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Dont bother with the NC bar. Just get the Rx8 PT front bar. Then PT rear bar or OEM Rx8 R3 rear bar (R3 bar doesnt engage as harshly as the PT bar from what i understand). Using Evo-R adjustable endlinks front and rear.
Ha! So sure? Balance right now is to understeer. It’s ok now but will need to dial in some more rotation as I get better. Pt rx8 front bar, which is the stiffest out there and orange dot rear bar, which is a touch stiffer than stock... will exasperate the understeer, right?
Also, the rx8 has lots of roll but it works. It finds grip everywhere. I don’t want to lose that by over baring it. That’s my concern.
However once I add the tires (maybe bfg rivals) I am sure I will be looking for much more roll stiffness. But it’s still a street car.
Ha! So sure? Balance right now is to understeer. It’s ok now but will need to dial in some more rotation as I get better. Pt rx8 front bar, which is the stiffest out there and orange dot rear bar, which is a touch stiffer than stock... will exasperate the understeer, right?
Also, the rx8 has lots of roll but it works. It finds grip everywhere. I don’t want to lose that by over baring it. That’s my concern.
However once I add the tires (maybe bfg rivals) I am sure I will be looking for much more roll stiffness. But it’s still a street car.
Trying to balance that all out.
Yes, upgrading the front bar while using stock rear bar (or even the R3 rear bar) will make the car understeer worse unless you change spring rates.
I have a set of used Hotchkis RX-8 swaybars that I just took off in lieu of doing a PT front swaybar and no rear bar (might do a stock rear bar) but my spring rates are really aggressive vs what most street or track RX-8s have traditionally used. (800 lb/in front and 600 lb/in rear)
^^^apparently everybody who raced B Stock back in the early - mid 2000s had no idea what they were doing then … because we all pretty much ran a stiffer front bar on the S1 RX8; Mazdaspeed with added stiffer endlink position hole was common (can do same to the OE front bar), I had a custom 1.25” OD x 0.125” wall bar with adjustable endlink holes, which can now be duplicated by an equivalent wall thickness speedway bar.
Maybe read what I said with context, c'mon Mark.
He has Bilstein PSS and the car is already understeering with his current swaybar setup. Putting a much stiffer front swaybar on the car is *not* going to magically make it looser.
My STX setup also has nothing to do with what you guys ran in B Stock...
and a 1.25" OD x 0.125" front bar isn't very stiff vs the PT RX-8 bar either.
Yeah, I completely missed that, so thanks for getting me straight on it.
.
Sorry if that came across rude, I've been seeing a lot of people arguing that stiffer front swaybars add grip and therefore the car will understeer less... Yes it adds grip but it changes the roll couple a lot. I'm sure you know this
Originally Posted by Nadrealista
"Set the ride height to 13.75” and a streetish alignment at -1.5 camber, 6.5 caster and 0 toe front. Rear at -2.0 camber and .2 deg toe."
I would say he first needs to align the car properly by swaping those front and rear camber numbers, that should help with understeer/rear rotation...
Agreed. I daily drive my car with -3.8 front camber and -2.5 rear camber and the tire wear is pretty even, 0 front toe and 0.45 degrees of total rear toe-in.
"Set the ride height to 13.75” and a streetish alignment at -1.5 camber, 6.5 caster and 0 toe front. Rear at -2.0 camber and .2 deg toe."
I would say he first needs to align the car properly by swaping those front and rear camber numbers, that should help with understeer/rear rotation...
yep, I assumed that already. Wear marks on the rear indicated less roll over than on the font. I should have room to balance out the car with alignment. That is why I am looking for sway bar ratios similar to stock.
Sorry if that came across rude, I've been seeing a lot of people arguing that stiffer front swaybars add grip and therefore the car will understeer less... Yes it adds grip but it changes the roll couple a lot. I'm sure you know this
Not at all; thought I was in a different thread and obviously not paying attention is how I got the context wrong. You were completely reasonable in your response and it’s my apology for the misplaced comment.
I think the one comment about swapping front/rear camber alignment specs is what I’d do first though. It’s a pretty common RX8 setup error to run too much or more rear camber than front camber that generally results in an understeer condition.
Ended up going with the PT RX8 bars. So far I am happy I did. Went with moog endlinks which are not adjustable but are solid, greasable and reasonably priced.
Install was straightforward and has been covered here. Other than cutting a frozen rear endlink, the back was a no-brainer. The front, I decided to use the racing beat technique by not removing the lower radiator brackets and under tray. Fed in the new bar from one side. It worked but took some trial and error. Might have scratched the bar a bit but otherwise no problems. Not sure it was worth the hassle but it can be done.
Initial feedback from street driving. Glad I went with these so far. On the softest setting the PT bars add resistance to the ride that I would say is about 20% stiffer than the yellow dot. Just driving around, I noticed the difference but I doubt any passengers would. Ride and comfort penalty is very small.
Handling wise these might have made more of a difference than the PSS. Temps are getting cool and I am still on Ventus Nobles so I didn't expect much but... woah. The whole attitude of the car taking a set is drastically improved. It feels ready to attack and seems better with aggressive inputs. Even in provoked oversteer the response to corrections comes with no more of a whiplash feel as with stock. I know theoretically there should be less mechanical grip, however in this short test I could not tell. It feels to me like the chassis is driving the outside tire down into the pavement. Grip is good until breakaway but confidence remains high.
Thank you to those who recommended going with something on the stiffer end of the scale. Even with the PT bars the RX8 still has a reasonable amount of roll, these are very much not overkill even for the street. I am surprised how much bar the RX8 can take, although the PSS does have modest spring rates. Cant wait to use these bars on the track with some real tires. Its nice to know I have some adjustment headroom if I find I need higher rates for the track. Will have to wait for spring on that.
Initial feedback from street driving. Glad I went with these so far. On the softest setting the PT bars add resistance to the ride that I would say is about 20% stiffer than the yellow dot. Just driving around, I noticed the difference but I doubt any passengers would. Ride and comfort penalty is very small.
Handling wise these might have made more of a difference than the PSS. Temps are getting cool and I am still on Ventus Nobles so I didn't expect much but... woah. The whole attitude of the car taking a set is drastically improved. It feels ready to attack and seems better with aggressive inputs. Even in provoked oversteer the response to corrections comes with no more of a whiplash feel as with stock. I know theoretically there should be less mechanical grip, however in this short test I could not tell. It feels to me like the chassis is driving the outside tire down into the pavement. Grip is good until breakaway but confidence remains high.
Thank you to those who recommended going with something on the stiffer end of the scale. Even with the PT bars the RX8 still has a reasonable amount of roll, these are very much not overkill even for the street. I am surprised how much bar the RX8 can take, although the PSS does have modest spring rates. Cant wait to use these bars on the track with some real tires. Its nice to know I have some adjustment headroom if I find I need higher rates for the track. Will have to wait for spring on that.
Now that you have had these for a while what are your thoughts. I am considering PSS coilovers to replace my stock suspension and am also thinking about sway bars. My needs are primarily street but I will probably be doing a few track days but nothing serious. I will most likely replace the coilovers first and then decide on sways, like you did.
11-07-2021, 07:37 PM
