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View Full Version : Scaling problems!!! Help



crateracer16
03-31-2012, 09:11 PM
Ok. I missed the first race tonight because I couldn't get the scales to come out right. I just got this car too. 04 bms mod. 4 bar. Springs are rf 750 of 650 or 175 rr 225. Lr shock in front spring behind rr is coil over in front. No matter what we did the rr was always heavier by at least 100 lbs. I just can not get any wedge in the car. We've gone over everything 10 times tonight and we can't find an issue. Nothing is touching or binding anywhere. We even went as far as pulling lower a arms to check jacking bolts and plates for a bind. Everything looks like it should. Measured the chassis and it is square(thought it may have been bent) I weigh 290lbs and thought I would have too much wedge but no. We put the car on 2 different scales and the same outcome. Someone told me you are supposed to pull the lr axle out to scale. I didn't do that but would it cause this headache? Any suggestions. I would like to go to a practice session on weds but want the car to be close on the scales. Thanks

JCSullivan00
03-31-2012, 09:27 PM
Is the rearend squared in the car?

crateracer16
03-31-2012, 09:28 PM
Lr is leading by a half inch.

chapa9
03-31-2012, 09:48 PM
Pull the axle. Also it maybe obvious but be sure leads are right. When I scaled mine last weekend I had similar problem and had the rf plugged in rr. Had them swapped. Was simple mistake that I scratched my head over for about an hour. Try pulling shocks too

crateracer16
04-01-2012, 05:15 AM
What will a rr heavy car do? Would it be a little more tight? Thanks.

1Blacksheep
04-01-2012, 10:10 AM
Clean out your inbox crate .

crateracer16
04-01-2012, 11:03 AM
Sorry. Inbox is cleaned. Thanks

LM14
04-01-2012, 10:24 PM
Put it back on the scales. Turn the RF weight jack down 3 turns, turn the LF weight jack up 3 turns, go to the LR and put 3 turns into it and take 3 turns off the RR. If that doesn't get you headed in the right direction, let me know.

With your body weight, you may want to put 90# in the seat and floorboard the first time you scale. Most chassis builders baselines are for a 200# driver. Some gie reduced percentages for other driver sizes.

How about posting your wheel weights?

I'll argue all day long, leave the shocks hooked up. You race with the shocks on the car, scale it with them. You will find a huge difference if you run gas shocks, too.

A bent shock will cause a problem like this. So will the rear springs rubbing on the birdcage or bars.

Good luck, send me a PM with any questions you may have.

SPark

xxxmod
04-02-2012, 01:11 PM
The plutonium under the hood must be throwing the scales off........
seriously though do the wheel weights change when you push down on the car?
tire size and air pressure right?
If you jack up under the center of the housing with a 100lb RR bite the left rear should come off the ground first

joedoozer
04-02-2012, 01:30 PM
Lets start with the basics. Is this the first time you scaled this car? Are you scaling with or without the driver? Is it possible the other driver was a big fat dude and all the ballast is on the RR to counter the fat guy in the seat? And now you are a skinny guy and the right side is heavy. You can crank on wedge bolts all night long. If you want to move weight, you need to physically move weight.

oldtrackchamp4x
04-02-2012, 02:24 PM
Joe: His post says he weighs 290 so he's definately not skinny. I had a similiar problem last scaling, started over by resetting the ride heights to builders specs. I then adjusted the screws except i put twice the rounds in the rear than i put in the front. Ride heights are right on and weights are as builder recommends. Doing it this way works for me. Agree with LM, put 90 lbs in seat before doing any measuring on car. Maybe just start over again. JMO

crateracer16
04-02-2012, 05:43 PM
Lr wheel weight was 442 and rr was 648. Sorry don't remember the front weights. I'll have it back on the scales weds. I believe I found a bent shock. Waiting on the new one to come to rescale it. This is the first time I scaled it and I was in the car during the process. I'm going to start over from scratch. Thanks guys!

Racer111
04-03-2012, 11:29 AM
unhook your shocks also.if its on a pull bar unhook it also.

washeduptoo
04-03-2012, 11:43 AM
Unhook Pull bar?

dirttrackrocker
04-03-2012, 11:58 AM
??? Never heard of unhooking pull bar??

powerslide
04-03-2012, 12:27 PM
unhook your shocks also.if its on a pull bar unhook it also.

