Changing the track.

[Lizardracing]

I hear of a lot of teams not changing to much between the heats and features once they find a setup that works pretty well. I'm currently changing everything but my underwear between the heats and feature and it seems excessive and something doesn't seem right.

I want the car looser on entry(without using too much brakes) in the heats so it will rotate well on the throttle when the track has some traction in it.
I also want the car were more a tiny bit looser on entry in the slick but with more side bite in the middle. Forward bite isn't that much of an issue. This car goes forward pretty good. It just always way too tight or a little too tight on entry. It's just a trait of this car. I'm afraid of adding more RF spring to free up entry and tightening up the middle more than it is.

What do you do when you know what you want the car to do but don't know how to get it there?

I'm really wanting the car to be really free on entry(still drivable though) and when I pick the throttle I want to finish rotating, take a set(settle in yaw) so the RR carries me through the middle. If I could get the entry and middle like I want it I think the exit will be great and Ill improve in finishes. Maybe even win! Is that too much to ask?

[oldtrackchamp4x]

I either raise RRL bar one hole or raise j bar on pinion one hole. Try one at a time to see which one you like best. Maybe try changing how you enter corner. JMO.

[Lizardracing]

I've done both but on this car it isn't enough between the tack and the slick. I'm wondering if the over all set up isn't close enough necessitating big swings in adjustment's. Or maybe the car is just worn out.

[oldtrackchamp4x]

Might try raising RRL a couple of holes. If that doesn't work i would definitely check overall setup and call the chassis builder. JMO

[Confused?]

You've made a couple of statements in you post that make me think your cars is WAY too tight. Contact your chassis builder and get a base setup. You can tune from there. You have given no info other than you want to loosen up the car. Nobody on here can help you without setup info like bar angles, ride heights, wheel weights, tires, springs, shocks, etc. Chevelle or metric clip?

[powerslide]

I would free it up on entry and leave it one night and see how the feature is. If you change anything just try air pressure, wheel spacer or some wedge.

[Lizardracing]

Alright I get it. If you ask a generic question you get a generic answer.
I'd love some feed back from the chassis builder but he doesn't like me much. When I figured out I don't like him him very much I kinda cut up the car and did what I thought was best. The car improved, I improved, things were going well till the divorce got everything. I walked out with nothing but my truck, a blanket, and three pairs of work clothes and a .40 pistol. I even lived in my truck for a while. Thankfully after nearly two years the courts gave me some of my stuff back including my kids. I'm a lot better off now than I was for sure but it's been a rebuilding of ones life, a process. You guys didn't ask about all that but I've been out the game for minute and so I come looking for advice and ideas cause in the process I also lost my set up notes and book. 10 years of notes at that.

The car is a 08 Impressive. In 2011 I changed some things in the front end and added my own designed four bar brackets that are on the proper radius. Nothing atypical of todays cars. I just redid it better than Impressive that's all. Fixed a lot of crappy welds and things like that. I had to do something on my own cause I wasn't getting help.

Here's the complete set up. Typical Hook set up. LR behind on a slider and RS front on a coil over. Chevelle clip.

I aready know this board isn't going to format this correctly so I hope it's readable. If not, I can email anyone the set up sheets I made.


Date 5/5/2017 Conditions
Track LOS Heat Dusty
Heat Total 2240 Rough bottom
LS 52.50% Powder on top
Rear 53.40%
LRB 110

LF RF
Ride Height 3.25 1/2" toe out Ride Height 3.75
Spring Rate 580 Spring Rate 600
Tire Pressure 10 Tire Pressure 12
Shock 7/3 Shock 7/4
Wheel Offset 2" Wheel Offset 2"
Castor Degrees +3 Castor Degrees +5
Camber Degree +3 Camber Degrees -3
Corner Weight 625 Corner Weight 525
Tire Roll Out 81.5 Tire Roll Out 81.5



LR RR
Ride Height 5 11/16 Ride Height 2.5
Spring Rate 225 Spring Rate 175
Tire Pressure 12 Tire Pressure 14
Shock 8/2 Shock 3
Wheel Offset 2" Wheel Offset 2"
Castor Degrees 0 Castor Degrees 0
Camber Degrees 0 PanHard Angle Camber Degrees 0
Corner Weight 675 6" Rake Corner Weight 575
Tire Roll Out 81.5 Rear Gear Tire Roll Out 84.5
Upper Bar Angle 5 5.83 Upper Bar Angle 4
Lower Bar Angle 2 Lower Bar Angle 3

I don't have the exact bar angles right now. I know those are easier to compare than hole numbers.
On my brackets, I have 5 holes 1" apart.
1 is level or zero degrees
5 is 45' so each hole is about an additional 10' of bar angle.

Ignore the RH. I have tabs welded on the frame so those are from the tab to lower control arm in the front and from the tab to the axle tube on the rear.

