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badfast47
04-12-2012, 05:08 PM
I have a metric clip with nova lowers using a 650 RF spring, 4/6 shock, 600 LF spring 5/3 shock. LR 7/2 shock in front, 200 spring in back on a slider 4 bar floated. RR 3 link set up clamped. Rod is at about 5 degrees up. 200 spring on top and 94 shock behind rear end. I'm using a shorty bar at pinion and 3 inches of rake to the frame. There is about a 1/4 inch of lead in the RR. The car wont turn enough when i enter the corner. It can be very unpredictable because once i DO get it to turn
(if it doesn't push) it doesn't give me the bite i need till i get straight. See any thing i can do to help this ?

Hagen14t
04-12-2012, 05:32 PM
How much bite?

xxxmod
04-12-2012, 06:21 PM
Square up the rear end and put in 4 degrees caster split.

TCmod
04-12-2012, 07:04 PM
I have a metric clip with nova lowers using a 650 RF spring, 4/6 shock, 600 LF spring 5/3 shock. LR 7/2 shock in front, 200 spring in back on a slider 4 bar floated. RR 3 link set up clamped. Rod is at about 5 degrees up. 200 spring on top and 94 shock behind rear end. I'm using a shorty bar at pinion and 3 inches of rake to the frame. There is about a 1/4 inch of lead in the RR. The car wont turn enough when i enter the corner. It can be very unpredictable because once i DO get it to turn
(if it doesn't push) it doesn't give me the bite i need till i get straight. See any thing i can do to help this ?

I would trail the RR just by looking at what you got here. I really wouldn't worry about forward bite till you can get you entry fixed first.

OCrace2
04-12-2012, 07:24 PM
I've had that problem before. Take the short bar and put on a jbar, dont need tons of angle. It will corner a lot better. Also go softer on the RF spring. Either LF 650 RF600 or just soften RF to 600. Trailing the rear end will kill forward, no need for that. Jbar should make the corner a lot smoother and since youll go through the corner well, you will have more momentum, fw bite etc good luck

washeduptoo
04-12-2012, 09:02 PM
Your rr bar is 4-5 inches longer than lr bars? I would swap the front springs, we also ran the rr trailed .25-.5 compared to lr. Also do the caster split. The Jbar will also make the car easier to handle. Just some suggestions and good luck

Mosidebite
04-12-2012, 09:16 PM
When I ran my Hoffman car 4 bar/ 2-bar the biggest thing that made it turn was RR bar angle. We ran 5 degrees to start with too but learned that when these cars roll over as far as they do with only 5 degrees of upward angle the bar levels out and sometimes ends up past level shortening the right side wheel base up and makes it TIGHT. While all that is happening you also have no drive in the right rear due to no angle left to drive off the right rear. Jump it up to 10* at ride height the next time the track is good and hooked up and go from there.

thfleshman
04-13-2012, 11:14 AM
I for one agree with the softer rf spring. It will help loosen the car in and better corner entry= better exit. Once you have fixed the corner entry , and your still lacking side bite, raise your straight bar on the frame side. Helps(in my oppinion) corner exit as well as long as it dont tighten it up too bad .the j bar is much smoother than a straight bar, but seems to me you can get a ton more drive and side bite with a straight bar. also you could try something if you are at the track and hurting on time if you want to loosen the car up something as simple as a deeper offset on rr (example: if you are running a 3 off swap to a 2 off) or add a wheel spacer to rr. You could also try a deeper offset on rf or wheel spacer b/c in essence that's all you basically are doing is lowering spring rate when you take the wheel further away from the spring just my 2 cents

racin6mod
04-13-2012, 12:54 PM
I agree with the others go to a j-bar and swap the front springs. I would add put the spring on the rr on a slider or coil over in front of the axle the spring on top maybe the reason the car is unpredictable from center out. that set up works well with a z-link but I had the same issue with a 4 bar set up on the rr once I switched to spring in front the car had good forward bite and the car was consistant.

HRJ
04-13-2012, 02:12 PM
Are you entering the corner on the gas or off?

powerslide
04-13-2012, 04:09 PM
I for one agree with the softer rf spring. It will help loosen the car in and better corner entry= better exit. Once you have fixed the corner entry , and your still lacking side bite, raise your straight bar on the frame side. Helps(in my oppinion) corner exit as well as long as it dont tighten it up too bad .the j bar is much smoother than a straight bar, but seems to me you can get a ton more drive and side bite with a straight bar. also you could try something if you are at the track and hurting on time if you want to loosen the car up something as simple as a deeper offset on rr (example: if you are running a 3 off swap to a 2 off) or add a wheel spacer to rr. You could also try a deeper offset on rf or wheel spacer b/c in essence that's all you basically are doing is lowering spring rate when you take the wheel further away from the spring just my 2 cents

Please explain to us how a softer RF spring loosens corner entry.

Original poster.
If your Right side wheel base is shorter than the left i would get that fixed and go try again. I would try it straight up to 1/4in longer on the right side. HRJ does pose a good question. If you are trying to enter on the gas on a tacky track it is very likely not wanting to turn try coming completely out of the gas.