Stop please. You are confusing alot of people. If you unhook the pullbar the driveshaft will either bottom out in trans or pull out and let the rearend fall forward until the j-bar heim binds up.

Original poster. when you say you did everything. I assume you are cranking on the weight jack bolts and the wedge is not changing?

Do you have any racing veterans in your area? I would have someone look over it.

Sounds like a shock is bent or maybe bottoming out? Birdcage binding? Driveshaft bottoming out? Look at LR shock/slider

sj valley dave
04-03-2012, 02:38 PM
I agree...I don't care if you have 100 lbs of RR static weight in the car...You should look around and see where your lead is located though....Once you start cranking down on the LR shock and RF shock you should start seeing the bite come up on the LR...period...We do not disconnect our shocks as some people say, as we are on the track with the shock connected to the car...All that aside, if you are cranking in more preload in the RF and LR and taking out preload on the RR and LF and you don't see anything changing, something is bent or bound up..

TeamGRT12x
04-03-2012, 06:06 PM
Weight jacks do not put pre load on springs. Where did you come up with that?

crateracer16
04-03-2012, 07:14 PM
Yes we were cranking jacking bolts and coil overs. We didn't change all 4 corners to keep all the ride height though. Going to try it tomorrow hopefully. there is no lead on the car at all. Im 200lbs over our minimum weig as it is. If I need a little to get the numbers right then I'll put some on. The driveshaft isnt bottoming out. Double checked that. Going to pull all shocks off tonight and check to make sure that they are straight.

texas racer
04-03-2012, 09:54 PM
I would put it on stands pull lf sus. all the way down and put it back on say thing on the rf. Put jack under the center of the rear end pull everything loose and ck. Make sure the drive shaft does not have the spines twisted and it sides in the transmission with ease.

powerslide
04-04-2012, 08:58 AM
Weight jacks do not put pre load on springs. Where did you come up with that?

When you turn a weight jack the spring is either getting shorter(more preload) or getting taller(less preload) It may not be a great term to use but i believe this is what he was trying to say.

sj valley dave
04-04-2012, 01:59 PM
If you are talking about my post, maybe the term is not what you use, but if you take your coil over adjuster and crank it down to shorten, or put more pre load on the spring, you should see the wheel weight number go up...period

TeamGRT12x
04-05-2012, 02:12 PM
The spring doesn't get taller or shorter. The chassis changes ride heights, which changes wheel weights. The only way a spring is going to compress more is by putting much more weight on it than it currently has. Why do you think when you put 5 rounds in the right front, the chassis height raises on that corner? If what you think is true, the ride height would drop.

sj valley dave
04-05-2012, 06:10 PM
So let me ask you, if the shock is extended all the way out and you keep cranking down on the adjuster what do you think happens...The installed height of the spring does get shorter. Granted, when the car is at ride height and you screw down the adjuster you are altering ride height, but there will come a point when the shock is fully extended and then you are compressing the spring

TeamGRT12x
04-05-2012, 10:03 PM
If your shock is fully extended, then you need to work in that area of the car. Are we really having this conversation? This is race car scaling basics. If that was the case, you'd need to change spring rates all the time.

dirttrackrocker
04-06-2012, 09:20 AM
I agree... If your shock is fully exteneded, you have a very different set of problems to worry about. GRT is correct. Weight jacks do not add preload to a spring. When one end of the spring is on a movable part (control arm) you are not compressing the spring and adding pre load, you are simply adding static weight.

stock car driver
04-06-2012, 10:10 AM
The spring doesn't get taller or shorter. The chassis changes ride heights, which changes wheel weights. The only way a spring is going to compress more is by putting much more weight on it than it currently has. Why do you think when you put 5 rounds in the right front, the chassis height raises on that corner? If what you think is true, the ride height would drop.

When I crank down on my rf or lr wt jack bolt that puts more weight on that corner and in turn makes that spring shorter...

