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View Full Version : Pre loading a strut bar



guaynabo89
05-23-2003, 05:35 AM
Anyone know what effect pre loading a strut bar will have on the chassis? Either pulling or pushing the two strut towers.


I've been thinking about this and wonder if anyone does this and if will have any effects whether it be positive or negative.

Or if anyone knows any good sites that might answer my question please post.

crwa
05-23-2003, 07:21 AM
What do you mean by pre-loading???

guaynabo89
05-23-2003, 08:08 PM
Adjusting the screw on the srut bar so its either too short or too long to lign up with the brackets that bolt to the top of the struts.( you'd have to force it into place then)

That way you would make the strut bars either pull in or push out on the body of the car.

Jims 86LXI HB
05-24-2003, 07:59 AM
I would think it makes perfect sense to preload the strut bar. As to which direction to load it to, that's anyone's guess. I would be inclinced to think that most of the movement between the towers would be inward, theirfore I'd load them to push on the towers vs pulling them.

guaynabo89
05-24-2003, 01:16 PM
Originally posted by Jims 86LXI HB
I would think it makes perfect sense to preload the strut bar. As to which direction to load it to, that's anyone's guess. I would be inclinced to think that most of the movement between the towers would be inward, theirfore I'd load them to push on the towers vs pulling them.

I would also think that a slight pressure pushing the srtut tops apart would make sense, but I'd like to know if someone's done it from experince, maybe some autocrossers.

Anyone know any good autocross sites with lots of info on suspension tuning?

Jims 86LXI HB
05-24-2003, 04:45 PM
Originally posted by guaynabo89
I would also think that a slight pressure pushing the srtut tops apart would make sense, but I'd like to know if someone's done it from experince, maybe some autocrossers.

Anyone know any good autocross sites with lots of info on suspension tuning?

The one's I've visited tend to assume you already know about suspension tuning, least the the sense I get. Never the less here's a good one to check out

www.sccaforums.com

Jims 86LXI HB
05-25-2003, 09:02 AM
Ya know I can add, in terms of the 3g. It will perform better with stiffer springs and better strut control. I recommend Ground-Control coilovers with custom rates 400lbs front and 325lbs rear. Run them with revalved Bilstiens that have been matched to those rates. I also wanted custom sway bar sizing. 1" in front and 7/8" in the rear. Also part of this would be to have the car corner weighted and to call Ground-Control and give them the corner weights and and them where I should transfer weight around by adjusting the coilovers. Corner weighting is the number on REAL reason to equip a car with coilovers.

With the H&R's and Koni's, the car performed great, it was soooo much fun to drive and easy to drive to the limit and get the best possible performance out of it. BUT,...past say 8/10th's of the limit you could tell that you did not have enough spring stiffness or strut power. You could feel the suspension moving to much, going to the bump stops all to close. That being said, I don't think we have a bunch of members that take their 3g to the limit like I did all the time. That is why I pulled my Bilsteins out and had them revalved, I was planning on getting the custom rated Ground-controls and setting the car up to be much stiffer. That way up to 10/10's of the limit I would NOT run out of suspension power, to make the car all that it could be.

superaccord
05-25-2003, 11:30 AM
so which one is it....do you tighten the strut bar in or do you push the struts out? good info ya know.

AZmike
05-25-2003, 02:46 PM
Since the strut tower bar is only supposed to increase chassis rigidity, I would preload it outward just enough that all the slack was out of the joints, but no more. Using the strut tower bar to bend the unibody will not increase its stiffness, it will just bend it out of the shape that Honda thought it should be.

superaccord
05-26-2003, 06:18 AM
cool, thanks

AccordEpicenter
05-26-2003, 09:41 AM
yeah, i bet it would actually change the camber of the front wheels if you preloaded it too much

markmdz89hatch
05-26-2003, 07:37 PM
if you were to pre-load the bar so much so that you would have camber issues, then the camber issues would be the least of you worries. The more would be the severly weakened strut towers/mounting points. Oh well, anyway, I went to the Limerock Raceway here in CT yesterday and got to speak with many Honda/Mazda race techs. and many mentioned that with the FE/FWD, the biggest concern should not be rigidity in the front, but instead, more-so the rear. In fact, a little (only an iddy-bitty-tid-bit) of flex allowance up front may actually aid the steering issues associated with FWD cars. The rear is what you want nice and tight. Just thought I'd add my $.02.

guaynabo89
05-26-2003, 07:45 PM
I went to the forum that Jim put a link to and read through it for a while.

They also sugested tightening up the rear end of fwd cars to reduce understeer.

Pre loading is not necesarily a good thing, but it might help on the rear end.

Since its just a brace the best way to install one is with the vehicle on the gorund at normal height and adjust the bar until it fits nice and snug.

Jims 86LXI HB
05-26-2003, 11:03 PM
Originally posted by guaynabo89
I went to the forum that Jim put a link to and read through it for a while.

They also sugested tightening up the rear end of fwd cars to reduce understeer.



To bad Eibach ignor's that fact with the pathetic rear spring rates that use on the sportlines and prokit's. Tightening up the rear means higher rear spring rates and thicker rear sway bar diameters. Both or either will lesson understeer. Lower rear spring rates will increase understeer, we get enough of that from the factory as it is.

Glad to hear to went to the link.

guaynabo89
05-27-2003, 04:46 AM
Originally posted by Jims 86LXI HB

Glad to hear to went to the link.

Yup. Thanks for the info.


Actually it got me to thinking about getting a larger diameter rear sway bar to replace the S.T. rear bar I have.

Hey Jim any idea on what would be a good diameter for the rear taking into account that I already have the s.t. front?

I remember you posting a link to a place that will bend you a bar to any diameter you wanted, you just had to send one in.

Jims 86LXI HB
05-27-2003, 09:21 AM
Originally posted by guaynabo89
Yup. Thanks for the info.


Actually it got me to thinking about getting a larger diameter rear sway bar to replace the S.T. rear bar I have.

Hey Jim any idea on what would be a good diameter for the rear taking into account that I already have the s.t. front?

I remember you posting a link to a place that will bend you a bar to any diameter you wanted, you just had to send one in.

Now your thinking;) :D

I was thinking of running 7/8" or 15/16" in the rear. I think anyone would benefit from doing a larger rear bar. But anyone running the Eibach springs REALLY should put such a mod on their "to do list", high up the list that is.

Here's the link to the place I've posted about before.

www.sanerperffab.com/products.htm

$180 per bar (as of last year), includes poly bushings. You send them a bar and all the links and mounting hardware to copy. They are very busy, it took them awhile to answer my email.