Thanks for the measurements Gary. By my calculations your springs would put my car at: 1. With my tires (25.4"F and 27.5"R) 0.4" lower in front and 1.35" lower in rear 2. With your tires (26.0"F and 28"R) 0.1" lower in front and 1.10" lower in rear By lowering the rear my LCA will be closer to level. Mark, does this book talk about a starting point for IC and anti-squat for various power levels? I'm thinking a good starting point would be IC ~42" and AS of ~140% for a 3.42 gear 530/550 (435/435 at the tires) combo.
Instant Center: Check this out. Sluggers' mid 11's car went from 1.65-1.75 60ft to an incredable 1.47-1.55 with this set-up.... He said: "The rearend was installed with adapter brackets I designed, jigged and welded on the lincoln Versailles housing."(I think Slugger raised the upper arm brackets about 1.5" like Moser does.) "The lowers arms are factory, boxed with 1/8" flat stock with poly bushings. I built the Upper adjustibles arms last year after I calculated the Instant Center and Anti-squat and determined that I needed to make adjustments to the Instant Center of the car to a vertical line just forward of the center of the doors and on a 14" above ground level on the horizontal line. This location gave me Anti-squat of about 106% which is as close as I could get it when I ran out of adjustment on the upper brackts." "Thats when the front tires came off the ground!! I built the Anti_sway bar to level the launch a bit and eliminate the airbag and went to the stock springs." "Some one else thought the 60 ft times should be in the 10:80 et area which I feel is a real compliment because my ET's are almost exactly 10:00 sec more than my 60ft times on each pass and that is 11:50s @ 115.85MPH." "Now if I can just find the HP to get in the 10's." Slugger
Thanks Gary, sounds like a good setup. Well... I got the uppers installed, replacing the previously "clearanced" one in the process. I set the pinion angle at -3 deg., set preload on passenger side one turn shorter (six flats), adjusted headers up .4" and lowerd the rear of the car about 1" (reduced air in shocks). The lowering actually put my IC in front of the car, be it way out there. Next weekend, after I replace the bronze distributor gear, I'll take it out and see how it does. More to do but end of step one...
from your report the back of the car is like a rock, no give. when your at the track go around and feel the rears of a few cars like yours that hook. (whats the condition of the track/ other cars hook?) for a no dollar test, let the air shocks empty and 5-15 lbs in the right rear bag, left side empty and no hops. i've seen this work for a few skylarks. i'm not saying to run it like this for ever! put a set of cylinder heads (as far back as you can get em) in the trunk (120lbs), just to see what happens with your car. keep working on it you'll get it, it will come around. Good Luck
I do not have no-hop or lower lift bars at this time. I may try lower lift bars at 2"drop in the future after some testing with new Del-a-lum bushings in the front a-arms (These bushings have almost no friction, yet are rock solid as far as lateral stability and holding alignment dead on). You need the front to rise fast for either type of bars to work, or they will lift the rear/load the tires, then unload/spin. * TA no-hops are shorter than Edelbrock and much shorter than cheap brands. * Lift bars can be simple as UMI drop brackets. No need to buy the actual bars. Never use both together; just one type.
interesting, so there are 3 different size No-Hop bars? anyone know the dimensions.. what are lower lift bars? * Lift bars can be simple as UMI drop brackets. what are UMI brackets? i'm running QA1's ft/rear. Moroso drag springs fr/rear Hotchkis upper/lower rear arms Hotchkis sway-bar Edelbrock No-hop bars. stock ft sway bar and A arms 1.80-60's dead hooks on any decent track
Are your QA-1 shocks single or double adjustable ? I have the cheap 3 way shocks set on 90/10 seems like it lifts in the rear before the front lifts & (if the front does come up first ) it will hook but front comes back down very fast & I loose traction ... not enough compression on front shocks ? . I have cheap KYB G2 gas shocks in back ... maybe to stiff on compression to allow the front to transfer weight( pitch rotation ) ? I am going to loosen my hardware at the bushings & see what happens before buying shocks. I guess I could just go back to my baseline set up with stock lowers & UMI adj uppers ...it hooked better than this set up , but I hate to give up because I won't learn anything doing that & for me it is about the learning process ,seems like now days too many just throw money at it until they get results .... I Gary's case he seems to be doing more with less ,my hats off to him ! Have a great labor day everyone ... mine will be laboring on my Skylark ick
No-hop bars raise the rear of the upper arms control arms. Old style Lakewood & J.C. Whitney 4" with all metal upper mount hole (for bolt, not heim joint) http://www.speedwaymotors.com/Garage-Sale-Lakewood-GM-A-Body-No-Hop-Traction-Bars,18980.html ....JUNK! Edelbrock/QA1 no-hops are 3 3/4" with upper poly bushing LOOK.. http://www.youtube.com/watch?v=g6WtfPG2WHM TA no-hops are 2 7/8" with upper poly bushing (shorter is better for 500+ torque) More expensive no-hops have 2 or 3 heim joint holes for raising the upper arms, starting at about 1.5" or so. Not cheap. Search Dick Miller and other brands. http://store.dickmillerracing.com/suspensionaddustableuppercontrolarmswithno-hopbars.aspx Lower "lift bars" are brackets that relocate the rear of the lower control arms to hang 2" or more lower than the stock location. Page down for pictures of installation. http://umiperformance.com/catalog/index.php?main_page=product_info&cPath=1_18_22&products_id=30 Both, lift bars and no-hop bars, are designed to change the instant center to a position that improves traction.
Well I have been working on the set up for my Skylark ... this is what I have come up with . Up front are 260 rate springs & 90/10 shocks ,ft. bump stops trimmed 1/2" sway bar removed. Rear T/A no hop bars adj control arms, 121 rate springs -1.8 pinion set trans vrs. diff. M/T 275 60 15 28''dia. When launching the car hooks a bit & them unloads ... if I let out & hammer it again it hooks 100% . If I drive the car off the line with a progressive throttle I can hook it up ,but if I throttle to W.O.T. it spins hard & the front does not lift. When it does hook up you can feel the car lift up both front & rear & shoot out of the hole. I tried a slow rate lift & it got worse (70/30) so I feel that it is not lifting at a fast enough rate ,I have loosened all the retainer bolts on the suspension & am going to try it . On my lift it seems to drop the a arms at a good rate but that's not under power . Is it possible I may need less compression Or more rebound @ the rear shocks so the front can have more time to transfer before the rear lifts ? One thing for sure the timing of the hit is very important vrs. the rate of front lift. With stock rear control arm location & w/o no hop bars & the front with the short 454 rate springs & 90/10 the car hooked just as well as it does now unless I get it to lift fast then there is a big difference with the no hops & with a slight roll it hooks very hard & I can feel the pass rear tire pounding a little with just a slight hop .
Definately set your rear shocks to resist the lift of the no-hops and allow the front some time to lift.
I'm not saying it's your case but the track can be a big factor. Are other cars similar to your dead hooking? my car spins .03 at my crummy local track but at Pomona and Bakersfield it hooks every pass. Just wondering what kind of power is it making, whats it run? Cheers!
