lower control arm alignment

[Rocket5353]

Leading the left front makes sence to me when I visualize it but this is the first I have heard of someone actually doing it! I'm going to attempt to try it square and go from there !

[7uptruckracer]

Yeah I would have to say I agree more with that then litteraly having to flex my lower to get it to mount up! Also is there supposed to be any spacers or anything on the front mounting point ? It's a 2014 with raised cross member. Same question for the left side ! I appreciate everyone for taking the time to explain these things !

That's a good car set it up geometry wise how the book tells you. That's cars are pretty good on entry so post what you have under it will Probably be more helpful then messing with the front end

[25drtrkr]

That's a good car set it up geometry wise how the book tells you. That's cars are pretty good on entry so post what you have under it will Probably be more helpful then messing with the front end

I agree with you 7up! Every Blue Rocket I have worked with turned very well, sometimes too well. I would make sure everything in the front end is set to Rocket specs. Im not saying that you cant improve their std setup but I believe there are setup problems elsewhere.

[billetbirdcage]

I'm going to open a can of worms here.


Someone want to explain this theory, that leading/trailing the RF over the LF can/will make the car turn/not turn differently??

Lets for argument sake, say a change of 1/2" or even 1" take your pick. Remember a 1/2" change is a half of 1% of the actual wheel base (typical 104" wheel base).

I have drawn 2 cars both the same only difference is the pink car has front tires inline and the blue car has the RF lead .5". Caster is the same on both cars as is the caster split, only difference is either the control arm mounting points are moved on the frame to get the lead or your doing your caster with the uppers vs the lowers to get a lead on the RF.

[7uptruckracer]

If this is a crate Blue front end rocket if its who i think it is. Drop the rear a lot from rockets baseline and up the LS.

[7uptruckracer]

We have this adjustment with the lowers on the asphalt LMSC. It effects how weight is held onto and off of the RF. Dirt is no different these days the gap is closing in some aspects. They will Lead the RF or trail the LF to make it turn in on the gas better for dirt. It's "similar" for the turned stub modifieds. You can't just go changing it from the builders design or your affecting ackerman, spring angles, depending on how you do it caster gain, bumpsteer. You have to take all that into consideration. Rocket has gotten ummmm a little off and crazy with their design especially since the orange came out, they aren't as dominant. I've been working on one and it takes a lot to get it to run with the Longhorns, MBH, Club 29 cars. I saw some Jbar stuff the other week they had that absolutely blew my mind. Post your setup if your that tight for as much as you can alter your LF to RF lead or trail it probably wont make much different in what your entry.

[dirtslinger71]

I posted this over a year ago and now no longer have the rocket. I converted to a smack down this year and love it! Winning races and setting poles. But the the lower control arm adjustments probably weren't my problem at the time ... But it did make for a good discussion and I feel that the lowers should be square and adjust caster on uppers. No other type of race that I have worked on other than a dlm do u ajust caster with lowers... Jmo. Thanks for all the info also guys.

[25drtrkr]

My only concern when I see these type of posts, is what type of system was used. You have to establish the true centerline of the chassis to determine the proper alignment. Its not difficult but takes a proper method when stringing a car. When used properly, you can:
1) set caster lead or trail
2) set tie rod lengths
3) align rear tires with front (parallel)
4) align rearend side to side
5) align birdcages

I was fortunate to have an engineer pass this down many years ago. It takes very little $$ to do it, but takes a fair amount of time to do it right to obtain precise measurements.

[save the racers]

Pulling the r/f forward would change the ackerman, which could help the car turn in.Weight distubution would change a slight amount, might or might not help entry.I've offset the wheelbase in other classes to beat rules.A lot of times that is how it all starts.

[7uptruckracer]

Well if its designed into it by the builder it wouldn't if you change it after it would. Anything moving a tire away from centerlines will change the weight the tire sees