Not sure why your in this argument, your not helping anyone get faster or smarter thats for darn sure. If you want to argue for arguement sake go to the gossip section.

powerslide
04-06-2012, 10:31 AM
When we put "wedge" in a car we go around the car maintaining our R/H's. For this to occur something is compressing and something is lengthening. IE the spring so therefore the spring is getting shorter/longer or in SJ's term getting some "preload"

HEAVY DUTY
04-06-2012, 12:40 PM
When we put "wedge" in a car we go around the car maintaining our R/H's. For this to occur something is compressing and something is lengthening. IE the spring so therefore the spring is getting shorter/longer or in SJ's term getting some "preload"

Absolutely right.
If they didnt get shorter with weight added and taller with weight taken away we would never be able to change the wedge without changing the ride heights a bunch. This is something most guys dont understand when scaling a car.If you screw a half inch into a spring, it usually doesnt raise the car a half inch, because the spring is compressing some when weight is being added to it. The corners straight forward and straight acroos will get higher because of weight coming off those springs.That is why you have to check all 4 corners when making an adjustment to one spring.

crateracer16
04-06-2012, 12:51 PM
Ok. Changed my ride heights a little. Moved the fuel cell to the lr more. Lf shock was extended all the way(moved the mount down) and had the lr spring slider catching on the birdcage. Got her right on the scales now. Went to practice and turned 3rd quickest time on record and I've been out of a car for 4 yrs( not to toot my own horn. Lol) thanks for suggesting the 90lbs in the seat. That was a lot easier than me getting in and out of the car since I'm such a small guy. Thanks for all the help!!!!!!!!!!!!

stock car driver
04-06-2012, 01:33 PM
Ok. Changed my ride heights a little. Moved the fuel cell to the lr more. Lf shock was extended all the way(moved the mount down) and had the lr spring slider catching on the birdcage. Got her right on the scales now. Went to practice and turned 3rd quickest time on record and I've been out of a car for 4 yrs( not to toot my own horn. Lol) thanks for suggesting the 90lbs in the seat. That was a lot easier than me getting in and out of the car since I'm such a small guy. Thanks for all the help!!!!!!!!!!!!

I do all my scaling minus driver. Its a lot easier.

crateracer16
04-06-2012, 02:10 PM
Ya. I never had enough weight to make up for my body weight difference cuz my setup sheet is setup for a 210 driver. but it was a LOT easier being out of the car! Thanks again guys

TeamGRT12x
04-06-2012, 06:01 PM
Jeff,
Trying to help someone not make a mistake. I have never in my life heard of someone say that when you crank on a weight jack, you are making the spring taller or shorter. It's such a minute amount that it isn't to be worried about. If you are worried, you better carry quite a few springs.

When does the JNJ Stock Car come out? I noticed you had it for sale???

stock car driver
04-06-2012, 07:14 PM
Ya. I never had enough weight to make up for my body weight difference cuz my setup sheet is setup for a 210 driver. but it was a LOT easier being out of the car! Thanks again guys

In that case I would scale with the 210 in then remove it and write down your bite, left, rear and total and scale to those numbers from then on and adjust from those numbers etc.

oldtrackchamp4x
04-06-2012, 07:22 PM
As fast as you are i would leave the car alone and get used to driving it. You did write down all your setup numbers, didn't you? Continue scaling the same way you did it the last time as it sounds like you are right on on the setup.JMO

stock car driver
04-06-2012, 07:25 PM
Jeff,
Trying to help someone not make a mistake. I have never in my life heard of someone say that when you crank on a weight jack, you are making the spring taller or shorter. It's such a minute amount that it isn't to be worried about. If you are worried, you better carry quite a few springs.

When does the JNJ Stock Car come out? I noticed you had it for sale???

I havent bolted a single part on it. Everything I have is for sale always. I would like to quit or at least cut my racing down to 20 nights approx this summer. I am down to only 2 motors 1 imca 1 USRA and parts for most of another of each, this is the lowest in hard parts Ive been in years. The IMCA USRA differences really suck for me.

