RX7Club.com - Mazda RX7 Forum

RX7Club.com - Mazda RX7 Forum (https://www.rx7club.com/)
-   1st Generation Specific (1979-1985) (https://www.rx7club.com/1st-generation-specific-1979-1985-18/)
-   -   Wow, g force panhard/trilink (https://www.rx7club.com/1st-generation-specific-1979-1985-18/wow-g-force-panhard-trilink-725215/)

Kentetsu 05-07-08 02:41 PM

Mine is on the way to me right now, I can't wait! My Racing Beat bar is going to GSL-SE Addict.... :)

jgrewe 05-07-08 02:47 PM

The stock front bar can be fine with the rest of the car set up properly. When you have urethane or delrin bushings in the rear suspension you are increasing roll stiffness back there. The delrin is the worst because when the car leans the lower arms have to twist, that means its actually a sway bar too.

With everything swinging freely and the strut spacers(not CSP legal) the stock bar is just right. Without the front spacers you will need a little more than the stock bar can offer.

Zyrano 05-07-08 06:33 PM


Originally Posted by jgrewe (Post 8169155)
The stock front bar can be fine with the rest of the car set up properly. When you have urethane or delrin bushings in the rear suspension you are increasing roll stiffness back there. The delrin is the worst because when the car leans the lower arms have to twist, that means its actually a sway bar too.

With everything swinging freely and the strut spacers(not CSP legal) the stock bar is just right. Without the front spacers you will need a little more than the stock bar can offer.

Are you referring to my setup? and when you said I'll need a little more than the stock bar can offer, is that front or rear?

I know I have quite a bit of tuning left, I'm going to play with the panhard a bit more, and then see where to go. I am afraid to go with a bigger front bar, because I'm almost out of ability to increase rear roll stiffness, since a front bar will lead to understeer, but it sounds like maybe I should try it?

justint5387 05-07-08 08:20 PM

Alvin, I have a RB front sway for sale, or you can try it first and see how you like it.

elwood 05-07-08 08:30 PM

Suspension Pic
 
1 Attachment(s)
Here is the only decent shot I have of my stuff installed (they guy in the photo isn't me)

Kentetsu 05-07-08 08:57 PM

Elwood, I understand that your suspension setup is quite different from mine (very sharp btw), but adding the heavy bar to the front of my car made more difference than any other suspension mod I had made up to that point (which was quite a lot). My co-driver is of the same opinion.

Last fall I gained possesion of an adjustable rear bar, which has three different points where you can mount the endlink. I run it on the stiffest setting, along with 150# rear springs and Billy's adjustable perches, and I'm in love with my current setup. Its hard to imagine anything handling better.

Anyway, maybe adding a heavy bar to your suspension wouldn't make much difference. But my personal experience is that it was the best upgrade of all. It even let me put the stock rear bar back on without fear of snap oversteer. Just my 2 cents....

jgrewe 05-07-08 10:36 PM


Originally Posted by Zyrano (Post 8169795)
Are you referring to my setup? and when you said I'll need a little more than the stock bar can offer, is that front or rear?

I know I have quite a bit of tuning left, I'm going to play with the panhard a bit more, and then see where to go. I am afraid to go with a bigger front bar, because I'm almost out of ability to increase rear roll stiffness, since a front bar will lead to understeer, but it sounds like maybe I should try it?

With the delrin out back you may need more front bar than a stock one.

There a million different combinations of springs and bars that will feel pretty good. When you are fighting to get that last couple 10ths on a lap everything has to be working correctly.

Any time you have a sway bar it should just be used to tune the feel of the car. If you need a huge bar on either end of a car that is almost perfectly balanced something is wrong. The same goes for spring rates. The biggest difference front to rear on the FB is the weight of the rear end itself being unsprung weight. What is going wrong back there that a 150-175lb/in spring feels good to the driver and the front springs are in the 400 range? There are other things that are acting like springs that shouldn't be. Its hard to get your shocks right if you are asking them to control a soft spring vertically and a bunch of unknown twisting bars when the car leans.

I personally don't like much of what I see from ISC. Its under engineered and not very well thought out but in many ways the stuff can be made to work. The whole package of stuff before he copied the tri-link design was like having one foot in a bucket and putting your other in another bucket so you would feel balanced. Funny thing is there are a bunch of fast cars that run the stuff, the ones that beat those cars run the GForce Engineering package.

