suspension setup questions
 

So after I did a track day earlier this week, I've realized I need to do a few things to the suspension in order to get it to my liking for next year.

First off, trying to decide on a good spring and shock combination. I'm split between RB Springs with Tokico D-Specs, or Eibach's with Koni Yellows. I would like the slight extra drop of the Eibach's, especially in front, but the price and reviews of the RB springs and Tokico's seem good also.

I'm going with the Enkei RPF1's for the great price and low weight, but can't decide on 17s or 18s. The 17s would be great for the weight savings and reduced price of the wheels and tires, but I'm going to be using these on and off the track. Does anyone have pictures of an RX8 on 17s, I just don't want it to look like a monster truck.

Now brake pads... I'm going to stick with the stock rotors for now since they have a lot of life left in them still. I can't decide if I want to go with the Hawk HPS or Hawk HP+. The big questions I have is, do you swap to track pads before each race or drive around all of the time with the same pads on the street also? The HPS's look good for the low noise and dust and better than OEM performance, but the HP+ seems like a better option for the track while they will be noisey and dusty on the street.

Just looking for some input at the moment on what you would recommend.

I did H-Tech and Tokico D-Spec. Love them. Still have enough suspension travel and the car is great on the track "3" and around town "7". You want shocks you can adjust WHILE THEY ARE STILL ON THE CAR. I can do all 4 in 4 minutes.

I went with HPS instead of Plus because of the cold performance. It is a lot colder where you are. I am nowhere near the limits of the brakes. I might be in a few more trips, then might change. Lot depends on the track. I do Roebling. I only hit the brakes 3 times a lap or so.

Swoope did the Eibach's He ended up with spacers in the rear. I think he has 17's as well. I suggest a PM, he has been off lately.

If I had the change, I would do a 17 set of very track like tires and use the 18s for the street. I cannot afford the extra set at this time. shorter tire gives more grunt out of the corner.

The tokico makes a complete spring and strut package. I used it before going with coilovers and I thought they worked great. The drop is around 1"-1.2" which is perfect for the track and street.

If you are going to switch pads for the track, the hp+ are a better choice, but if you are new to tracking the car you should be just fine with the hps.

If you decide to switch out pads for the track, be sure to clean and sand the rotors (120 grit sand paper) otherwise you can get uneven pad deposits which will cause a vibration.

If you plan to do track days more then once or twice a year, I suggest you go with the 17's and make them track only wheels/tires. Using street tires on the track will get expensive very fast. You are better off with a r-comp tire on the track and a regular street tire for the street. It will save you money in the long run. Downside: R-comp tires mask poor driving. It is better to learn on street tires and switch the r-comps after you have some time under your belt.

Easier than sanding rotors, use Acetone, cleans the pad deposits right off, really easy. just use a towel to rub with.

Decide if you want an even drop or the same gap over the wheels. I did the h-tech to get the gap the same and provide a more aggressive stance.

I will try the acetone.

Same gap looks nice but it puts more weight toward the front and throws off the balance of the car.

Bottom line, either one will work well. I would just suggest not following one of us for one side, and the other for the other.

One the acetone, it worked great. Just understand, no smoking.....

And, the lower front seemed to improve MPG, that was the weird part, almost 2 MPG.

Save your money and get more seat time

17" rpf1 wheels and r-comp tires = $2000+
Suspension upgrades = $1000 and up (sky is the limit)
upgraded brakes = $300 and up (sky is the limit)

More seat time = Priceless.

agree with more seat time but it aint free, lol.

Speaking of seat time, you gonna take any more of those pictures in you sig any time soon?

^me?

Ok, this looks like the right thread to jack!:lol:

My 8 is a track toy. I drive 300 miles to every track four times a year, and I want to fix my saggy rear GT springs shock crap.

I'm really sold on Bilstein HD's for the shocks, but WHAT SPRINGS DON'T LOWER BESIDES RACING BEAT?

When you search springs everything is : LOWERING SPRINGS so a search for a real performance spring came up with like 954 threads.

See why this forum gets some dumb questions? Too much data overload!

