fixing the tight in will mostly fix the loose off. I can let you know what I run for shocks if you want. But again, I'm in a #3300 110" wheel base 75 Malibu on a 1/4 mile banked track. Also running 10" wide asphalt pull offs.
|
|
|
|
Post by thedubdude on Mar 21, 2022 15:20:15 GMT -6
If PAS is tacky and doesn't go dry slick, you may want to at least bring a #1000 spring for the RF. If you are tight in I would put a stiffer spring in. But only make small changes and 1 at a time. Try to keep the front spring split to #100 max. If it feels loose off I would lower the rear rates by #25. The Bilstein shocks are around $90 and they have a good selection to help you tune. But remember they list rebound first. Opposite of other shock companies. I would start with these tire pressures and adjust from here. LF 24, RF 30, LR 26 and RR 28. So I had the first race on Saturday night and the car felt pretty decent. Not excessively loose or tight for the main and it liked the upper line. Maybe it was slightly tight mid-corner and a little loose off, but nothing too crazy. Corner entry felt pretty balanced. The track stayed pretty tacky and I ran a 900lb LF and an 1100lb RF spring (mostly because I don't have a 1000lb spring) with the following tire PSI: LF 20, RF 23, LR 18, RR 20 thanks to some of the Super Stock OG's that I pitted next too. Unfortunately the track frowns upon bilsteins and considers them a "race shock" even with them being "over the counter" 🙄. I may drop the RF spring to 1k lbs sometime soon, but im happy with how it handled for it being my first time out. Started 8th in the main and finished a nose behind 4th. Thanks again for the insight! |
|
one8
Fourth Place
Posts: 52
|
Post by one8 on Mar 22, 2022 15:03:07 GMT -6
Make some white marks from the tread down the side wall of the right side tires. This will tell you if you're rolling the tire over and need more air pressure. If you have spare front shocks for the car compair the compression on all of them and put the easiest to compress on the right front. I can't remember if you said you can run spacers. If so try a 1/2" spacer on the RR. If you get a #1000 front spring try it in the LF first. Again, only try 1 change at a time. I'm glad she ran good for you.
|
|
|
|
Post by thedubdude on Mar 26, 2022 18:26:52 GMT -6
Yeah im going to mark the tires to watch the psi. Spacers are fine too so I'll probably see how that works eventually.
|
|
