No grip in the corners?
 

Hey.

I feel that my lowered on tokico hp / tein combo RX8 doesn't have much grip in the corners. I'm not sure if the problem is with the tires (performance all seasons) or something else. Compared to my Mazdaspeed Protege, the RX8 has beautiful balance but nowhere near the grip my MSP had. I have a mild alignment of about -1.2 deg. camber all around and 0 toe on the RX8. The 8 feels like it'll easily slide if i drive it at its limit. Is this an issue with the tires or something else?

Thanks!

more than likely it's the tires.
what tires do you have?

All season tires is your problem

All season tires in a state with ONE season.

Ditch the shitty tires and put some Max Performance Summer tires on.


Do you have coil over shocks? If so have you adjusted them on corner scales yet?

Did you do a front sway bar?

What Spring rates are you running?

Have you changed spring rates in an effort to find the right setup or are you more concerned with slamming it to the ground?

It took me 3 tries to get the right spring rates on my RX7 and multiple trips to the corner scales to balance it right. As well as multiple trips to the alignment rack.

I run Falken Azenis RT-615K tires on my 7. On the 8 I plan on running Bridgestone Pole positions when the crappy tires I have on now wear out. I also have a set of track rims for the 8 that will be getting Dunlap Star Specs on them soon.

+1

if you want an example of how important tires are, we went from Toyo R888's to Hoosier R6's and it dropped almost 3 seconds from our laptimes.

there is nothing else on the car that changed laptimes that much. we even put a different engine in, that is 60hp more and that might be about 2 seconds.

tires are the only thing between the car and the road

Boggles the mind.

Makes sense, fellas. I had purchased the 8 back up north with these tires. I believe they're a sub brand of Goodyear. I should mention that I don't plan on racing the 8. My MSP also had all seasons, one of the Falken's, to make this a fair comparison. I was thinking that this could be due to the alignment or possibly the lowering on my part with the mentioned setup. I'll be picking up a set of Enkei's soon, either the GTC-01s or maybe the WDMs and plan on using summer tires then.

Un-boggle your mind and don't be so quick to jump to conclusions

I've used a couple of all-season type tires on my car. The Pirelli's were quite trackable. The Continentals, while they handled quite well, were biased more to the wet/snow weather.
That said, it still could be the model of GY tires your using.

I picked up some Work emotion cr kai's and bought Firehawk indy 500 wide ovals which I was not impressed with at all. Everybody I have talked to has said go with Pirelli pzero's. They come from factory on the 911 gt3 and on the Italia, and are apparently very impressive. Just something to look at when the time does come! GL grippin =)

There was no conclusion. Only confusion.

What he said: model of tire makes a bigger difference than make of tire. Compare Kumho Ecsta XS to Goodyear RS-A. People that only pay attention to brands will think that the Goodyear will be the better performance tire. And they will be so, so, soooooo wrong.

Falken rt-615k stick im running bridgeatone ponteza re90 there pretty good too. But im running 265/35/18

i think the FWD vs RWD platform has something to do with it as well.

I think unconsciously you pushed the fwd car more because there was no chance of sliding, if it started to plow, you eased off the gas and that was it, full potential.

I think you have a sport, so no dsc/tcs and the tires start chirping and nervousness sets in? Ultimately the tires are extremely important and will get you faster times.

I could be wrong, but thats how it is with me. I havnt had enough experience with controlling a slide so i dont push it as hard as fwd cars ive driven.

I hear a lot of things about the RT615K not being able to control heat, and losing grip fast. check out the RS-3's maybe? Direzza Z1 Star Specs? RE-11's? Federal 595 RSR's(not regular 595's, those suck)

depending on what kind of driving you do... (generally...) RS-3's are good for track driving, star specs for autocross, Federals for mountain runs

Dsc/tc is so not needed. Driver mod is whats important.

Whether a Sport model has DSC/TSC, depends on the model year. Mazda made a change in the model designation around 2006. My 2004 Sport has those features. There was a base model, at that time, that did not.
I have no problems with that statement.

