gator's 99TA

iTrader: (2)

wouldnt some different in teh madman tq arm and the bmr crossmember with stock type tq arm be the length of the tq arm?

the short arm "lifts" farther back changing how the car hits the tires.

JL ws-6

iTrader: (50)

yes, but an instant center adjustment should fix that, wether it be lowering the connection point of the lca'a to the lowerst hole on the relocation brackets, or moving the tq arm up or down on the mount.

I'm not sold on needing a short tq arm to get a car to hook, there's plenty of cars out there with full lenth tq arms that leave hard.

kp

iTrader: (34)

If you use a fixed pivot on the front of the torque arm then moving the mounting point will change IC, just like a ladder bar or a three link, or even a four link which you are moving an imaginary intersect front mounting point. To a lesser degree with the link but it would have some effect. Problem with the fixed point is you have different arcs on the LCAs and the torque arm, if the lengths arent correct it will all be working in a bind and will tear out the front mounting point eventually. The fixed front TAs can be very effective, madman's seems to work pretty well.

A slider like the stock arm is only pushing up (or down) on the chassis, not forward so the only way to change instant center would be with a longer or shorter torque arm or LCA angle There is a little friction involved on a stock type arm but its effect on anti-squat is nil. LCA angle is king on a stock type torque arm car.

Now a link type like the BMR extreme I assume some change in instant center would occur since it travels in an arc and the arm pulling up is going to try to keep the link vertical, maybe not, but the chance of binding due to uneven arcs is gone. Seems to be effective though, the BMR extreme on my old camaro had a shitload of antisquat and would wheelstand with the LCAs near horizontal.

Here is a pic of of a TA suspension and how to get IC on a torque arm car. I used to think this was wrong but it isnt, notice the angle of the TA is not even a factor but the length of the TA and the angle of the LCA is.

Just keep an open mind and try to picure exactly what is going on when the rear end is pushing the car forward, thats what its all about..

JL ws-6

iTrader: (50)

o.k.... after looking @ the picture you posted I am understnading it a little better now. If the slider style front mount position has no regard to the instant center position, then why did BMR put som many differnt positions on the mount? If moving it has no effect because it is a sliding type mount, what is the purpose of moving the mounting point up or down, if the lower control arm angle is the only part of a slider type tq arm that will effect the instant center adjustment?

I'm trying to understand the whole thing because I'm having a serious traction issue off the transbrake, car just blows the tires off for the first 100 feet if I leave off the brake, but if I footbrake the car I've run as good as a 1.46, on goodyear drag radials of all tires. I am 100% that a m/t radial, or a 28x10S will certainly work better, but I doubt the tire is all the problem if I can get a 1.4x off the footbrake.

SScam68

iTrader: (20)

This stuff is only one portion of a bigger puzzle . Drag bar, shock setting etc also come into play.

JL ws-6

iTrader: (50)

I understand that after trying a bunch of **** and none of it doing any good to get the car to leave off the brake. It's starting to kinda **** me off because I know that if I could get it to leave off the brake rather then rolling into it fast from a 2800 rpm footbrake launch the car would go a ton faster.. but it feels like I still have the stock F1 tires on when I let go of the button, the car actually will smoke the radials again off the line it's so bad. I know I have the tire pressure about where it should be (19 to 20 psi) and I've seen cars on the same tire 60 foot off a transbrake, I'm just chasing a gremlin that I can't seem to find, and it's getting old.

SScam68

iTrader: (20)

How many things are you changing at once?

kp

iTrader: (34)

All those holes look nice I guess, plus if you have a non adjustable TA you could get your pinion angle close. if you notice the Yank crossmember doesnt have have holes, call Yank and ask them why it doesnt..

Are you using a two step with the brake? If not the car will most likely just kill the tires off the brake at WOT if its 60 footing that well off the foot brake. Thats a converter thing not a suspension issue..

JL ws-6

iTrader: (50)

I am not using a 2 step, maybe that would be enough to get it to hook I dunno.. I tried a friend of mone's slicks, tiny *** 26x8.5x15 et drags and the car ran a 1.59 off the transbrake and those tires are a couple season's old on top of it, so I think with a set of 28x10 stiff sidewall's it would certainly do better, but I still think there's something left to be gained in the suspension setup. Car's still heavy too at 3465, I am going to try stiffening the rear shocks up click per side next time I run it, maybe the fronts too but there's still some more to be found.

I was considering putting the rear lca's in the lowest hole, but I don't think the car makes enough power to lift up thw whole car that way.