I typically drive in the corner and roll off the gas and roll on some brake while turning left. When the car begins to rotate, I start rolling off the brake and just before the car finishes rotating (like I'm catching the car with the throttle from over rotating), I'll pick the throttle slightly so it will load the tires at mid corner then I steer it with the wheel and roll on as much throttle as the tire can take or traffic will allow. I'm not one to really like the car hanging way out there. I like to keep it under me and a bit straight but the car really needs to be free enough I can turn it on the throttle.


In the heat...on the bottom it was way tight, slight throttle push in the middle, forward bite was good once it got pointed in the right direction. Better on the top, didn't throttle push as bad, forward bite good.

For the feature we added two rounds to the RF and took out two rounds on the LF, Raised the RRB one hole, Raised the RRU one hole, Raised the LRU one hole all in a an effort to free up entry so the middle didn't throttle push and exit still had forward bite. I feel like this was too much to have to adjust. Something else is wrong I think.

The track went stupid slick, turned into a bluish dust covered mess with a huge ruts in the bottom.
I rode the very top in the powder. I was still a bit too tight on entry but it didn't throttle push too bad and forward bite was ok. I could feel the car rise up on the RR on corner exit from excessive bar angle and it would twitch a little as the car came down off the bars on the next corner. Passing was hard but we went from 12 to 7th. Almost got 6th but the bottom was so rough and the car was tight I couldn't make anything happen the last 3 laps.

So in all this, what I'm saying is I feel the car starts the heat way way tight on entry, we free it up even more for the slick and its still too tight on the slick but better.
So how do I free this thing up on entry without it throttle pushing?

[JustAddDirt]

soften LF spring
soften LF shock compression

[a25rjr]

Increase stagger in front but don't change corner weights. With them the same size, you are de-wedging the car quite a bit, in the corner.

[stock car driver]

Those are crazy front shocks if 7 is your compression
i never ran that low of camber on front left or right 4-5 degrees on both

I dont know where your measuring ride height but if thats to the lower a arm bolt which is what most people reference your crazy low and your lower a arm angles have got to be way upward.

100 bite is a ton for a modified, Id say your not remotely close on set up. When I was running some old school bilst but with todays current valvings I was up there, once I got some good shocks all bv I went down to 20 and had more drive more steer etc.

you never say what tires

[3dracer]

Impressive measures from the top of the lower a arm to a hole in the frame. That is why his appears to be low. But I think 100 lbs lr is too much. Almost sounds like a jbar push on entry. Location of that? Also sounds like he might be on AR's.

[Lizardracing]

SCR.....The 7 represent the shock lenght not the valving. I use straight valves shocks on there right now for the track I'm currently running. I have a slick package I'm wanting to try but I wanted the car closer so I could a difference.

As posted above the RH are from the tab welded on the frame to the LCA. I find them easier to read that way.

J bar is mounted the usual way. LS frame to RS of pinion in front of the axle. 6" difference in height from the frame to the pinion. Pinion end is level with the driveshaft. If I raise it on the pinion, it's better but not by much.

On AR G60's.

LOS is a small 3/8 mile clay track sitting in a mountain top with lots of solid rock. Banking is only 8 degree's so there.s not much banking or a cushion of sorts to stick the RR into. It's just this year reopened with a new surface so it tends to get filled with ruts and is and always has been dusty.


If I change to a 550 spring from a 580 spring on the LF only, do I also need to reduce the LRB some? Maybe 60 Lbs?

Any and all ideas welcomed. I've tried to be a detailed as possible. Forgive me if it's a long read.
I too think 100lbs of LRB seems a bunch however I don't get caught up in what everyone else is doing, Entry is way way tight with less.

[oldtrackchamp4x]

Like i said, raise RRL two holes check indexing on both sides, o deg on both. If that doesn't do it lower j bar on frame an inch and raise an inch on pinion. Have a buddy that was fighting the same issue and he did the above and it helped him immensely. He's down to 3.5 inches of j bar split. Top three car now. Make sure where your rear end is located side to side first. JMO

[a25rjr]

[QUOTE=Lizardracing;2103797]..... Entry is way way tight with less.

Don't get hung up on a number. Putting more bite in should loosen your entry (off the gas).

[dirtracr33]

if you're wanting to affect entry only...change lf spring...to tighten entry - stiffen, to loosen - soften....

or move right lower bar...

[powerslide]

More camber in both tires. Soften LF spring more than 30pds. Try a 500. Do you run spoilers? If so they seem to really tighten entry.

[stock car driver]

Never heard of anyone running a straight valve rf shock on a modified under any conditions any circumstances.

call up bob harris and gets some modified shocks from him.

His jri package is incredible, they are all bv. When I bolted them on my car it was like a new car. 6-7 would cover all track conditions.

rr base
rf base to run on lf
rf dry
lr base



rr heavy
lr dry afco
rf heavy

would be 3 adjustment shocks and cover every condition

he doesnt call them this he has rates on them but hell know what Im talking about

[Lizardracing]

I can agree with ya the shocks are important but when the car isn't even close yet the shocks will not take me from mid pack to the front. I already have a shock guy and he is very good. When I have some consistent handling I'll reevaluate my current shock package.