It would also be nice to know your %'s and how much driver weighs

Mosidebite
04-13-2012, 06:23 PM
Just a quick question...how many have ran 4 bar left with spring behind and RR on a clamped up 2- link?

washeduptoo
04-13-2012, 07:21 PM
If your talking about rr on axle tube with the spring behind lr, we have. Didn't run it very long before going 4-4, couple of races. We did run the rr bar about 10 degrees.

OCrace2
04-13-2012, 07:48 PM
Please explain to us how a softer RF spring loosens corner entry.



I wouldn't say it really loosens entry...it makes the car have more sidebite which is what the poster seemed to need and from my experience gives the car a lot better feel going through the corner.
The reason it works>when you go into the corner, weight transfers to the front of the car. If the RF spring is softer less weight will transfer from the RR tire to the RF tire due to the spring being softer, therefore you will have less wedge during the corner and more sidebite.



All the suggestions seem reasonable but for the original poster....just try one thing at a time, I wouldn't suggest getting carried away changing bar lengths and your RR trail. NO QUESTION a Jbar will help smooth out the corner. Short bars make you "feel" like you are getting a lot of drive but it doesn't matter if you cant get through the corner. Let us know how it works, good luck

Dirtrunner35
04-13-2012, 08:24 PM
On my stock car 3 link, I had the RR trailing arm lower on the chassis than I did on the axle to limit rear steer on that side. At least square the axle up, thrust line to the left will tighten the car on entry. A lower short bar will give you more chassis roll but less weight transfer and will make a tighter car. I had mine at 10 inches. It all depends on the rest of your set up.

Mosidebite
04-13-2012, 11:51 PM
If your talking about rr on axle tube with the spring behind lr, we have. Didn't run it very long before going 4-4, couple of races. We did run the rr bar about 10 degrees.
I remember talking about this set up with you a while back. I don't think many have played with this and know the ins and outs of it, hate for a guy to try a million other things when I know one thing has to be changed before he is gonna be fast.

chapa9
04-14-2012, 12:07 AM
For what's it worth I run a 2 link with spring on top RR and my car seemed to like more angle on the RR bar. Expicially when I made some changes and was rolling on RR a lot more. I know it doesn't exactly go with what ya got but just giving ya some feedback.

washeduptoo
04-14-2012, 09:40 AM
I understand, your probably right. He needs to try one thing at a time, first I would try trailing the rr, next moving the rr bar up, etc. Good luck.

badfast47
04-14-2012, 01:35 PM
One thing i did do this week was take out the biscuit bar and put back in the spring loaded bar. Never had trouble with forward bite till i did that. Rained out today so i cant test it till next week. My first thought was to raise the RR trailing arm and i will change that. The RR spring in front was something else that crossed my mind. I have read on here the 4-2 set up i have can be very tight and that might help loosen it up. I'm entering off the gas wanting the car to turn by itself or using very little break. I have learned my lesson about changing too many things at one time for sure. I think first i will raise the RR trailing arm up and i will still have the option of putting the spring in front on a slider and sticking that RR wheel out a more but i think i will go with trailing arm first. Thanks everyone and i'll get back on here next week let you know what happened.

LM14
04-14-2012, 08:15 PM
I'll argue your front springs are too soft. You're not planting the front tires on entry, you are either bottoming the RF a-frame and sliding the tire or there's not enough resistance to plant that tire.

You have a metric stub and you're running chevelle stub spring rates, that's also where the 600 rf suggestions are headed, chevelle numbers. Go to a 700 RF/650LF or even a 750/700. Square the rearend and loose the straight bar and get a j-bar on it.

JMO
SPark

badfast47
04-18-2012, 07:27 AM
Pulled the front springs. The RF was a 625 and has some age on it. This could explain the shock body having a dent in it from the spring compressing too far. The LF had a 700. I put the 700 in the RF and a 800 i had in the LF. These are the heaviest front springs i have for now. RE-set the ride heights. If I'm still having trouble i could swap front springs or go just heavier on the RF ? I also raised the RR trailing arm up to 11 degrees. Thanks for every ones help so far.

Egoracing
04-18-2012, 11:55 AM
Remember a tire can only do X amount of work, forward or sideways the max traction it can generate will be X.
When you let off of the gas or hit the brakes the chassis weight still tries to move forward loading the front tires. The heavier spring will get most of that load. IF that spring is on the LF it will increase drag on that corner and increase traction to a point. IF that tire is the RF tire that tire will increase drag on that corner. The corner that has more drag will cause the car to want to turn toward tat direction.
The RF tire is used more in turining into the corner than the LF AND the cars side loading during cornering and weight transfer form cornering increase the work load on that tire. IF it is also catching the weight from the deceleration it can EASLY put that tire beyond X which will shear the contact patch and cause the car to go straight.
To get the car to turn into the corner better adding LF spring rate increases load on the LF csusion the car to want to turn into the corner and then it carries more weight allowing the RF to turn the car better. This also compresses the RF with will allow the LR to stay raised more which helps promote forward bite from center off without a radical chassis attitude change.
Watch the late models as I know VERY VERY few people that run a RF spring that is stiffer than the LF and I have seen a 450-550 LF and a 250-275 RF.