Jonathan@Tick

iTrader: (5)

I find all of this very interesting. I'll be honest, I have little background when it comes to setting up a suspension concearning a ladder bar, 3 link, or madman style torque arm. I also need a little more info on IC before I can even comprehend most of this thread.

With that said, here is my suspension combo that sixtys 1.2's all day long with a best of a 1.26. This is leaving off the footbrake with a 4800 stall, and 325 50 15 MT radials @ 3350 raceweight:

Spohn chassis style torque arm (-2 degrees pinion angle), Spohn drag swaybar bolted on the car (not welded to the housing or even adjusted for that matter), Non-adjustable BMR boxed LCA with poly bushings, Spohn adjustable panhard set to stock legnth with poly bushings, QA1 gen F front shocks set to number 10 out of 12 with 12 being most firm (not the R's), 275 lb springs, BMR k-member and arms, Comp engineering rear shocks that I'm not sure even adjust LOL

Thats basically it, the car still has the factory rear springs. The LCAs are mounted in the factory position because I have no relocation brackets.

I'm not sure how I could possibly make the car work any better, with just a fine adjustment to the front shocks It will go from dragging the bumper to just getting about a foot of air. With the current combo, I guess I've only made about 40 passes maybe, and the car has never broke traction on a single one of those runs with air pressure ranging from 14 psi to 22 psi in the radials.

kp

iTrader: (34)

I pretty much have the same setup except I'm using a stock style torque arm and the car sits fairly low so I need to use LCA relocation brackets. Without them I get no anti-squat at all.

I can 60' from 1.24 to 1.26 anywhere 28 x10.5 on ET drags or and have a best of 1.280 on 275 MT DRs so there really isnt a whole much to it. Plus my car is nose heavy as hell with the blower/IC and piping all in front of the axle. Cool thing is I can do it lifting the front tires an inch or to for 20-30' and thats it, not good for the camera but a little easier to drive off the line.

My 60 foots are almost identical off the footbrake or trans brake, which is exactly what it should be if you have the right converter in the car (unless its a big turbo car of course).

tektrans

iTrader: (23)

I have a stock length TA and my control arms sit pretty much level.
JL, you're running radials? Not surprised they won't hook off the brake, I never was able to hook them myself off the brake.

JL ws-6

iTrader: (50)

radials on the car for now, but the next set of tires that go on will be a set of 28x10s et drags, put an end to that part of the mystery.

kp

iTrader: (34)

That will do it, hard to beat 10.5x28 ET drags, except in the rain

JL ws-6

iTrader: (50)

I hear ya,considering the radials will not hook for the first 100 feet off the brake LOL, and a set of 2 year olf 26x8.5 et drags gets me a 1.59, I'm suspecting that it may put the car right into the 1.3's where I think it should be. If it does the car's going 10.4 or better for sure, not too bad for a 3465 lb car with a nitrous motor and an n/a converter, running on motor. Over the winter the converter will get tightened up and the nitrous goes on, then the real potential will be seen I think.

kp

iTrader: (34)

I like the MT radials, been playing with some 325s and they work decent I guess but I always go back to the ET drags. Mostly because track prep is very hit and miss around here or no prep at all at times and radials dont seem to like a slippery track.

JL ws-6

iTrader: (50)

heh... try running at lebannon valley dragway. Although I think that the place is substantially better then it has been in the past, it's still hands down known to be slower then the 2 next closest tracks to me (island dragway and new england dragway)

kp

iTrader: (34)

Well some tracks around here are interesting to say the least as well, thats why I look forward to going to bigger events where they pick up windshield wipers and t-tops off the track and even spray a little VHT before letting cars run

1fstGM

iTrader: (13)

Mine has a sphon tq arm, BMR LCA, relocation brackets, BMR Adjustable panhard rod, BMR Extreme Sway Bar, Double diamond subframe conectors, Rseries QA1's in the front with 275lb springs, BMR K-member, TH-400 BMR Cross mount. I am looking for some rear shocks and was wondering what to get, which is why I started this thread. I have been contemplating the 2 way adjustable QA1's, Afco's 2 way adjustable rear shocks, or even the single adjustable rear QA1's because I know ton of people are having good results with these. Which rear shocks do you guys recomend. What do you guys think?

JL ws-6

iTrader: (50)

if you have the $ I'd do the double adjstable afco.. if not the 12 way qa1 will work well too... too many people use them with good results to say they don't work