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A few weeks ago I purchased an 07 with 65kmi. It is not perfect but seems to run good. I'm using it for a daily but would like to do some track days occasionally. Looking for suspension, tire and wheel recommendations. I have read many of the posts about 5hrs of reading and still a little lost. Have been looking at the enkei rpf1 18X8.5 40mm with either a 235X45 (26.32" od) or 245X40 (25.72" od). In general would it be better to go with a smaller or larger OD?
I have read so much about on the suspension thread about coil overs that now I'm thoroughly confused, so many different opinions. I have been looking at the PSS9 and Tein street flex. I guess the newer Tein's can't be re-valved or rebuilt. Any recommendations would be appreciated.
I'd say start tracking with the stock suspensions and spend money to address specific problems from there. These cars are VERY capable in stock form, in most cases the car is not holding you back, you're holding it back.
As for tires, don't worry about fractions of inches of OD. Get a good track day tire like Hankook RS4 and go driving. I guarantee the OD differences will have no tangible effect.
Also consider spending money on engine health upgrades first. Won't get far without an engine
Get a compression test.
Check your catalytic converter.
Upgrade your ignition system.
Test your solenoids and vacuum actuators.
Change all fluids.
For track duty, I recommend going with RPF1 in 17x9 with 255/40-17 Hankook R-S4 tires.
As for suspension... That's a science so advanced (and with so many variables) it might as well be art to anybody that isn't an engineer. If you're just wanting to tool around the track for fun, leave it stock until you have a good feel for how the car behaves. If you want to be competitive, nothing you mentioned will be good enough.
Thanks for the replies. I'm at the limits of the stock suspension. The dampers must be past their prime plus it feels softly sprung compared to my last car VW R32.
I have changed all of the fluids and I'm premixing. The motor pulls good to redline and starts and idles smooth. I'm also looking for a few core motors for the future. Will check all of the controls and do a compression check. Need to get a gauge set for the wankel.
I had Redline 5-30, MT90 and purchased the RL 75-90 GL5 for the diff. I purchased the OE NGK iridium plugs, but when I pulled the old ones out they looked nearly new so I reinstalled them. Will go with the BHR coil setup when I install the new plugs at the next oil change. I have some suspension tuning experience but know enough to know that every vehicle is different and don't have much experience with some of the manufactures for the 8.
There are a few other things that need to be addressed also. it has some rattles, one in the rear exhaust and another from the front end. My friend owns a shop and when he is not busy he lets me use his lifts. Just waiting to get it up in the air.
I'm not apposed to going with 17" wheels but it seems that most that run them run high tire pressure. Is this to offset the higher slip angles of the taller side wall?
17" wheels are lighter, cheaper, have an appropriate amount of side wall and the tires are cheaper. Pressure is a function of tire temperature, you run the pressure that makes the tire happy. I found Hankook RS3s in particular like higher pressures.
You're way overthinking this
PSS9 is great kit with a good price. You'll be Happy with it. Never driven Tein in this car, but in other cars they never felt great for me.
If you have the dinero, Ohlins is where it's at. I run MeisterR and find them fantastic.
You may find more product comparisons on Miata forums. Much bigger community, and the Miata and RX8 suspensions are basically identical.
What these guys said except for one thing. If the shocks are gone, you will want to replace them. Or, at a minimum, make sure the bump stops are still there, especially on the rear. This car is sprung soft, it actually will corner on the bump stops. Unless they are not there, then it will corner until it bottoms out, instantly give you an infinite spring rate, and spin (took me awhile to figure that one out).
1. Agreed on the 17x9 Enkei rims, but with 235 45 17 tires. 255s just add a muffin top that squirms plus weight and cost. The actual contact patch is the same size between the section widths (dictated by the rim width). I have measured it. 245 45 17 is another good choice.
2. Suspension: Ohlins if you have ~$2100 to spend. Feal if you have $1500 to spend. Bilstein PSS if you have $1000 to spend. Keep the front to rear spring ratio to ~1.6 Medium front bar, stock rear bar.
3. Alignment: -3.5 camber front, -3.0 camber and 1/16 total toe rear. To get that much front camber will require offset bushings.
4. Cooling. CSF or Koyo radiator. Do NOT buy Mishimoto.
5. Catalytic converter. Inspect it frequently to make sure it isn't clogged or get a catless BHR midpipe.
6. Brakes. The stock brakes have plenty of stopping power, but inadequate cooling. Front ducts are a must. 2.5" hose fits without rubbing. AWR MX-5 spindle attachments fit.