Ok, flame suit on, I like Racing Beat, but I don't want any progressive spring or lowers more than half inch. Any ideas?:scatter:

Your 8 is a track toy but you dont want to lower it? I am a little confused why. Lowering the vehicle around an inch will improve the handleing over just stiffer springs and struts.

With that said, every performance spring will lower the car, even the racing beat springs lower the car about .5"-.8" IIRC. If you absolutely dont want to lower the car, you will probably have to go with a coilover and will need at least $1000 for a decent set.

And what is wrong with progressive rate springs? They provide all the performance of a higher rate spring but dont make the ride too uncomfortable.

If you decide to go with racing beat springs, check out this for sale thread, tokico specs also for sale. Both are good deals. I have used the d-specs before going with coilovers and I really liked them.

https://www.rx8club.com/rx-8-parts-sale-wanted-44/racing-beat-springs-set-tokico-d-spec-shocks-205832/

Now see, that's the fire I wanted to light!;)

I'm about sold on that RB and Tokico combo in these photos.

In fact that'll RAISE me about 1 inch!

You see why I'm a track guy, but still confused. My car is stock, but obviously with blown rear shocks, so I think I could actually fix it with just shocks, but I'll put RB's on the rear to make sure while it's off. My front measurement is 13 and 1/2 inches which many people has said they have. The rears are 13 which are essentially lowered already as stock (on the bump stops).

So tell me, are those Tokicos anything like our stock shocks? I thought they were Tokicos. :dunno:

Here's my car on 17's

http://www.flickr.com/photos/nycdriftking/4758757675/http://www.flickr.com/photos/nycdriftking/4758757675/ by http://www.flickr.com/people/nycdriftking/, on Flickr

NYC Drift King,
Yeah, your 8 has a good stance, and very tasteful mods!

I assume you have a garage to lock it up, because it has to draw attention.

Not true partner. The RX8 geomety actually doesnt benefit from lowering it. The front actually benefits from RAISING it.

The most economical thing you can do with a stock car is to check and put a track alignment on the car. New drivers who add mods to thier car MASK their driving deficiencies which is why a those who don't modify their car learn faster than guys that buy all the bullcrap for it. I've seen this happen dozens of times. Just because the car can go faster doesn't mean the driver has learned to go faster. Put a turbo on the car and reduce your lap times by 5 seconds---are you faster now? No.

The point I make is that there is nothing smarter than seat time. I can hoof a stock car faster than most drivers who own a modified car. The trick is to get the tires contact patch on the ground. This saves your tire wear and reduces some of the undesirable effects of pushing the stock suspension.

A more aggressive alignment with a generous amount of camber in the front (depending on the type of track your running) will allow you to understand what your car is doing better than a heavily modded car.

Too often that not THE MAJORITY of drivers have no clue how to play with shocks. Shocks are not easy to use properly let alone understand what your car is really doing.

Bars are a smart choice (after lots and lots of seat time) as well as an increase in spring rate. Increased spring rate can really influence your street cars ride but front spring increase really helps the nose dive when getting into your ABS (which all RX8 drivers need to learn how to do). Stock spring rates will unload the rear tire contact patch and aggressive trail braking from high speeds will allow the rear end to get light and come around on you.

Again, the best thing to do is get more seat time in a stock car to understand what the car wants to do (any car) before modifications. You then went to add one mod at a time to understand what the car wants to tell you. Done properly you'll want to get lots and lots and lots of seat time and listen to these new mods.

Something I like to tell sporadic drivers who beleive they know it all is this: Do you have 5 years experience or 1 year experience 5 times.

Buy a tire pressure gauge, a pyrometer (or share one with a buddy) and buy your wife or girlfriend a purse and flowers because proper seat time for a beginner-expert DE driver requires lots of seat time. Lots of seat time and different tracks to be direct with you guys. Please don't base your skill set by driving Road America 52 times. If this is your only option find a very talented instructor (professional preferred) and re-learn your home track in your car. This will be an eye-opening experience. This is kinda like golfing with Tiger Woods or throwing the football with Payton Manning.

The bottom line is there is more in a stock car (any car) then people understand. Save your money and get seat time.