Zyrano 05-07-08 11:26 PM

I guess I'm confused jgrewe. I'm not sure if you are talking to me still, I hear what you are saying, but I don't have any delrin in the back of my car, and I'm also running 250 lb (or was it 275?) springs in the back to match my 375 in the front.

I use to run the 175 in the back, but realized that the rear suspension wasn't really working, and that's why I picked up the gforce stuff. The only "beef" I have with the gforce stuff is that I can't run the entire package for street prepared. By not being able to run the heim joints and the turn in spacers, I know I have more tuning to make it work. But so far i'm fairly happy with what i have...

jgrewe 05-08-08 08:43 AM

Sorry to confuse you Zyrano, not just talking about your set up. It sounds like you're doing what you can within the rules. I'm just talking about what I see in the threadin general.

There are still a bunch of people that think putting some huge bar on the front of these cars is the final answer no matter what else is on the car. A lot of the parts that have been available have been just a way to make one end of the car work equally as poorly as the other. Other parts like delrin bushings come from not having a clue as to what the suspension needs to be able to do. In the end you end up with a car so bound up in roll that you can't tell what its from or how to fine tune the handling.

jgrewe 05-08-08 08:50 AM


Originally Posted by Zyrano (Post 8166994)
I'm actually somewhat limited in the use of heim joints because I run CSP, which doesn't allow heims in any stock locations. But yes, I have heims in the panhard and trilink, as well as the delrin isc lca bushings, the car is totally livable, what is not livable is not passing smog for cali law. Anyway, I'm currently running 375 fronts and 250 rear with stock fr/rear sways and the panhard pretty much as high as it will go, the car is totally fun to drive. can't wait to do some more tweaking...


Here is where I got the delrin thoughts. Unless you have some twisting ability in those lower control arms they are acting as a sway bar.

Zyrano 05-08-08 09:08 AM

Thanks jgrewe! I think i'm up to speed now.

Re-Speed.com 05-08-08 09:43 AM


Originally Posted by Zyrano (Post 8171584)
Thanks jgrewe! I think i'm up to speed now.

Your delrin is in the front control arm pivots, not the rear lower control arms, correct?

-billy

Zyrano 05-08-08 10:00 AM

yes, but all jgrewe is saying is that i'm essentially increasing my front roll stiffness.

Zyrano 05-08-08 10:04 AM

which is fine, basically, you don't want too big of a difference in spring rates between front and rear, since the 7 is mostly a 50/50 car. Where as a big mismatch in spring rate is telling you something is setup incorrectly that is being compensate. There will be a bit of mismatch because the rear end is a lot of unsprung weight, which is why i'm where I'm at now at 375/250.

Although, at some point down the road, i'm looking at the new 255/40/13 a6s, then i'm not sure if this setup will work... (i'm dreaming mostly here...)

jgrewe 05-08-08 01:11 PM

Delrin will cause trouble in the front control arms as well just not anywhere near as much. Unless there is a way to allow it to swing in two axis the arm has to twist just a little because of the tension rods. They are close to being lined up front to back with the inner control arm pivot but they make the arm swing a little forward and back. At the amount of travel we use on track I doubt that it would bind things up much. I bet the delrin just wears a little eventually and give just enough slop for the arm to move the way it wants.
I would file that problem under "looking for that last .01 second" right after buying some $11,000 shocks. lol

Zyrano, if the car works now the new tires will probably only require minor adjustments(unless its a totally different type of tire, ie. street radial to bias slick) The biggest adjustment will be to the driver. You may end up with more lateral grip which may make your car lean more and that may move the suspension out of its "controlled binding" zone you are confortable with. Let us know if you end up getting them.

Re-Speed.com 05-08-08 01:22 PM


Originally Posted by jgrewe (Post 8172261)
Delrin will cause trouble in the front control arms as well just not anywhere near as much.....
I would file that problem under "looking for that last .01 second"

My thoughts exactly.

Zyrano, are there any CSP rules against a replacement Stay rod?

-billy

justint5387 05-08-08 01:31 PM


Originally Posted by bwaits (Post 8172296)
My thoughts exactly.

Zyrano, are there any CSP rules against a replacement Stay rod?

-billy

I don't think you can replace the stay rod in CSP.

Zyrano 05-08-08 01:51 PM

basically, stock bushing can be replaced but without increase the amount of metal, for example poly and delrin are within the rules, but solid metal and heims are no nos.


All times are GMT -5. The time now is 04:32 AM.


© 2024 MH Sub I, LLC dba Internet Brands