sj valley dave
04-18-2012, 12:50 PM
It also really depends again on if you are entering on or off the throttle. You will see bigger reverse splits in the DLM world if the driver is hammer down getting into entry...If he is off the throttle and rolls it in you will see less split...We really had issues with the car not turning when he was off throttle rolling in and when Skip Arp told us to change the front springs, bingo, it worked...We ended up with a 450 LF and a 400 RF, car would turn anywhere he needed it to...Now we run a 500/400 split and a 500/375 on dry flat stuff...just an idea..

LM14
04-18-2012, 10:32 PM
Badfast47.....

I really respect Ego and SJ Valley and think they are giving you some good food for thought.

That being said, you need to remember you have a metric stub mod and not a late model. We ran springs closer to what they are talking about when we ran LM but you need to do some math.

There is a ratio of the spring location compared to the a-frame length between pivot points. A LM runs a coilover that is acting within 2" of the ball joint location. You are running a spring that is several times that distance from the ball joint. That distance creates a ratio, thus the heavier springs you need to get the same "feel" a LM would with it's lighter springs. A Chevelle stub has a different spring ratio than your metric or a car like ours with a metric Impala stub. In our case, I am generally rated at least 50# heavier than a Chevelle stub car when it comes to springs. It has to do with the spring location in the lower a-frame.

In addition to that, you are probably running a smaller and harder tire than most LM cars. Your car is probably heavier than most LM. Less side bite and forward bite is available to you than a LM has. This all has an effect on your spring choice also.

I am currently working with 2 different drivers in out 2 cars. Both want different things from the cars. One wants RF heavy spring and the other wants LF heavy spring. Both seem to do fine. One trail brakes, the other drives in. They take totally different setups. See what works for you.

Be careful when people recommend a spring, they may be on a different stub, tire or different program entierly than you are. The theory may be applicable, but not the rates they suggest.

Try the 700RF/800LF, you own it. Be sure your shocks are good, get them dynoed. Get your springs rated so you know exactly what you have. You said you have signs of it bottoming out. Fix that problem. You will chase your tail until your car runs on the proper springs and not the frame.

JMO,
SPark

sj valley dave
04-18-2012, 11:24 PM
I totally agree with LM14 in that our old Super Stock with a Camaro clip and fabbed frame is closer to what you are doing..We only ran a reverse split on a couple of unique type tracks...just don't be scared of trying different set ups until you hit it and at that point who cares what the numbers are!!make it work for you as the leverage points are totally different compared to what we do with the DLM..

washeduptoo
04-19-2012, 05:30 AM
I think he is running nova lowers which could take a different spring than metrics, more in the chevelle range or a little heavier. Good luck in your choice.

badfast47
04-19-2012, 06:31 PM
I am on the nova lowers so i hope i went the right direction with the springs, sounds like i have. I should be on the track saturday night to see what happens, I will post it on here the next day. I have got a lot of good help on here and feeling good about it. Theres a lot of competition in the modified class and i want to be right in there with the rest of them. Thanks EVERY ONE.

justdrive33
04-29-2012, 02:40 PM
I'm on 4/4 and mine will not turn in either. Have tried everything under the sun except remove my 90/10 completely. finally realized it was holding it up on the bars entering (off gas) thus making it tight. Are u running a 90/10

badfast47
04-29-2012, 03:46 PM
No i am using a 70/10. haven't been able to test the front springs because of the weather.

JustAddDirt
05-01-2012, 12:28 PM
If you are on nova lower a's you need to be around a 750 lf and a 700 RF depending on tire, and shock package.
remember when you change a spring say 100 lbs on a nova lower, figure the 30% motion ratio, you are actually changing a spring rate by 30 lbs. 1/2 that for a 50lb spring change.
I ran the 750 lf 700rf on a ump tire.
If you are on kk704's or a IMCA tire, you may need to soften up a bit due to sidewall flex, and hardness of tire.
If you are on American Racer, say a TSMA, or open tires, you may need to stiffen a bit due to softness of sidewall and tread compound.
Also the shock compression and rebound need to be accounted for as well for spring choice.

If you have a go-pro or some sort of camera to watch the RF suspension you will gain a wealth of knowledge what the car is doing on corner entry, and through middle, and off corner.

JAD

badfast47
05-06-2012, 07:18 PM
The springs made a big difference, (wow) !!! It's turning just like i want now. The only two other things i did as i said before was put the spring pull bar back in and raised the RR trailing arm. The middle of the turn and coming off is better but feels Like i need to plant the RR a little more. Thinking of taking out the shorty bar and putting in the j bar, as suggested before and /or putting in a stiffer RR spring?? Plus a stiffer rebound shock on the RR ? Which one of should be my first move? Thanks. I'm headed in the right direction.