OutlawZ

iTrader: (4)

Here's a question for those of you that race in "stock suspension" racing classes around the country. I'm trying to get a general consensus of what you guys feel about a topic that I ran into when mocking up wheelie bars at my fabricators shop.

Long story short my car has huge wheelstand problems and i'm leaving on a paltry 150 shot off a t-brake. I have travel limiters, I have double adjustable rear shocks, I have brand new MT ET Drags 28x10.5W.... We are pulling alot of timing off the line to reduce power but it still wheelstands. I've crushed a set of SYA bars and almost lost my car into the wall.... We've tried some options but I just don't feel comfortable testing anymore and "Trying" things which could result in the one pass where I crack the block or worse hit the wall and kill myself and/or destroy the car..... So wheelie bars it is.... They are going on as a tuning tool and to make me feel better about coming out on everything the car has... No longer will I have to pull timing or reduce power. Myself and my chassis guy want to leave on the bars and just straight GET IT... We're trying to beat the LT1 nitrous world record. Car has gone 1.38 60' lifting and pedaling it to keep the front down... we think 1.2's are possible ***** out with more spray off the line....

Okay sorry for that.... In fabbing up the wheelie bars my fabricator wants them at a certain height and setup a certain way so that the rear won't unload when it is on the bars. Problem is that the stock panhard is in the way. His fix is to run a chassisworks panhard bar where a tab is welded to the frame and then to the top of the housing and a roughly 2' bar with spherical rod ends is placed in between. It's a double adjustable deal so you can move the rear right and left to center it....

My question is would removing the stock bar and going to a panhard bar that is shorter and has different points where it's connected make the car illegal for stock suspension shootouts or class racing? My chassis guy says no, cause the car came with a panhard bar and we're not adding anything the car didn't come with stock just going with something smaller and stronger for clearance reasons. This chassisworks bar does NOTHING that the stock panhard bar doesn't do it just does it better with less flex and being smaller gives us the room to put the wheelie bars where we want....

Opinions?????

DMH Fabrication

iTrader: (126)

I'm sure Madman or someone can give you a better idea on your specific question but 2 things I see. First, you can get wheelie bars to fit fine and work w/ the stock panhard. Get Madman to build you a set. Second, pulling timing is not the solution. You don't want to dead hook a slick or your going to have problems with it going on the bumper. You can always scale the car and move some weight on the front if needed.

OutlawZ

iTrader: (4)

Car was scaled already per madman's specs. Yes I can have madman build me a set of wheelie bars but i am close personal friends with Chris Alston Jr from chassisworks. So buying a set of wheelie bars that are fabricated already and having them shipped to california with today's outrageous UPS shipping rates would run me upwards of a grand when all is said and done.... I'm paying about 600-700 complete for a full chromoly set of unsprung bars WITH setup on the car... Putting weight on the front we are reserving for later if the car hits the bars too hard.

A real panhard bar that coil over cars use is far better anyway. Don't know if you've checked out the stock mount that the panhard uses as it's attachment point on the frame? It's not boxed, it's not strong and probably flexes like a **** when it's torqued...

If I lived in louisiana near madman i wouldn't be asking the question. he would fab the bars and whether or not they cleared the panhard would be his deal.... but my chassis guy who goes to the track with me and tunes the suspension (and he does all the chassis work on several 7 second doorslammers so he's quite qualified) wants the wheelie bars in a certain location and alignment on the car......

pmbmax

Most rules say stock style or some say must bolt in stock location. coil overs or different mounting points would leave you out .

MADMAN

iTrader: (4)

If you run a short panhard bar the rearend will shift dramatically side to side when the suspension is working. You will still have to pull timing out or leave the frontend tight on the limiters or you will hit the bars too hard and unload the tire. UNLESS you use spring loaded bars which are extremely unsafe and hard to tune.

I put bars on these cars all the time and I run the upper bars above the panhard and the lowers below it. Works great and I still have a 7" spread on the bolts.

DMH Fabrication

iTrader: (126)

Box the stock panhard mount and it is plenty strong enough.

So you would save a little bit on the wheelie bars, but what about after you add a new one off panhard and the install for that?

Why not just call the organization you want to race in and ask them your legality question? After all, that's the only answer that really matters.

FASTFATBOY

iTrader: (23)

If madman can run 4.80's in the 1/8 mile on drag radials with no bars, the tires 3 inches off the ground and a 1.2x 60 foot. There IS a solution.

Seems to me you need a progressive NOS controller, a 2 stage system and some weight moved to the front.

Move the engine forward an inch if ya need to. There ARE ways to solve the problem. Bars is not one of them IMO.

Dont put bars on the car to run 8.90's.

Look up RIck Intrau on Google. There are pics of his rear suspension with wheelie bars and the stock panhard bar.

Have you tried moving the instant center forward in the car?

OutlawZ

iTrader: (4)

These bars will be unsprung.... We plan on still keeping the front end limiters on and tight.... So Madman you say the rearend will move around ALOT???? The long stocker keeps it in place better???? I want to make sure i'm not doing something dangerous.... I'm gonna have to call my guy and tell him we gotta rethink this if it's gonna start getting crazy off the line like pulling right or left..... Why would a short panhard let the rear move and a long doesn't???? The chassisworks panhard is double adjustable and has spherical rod ends instead of rubber bushings like my panhard now....

Fat-Progressive isn't possible cause I run a dry system. I do have multiple stages available... I'm coming out on the smallest hit possible and it wheelstands.... I know it CAN be done without bars but i almost lost the car into the wall testing and i'm not willing to go out there again and again trying to find the sweet spot with the possibility of losing my car... I'm using the bars as a tuning tool so we can find that sweet spot without fear of killing myself...