2009 sports did not have dsc.
2009 touring/gt/r3 had dsc

i know, i owned a 2009 touring

sports came with cloth seats,no sunroof, no dsc toggle, halogen lights, and no foglights.
touring had cloth seats,fogs,dsc,no sunroofm,hid
gt came with leather seats,fogs,dsc,sunroof,hid
r3 came with recaros,fogs,dsc,no sunroof,hid

in 2010 they removed the touring designation(imho the best of both worlds between performance(no sunroof and cloth seats) with practicality(hid and dsc switch)

at the end of the day, driver mod is the most important, but im saying that unconciously the dsc not being there has an impact on someone with a low driver mod. for example myself. I have not yet learned how to control the car sideways with it turned off.

^^^ That's when SCCA comes in, and you can learn full car control, then time attack course ;)

I practice full car control from doing scca and drifting, Also learning from two U.S pros Tony Angelo and Ryan Tuerk. both great guys and down to earth.

Yes, my sport has no kind of driver aids, which is the way I like it. I've gotten the rear end to slide out a few times in slower, tighter turns. The 8 just feels like it's gliding along instead of gripping, especially on steady, faster corners. I guess the verdict would be in once I get the new wheels/tires, but it makes sense that the tires are probably the big factor here.

make sure to get a proper alignment, one that is more aggressive than stock settings to further increase handling.

ive learned a lot by posting in there today.

Thanks for the recommendations, I'll look into those. BTW, FWD could be very tricky to handle as well, especially one with a stiffer setup like the Mazdaspeed Protege, and mine in particular. Any sudden transfer of weight from back to front would cause the rear end to slide out. Thankfully I've had plenty of practice with that over the 8 years of ownership of the MSP, some in the form of the beautiful / tricky Los Angeles mountain roads.

I already run about -1.2 deg of camber all around and 0 toe with +6 deg of caster.

i can't say if your tires are good or not, but i can chime in on the fwd to rwd feeling as I recently came from a Mazdaspeed 3 to an R3.

On my favourite twisty road my MS3 felt like a train on wheels, the first time I made a pass in my rx8 it felt like there was less grip except when I noticed the speed and saw 10-15kmph more through the middle of the corners. the rx8 rotates vs. pushing and that feels different at first if you've always had a fwd car

Excellent feedback. This also makes a lot of sense.

May I recommend the Yokohama Advan Neova AD08. :yesnod:

and to pimp out my review :lol2:

https://www.rx8club.com/showthread.p...wpost&t=240548

Great review! Was that in MPH or KPH? I really only need tires which would offer a combination of good dry/wet traction, turn-in, life. I'm sure that there are more than a few choices on the market with such attributes.

Thanks, and it was in MPH.

I would really recommend the Michelin Pilot Super Sports if you are not tracking nor autoxing. I think you could get an easy 20k+ out of the tires and Michelin provides a 30k warranty for the tires. I thought they were really great on the street in dry and wet (I live in Seattle), I just hated them on the track.

Another tire that was brought up earlier, which will be a lot cheaper are the Dunlop Direzza Z1 Star Specs. I do not have any experience with these tires, but a lot of the 8rs up in the NW where it rains a lot use this tire for autoxing. They claim it has excellent dry and wet grip. The only reason I haven't tried that tire is because I hear it doesn't hold up well on the track. I think the Dunlops will save you a good $300 over the Michelins, I just don't know how long they will last.

Good luck finding a tire. There are so many different tires, and it is a lot of money to find out if you are happy with your choice :)

The camera's depth of field distorts the perception of speed, a lot.

I have used Dunlops before, their DZ101, and did enjoy them.

I appreciate the feedback.

By the way, if anybody is looking for a good deal on Enkei wheels don't hesitate to contact me!

Slight update for those interested; I just installed the Fat Cat Motorsports shorter (than stock) / stiffer bump stops and can tell you that the car has a lot more grip. It turns out the replaced bumpstops were cut too short causing too much lean / weight transfer in hard corners and possibly change in suspension geometry as the RX8 / Miata are designed to corner on bumpstops. These new stops are amazing and a very worthwhile mod for all lowered 8s. There's definitely more grip now as they effectively increase the spring rate at the limit.