I think if I could sell the purple car. I have a very hard time working in my shop when the weather is as nice as its been lately and I got an awful lot more satisfaction hearing about the hobby I built race at Beatrice than I ever thought I would.

kencar87
04-06-2012, 07:59 PM
Ok. I missed the first race tonight because I couldn't get the scales to come out right. I just got this car too. 04 bms mod. 4 bar. Springs are rf 750 of 650 or 175 rr 225. Lr shock in front spring behind rr is coil over in front. No matter what we did the rr was always heavier by at least 100 lbs. I just can not get any wedge in the car. We've gone over everything 10 times tonight and we can't find an issue. Nothing is touching or binding anywhere. We even went as far as pulling lower a arms to check jacking bolts and plates for a bind. Everything looks like it should. Measured the chassis and it is square(thought it may have been bent) I weigh 290lbs and thought I would have too much wedge but no. We put the car on 2 different scales and the same outcome. Someone told me you are supposed to pull the lr axle out to scale. I didn't do that but would it cause this headache? Any suggestions. I would like to go to a practice session on weds but want the car to be close on the scales. Thanks
Listen to lm14 he has got it right. 1. set all your ride as directed by the manufacture. 2. see , what you got and go from there, in your case I would do as lm14 said,put 3turns in the right front and take 3 out of the left front, go to the rear and put 4 to 6 rounds in the left rear and take out the same on the right rear, car will sit just like it did when you set it earlier. this should put left rear in the car and you can work from there as needed. always scale the car with your poundage in the seat, this is how you race the car, so scale it the same way you race it. It is that simple. Leave the shocks hooked up, pull bar in and hooked up. This works for me every time, and make sure you check for binding, it will throw your car off every time. Hope you got something out of this and some of us here are ready to help and I hope through this forum you get the help you need to have the fun that all of us out there are having now. See ya on the track! Good luck.

crateracer16
04-06-2012, 08:37 PM
We did a lot of what lm14 suggested along with modd55 and it got us running quick. Thanks!!!!

Mosidebite
04-06-2012, 09:57 PM
You can also take anything HEAVY DUTY has to say to the bank, as he has built National Championship mods and actually understands what these things are doing and why. Some of these guys...well they just confuse people

sj valley dave
04-07-2012, 12:22 AM
Jeez...I never meant that in the real world that you would have a shock fully extended, I just replied when someone said that you NEVER could shorten a spring by cranking down on a coilover adjustment...I was taking it to the absurd to prove that yes you can...Have fun with this discussion as I will just go back to racing our DLM...LOL Some people take themselves sooo seriously..LOL

TeamGRT12x
04-07-2012, 01:56 PM
I never said that it NEVER changes the free height or compressed height. I stated that's not what you adjust weight jacks for. Sorry, you guys are right, I'm so wrong.

sj valley dave
04-07-2012, 09:18 PM
Weights jacks are for ride heights...OK...When you raise the ride height you will see more weight on that wheel..OK...He was saying that no matter what he did with his jacker he saw no change in the wheel weight on his scale...OK...He has an issue...Very simple, and it was blown out of proportion..

powerslide
04-09-2012, 11:00 AM
I never said that it NEVER changes the free height or compressed height. I stated that's not what you adjust weight jacks for. Sorry, you guys are right, I'm so wrong.

Your crawfishin on us Brett. You clearly stated that the "Spring doesnt get taller or shorter"

I agree in most cases it is a very small change but it does change. If i was to go from a low or reverse wedge setup to a high wedge setup you would see a pretty big change. Get your tape next time and see. I agree its not something we should worry about but it helps people understand how a car works and why.

Crate man glad you got your issue's fixed and congrats on your lap time.

LM14
04-09-2012, 05:13 PM
How does all this arguing help the original poster?

Glad you got your problem solved, let us know if you have other questions and we'll try to help, hopefully without a pi$$ing contest attached.

SPark

TeamGRT12x
04-09-2012, 07:18 PM
SPark/Powerslide

I know, and you understand what I was saying. The problem is, nobody cranks on a weight jack to increase the pre load on a spring. That's my point. Hope the car is scaled and working good.

sj valley dave
04-10-2012, 12:20 AM
And I agree and you know what I mean! You crank down or up on your coil over adjusters to move LR bite on the chassis...very simple concept

crateracer16
04-10-2012, 02:45 PM
Thanks again guys! And I'm sure I'll have a lot more questions throughout the season.