Ok, I reread this like 10x before I made any sense of it (AB, somehow your typos were in just the right pattern that I couldn’t make any sense of what you wrote till I was in just the right mood, not sure what that means but it did throw me for a loop). and I’ve come to the conclusion that I had a much better handle on this and what I thought you guys were going to say before I asked, nutshell:
Awesomebill: airbags are dangerous and aftermarket bars are a waste of time, run stock or stiffer front and rear bars (I have 36mm hollow front and 24mm solid rear on it now, stiffer then I actually like on it now)
BillyShope: there is never a reason to run a front swaybar on the street (it’s not that heavy, the hollow one is 13lbs with hardware) and only said that the adjustable rear bar is superior IF it appreciably increases rear roll stiffness (not sure what else it would do)
Ed-vancedEngines: Don’t worry about all this just get an aftermarket TA…
Huh… OK, none of this really agrees with each other or with the stuff that you guys have written in the previous suspension threads, which I find somewhat confusing. I could have sworn one of you (I was pretty sure that it was AB…) wrote something along the lines earlier that the only great way to prevent twisting issues coming off the line is to have as little roll stiffness in the front and as much as possible in the back so the front has as little effect on this as possible to prevent from upsetting the back once the front comes up. Instinctively, after having tried both with a front sway bar and without when the car was running slower (11’s @120), I found that disconnecting my front bar did nothing for my 60’ times, it really doesn’t seem to do anything for the launch but allow the front driver’s side to lift more aggressively.
Ed-vancedEngines wrote:You mentioned you have a FireBird. Is it a 3rd or 4th generation car?
Big difference in the factory setup and rear to front weight distribution on both of these.
I actually have 3rd and 4th gens that see the track, but the car in question is a 3rd gen (87) formula.
You mentioned that you have the sliding link torque arm. If it is factory, ditch it. t is designed to flex and to twist. Also the transmission mouted torque arms are good for tearing loose the transmission mount.
There are many aftermarket torque arms on the market and most are similar in the way they perform but are different in appearance. You do not want a direct bolt on factory replacement with same dimensions as is made by many suppliers.
Not a problem… the car is using a 4L80e for a transmission which is way too big and in the wrong place to use a factory style mount. I’ve been debating if I’m going to make the new mount hang off the back of the tranny crossembmber (with some extra floor pan bracing, don’t like how most of the aftermarket stuff cantelevers stuff off the back of the stock points on the 3rd gen designs, I've seen the spohn stuff tear 3 or 4 front subframe rails now) or if I’m going to add some sort of crossmember (prefer not to for clearance issues).
Wolfe Racecraft makes a good one but it is almost identical to the one made by Steve Spohn at a much higher cost.
Steve Spohn makes the best torque arm and suspension parts for the F body 3rd and 4th generation cars that I have seen or used.
Honestly, I see an artistry in Wolfe’s designs… Spohn, well his stuff rubs me the wrong way, I have a bunch of it that I took off one of the cars and have hanging on the wall in the garage. In general the spohn stuff appears to be under engineered and overbuilt. Usually it doesn’t break but is often many times heavier then it needs to be (his adjustable control arms are a little over 2x the weight of a set of stockers boxed with 1/8” plate and either will work in a 9 second car)
I like to use his 4th generation bar in the 3rd generation car. It is shorter, and to make the front mount to be more adjustable as well as making the front supporting crossmember to also be with an up and down mounting position adjustment. That way I can easily change the point of Instant Center to higher or lower as needed. He makes his bars with many different capabilites too. I like to get them custom made to my specs and use them a little different though.
Can you give details/pictures? Which style bar are you starting with. I know a number of people that have had issues with his sliding link design and in general like BMR and wolf’s (as well as GW but they are in a different category) designs better, although I haven’t sufficiently satisfied myself that a pivoting front link works the same as a sliding front link. How are you mounting the 4th gen assembly in a 3rd gen (most of the 4th gen assemblies tie into the g-load brace area of the 4th gens where the 3rd gens have nothing there but sheetmetal, I know that the jegster TA has a large, ~1/8” thick contoured plate that bolts into that area and they bolt their front pivot to that)
This torque arm is exerting the lifting force near the center of left to right balance of the car with driver inside so it does work pretty good. He and others also do offer a rear bracket for the lower rear suspension control arms that will lower the rear of the control arm bars to also cause a change in the combined torque arm-rear control arm bar connection of an instant center.
I have a set of his relocation brackets on my 4th gen WS6 (6 speed car) and have found that the suspension hits the tires too hard with them, it will hook hard off the line then a few feet out the back tires literally hit the ground so hard that they bounce and you loose traction (somewhere I have video of this), so I have them mounted back in the stock pivots. On the 1-2 shift there isn’t as much torque available and they actually do help there, but I’ve found that overall on that car I lost more a few feet off the line then I gained by totally eliminating any chirp/spin on the 1-2 shift.
In some ways that car's rear suspension is different from what we think of in rear suspension adjustment and placement of the mounting of components but in actuality it is still using the same laws of physics to direct the torque force to the rear tires. It is just done differently.
I also do suggest on that particualr car to be used in both drag racing and for street to keep the front sway bar but I suggest to use a spacer between the mounts and the frame to allow it more front rise.
That makes sense (I’ve been meaning to do it but never actually got around to trying it) and easy enough to do since I’ve been reproducing TTA front sway bar mounts since they’re not made by GM anymore an I seem to know way too many TTA owners, they spaced the sway bar down roughly an 1” to clear the intercooler on that car.
I have been guilty of using air bags in right rear but do not suggest it for most cars. I hate air shocks in any drag car. I do like to pre-load the right rear and the left front spring some. I guess I am still stuck in old school about that.
I’m with you there… air shocks are a disaster in a performance application. OTOH, I’ve run air bags on my WS6 with good luck, but part of it is that I like stiffer rear spring rates at the dragstrip then I like in a handling situation so I end up running 5-8lbs in the driver’s side (which makes a suprising difference) and usually >20lbs in the passenger side.
That car with the right bolt on suspension parts is a wonderful car to race in factory suspension classes.
I agree and the fact is that you can get good straight line and handling out of it with very minor changes, I’m just trying to figure out how to tweak the straight line as much as possible now since the new engine combo will test that very hard.
Also steve makes an adjustable replacement coil over style front shock for it.
There’s a few designs out there for 3rd gens, none of which I would run, they all have insufficient top mounts which eventually mess up the tops of the strut towers. The 4th gen design is different in that way, the front suspension is basically a coil over from the factory.