Adding forward and side bite

[ambonci21]

looking at swapping rear springs around. we are currently 15" 200 on the LR and 13" 175 on the RR. we are looking to add a little forward drive and add a little side bite. Also hoping that this will help snug the car up just a tad. We are not far off on setup just looking to try something different with spring rate. We are thinking of putting a 16" 175 in the LR and putting the 200 in the RR. Correct me if I'm wrong but the softer LR will unload faster and will get on the bars faster. this should tighten up corner exit right? Also is putting a stiffer RR help snug us up and add side bite?If we swap to a 200 RR should we put in the longer spring or the shorter? Thanks for reading. Happy labor Day!!!!!!!

[xxxmod]

JMO leave your springs alone and move the RR forward for tighter entry and exit

[ambonci21]

we are at about 3/8 ahead on rr

[mcarter815]

Depending on what you're running now, being less aggressive with your LR shock can help with forward bite.

[ambonci21]

I gathering that switching springs is not a great option? I think LR shock is a bilstein 8-2

[CCHIEF]

Perhaps a 2-8 Bilstein?? if it is a 8-2 that likely poses a problem. Bilstein's are rebound-compression, opposite of most manufacturers.

[mcarter815]

I gathering that switching springs is not a great option? I think LR shock is a bilstein 8-2I'm new to this stuff, but my understanding is that springs just control the balance of the car. If you are wanting to influence the rate of movement on corner exit, you do that with shocks.

[ambonci21]

Chief, you are correct its a 2-7 bilstein. thanks for clarifying that. the one thing I have been thinking about is we set the car with tilt in it, meaning its tilted to the rf a bit. we have very little preload on the rf spring. thinking we are going to switch rear springs and take the rf tilt out so its not pulling the car off the LR as much. what you guys think.

[JustAddDirt]

I would change springs and leave a bit of tilt in car.
What tires and rule packages are you running? You never mentioned any of that info that info would also help us help you.
Ump
IMCA
Usra

[ambonci21]

Just add dirt, Sorry about that, we are running IMCA. like I said we are very close just looking for a little tighter from middle off. I was thinking taking tilt out because last year we started with an 8-2 on the rf changed t a 5-3 and man what a difference with handling and drive off. When I look at pictures from this year, the car is all jacked up on the rf, way more then others. we have had a lot of bad luck with engines this year and getting wrecked but have had a DECENT car every week, DECENT not GREAT. so I am wondering if we have to much tilt. we are about 1/2" lower on ride height then what our chassis manufacture suggest.

[JustAddDirt]

I would probably go with builders recommended ride heights.
Might try dropping lr Lower bar a hole. That will tighten middle off.
I run ump, but I hear a lot of Yantz, imca cars run a pair of 225's on the rear.
I am on a 225 rr and car scotches up very well.

I would try the 175 lr preloaded , and the 200 rr
That should improve scotch and should help car up on bars with the addditionsl preload on lr during.
Are you on a pullbar or lift arm?

[stock car driver]

you want tilt and softening your rr sping will reduce side bite not add side bite

lower your rr lower bar and it should plant the rr more on entry to middle which would be a tightening up effect. also look at j bar adj, but rr lower is what I could use to make my car plant the rr a ton anytime I wanted it to

or stiffen the rr spring if your really wanting to change springs

[stock car driver]

Are you on a pullbar or lift arm?

IMCA doesnt allow lift arms.

[JustAddDirt]

IMCA doesnt allow lift arms.

Now that you say that, I thought I remembered hearing something about that a year or 2 ago.

[ambonci21]

SCD, we plan on stiffening the RR going from 175 to a 200. we usually put the RR lower bar all the way down. Just Add Dirt, how much preload are we talking? We did that on our last car with lots of preload in the LR spring and the car would throttle push bad at times. just wndering what a good starting point. an inch or more? Thanks

[JustAddDirt]

I do not run a lot of wedge. at full drop I think I am at 1.25"-1.5" preload on lr spring.
generally about 25"#with driver.
All I feel with more wedge is a looser corner entry if you have to get off throttle, and a bit tight, when you pick throttle up if you are totally off throttle.
once the car is against limit chain, the LR spring, and the amount of wedge mean nothing

[mod88s]

By switching your springs, it will help achieve what you are thinking. Thats what I run for the last few years and I like it. 175 LR and 200 RR

[powerslide]

All I feel with more wedge is a looser corner entry

I highly agree with this, we practiced one night after the races and it was slick and the driver swore up and down he needed more drive off and he was going to add 100lbs of LR. All he did was spin out on entry after doing it. He was not a trail braker.

[ambonci21]

made the switch from 15" 200 LR and 13" 175 RR to a 16" 175 LR and 15" 200 RR. We scaled tonight and have about 1.5 " of preload in LR slider. kept some tilt in the car and went with around 67 LBS LR bite. We race tomorrow. last time we ran at this track we finished 2nd earlier this year, finished 3rd last year the one time we went. We will see how things go tomorrow. the driver absolutely loves this track as its super fast. Will let you know the results. Thanks for all the input.

[ambonci21]

well the car was absolutely junk Super loose from the middle off. spinning like crazy. so the only thing we changed from this time an the last two times we went there were the year springs. LR bite was within 5 pounds of those previous times. From the middle off there was a major lack of sidebite. I am wondering if the right rear spring is to tall. the car looked to have a completely different attitude in pictures, before it would definitely lay on the rr, after the spring change its not on the rr very much or any at all.

[JustAddDirt]

I ventrure to say that you have more problems than rear springs rates.
things to double check:
binding in j bar
birdcages rotate easily
how far below axle centerline is your RR shock mount
how much split in J bar mounting
where are you on pinion for j bar mounting
how long is your j bar


does car trip onto RF when entering corner (stand up on LR & nose over on FR and stay there?



my car rolls more with the 225 than it does a 200, which means it is planting car harder on RR.

[ambonci21]

Just add dirt, the jbar is almost buried at the pinion. not sure on the jbar split. I was not there Saturday but the pictures look like its stood up on the lr and nosed on the rf. I will try to send you a link to the picture. Its just odd that the only thing we changed were rear spring rates and spring heights.

[ambonci21]

I tried to PM you but your inbox is full.

[JustAddDirt]

cleaned out.

[stock car driver]

you say early on in reply to someone your 3/8 forward on the rearend, id trail that.... that will cost you side bite and forward drive. 3/8 trail would be LOW....

once you do that youll probably be able to raise your rr lower as well as any other stuff you have off from the base set up that is being used to try and fix or mask the fact that your rr is forward

[JustAddDirt]

too much pandard bar angle will hurt forward bite.
car is laying on the j bar and not going forward.
with it buried on pinion, I bet car is tight on entry, then driver pops it loose to rotate center,and there is no traction from there.

and if you indeed are short on right side wheelbase, that will cause more of a tight condition, and car will not want to rotate.

[stock car driver]

and if you indeed are short on right side wheelbase, that will cause more of a tight condition, and car will not want to rotate.

if hes making it around the track with it 3/8 lead then hes clearly busting it loose to turn

thats first thing he needs to fix

4 bar cars are easy to get traction, you can get all of it you want any place you want it easily.

[ambonci21]

we are around 3/8 shorter on the right side than the left. we usually have both right side bars low as they go and left lower as low as it will go. last year we ran this way and was a top three car all year long. and ran it like that this year will lots of back luck. the only major thing we have changed are the rear springs. I believe there is something else going on but car went from god to total garbage with a spring change. I can provide more info if needed.