Respectfully,

Eric

I hate to jump into this thread outa the blue but i have a few questions about suspension.

I was wondering mainly Lowering springs vs. Coilovers. I know that the overall better choice is coilovers but i have some concerns with getting them. I have heard its a pain to get them all to the correct heights and weights, without scales. And I dont want to pay someone to do work for me, I want to learn the hard way by just doing the work.

I also was wondering how hard is it on the stock struts to put lowering springs on, how long will they last?

My main goal is to get a nice Mildly aggressive stance and stiffen up the ride a little bit, I want to get the look of the front being higher then the back gone. I was also thinking about stiffer sway bars but im unsure as of yet. I want to start autoX when i get back but that will be about 5 months. I am new to the RX8 (3 Months) and new to any car modifications besides basic maintenence. I have read up alot about this car and am starting to learn alot about it. I am currently in IRAQ but when i get back I plan on doing some modifications to the car with the extra money. I want to first fix my APV issue then focus on the suspension and brakes.

Any and all suggestions will be great. And any suggestion about the car will be deeply looked into. Thanks

O yeah, its a
2005 M/T
87k Miles Original enginge
GTX 5-30

Setting up coilovers not only requires scales but a lot of knowledge and seat time as well. You can't expect to install them be done with it since rebound\damping etc all need to be addressed after you know how the car behaves on a determined track etc.
Coilovers aren't cheap either, the good ones i mean :D

That is kinda why i was just wanting to go with springs, and maybe a struts... I just want to get a decent even setup, but i need to get APV working properly as it started sticking about a week before i left, right after mazda did a carbon cleaning. The guy that is looking over it right now hasnt seen it throw a code though. I do want it lowered, not drastically, i was thinking 1.5" front and maybe 1" rear? any suggestions?

\\


Let's fix your first problem first. Why do you think your APV is not working?

\

Hats off to you and your look into the future. This is a great perspective to have. If your new to AutoX (or road course driving) the first thing I'd do with a stock car is drive it in stock condition. Learn what a car wants to tell you. Do it again and again and again. Mods are fun and easy and can lead you into a trap quickly. The type A personality with a budget is usually the guy that spends the most money and crashes the most. The Mechanical Engineer with a budget is usually the fastest to learn to drive quickly (no kidding). Teachers are good too because they are "students" and understand learning. Learning and practicing is the key to becoming a better driver. I digress.

I'll steer away from AutoX suggestions because I know nothing. Perhaps our friend Team could chime in on this one. I would trust his guidance for car mods (or lack thereof).

The mazdaspeed swaybars (or RB) are a nice compliment to a stock car. Be prepared to find a local race shop (ask several different racers from your local track for their advice) and have your car track aligned. DO NOT fall prey to the local Goodyear tire store alignment if you want a track alignment. Most all of them have no idea of what this is about. Find an experienced shop that RACERS ARE USING AND RECOMMENDING. Ask to watch them and take notes. Show up with your car in drive trim (the tires you would normally run and the amount of fuel you normally run with (even though the location of our fuel tank has very little change in cross weight AT ALL)).

given the basic premise and overall response you really can't go wrong with the full MazdaSpeed shocks/springs/bars package since there's nothing to turn or adjust other than alignment, tire pressure, and most importantly driver skill level i.e. KISS.

well said.....very good post:score:

Team, Eric,

Anyone else. The few posts here are among the most useful and helpful I have seen on this topic. Wish the was out there a year ago. Only problem is, without the year of playing around, and doing it slow, and making mistakes, I am not sure I would recognize it as incredibly useful. Those just getting started, take it on faith.

Also, the note about a shop that understands track alignments, take it from the guy who did one shop 5 times in a week... Find a good shop, or, write down exactly what ALL of the numbers are supposed to be and MADE SURE THEY GIVE IT TO THE TECH!

Either its not opening up fully or its stuck closed... stated messing up about 4 days after mazda did a carbon cleaning. I think some broke loose and jammed the cylenders closed. When i get back i will try to spin the gear, and if i cant break it loose then i will just replace the LIM. That is if I still have problems when I get back. Which I Probably will. And I rev it to redline almost every time I drive it, but about a day before it had the P2004 code, it felt sluggish in the upper RPM's which is why I think its stuck closed, or possibly the motor is burnt out, I will test both when I get back.

