Alright here is the deal. I have read alot of archived threads about caster/suspension theory. But there seems to be no general consensus regarding caster's affect on tramlining. Many argue that adding positive caster (say by swapping the uca's on a dc2 and going from 1.0 degree to roughly 3.0 degrees positive) decreases the amount of tramlining. The argument is that increased positive camber promotes self-centering, thus the vehicle is less affected by uneven or rutted road conditions. Is this true?

I am aware that there are many factors that lead to tramlining, such as tire selection and bushing condition. But will adding 2.0-2.5 degrees of caster noticeably reduce my dc2's tendency to follow the longitudinal ruts and/or grooves in the road?

Thanks is advance! And sorry for my low level of intelligence.
-Conlan

 

I didn't do the swap on the upper arms for this reason but it did seem to help a bit with tramlining. But then I also hit some grooves that were really bad and the car was "stuck" in them.

 

I've got just over 4* caster, and my DC2 doesn't tramline nearly as much as it used to when I had 0.5* (stupid Ingalls camber kit).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TunerN00b &raquo;</TD></TR><TR><TD CLASS="quote">I've got just over 4* caster, and my DC2 doesn't tramline nearly as much as it used to when I had 0.5* (stupid Ingalls camber kit).</TD></TR></TABLE>

I have the same Ingalls camber kit. Did you use the swapping uca's method to increase your caster? Also, were there any ill effects for daily driving?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dvp &raquo;</TD></TR><TR><TD CLASS="quote">I didn't do the swap on the upper arms for this reason but it did seem to help a bit with tramlining. But then I also hit some grooves that were really bad and the car was "stuck" in them. </TD></TR></TABLE>

Did your car experience alot of tramlining before you swapped the uca's? I think being somewhat stuck in the grooves would be better/safer for me then being pulled badly.

 

subscribed.

 

Does anyone else have anything to say? I had a very good conversation with TunerN00b via PM and I feel more confident that tramlining will be reduced by having a few degrees more positive caster. Any objections to this statement?

 

I wouldnt add caster for the sake of self centering but for the affect of camber change for cornering...when you have power steering, you can deal with a lot of caster...if you dont, start hittin the gym! or subscribe to a bunch of **** lol...if you got that one

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HapaHaole &raquo;</TD></TR><TR><TD CLASS="quote">I wouldnt add caster for the sake of self centering but for the affect of camber change for cornering...when you have power steering, you can deal with a lot of caster...if you dont, start hittin the gym! or subscribe to a bunch of **** lol...if you got that one </TD></TR></TABLE>

Yes, I have p/s. So the increased turning strength needed doesn't really apply. Hated the feel of driving my car when it had the manual steering rack.

I definately know what you mean about the ****. The more I watch the larger my forearm becomes, it's crazy.


Modified by slim9300 at 8:37 PM 4/19/2006

 

lol

I just meant to pass time till more people answer this thread...jk

 

I swapped over the a-arms right before I got it aligned and ended up with 3.5 degrees ish on both sides but I'm not sure how much better off I am. It really seems to slide a bit more now, but the turn in is nice and it feels like the stability improved.

 

Anyone else with some experience on swapping the upper control arms?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wildoutwhitegsr &raquo;</TD></TR><TR><TD CLASS="quote">Anyone else with some experience on swapping the upper control arms?</TD></TR></TABLE>

There are some more vague threads about it if you search caster.

Is there anyone who can argue for, or against, the idea that adding caster leads to reduced tramlining?

 

Well, the results are in, but here is a little background info first... I swapped the UCA's this morning and took her in for an alignment. I took a look at my alignment specs from last week to see what my caster looked like before today's alignment. The driver side was -0.23, the pass. side was +0.43. I didn't even realize that my caster was actually negative on the driver side. For the record, before I put in the engalls kit last week the caster was +0.96 and +1.21. Also for the record, the car always experienced heavy tramlining, the worst on the freeway. And there really was hardly any difference in the amount of tramlining between the two caster settings mentioned above. So basically, the variance in caster was due to the design of the Ingalls camber kit, which allows for some slight adjusting to caster. If you can't picture how this is possible, look at the picture below, think of the left camber adjustment being offset the opposite of the right. As you can see the Ingalls kit can affect caster about a degree if not adjusted while paying attention to caster. (Here's the pic, but you probably know what I am talking about:



Anyways, enough with the BS. After the alignment was done (after sitting and giving directions to the H-tech ) with the UCA's swapped. The front caster went from L: -0.23 to +3.05 and R: +0.43 to +3.45.

First off, I have P/S so this first comment is kind of pointless for anyone without P/S. My initial impression was a slight increase in "effort" required to turn the wheel. (As expected) This was slightly more noticeable at low speeds, compared to higher speeds. (Obviously ) I actually like this feel better then what it was for before, but the difference probably wouldn't even be noticeable to most people.

Secondly, THE TRAMLINING WAS SIGNIFICANTLY REDUCED! (Thank God. ) From 5-40 mph tramlining is reduced, say 50%. (Enough to to easily tell) From 50+ mph tramlining almost doesn't happen. At a nice clip on the freeway, a section where the ruts used to pull mild/medium, I can now let go of the steering wheel and the car stays nice and straight. (Letting go=holding my hands an inch away just in case. So, no flamming.) On portions of the freeway with heavy ruts, like the far right lane or King County (very bad), tramlining is still there a little bit, obviously. But much less then before. Long story short, the faster you go the less the vehicle experiences tramlining. Before with normal caster, the opposite was true. I hated driving on the freeway, even through I drove 500 miles a week. Now it's like I am driving a whole different car.

Also, for those worried about bumpsteer I felt no noticeable increase in this behavior. Granted this was all street driving and I am not going to be an idiot. But where I am from there are alot of country roads where nobody is around. I got a good feel for what the car has/can do and I didn't experince any negative feedback, only positive. Many of these roads aren't the smoothest, so I feel it was a good street test at the least. Anyways, if you have any more questions or comments let me know. I am not the greatest with suspension theory/understanding/lingo, so I am sorry about any bastardization of the field. I hope this was helpful.
-Conlan



Modified by slim9300 at 11:52 PM 4/21/2006

 

Wow, that's a big adjustment. Thanks for the report.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LudemanDan &raquo;</TD></TR><TR><TD CLASS="quote">Wow, that's a big adjustment. Thanks for the report.</TD></TR></TABLE>

It's kinda funny, I was under the impression that I would gain roughly 2-2.5 degrees of caster. I guess it depends on the dc2. I am happy though, since I would rather have 3 degrees then 2.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HapaHaole &raquo;</TD></TR><TR><TD CLASS="quote">I wouldnt add caster for the sake of self centering but for the affect of camber change for cornering...when you have power steering, you can deal with a lot of caster...if you dont, start hittin the gym! or subscribe to a bunch of **** lol...if you got that one </TD></TR></TABLE>

Also, adding caster increases dynamic weight jacking - a similar effect to what happens when you corner weight your car. As a result, you can increase caster to help rotate the car. Of course reduced rear camber, higher rear tire pressures, more rear biased roll stiffness, and trail braking can all be used to help rotate the car.

 

Here is a link to the same thread in the Suspension Forum: https://honda-tech.com/zeropost...99103

For all the people that preach about not double posting, I understand why this is a rule. But, I would have never gotten the same quality of feedback that I did if I hadn't put the thread in both. Hopefully you understand.