Visit The Dirt Forum for More Information

Author Topic:   Forward bite
Still Learning
Dirt Roller

Total posts: 21
posted April 10, 2005 06:27 PM  
Trying to figure out how to get more forward bite. DW 8 2 link. Spring pull bar with 700 lb 5 inch diameter spring. Bottom hole on chassis. AS much angle as I can get.
52-53 % cross weight.
Lr plug with link on top hole. Rr is on middle hole.
200 lb sring on Lr. 150 spring on rr on top of housing.
How do I get more forward bite? NOt sure how to set the preload on the pull bar.

tilley88
Dirt Forum Champ
Total posts: 879
posted April 10, 2005 06:54 PM  
On the pull bar, snug up the spring, then go 1/4" more(preload). May need to go to a stiffer spring or biscuit bar. 17*-20* angle on the pullbar, 15* LR bar, 10* RR bar. Where's your panhard bar, what type, length, and angle?

dirtbuster
Dirt Forum Champ
Total posts: 2007
posted April 10, 2005 07:11 PM  
more rear% will help on really dry slick tracks

tilley88
Dirt Forum Champ
Total posts: 879
posted April 10, 2005 07:54 PM  
Good eye, dirtbuster, I failed to notice that was'nt posted. Just assumed it had lotsa rear%, I guess.

Mastersbilt05
Dirt Roller

Total posts: 21
posted April 10, 2005 10:00 PM  
The reason that you might feel like you dont have any forward bite might be in the track that you are racing on. What I am saying is that the pullbar in the bottom hole on the frame is for the instant traction kind of like a 4link car with the bars high. If you are on a momentum track then you get bite instantly and then loose it right away. If you are on a shorter track (Stop and GO) then it might be right, but I never like running mine in the bottom hole unless I was running a 6.00 gear or more.

M. Robertson

Still Learning
Dirt Roller

Total posts: 21
posted April 10, 2005 10:08 PM  
REar % is right at 60%. Shorty bar... 7" on frame and bottom hole on the pinion.

I am on a 3/8 more of a momentum track.

Lots of good info... keep it coming.

Thanks.

Xtreme12x
Dirt Forum Champ
Total posts: 874
posted April 10, 2005 10:23 PM  
sounds like your pretty dang close...
you might consider taking some panhard angle out to free the car up in the center, not loosen it, just free it to see if you gain some rpm, and get thru the center quicker...

N4cer5
Dirt Roller

Total posts: 13
posted April 11, 2005 08:28 AM  
Any pullbar adjustment affects your drive all the way around the track, mastersbilt 05 is right, to much pullbar angle will give you instant bite and then lose it right away, try setting your pullbar at 17 to 20 degrees of angle, it also seems like the 700lb spring is a little soft. I sometimes switch back from a 1050 or progressive spring. All this should get you goin in the right direction and then it is fine tuning after that, Good Luck

HERNDON
Dirt Full Roller

Total posts: 73
posted April 11, 2005 11:51 AM  
Is the LR spring on top, or in front of the housing??


Still Learning
Dirt Roller

Total posts: 21
posted April 11, 2005 03:53 PM  
LR spring is in front of the housing.

Do I want a stiffer spring on the pull bar for dry slick or a softer spring?

2nd2none
Dirt Forum Champ
Total posts: 755
posted April 11, 2005 03:58 PM  
how long have you been driving? I know alot of rookie's (even some few seasoned guys) have their cars so tight on entry that they are loose coming off. You need to really evaluate the cornering and make sure you aren't tight getting in.

Still Learning
Dirt Roller

Total posts: 21
posted April 11, 2005 04:52 PM  
Been driving for only 2 years now. You may have a good point. I do try and keep it tight going in.
What about the spring rates and preload on the pull bar. Tacky vs. dry slick???

Mastersbilt05
Dirt Roller

Total posts: 21
posted April 11, 2005 06:56 PM  
N4cer5 is right too by saying that the pullbar spring is too soft. I will tell you a way to see just how much the pullbar moves. Watch the 4link RR video in the tool box on this website. When I watched that I got a better understanding of just how much a pullbar can move. Now we are going to a progressive spring like that. I believe that whatever you can get that is stronger is best. Some people around here that I race with run a solid bar with no biscuits or springs or anything and they have just as much or more bite than anybody with a biscuit or spring. If you are running on a 3/8 track then that is your problem. Running that pullbar down at the steepest angle will do nothing at all. That is from experience. We usually run ours about level or maybe a little bit down from that at a track that big.

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted April 11, 2005 10:55 PM  
Definately put a higher rate spring on the pull bar. Start with either a 1050 or a progressive (your choice) When the track dries out you want the spring weaker. To a certain extent. Thats where a progressive spring can come in handy. Start with 1/4" preload on the spring. Do you have a travel indicator on your pull-bar? If so see how many inches of travel your getting. Shoot for 2-3" If your getting like 4" then you need a stiffer spring and if your only getting 1" you need a weaker spring (assuming that nothing is binding)

N4cer5
Dirt Roller

Total posts: 13
posted April 12, 2005 09:28 AM  
yea, if you have a pull bar travel indicator then use that to check your travel and then adjust your spring accordingly.

showtime13
Dirt Full Roller

Total posts: 60
posted April 12, 2005 06:19 PM  
How much stagger are you running?

Still Learning
Dirt Roller

Total posts: 21
posted April 13, 2005 05:27 PM  
I try to run about 1" on tacky and less on a dry slick.

I do not have a travel indicator. Where do I get one and what does it look like?

I moved the pull bar up and have about 14 degress of angle and now have 1/4 inch preload. Before I had the spring very loose. Should I go up as high as a 1050 pound spring? I don't think I can get one here before the weekend so I will try this angle and preload. Any other ideas?

2nd2none
Dirt Forum Champ
Total posts: 755
posted April 13, 2005 06:40 PM  
with that soft of a spring, put atleast another 1/4 to 1/2 inch more preload if you cannot get a stiffer spring.

If you had it so the spring was loose then you are on the right track to getting more forward bite. With that spring loose in there, the rearend was wrapping up freely not transferring any weight to the tires.

That pullbar is what helps lift the back of the chassis, the stiffer the pullbar the quicker it will transfer weight to the tires AFTER it runs out of spring (ie: when the spring gets stiff enough to start lifting the chassis.

This is why a stiffer spring is needed. A 700 is just too soft and it wont allow the pullbar to do its job.

Hope this gives you a better understanding.

Back to the Archives