How much lower are they then stock? I have not driven the car on a track yet, but i have however driven it on some roads that i know very very well, and I niticed the car had quite a bit of understeer, any way to start eliminating this? and the best route to do this... I know while braking (transfering the weight to the front of the car) helps, but any setup features that could help?

Check out
http://www.tirerack.com/tires/tirete...jsp?techid=58&

Lot of data in one place. Also, it will be nice to see what this group thinks of it.


The raw text is inserted below, use the link above to see pretty tables.


Air Pressure for Competition Tires


The table below suggests tire inflation pressures to be used during competition. Tires should be reset to normal inflation pressures when returned to the street. These recommendations should be used as a starting point. Pressure can be adjusted to match the driver's preferences. Adjust pressure in 2 lb. increments.


Type of Vehicle Position Pressure
Front Wheel Drive Front
Rear 35-45 psi
30-40 psi
Front Engine/Rear Drive Front
Rear 35-45 psi
30-40 psi
Rear Engine/Rear Drive Front
Rear 35-45 psi
35-40psi

When racing on D.O.T. approved tires air pressure is a major consideration in tuning the handling of your car, especially in cases where suspension adjustments are limited. The chart below shows some of the changes you can make to change the balance of the car.
Guide To High Performance Handling

Adjustments Decrease Understeer Decrease Oversteer
Front Tire Pressure Higher Lower
Rear Tire Pressure Lower Higher
Front Tire Section Larger Smaller
Rear Tire Section Smaller Larger
Front Wheel Camber More Negative More Positive
Rear Wheel Camber More Positive More Negative
Front Wheel Toe Toward Toe-Out Toward Toe-In
Rear Wheel Toe Toward Toe-In Toward Toe-Out
Front Wheel Caster More Positive More Negative
Front Springs Soften Stiffen
Rear Springs Stiffen Soften
Front Anti-sway Bar Soften (Thinner) Stiffen (Thicken)
Rear Anti-sway Bar Stiffen (Thicker) Soften (Thinner)
Weight Distribution More Rearward More Forward

To get even tire wear when using D.O.T. tires you must be very careful not to use too low of a tire pressure. The Hoosier Radials can wear unevenly if underflated and seem to work best at much higher pressures, such as the mid 30s to as high as 50 psi. Underinflation will cause a thin ring of wear at the very edge of the tread. The best results on the Hoosiers seem to come when they are properly inflated, on fairly wide wheels, and with a good amount of negative camber. If properly inflated, these problems can be avoided. Probably the biggest adjustment you can make to improve tire wear is the driver. Avoided sliding the tires, locking up the wheels under braking and drive as smooth as possible.

TIRE PRESSURES IN THE RAIN

For both autocross and road racing, increase tire pressures 6-10 psi from what you would normally run in dry conditions. Hydroplaning occurs when a wedge of water develops between the tire and road surface. This wedge can actually lift the tire off the road and eliminate traction. Increasing the pressure rounds the profile of the tire by decreasing the deflection of the tire. This results in a smaller contact patch - narrower and shorter. It also helps keep the grooves in the tread open so they can channel the water out from under the tire.

Understeer in an unmodified RX-8 is mostly an alignment/tire choice-pressure/driving style issue. The OE shocks are not particularly good and they wear out quicker than most people recognize.

As for the previous post, generalities are only that. Sometimes a change can result in the opposite effect depending on what the actual cause is.

.

i can get some oversteer out of the car but it seems to be a little more tighter than i would like, almost like the front end loses grip too easily. I agree could be alignment or driving skills since i have never actually raced a car, did race ATV/s back home but I want all attention turned to the car. I was thinking about getting the TEIN BASIC Coilovers, for that look. Will give a little bit of adjustability but nothing that dramatic. Am i correct?

If your driving a stock car and nothing is broken, your understeer beliefs are most likely originating from your driving style. Please record an incar video and share. Many a new driver experiences understeer (my experience) when adding generous throttle with the wheel turned. As a general rule of thumb, if you are adding throttle AND turning in more wheel input at the same time then the driver is the cause of the u-steer.