Thanks to everyone for the info. I have decided to go with the 17X9 RPF 1 and 245X45 tires. Most likely going with the PSS9's. Is there any draw back to using a mid pipe with resonator? I have heard it is not just loud but fire shooting and obnoxious sounding. I would like to run one to save my cat because at the track I want to like run more premix. Would it sound better with the stock exhaust instead of a cat back and can I use a emulator to prevent a cel?
The only way to beat the P0420 for not having a cat is to use a Cobb AP, MazdaEdit or Versatuner to mask off the readiness monitor.
If you're only swapping the midpipe out for trackdays, you can just ignore the CEL. IMO, you have to run a lot of premix before it will have a significant impact on your cat.
Are any of these tuners still available and do they increase power or longevity?
How is the sound with something like an RB mid pipe and the stock exhaust compared to the factory cat with a cat back? I listened to the samples and read the thread on the exhaust but it is hard to tell from a vid. In stock form it is to quiet. I live in a rural area and have only seen a handful of other RX8's in the past 10yrs so I have not experienced any modded 8's.
Originally Posted by NotAPreppie
The only way to beat the P0420 for not having a cat is to use a Cobb AP, MazdaEdit or Versatuner to mask off the readiness monitor.
If you're only swapping the midpipe out for trackdays, you can just ignore the CEL. IMO, you have to run a lot of premix before it will have a significant impact on your cat.
Save your $500 if you want Bilsteins and buy the PSS instead of the PSS9. The PSS9 adjuster is an expensive gimmick that does nothing good in any positions except 4, 5, 6. You will mess with it for a few months, get frustrated, set it to 5 and forget about it.
If you want to spend $1500 on a set of coilovers, JUST BUY FEAL. There is nothing else you should be considering at that price. Feal puts people on podiums.
Cheaters do not work on this car. The ECU checks are too sophisticated to be fooled. All of them have been tried.
The BHR midpipe is the one to buy. All the others blow out their packing under track conditions. It makes the stock catback a little louder and adds a rushing sound that is pretty cool.
You can turn off your CEL with any of the tuners. Adding HP is hit or miss, depending on your engine and particular set of sensors, and you very much have to know what you are doing to get any HP gain.
The Feals look good. Do you think 10K/6K, 560lbs/336lbs rates might be a bit high for some street use? I don't mind living with a cel, will it pass smog when I put the cat back on? I'm thinking about buying the wheels and tires from the rack but they don't sell hankook is there another tire that is recommended? 245-45 bridgestone re71r, toyo r1r, yoko advan ad08r, dunlop direzza zII or falken
10k/6k properly dampened is tight but not uncomfortable at all. That's what I have.
Read some comparisons with RS4s, Re71R are good, BFG Rivals too. r1r and ad08r are an even higher performance spec of tire, but since you're new to the car, I would learn on RS4s or equivalent. First they'll last longer and second they give you more warning before they let go. And you drive them on the street with ease. And they still grip plenty.
The Feals look good. Do you think 10K/6K, 560lbs/336lbs rates might be a bit high for some street use? I don't mind living with a cel, will it pass smog when I put the cat back on? I'm thinking about buying the wheels and tires from the rack but they don't sell hankook is there another tire that is recommended? 245-45 bridgestone re71r, toyo r1r, yoko advan ad08r, dunlop direzza zII or falken
I have 550 / 375 springs on my Miata, and they are firm, but not uncomfortable with good shocks.
It will pass smog with the cat back on. Just drive it roughly 50 miles, and the CEL will turn off, and the ready monitors will reset. That's what I did for several years, before having a race cat welded into my BHR pipe.
Start with Direzza II Star Specs. They are roughly equivalent to the RS4s and arguably last a little longer. Great tires to learn a new car with. Plenty of grip and good aural feedback.
RE71Rs are great autoX tires, but they overheat after 8 to 10 mins on the track, and wear funny and quickly. R1R is a level up in performance and wears quickly as a result.
Last edited by Steve Dallas; 06-15-2018 at 02:38 PM.
To track this back a bit, you mentioned you're at the limits of the stock suspension, but how does that manifest? Understeer? Oversteer? Tires rolling over? Have you tracked it already?
I'm fortunate because I live in a rural area and have a nice 12-15mi drive to work with good roads and some elevation change. In general it is under steering in the tighter corners but on the down hill stuff it is over steering. Fair amount of rolling and weight transfer. I do hear a noise every so often from the front and have been wondering if there is a swaybar issue. I looked at the bar briefly and believe the endlinks are not broken. It really need tires. Right now it has oe wheels and uniroyal tigerpaw tires that are in good condition. On my last car I ran Bilstein sport shocks with H&R springs, bigger bars and pilot sport ps2's or cups. It had a 60/40 weight distribution so it was a balance act in the corners. Think segway, but the limits were fairly high.
