Revival discussion

[billetbirdcage]

LR - basically tight against chain
RR - 1.5" max compression (a lot of time its way less) on turn in and out of gas. Once back into the gas it will be back to ride height pretty much instantly and then extend as much as 3" at some places (if the RR isn't limited)

[Jking24]

So let's see if we can keep a decent thread going let's talk about free roll steer vs grip/ weight transfer. When most people talk about "freeing up" or "tightening up" they associate wheelbase and load changes kinda as a pair. For instance to tighten up most would say lower right side loads and shorten right side wheel base (remove rear steer) but does that actually make sense ? Should we really remove free roll steer for conditions that we need to drive straighter in? People often associate to much steer with the car crab walking up the racetrack but is that what's actually happening ? Or is the excessive amount of lr drive just starting to show up when it's paired with more steer ?

[Jim11h]

Removing what we've learned to use getting us thru corners better makes no sense when tracks slow down. The corner momentum is your speed. Were basically using the rear steering like a Bigfoot truck. Both ends turn making cornering better kinda way I've always thought. Clearly could be crazy and obviously here to learn

[Punisher88]

I got a question here that someone may could help. I have a 604 crate car that I run and it turns on a dime on the fuel where I race weekly where we run wide open early in the night, I help alot of guy, but I have one guy that has the exact car as me that runs 602, I've had his shocks dynoed and matched to mine, went through the car front to back, plumb bobbed it front and rear, pulled drop out, lengthened j bar, all the way up on all rods, 5.5" stagger, everything the chassis manufacturer has recommended has been in the rear. We just cant get it to make that initial cut on entry like mine does. I recalled recently and added some rear % to what I run, which is 51.5%. I gave him 53. We run 8* camber lf amd 6 rf and 2.5 and 5.5 on caster. The cars have 3/4" of lead built-in to the front ends. Same rear ends and all. Just a motor difference. But it is a noticeable difference on entry. We can set quick time but its turned left all the way to the center and doesn't have the "feel" either of us would like when driving it. What would be your go to on the front end, knowing its maxed out in the rear.

[billetbirdcage]

I got a question here that someone may could help. I have a 604 crate car that I run and it turns on a dime on the fuel where I race weekly where we run wide open early in the night, I help alot of guy, but I have one guy that has the exact car as me that runs 602, I've had his shocks dynoed and matched to mine, went through the car front to back, plumb bobbed it front and rear, pulled drop out, lengthened j bar, all the way up on all rods, 5.5" stagger, everything the chassis manufacturer has recommended has been in the rear. We just cant get it to make that initial cut on entry like mine does. I recalled recently and added some rear % to what I run, which is 51.5%. I gave him 53. We run 8* camber lf amd 6 rf and 2.5 and 5.5 on caster. The cars have 3/4" of lead built-in to the front ends. Same rear ends and all. Just a motor difference. But it is a noticeable difference on entry. We can set quick time but its turned left all the way to the center and doesn't have the "feel" either of us would like when driving it. What would be your go to on the front end, knowing its maxed out in the rear.

Question, has one driver driven both cars? or just going off what each driver feels there car is doing

[Punisher88]

I've driven both. He's also driven mine. Bout drives through the infield when he drives mine it turns so quickly compared.

[billetbirdcage]

Assuming both cars are both the same style/year/brand/etc of cars and something different in set ups isn't being missed, I'm gonna guess its a frame flex/stiffness or a torsional stiffness issue or a mounting point difference on the two frames. Now the one known difference is the engines, one being alum headed and the other being steel headed and likely a 30 or 40# overall engine weight difference. I used to know the COG of a 604 compared to other engines but never messed with a 602 to say how it might relate to a 604 or other steel block stuff.

Anyways here's a few things I would check:

1. Measure the RR upper shock mount height between the 2 cars, the 602 car might for some reason be lower causing the tight in issue.
2. Measure the birdcage locations on rear end and shock mount drops.
3. You might temp add a long bar with rod ends to weight clamps from the dash bar around where the 5th coil bar meets it, to as close to the RF upper shock mount on the upper rail as you can to stiffen the torsional stiffness and see if the helps (only way is to try it).

[Punisher88]

When I say everything on the cars are the same, I mean EVERYTHING. The only difference is I pulled some drop out of his, and lowered j bar on the frame a hole. And lengthened his j bar a half inch the last time out when I drove it. I dont have it trailer back. I dont like trailing the rr. I also have his top bar indexed on rr. Which I also dont care for the feel of that. But we're doing whatever it takes at this point. I feel like the rigidity of the front ends are pretty good. They have x bracing in front of the radiator, and have a bar going from the door bars to the left front shock mount/upper cross member. I also feel like its something to do with the engine combo. Only thing we haven't done is throw my 604 in and try it.

[Jking24]

When I say everything on the cars are the same, I mean EVERYTHING. The only difference is I pulled some drop out of his, and lowered j bar on the frame a hole. And lengthened his j bar a half inch the last time out when I drove it. I dont have it trailer back. I dont like trailing the rr. I also have his top bar indexed on rr. Which I also dont care for the feel of that. But we're doing whatever it takes at this point. I feel like the rigidity of the front ends are pretty good. They have x bracing in front of the radiator, and have a bar going from the door bars to the left front shock mount/upper cross member. I also feel like its something to do with the engine combo. Only thing we haven't done is throw my 604 in and try it.

It sounds like maybe your headed in the wrong direction. In my experience lowering the j bar on the frame will free entry when off the fuel. And you say you lengthen the jbar so you moved the rear to the right again will free the car off the fuel but both of them in my experience have a huge effect on the car when in the fuel and they tighten the car alot. 602 really lack straight away speed compared to a 604 or open engine combo so my guess is the car is falling on the lr and their is probably also a difference in the nose weight/ cg. Remember when Entering on the fuel or at least initially turning in those adjustments will be opposite. Think freeing exit

[Punisher88]

We fixed the falling on the lr with shock package adjustment. We put my double adjustables on at a rental night and it helped the posture and helped a BIT with entry on the fuel but minimal at best. I'll definitely take that into account on the j bar. In qualifying here in a 604 or 602 you're wide open. So any little hiccup or bind is maximized with the little motors being bogged down. And like I said. He's set on the pole and won multiple times. We're mostly searching for a feel not necessarily speed. When I drovenit 2 weeks ago I went from 4th to 2nd in the heat, and took lead in the feature from 4th pretty quick with a half straightaway lead when my rod picked a fine time to leave. I appreciate the insite.

[TwistedFrame21]

If you're looking from the top of the car, the rear strut should be inline with the bolt for the lower arm at the crossmember. Meaning if you stuck a long rod thru it instead of a bolt it should line up with the strut's rodend. This puts the mount almost into the oil pan so many of the car with reverse struts end up with the strut too far right which causes caster gain under compression.

Next issue is the rear strut ends up hitting the tire when turned right so you end up with an S shape to it to make it clear and its weak.

Wouldn’t being reverse strut with rear strut further outboard cause caster loss? Assuming both points are on the same plane and taking upper control arm out of equation, in my mind the lower ball joint would move backwards essentially losing caster

[billetbirdcage]

Wouldn’t being reverse strut with rear strut further outboard cause caster loss? Assuming both points are on the same plane and taking upper control arm out of equation, in my mind the lower ball joint would move backwards essentially losing caster

Correct, I mistyped