93_z28

because of the pivot point.the longer bar has to travel further to get to the same point.

OutlawZ

iTrader: (4)

but wouldn't a hard mounted bar that controls side to side movement completely eliminate it????

I understand the pivot point theory but i'm still clueless as to how something mounted with spherical rod ends mounted to tabs on the frame and rearend housing would allow any lateral movement whatsoever....

then again i'm no suspension guru either....

edit: nevermind i just looked it up on wikipedia.... okay i get it... it says that the issue will only be noticed at the ends of spring travel. so if the springs are fully pressed down or fully extended.... Both of those probably aren't going to happen dragracing right???? My car mostly lifts a bit on launch when the tires slam down into the ground....

Madman can the use of a shorter panhard on my car be "tuned out" to avoid the car pulling at all??? or will it be so slight I won't even notice??? Like maybe more preload on one side would make it okay.

A pic of my car launching for a view of the wheelwell seperation.....

pmbmax

It is the arch that the rear travels when it goes up and down the longer the less it will pull the rear to atachment side. when the bar is parallel with the rear and it goes up are down it will get closer to that side as it travels thru that arch. the shorter the faster it will move because the arch is also shorter. I wish i could sleep

MADMAN

iTrader: (4)

If you have more NOS to go then leave on a bigger kit. By looking at your picture you need more air in the tires.

Carbed4thGen

iTrader: (2)

Exactly what I was thinking..if your wheelstanding then your suspension clearly works. Start hitting it harder until it doesn't work anymore then back it down from there!

Ed Wright

iTrader: (1)

That's what I was going to say about the air. Also, how wide are the rear wheels in relation to the tires? The wheels might be a tad narrow?

I see you are the "West coast's fastest LT1 period".

Do you know Chuck Norton?

JL ws-6

iTrader: (50)

I see a couple thigns that you probably coudl do to help the situation, #1 is the air in the tires. I don't know where you had it in that picture, but from the looks I'm gonna guess and say about 10 psi hot?

You need to put at least 2 lbs more air in them then what's in there now, that would be a good start.


What are the corner weights of the car, because if it's standing up that bad where you are it sounds like you need to get more weight on the nose of the car, or tighten the extension up on the front shocks at least.

I had my car do that last spring, putting the limiters on it totally stopped it, to the point that I had to go back towards my n/a setup suspension wise to get it to leave again. If you already have them on the car and it's still doing it you need to move some weight in the car. There's an assload of cars that are running way more power then you are in 4th gen fbody's and there not having the problems that you are.


I think the wheelie bars are a good idea don't get me wrong, but get them on there with the stock panhard bar. Box the panhard bar mount in as well.

You could always put the bar in the hole on the mount that th support goes in and then move the mount on the rear a little if you had to , but madman and the rest are correct, the shorter the phb is the more the rear will shift from side to side which is definately going to cause the car to pull in one direction or the other very badly.

If you are dead set on removing the phb, I would go strait to a wishbone setup and call it a day. This is one of those things that they may or may not like for stock suspension. But, from the exp that I have with it they tend to care about the control arms the most, they don't want you moving them around that's what they generally care the most about. Going to a wishbone could be considered a safety thing becuase with that you will have zero shifting of the rear side to side.

OutlawZ

iTrader: (4)

the wheels are 15x10's and the tires are 28x10.5W's... Tires were 10-11psi hot.... Yeah we probably could stand to up them and test it out...

No, is he a member here???? I've searched and searched and found nothing on anything faster other than Jeff Stevens' car which was sold and is no longer in cali....

extension on the shocks were tight (not in that picture shown) but on another pass where it went all the way to the bumper. The limiters were set one hole tighter than the middle hole... Moving weight around was something we thought about doing once the bars are on there to keep it from getting crazy again....

we're using the bars as simply a tuning tool and to keep me confident that it's not going to rocket towards the sky again while we're testing and tuning....

MADMAN

iTrader: (4)

How are you controlling timing?

OutlawZ

iTrader: (4)

FAST XFI, time based timing retard in the power adder tables.....

and update on the panhard bar. I just talked to my chassis guy and there was some confusion as to length of the panhard bar. He says it's only 2-3 inches shorter than stock and the fabricator (who i originally talked to) thought it was much shorter before he had seen it with his own eyes. He said because I don't have an upper panhard bar (which was removed to make room for the nasty performance sumped tank) that the bracket on the frame has no support. They are going to box that bracket for strength since without the upper on there he was sure it was not very sturdy. He said that he achieved a 7-8" spread on the upper versus lower attachment points of the wheelie bars...

So the panhard bar isn't going to be as short as originally advertised. My chassis guy started laughing when I said that I thought it was only like 2 feet long.... he said the rearend would shoot left whenever i launched and i'd probably chop the tree down at the track..

JL ws-6

iTrader: (50)

That's another good question, are you just starting the timing off down low @ the line, and how long does it stay out before coming back in?

I'd put those tires up to 14 psi and see what that gets you.

OutlawZ

iTrader: (4)

My timing map looks like this (+ or - a few degrees when we're playing with stuff)....

32 degrees of base timing....

we pull 8 degrees for the 1st 150 shot.... So 24 is the magic number when releasing the transbrake. However we pull another 10-12 and feed it back in over 3 seconds... So I'm leaving on like 12-14 degrees of timing in an attempt to kill the wheelstand... It doesn't pop or stutter off the line at all... just rockets out like a frikkin animal.... The wheelstand I pulled at pinks all out where it came out hard went a little above 45 degrees and just carried the wheels for like 120 feet or so wasn't because of timing or the engine tune it was because I short shifted the car into 2nd to kill the wheelie.... I usually shift to 2nd at 7200. that pass I pulled 2nd gear at 6450....