My plan is to rack it next week and check all of the bushings and suspension. I'm from the school of lighter bars and stiffer rates. With that said I'm sure the oe bars are a bit to light and I will need some recommendations. The Hotchkis stuff for the 8 seem a bit on the larger side. With out a trip to the track it is hard to tell how far I should go. This is not my only vehicle so I have the luxury of being able to error on the side of too much.
Originally Posted by Loki
To track this back a bit, you mentioned you're at the limits of the stock suspension, but how does that manifest? Understeer? Oversteer? Tires rolling over? Have you tracked it already?
I know. The guy who owned it was 75yo. It was his baby, unfortunately he passed away. There is no way to condemn the suspension without testing with good tires. Will a regular mechanical gauge compression tester work on the rotary? I have a nice Snap On that I have relied on for years.
I know. The guy who owned it was 75yo. It was his baby, unfortunately he passed away. There is no way to condemn the suspension without testing with good tires. Will a regular mechanical gauge compression tester work on the rotary? I have a nice Snap On that I have relied on for years.
I mean it's better than nothing, but 2 problems:
- it will show the best of the 3 faces per rotor. If you have 2 bad faces and one good one, you'll only see the good one. You can get around this by removing the schraeder valve and recording on video the needled jumping for each consecutive face, but..
- rotary compression depends on rpm. You could show good compression if your starter is turning at 300rpm, but failing compression if it turns at 200, and whatever speed it turns, you need to normalize it to 250rpm. foxed.ca has a normalization/conversion page you can use, but you need to know the exact RPM you're spinning at during the test.
The speed is an issue with all IC engines. That is why it is hard to do a compression test and get an actual measurement. Much more of a relative measurement. Is it worth investing $300 in a digital gauge or is there another gauge that costs less?
Originally Posted by Loki
I mean it's better than nothing, but 2 problems:
- it will show the best of the 3 faces per rotor. If you have 2 bad faces and one good one, you'll only see the good one. You can get around this by removing the schraeder valve and recording on video the needled jumping for each consecutive face, but..
- rotary compression depends on rpm. You could show good compression if your starter is turning at 300rpm, but failing compression if it turns at 200, and whatever speed it turns, you need to normalize it to 250rpm. foxed.ca has a normalization/conversion page you can use, but you need to know the exact RPM you're spinning at during the test.
I'm fortunate because I live in a rural area and have a nice 12-15mi drive to work with good roads and some elevation change. In general it is under steering in the tighter corners but on the down hill stuff it is over steering. Fair amount of rolling and weight transfer. I do hear a noise every so often from the front and have been wondering if there is a swaybar issue. I looked at the bar briefly and believe the endlinks are not broken. It really need tires. Right now it has oe wheels and uniroyal tigerpaw tires that are in good condition. On my last car I ran Bilstein sport shocks with H&R springs, bigger bars and pilot sport ps2's or cups. It had a 60/40 weight distribution so it was a balance act in the corners. Think segway, but the limits were fairly high.
My plan is to rack it next week and check all of the bushings and suspension. I'm from the school of lighter bars and stiffer rates. With that said I'm sure the oe bars are a bit to light and I will need some recommendations. The Hotchkis stuff for the 8 seem a bit on the larger side. With out a trip to the track it is hard to tell how far I should go. This is not my only vehicle so I have the luxury of being able to error on the side of too much.
I run a Progress MX-5 front bar and stock rear bar with good results. At 8K / 5K, I need more spring, though. Have a look at this thread:
Is there a way to calibrate the speedo? It looks like hankook does not offer the RS4's in a 245-45-17 so I'm contemplating a 235 but the speedo and mileage will be off a fair amount. The Dunlops are out of production and not readily available. They are replacing with a ZIII its just the release is slow. Also is there a vid or write up about installing the SOHN?
Is there a way to calibrate the speedo? It looks like hankook does not offer the RS4's in a 245-45-17 so I'm contemplating a 235 but the speedo and mileage will be off a fair amount. The Dunlops are out of production and not readily available. They are replacing with a ZIII its just the release is slow. Also is there a vid or write up about installing the SOHN?
You can't really recalibrate the speedo, but the difference between stock wheel/tires and 235-45-17 is 1.6mph at 60mph. Does that really matter? https://tiresize.com/calculator/
Your correct it is only 2.5% but it is low by 5-7% already with the stock size tires. I definiety don’t mind the extra wheel torque although the gearing is relatively low and trans ratios are close. I changed the diff oil and removed the exhaust pipe fron the muffler to the cat. Really not designed to be removed by itself but I made it happen. Inside was pebbles or melted cat? See pic below.
06-13-2018, 12:53 PM