At what rpm does the problem occur when you drive your car in 3 rd gear starting at a low rpm, depressing and holding the throttle at 100% up to 8,000 rpm?

May u also suggest please to take this topic to another thread to retain the integrity of this topic. Thank you.

Eric, what you are referring to is not managing the weight on the front end, right? Ideal turn process is Brake (weight on front), lift (still some weight transfer to front), turn (weight forward keeps front wheels planted better), now that car is turning, add throttle (weight shifts back to keep rear planted). Too much throttle moves weight back, off front, and you lose ability to generate turning force (understeer). Fix is to go back to the right order, or, if it happens in a turn, back off throttle to re-plant front while praying that you have not confused the hell out of the suspension and driver behind you, right?

Your on the right track big Mike.

MOST new drivers who have an aggressive driving style will try and go flat with their throttle (full throttle) too early in a turn. Add an early apex (because type A personalities often can do this) and you have a situation where the car is headed off the track under power. To avoid going off track the driver cranks in more steering AND keeps his/her foot planted. The car understeers like a pig. MANY A NEW DRIVER DOES NOT KNOW WHAT THIS "FEELS" LIKE. So they continue this driving style. Again, this is often heavily influenced by the early apex line. Your weight transfer theory is correct however it is possible to settle the car down, go to 100% throttle, turn the wheel big time and get the car to understeer. Add a decreasing radius corner and the problem gets worse. Add an off camber surface to this corner and it will also get worse. Add too high front tire pressures or bad tires or big, grippy rear tires and the problem gets worse.

The biggest issue here is usually the driver as he can be the contributor to the most influential components of understeer.

To put this another way...........you can drive a car with understeer. You just have to drive it differently. I am fortunate to know guys that can drive a car that handles like a POS. A few years ago I didn't have the skill set to drive this type of car. I "NEEDED" a well setup car to go fast. As I learned and learned and learned a new skill set arose---the ability to better understand small nuances in the car, adjust my driving style and get much more out of her. Often big time patience is required to accomplish this. WAAAY more than a new driver can often conjure up.

What's the moral of the story? Get good instruction. Listen. Have somebody better than you evaluate your line/driving style/application of throttle/wheel input rate/all of the above and see IF IT'S YOU. One of the reasons for data collection is to quantify what the driver is doing. If you have data many of this issues are quickly discovered.

And in my experience understeer experienced by a new and even novice (most novice actually) is due to an desire to go faster and going to full throttle too early.

Cheerio

I agree its most likely my driving, or the alignment/setup. And to get a video will be impossible because im in IRAQ until spring time. When I get back I will start to do some AutoX and see if some of the experienced drivers will ride along and give me critiques... (or however you spell it.) I know I do want to get the car a little lower, even if it barely increases handling. "As long as it does not make it worse, which i doubt it will." The car grips great but on agressive driving i would prefer to get oversteer vs. understeer if you know what i mean.

I understand what you're saying Eric, but what if you don't want to adapt to this understeer? My car is my fun toy/daily driver and I won't be doing trackdays. I race motorcycles, and don't have the time/money to take my car there too right now.

My last sports car was a 90 Miata, only mods were Azeni tires and an alignment. I never had the front end issues with it that I'm currently fighting in my 8. After reading alignment threads on here, I took my 8 in and maximized the front negative camber. I even took Team's advice and gave up over 1 to 1.5 degrees of caster just for that last 0.1 degree of negative camber. Initial turn-in was immediately improved, but overall grip is still very low in the front. Currently, I'm speculating that the rear shocks are shot, as there is an excess of rearward weight transfer during throttle application.

As it sits, I feel like I have to drive my 8 like a FWD car, where I'm tossing it into a corner to rotate the rear, then straightening it up with the throttle.

I think you have two options:

1. Something is hosed with the car. Find it, fix it and hope that your cars handling woes are gone/understeer is reduced.

2. Your car is fine and keep driving it with your current style.

I'm not sure your car's issue might be. But if it's fine, it's your driving style inducing understeer.

