CSP autox 1st gen rear suspension setup
 

I've been autoxing my first gen for 1.5 years. Been working on it bit by bit and actually have it working really well (predictable and easy to drive). The driver (ie me) still needs lots of work, but in the mean time, I'm considering taking the next step and redoing the entire rear suspension.

My current setup is
Custom Beeline MFG camber plates with about -2.5 camber, 4.5? degree caster
old koni shocks all the way around
375 lb front springs
175 lb rear spings
coilovers with close to 50/50 cross weigh setup
some poly bushings and delrin in the lower front control arms
215/50/13 V710 tires on 13x7 panasports

I'm also do not understand the meaning of the word comfort and drive this thing to work everyday (though on 15x7 panasports with es100 tires)

My question is this, I'm thinking of redoing the rear suspension to run Gforce Engineering pan hard and tri link. I understand this would require additional tuning with new spring rates and new shock adjustments (possibly new shocks), but my question is how big of a difference is this going to make? have anyone made this leap and can tell me whether it is worth the effort? I'd like to know especially for a autox setting, because I just can't afford too many track days (though the car is used for 1-2 track days a year).

I am by no means a good driver, and the thrid link and panhard on my car made a huge differance!! Get Jim's book when you get his rear suspension stuff too.

It has been about 6 or 7 years ago that I made the switch to the G-Force Tri-Link & panhard bar, and they are wonderful. They do not necessarily require a change of shocks and springs; your spring rate front/rear balance rate look pretty close to right. On smooth pavement, you will be able to run even stiffer springs. But for a daily driver, you don't want stiffer springs.

with my old gsl-se, it was always sort of a dance to get it around the track. jacks -se has the panhard, and its just plain easier to drive.

other than that the 2 cars are pretty similarly setup...

I haven't personally run the tri link setup, but have heard lots of good things about it. In the meantime, if money's a problem, I got a lot of improvement out of my car by disconnecting one side of the rear sway bar and going with a big ol' front bar. Worked pretty well in AX, never did a track day with it though.

rob81gsl has this set up, PM him Alvin. I highly recommend improving the flawed stock rear end, the watts linkage roll center is very high and the upper control arms are way too short and cause binding problems when combined with the watts.

Cool, sounds like something to look into before the next season. I'm really happy with the way the car is now, but it sounds like it can be even better with gforce setup. I already have the manual, just wanted to know if people liked the panhard/trilink better...

Thanks!

Alvin

Are the trilink and panhard both legal in CSP? I am thinking adding both as well during the off season.

Yes, they both are. Hey Zyrano, have you had any luck catching those damned Miatas yet? At the last race of the year, we really kicked some butt! We managed to bag 2 911s, 6 Miatas, 1 944, 2 STIs, a GTO and a few other notables. Next year I hope to get some racing wheels and race rubber, but it will probably be another year after that before I can start upgrading the rear end to the Gforce stuff.... :)

Heh, well, the driver needs work. But the car works really well. I had a really good driver in the car, and he was able to beat a 450+hp Z06 (though with old race tires) as well as a most of the miatas. However, the killer miata (national caliber) ones weren't at this event, so not sure how the car would do against those. But I personally have a lot of room for improvement left.

My black/white RX-7 is set up pretty much like yours. It's reasonable enough on the streets and makes a pretty decent autox car. A couple of years ago I was entertaining the panhard rod/tri-link setup. I opted against it because I didn't want to take the Street out of my car. I also went and bought another RX-7 that had all this stuff already on it ;) It's got all the g-force stuff on it including some double adjustable shocks. The previous owner placed in the top 5 in CSP with this car several years ago. I'm no threat of doing that though.

But to give you some information, I extremely glad I didn't put the panhard rod/tri-link setup on my black/white RX-7. The new car is extremely noisy with the revised rearend setup. The tri-link and panhard rod have bearings - not bushings.

I like to call my black/white RX-7 STREET prepared whereas the blue one is street PREPARED. Which one is faster???? The blue one accelerates like crazy and when the conditions are right it handles great. Sometimes its like I'm skating on ice though. Surely it's faster but I haven't done a back to back comparison.

Search this section of the forum, there's a good thread in here where we talked about setting up a 1st gen for autox.

Hum... So maybe it is something I should wait a bit on. I know it is only a matter of time my 7 goes off street duty (as california smog laws suck), and I'm probably getting a truck and trailer in the next year or so... but then again, the car is noisy as well anyway, what's a couple more rattles and such... Decisions Decisions... What do you mean when the conditions are right though? I was thinking that the panhard/trilink would almost always be faster at an autox... Thanks for the info!

yeah the g-force stuff is loud, mine needed new rod ends, but its still clunky.

12a's are tricky to get to pass, lemme know next time you need to smog it, there are tricks.

Sounds good, Thanx!

Like how good my tires are, how grippy the asphalt is that day, and the course layout. I would think on a very grippy surface the difference would be more noticable.

Edit: Oops, realized this reply was meant for Kentetsu, not the original poster.. you've already got that covered!


I've been autocrossing (though not in my Rx7) for about 6 years... my opinion?

The investment in dedicated lightweight wheels with true R-compound rubber will pay back much quicker than the suspension mods... like, IMMEDIATELY pay back :lol:

lol, yeah I have wet dreams about good wheels with race rubber on them... :) Hopefully next year!

Well, here's some pics of the car right now

a bag of weed has allways worked for some of my friends in Cali.

Prior to this season I changed the rear suspension to panhard and tri-link (my own design/fabrication) and the biggest difference I noticed immediately is how neutral the car is in a slalom.I also went to coilovers on the front to get the spring rates and camber settings correct.
Previously it was a handful because I was always chasing the rear end. So with these changes the car is much easier to drive.
Bruce

haha, never tried that!

Actually the car is really neutral right now. We got it as close to 50/50 cross weight as we can with the front coilovers (including stuff like moving the battery to behind the passenger seat) and used tire pressure adjustment to fine tune. It is extremely predictable, but it sounds like the g force stuff would make it even better, just matter of me making that leap... as for that bag of weed... Why, you can get high just with what is coming out of my tailpipe... =)