WTF.....are you thinking.....it is NEVER a good thing to be hitting the bump stops. They are there as a last ditch only. Instantaneous increase in spring rate at the limit equals very bad loss of traction and often a crash :(

I could be wrong, but isn't the Rx8 designed to corner on the bumpstops?

No car is designed to corner on the bumpstops....

Fat Cat Motorsports - Tokico products - Miata 06+, RX-8 04+

I doubt that they'd use false information to promote their brand. regardless, the stops I removed were 1/3 of the length of the "shorter" fat cat stops. Can't be good. Im not trying to argue with you, FYI, just trying to get the facts right. Also, the shock rod is only about 6" long full extended, at least the fronts. There can't be much left of it once the car is on the ground

I hate speedbumps...lol

I call BS on that site.

If you lower a car, there is less distance available until you "bottom out". That is likely why the call for shaving the bumpstop. It gives you back some of your suspension travel. Now the only question is if your shock becomes the new bump stop.

Which is why Moton's don't have them...And is why I am on Moton's!

Bump stops are there so that if a severe event causes compression it will not result in the shock bottoming out full metal on metal.....

Hitting the bumpstop is slightly better than that :)

If you are hitting your bumpstops all the time you have a problem with damping, springrate and likely with the design of the shock itself

The wording of that page is poor...and the premise is poor.....but having "tuned" bumpstops is better than hitting bottom

Food for thought, fellas;


The graphs in that video are of dyno'd OE RX8 and NC (same) bump stops. You get a rising spring rate on front bump stops. Simply cutting them would make this worse as now you've also increased the spring rate by having less of the softer initial rate and more material that's thicker (so spring rate and initial nose force are higher). If you combine this with a lowered car where the springs usually DON'T cause the car to oversteer you'll have stiffer front bump stops, stiffer front springs vs. rear springs and a car that WILL need a bigger rear bar or ridiculous driving antics to want to rotate. Very annoying situation, but very safe for makers of aftermarket springs. Granted, the car would probably not spend a lot of time on the stops, but they're not just there to prevent the shock from bottoming out only but to also play a role in the spring rates as can be seen in the dyno graph.

This might be an extreme picture but the physics of the suspension are against you by trying to kludge the factory stops. It would depend upon how else the setup is tuned, but my point about cutting OE bump stops is that they aren't designed to be linear because that would induce too much oversteer - the last thing lawyers for the OE want to see. So you would introduce even more non-linearities with random slicing. OEs are generally more worried about someone getting loose and nutty on the street, esp. in a car with great suspension design like the NC/RX8 have (and the power of the RX8 to get you loose faster than an NC). The NC has a 22mm front bar, the RX8 is 25mm or 27mm for Sport, I wonder if they chose those stiffer sizes for a reason.

The cars are quite different in weight and roll center.....so they need different bars

I watched the video...and they are talking about the rate in the bumpstop...not the spring

This still doesn't mean that you should be on the damn things in the first place.....

Stiffer sways will help keep the bumpstops out of play in hard cornering. These are on my car now and I really like them:

Progress Technologies MX5 FRONT and REAR AntiSway Bar Combo! for MX5 2006-2013

Yes, Miata bars. A modest but significant increase in rates together with being adjustable at both front and rear.

Good stuff. Would you know what the stock rear bar diameter is?

The simple truth is that most RX-8s ARE cornering on the bumpstops. Especially if you've lowered the car and run OEM length shock bodies with mild spring rates. In this configuration (which the OP has) trimming the stops too much will result in an abrupt change in roll rate once the stops engage with a resultant loss in grip at whatever end of the car hits the stops first.

Finessing bump stops can and will improve handling, and the FatCat stops are a well thought out product. To the OP, you chose well and it's good to hear you've solved the problems. Now put some good summer tires on and be prepared to be amazed.

Thanks for the input :)