If you don't want to adapt to understeer then don't. Tiger woods could choose not to adapt to playing out of a sand trap (if he wanted to) but he wouldn't be as good as he is. Let us know about the rear shocks (and anything else).

I didnt buy the car new... is the rear suppose to look lower than the front??? its not drastic but it is noticable" to me atleast" if not then i believe rear shocks could be bad? could cause understeer as well

the rear "does" look a little lower in the back. The gab between the top of the tire and the fender is less in the rear vs. the front. Alot of lowering springs will fix that and lower more in the front to even out the look.

I dont know why, but I really dont like that...

Please be careful everyone when using the gap or space between the top of the tire and the bottom of the fender. Purposeful manufacturing processes (Mercedes as an exsmple), cars that have broken or damaged suspension or frame items or (my favorite), cars that have been in accidents can give you false readings. The proper way to measure a car is to get underneath it (w driver) and measure hard points to the ground. 4.5 front and 5 rear is a great place to play (hint, hint)

I have been doing autocross in the 8 for a few years now, as well as a few track days. Suspension is pretty much stock with the exception of Koni yellows. I'm looking to reduce some body roll, and not ready to spend big on coilovers. Would the Progress sway bars be a good match with the stock springs, or too stiff? I'm not really looking to do springs, most of the them are only marginally stiffer than stock, so it seems like they are more for looks than anything else. MS springs would be nice, but there seems to be some debate over whether the rate was true. It'll help my limited LF camber though (1deg at most, even with min. caster).

Another inexpensive option you have if you want more camber (which is limited with ride height on the RX8: the higher the car in the front the less negative camber you can get), is to go to an offset front lower control arm bushing. SpeedSource makes these and their available via MazdaSpeed Development website. Made of Delrin. Will not hurt anything.

Basically you'll gain more neg camber opportunity.

Certainly sways over coilovers are the easy and cheap way to help eliminate some body roll + or - depending on the stiffness of the bar you choose. Because bar stiffness is pretty much a crap shoot depending on brand... the way to avoid that problem is to buy an adjustable bar (one with 2 or 3 holes at the link attachment point). Benefits are you can (actually) tune the under /over steer of your setup plus you can decide how much roll you want by choosing soft to hard settings. Cost over a fixed bar in minor.... Advantages are major.

For any serious improved camber however, you'll need coilovers, or (less good as they won't be as good match to your shocks) lowering springs.

Any idea how much the bushings are, and how difficult to install? Last time I install bushing in a different car, everything has to be taken apart and was quite a pain.

Mazdatrix is selling both the Mazdaspeed bushings and a cheeper set by drop engineering. Both upper and lower are available. Upper MS- $251, DE $212, Lower MS $386, DE $260.

Not mentioned here, but Eric made and installed some upper control arm delrin bushings to remove the stiction on the control arm. See post for explanation https://www.rx8club.com/showpost.php...8&postcount=15

I heard someone else installed some poly bushings that also removed the stiction, not sure how accurate that is.

Well, thanks for all the replies everyone even though the discusion went completely off topic. I'm going to start auto crossing next year and will start in novice and move to STX once I get booted. I've decided STX since I need to use an aftermarket seat thats lower which would automatically kick me out of the stock class.

I already have progress tech sways installed and then just need to pick up some new endlinks. Tokico D-Specs are sitting in the basement and I'm still trying to decide on H&R's or Teins S-Techs. Hawk HPS pads will be ordered along with the Corbeau Forza race seat.

I currently have the RB dual res midpipe installed, so I either need to switch to my stock midpipe or build a midpipe with a high flow cat.

Lastly, I still can't decide on running 245's on the 18x8's or shelling out the extra cash for Enkei RPF1 17x9's. Total package on tirerack for RPF1's including Hankook RS3's is about $1550. We'll see how much tax returns and work bonuses pay out in the spring before I decide.

Um,

depending on how low you need to go, you can lower the seat.

I've read the posts on trimming the padding or modifying the bracket, but it's still not enough clearance. Those usually net about 3/8" extra clearance, I need about 1 - 1.5".