Today I took the springs out and smashed em. Now here's the thing on my missing set up notes. Both spring in the front rated at 580lbs and not what's marked. Now that this has come to light I do remember having these tested before and since then the tag is no longer there.
For this coming week I'm putting in a 620RF and 580LF and reducing LRB to 40-60lbs. I would have left the RF alone but I don't have anything lower than a 580 at the moment. I'm also taking out some LRU and RRU bar angle by going down one hole and the RRL I'll start 1 hole up from level. Hopefully entry and the middle will get better and the less forward drive will be needed.

[billetbirdcage]

I can agree with ya the shocks are important but when the car isn't even close yet the shocks will not take me from mid pack to the front. I already have a shock guy and he is very good. When I have some consistent handling I'll reevaluate my current shock package.

Today I took the springs out and smashed em. Now here's the thing on my missing set up notes. Both spring in the front rated at 580lbs and not what's marked. Now that this has come to light I do remember having these tested before and since then the tag is no longer there.
For this coming week I'm putting in a 620RF and 580LF and reducing LRB to 40-60lbs. I would have left the RF alone but I don't have anything lower than a 580 at the moment. I'm also taking out some LRU and RRU bar angle by going down one hole and the RRL I'll start 1 hole up from level. Hopefully entry and the middle will get better and the less forward drive will be needed.

Personally, I'd change the RF shock first before I did anything. I don't see a point in adjusting the car to neutral and then changing the shock package and having to relearn/adjust the set-up. I only say this cause your so far off a typical RF shock valving, that getting just semi close there will make a huge difference.

[Lizardracing]

What do you recommend?

[billetbirdcage]

What do you recommend?

Get some rebound in the RF. While the old numbering system don't really tell you squat about a shock today, get something in the rebound range of a 10. With something in the range of a 4 rebound, the RF has to be coming completely back up at the end of the straight and so when you let off getting into the corner I'd bet the RF dives pretty hard. This in it's self will cause you consistency problems and just getting some rebound in the RF will likely get rid of a ton of your tight issues.

[Lizardracing]

I'll talk to my shock guy today. Thanks!

[MachineMasters]

Get some rebound in the RF. While the old numbering system don't really tell you squat about a shock today, get something in the rebound range of a 10. With something in the range of a 4 rebound, the RF has to be coming completely back up at the end of the straight and so when you let off getting into the corner I'd bet the RF dives pretty hard. This in it's self will cause you consistency problems and just getting some rebound in the RF will likely get rid of a ton of your tight issues.


100% agree. Your throttle tight condition in the center is because the RF is unloading.

You need to get some low-speed rebound in the shock. Somewhere around 250lbs at 3" and 350 at 6" should be in the ball park. That'd be close to a generic 4 compression 8 rebound. Ideally, you'd get some zero point in the shock - somewhere around 100-150lbs would make a world of difference.

[stock car driver]

If you HAVE a shock guy and he supposedly advised you to run the 4 you listed you need a new shock guy.

450 each will get you some great shocks

[Lizardracing]

Digging this up from the graveyard of posts.

I got some good shocks. My shock guy found me a good deal and now I'm on:
RF: 4-8
LF: 6-3
RR: 4-6
LR: 8-2

It's helped. The car doesn't push on the throttle anymore but it's not enough.
The next week broke a pushrod.
The next week a hole showed up in the oil pan.
Then another hole showed up in the oil pan.
Then the ignition switch went bad.
The following week the Pull Bar broke and I sat out for 6 weeks fixing all that and going over everything on the car trying to shake the monkey.
We have three weeks left now.
Last week the car was decent. Still a little tight on entry in hotlaps.
I moved the J Bar up on the pinion to 3.5 rake. That makes the straight part of the Jbar level.
The car was much better in hotlaps. Still a little snug on entry but turned well on the throttle and forward bite was good when pointed in the right direction.
Just trying something I put 4lbs of air in the RF and 4lbs in the LR to loosen entry more.
Car was okay but not great. Entry was a bit freer but still needed a little brake on entry but it still rotated well on the throttle and forward bite was good.
We left it alone for the feature hoping the track would come to me but it didn't. Car was free enough on entry but lacked side bite in the middle. Forward bite was good once pointed straight but the lack of side bite in the middle was frustrating. When I could get the LF up on the inside burm the RR would stick better but someone hit the tire and I couldn't do that for the last half of the race. We finished 10th but I want more.
Someone tell me what to do here.
More RF spring?
More LRB?
More Jbar angle in the slick?
All three?

Sincerely frustrated.....

[dirtracerl77]

I would switch to 200# springs across the back. Raise the lr ride height 1/2 inch.