I e-mailed Jimfab a while back inquiring about caster with the bar and while I was told that it can be adjusted a little bit, its not enough to give me the 5-5.5 degrees I'm looking for.

My goal is to achieve this without getting the higher priced Z10 bar, or the A-Sport upper arms, both of which are excellent, but spendy products. ($900/set for the A-Sports last I heard!)

I was going over ideas tonight and thought of something that may work VERY well, at least in theory . On each radius rod for the jimfab there are 2 holes that mount on the lower control arm. If 4 holes on each rod were created as shown below in the pic, caster could have a stock and a high setting, and then the minor adjustments could be dialed in at the joint near the xmember. I don't know what kind of range this would give as I don't have a bar to experiment with yet.

Any feedback at all is appreciated!

EDIT: For those who don't know, a shorter radius rod would pull the lower control arm forward, increasing caster.

 

why would you want to have positive caster?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crxgator &raquo;</TD></TR><TR><TD CLASS="quote">why would you want to have positive caster?</TD></TR></TABLE>

yeah fill me in why? Im getting one soon and also i dont have a clue on where to set the radius rods to.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.Saturn &raquo;</TD></TR><TR><TD CLASS="quote">If 4 holes on each rod were created...</TD></TR></TABLE>

Um, that is a HUGE amout of caster. Just think of what that would do to the control arms if you adjusted that far out of spec, the control arms would be on crazy angles - and thats just the control arms.. there are lots of other things that would be thrown far out of spec. Also, you want RR to be STRONG, i don't think it's a good idea to be drilling holes and making them any weaker. safty first...

The cheapest way would be to take out the bushings and use washers as spacers.. but i'm not saying that it would be a good idea.

 

Taken from Ben's EF resource -
"The more positive caster there is, the more camber gain you will have when you turn. Remember our weak camber curves? Yeah, more + caster helps fix that. On our cars, however, the caster is not adjustable."

And don't for a second think what I mean is "the more caster the better" 5 degrees is a safe amount of caster for improving turn-in. You could do the same thing with lots of negative camber but then you run into tire wear problems. Caster is not a tire wearing factor. Also with negative camber the inside tire will lost contact as it will be tilting away through the turn. As long as you don't mind the steering taking more effort, this is a great way to improve handling.

Also don't assume I'm basing this all on Ben's site. I have done my homework and am very confident with all this. (I would like opinions from some Road Race forum guys still)

Those of you who have ever worked doing alignments, have you ever noticed the level of caster performance cars have? And also have you noticed, for multi generation cars, as the generations went on, the caster usually increased. It wasn't because designers were learning that caster helped, it was due to better technology in my opinion. They always knew more positive caster would improve most cars handling, but also had to keep steering effort at a reasonable level for street. Things like better steering racks and thinner tires all help steering effort and I think this is why caster was increased over a number of years.

As for the radius rod strength... I don't have an answer for that one, if I can buy an extra RR set to experiment with when I order my Jimfab I will. I trust my idea on this enough to slap it right on my car the first day I could get to an alignment rack.

 

BTW Radius rod ends to increase caster have been available for a long time from companies like OPM and smaller road race parts stores. Also Whiteline makes kits for a number of Hondas to increase caster. If you read any of their suspension tuning articles this is almost always the first mod they do on FWDs.

 

Looks like you've been putting alot of thought into this.. I tried 3 dfferent ideas for my CRX and ended up with this...





Maybe you can grab some prelude radius rods from the bone yard.. they might be long enough so you don't end up with a unused hole.. also, if my visual memory is correct, they look a little beefier. Maybe custom lude RR and some washers/spacers could do the trick. Or.. just see how far forward you get get your caster with just washers instead of bushings. 5 deg is not much....?

... just some thoughts 8)

 

I ran 5 degrees of positive caster last year on my autocross EF, along with 2.5 degrees of negative camber. I used a copy of the Z-10 arms. It was not difficult to steer. And that with 225/45-15 Hoosiers on 15x8.5" wheels.

This year I'll be running 4.5-5 degrees of caster, but this time I'm using the SBMS Racing spherical bearings in the front crossmember (they're an improved design to the OPMs is what I've been told).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2point2 &raquo;</TD></TR><TR><TD CLASS="quote">The cheapest way would be to take out the bushings and use washers as spacers.. but i'm not saying that it would be a good idea.</TD></TR></TABLE>

What part exactly would I use the washers on? The plan is shortening the radius rods to pull the lower control arm (more accurately the lower ball joint) forward. I don't see much of a way on the Jimfab bar to do it with washers. I agree, that I doubt it is a smart idea.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2point2 &raquo;</TD></TR><TR><TD CLASS="quote">5 deg is not much....?</TD></TR></TABLE>

Much higher than stock (+3 degrees out of spec) but still well within streetable levels. The whiteline kit (granted... EG kit) is around 5.25 degrees and is designed for street/race. If my memory serves me right, EG caster spec is the same as CRX - 0 +or- 2 degrees. With a range of 4 degrees stock, you have to realize that Honda would only provide such a wide range if 4 degrees really doesn't make that much difference in handling. What we are all looking for is better handling so adjusting it outside of spec is a must.

Also the prelude arms idea is good for a stock crossmember, but for Jimfab it just won't work. For stock crossmember I would just go with the OPM radius ends, as they allow a stiff mounting point as well as shortening of rods.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr.Saturn &raquo;</TD></TR><TR><TD CLASS="quote">
What part exactly would I use the washers on? The plan is shortening the radius rods to pull the lower control arm (more accurately the lower ball joint) forward. I don't see much of a way on the Jimfab bar to do it with washers. I agree, that I doubt it is a smart idea.</TD></TR></TABLE>

I'm talking about modding your stock RR's... do you already have a jimfab?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2point2 &raquo;</TD></TR><TR><TD CLASS="quote">I'm talking about modding your stock RR's... do you already have a jimfab?</TD></TR></TABLE>

Nope thinkin ahead, workin on a turbo B18A and will need clearence. Probably gonna do the suspension before I have the engine in though and want to do it all at once.

 

up, any other opinions?