Help me improve my dual duty NB 1.8 Turbo
 

Hi all, i'm from Portugal and i'm a owner of a 99 1.8 Mx5. My current setup was made on the base on my dual duty needs at the time. I was making 15k miles a year on realy bad roads and seeing some track day's and back road drinving.

I have 7kg/5kg coilovers, front FM sway bar, no rear bar, Trackspeed 11"75 wilwood kit with rear sports ond PFC01 at all corners. 949 racing allignment (2 front camber, 1.7 rear, 0 toe 4 corners). Engine is a stock 1.8 oil burner with TD04 atached at 0,7 bar boost, so problably around 220rwhp. I use 205/50 r compounds. Car is full interior + rollbar, A/C and usually hard top, so fatty one!.

Since than i bought a daily driver and willing to make some setup changes (nothing major) and was thinking: new 9kg/6kg springs, 3 camber front, 2,5 rear and little toe in at the rear and a RB hollow 1,25 front bar.

I was pretty sure that was what i needed, but seeing emilio's post on the "DIY aero" thread got me thinking if my ideas are right because he advises OP to use a 14mm rear bar and way harder springs.

I'm struggling with beeing able to accelerate past apex and of course, some rolling. The grip level feel's like is ok to start accelerating but even a small throttle input make's it start oversteering.

So, knowing i still need some road maners, what would be your advise? I'll let you some pics and video to help try to understand my struggle. And yes, i know my driving needs some improvement to.

https://www.miataturbo.net/attachmen...ine=1466696610

https://www.miataturbo.net/attachmen...ine=1466696610

https://www.miataturbo.net/attachmen...ine=1466696610



(sorry for the cooldown laps, having overheating problems...)

If you go to 949's website in the XIDA section, there are recommendations for spring rates vs. intended use and tire size/compound.

I'm by no means an expert, but hopefully my advice will suffice until someone more qualified arrives: if I were you I'd go to a 225 width tire on a 9 inch wheel, and I'd honestly suggest saving up for some Xidas. They're not in everyone's price range, but they are well worth the money if you plan on doing any significant amount of track driving. I just installed mine today, and even though I haven't got them on track yet, I already feel like my purchase was justified. I ordered mine with NB tophats, dual springs, and 700/400 lb/in or 12.5/7.1 kg/mm rates. They are more comfortable than the 6k/4k springs on koni yellows that they replaced, and are worlds better in terms of grip. I haven't turned them from the softest setting, and I'm already able to carry something like 10-15 mph more on the roads around my house before the tires start to go, and I'm currently rocking 205 width 200tw tires on a 7 inch wide wheel.

Buy XIDAs in whatever spring rate suits your needs. I came off of 7kg/6kg TEIN FLEX coilovers which had some of the same symptons you're showing, like the annoying oversteer, etc and a terrible ride on basically any damping settings. Once I went to XIDA on 12kg/7kg springs, the ride IMPROVED and the handling is off the charts. The ride is so good, I regret not going to even stiffer springs from the start. Of 20 clicks I have mine set to 12 front and 10 rear and its a great mix for both going to the track, driving around there, and coming home. Turning it down to 8 and 6 makes it super comfy for longer and/or bumpier rides.
XIDA=WIN

What tires are you using?

What pressure are you running in the tires?

Some basic things to look at before spending $2000 on suspension.. That car looks very nervous on corner exit.. Is it hitting the bump stops? Maybe not enough low speed bump dampening?

XIDA 800/500 is nice setup for heavier car. Works for me with MSM full interior. Set at 20f/18r for autocross on 225/45/15 rival s. Racing beat front sway/MSM rear. With 949 end links you can simply disconnect 1 if you want to run no rear sway for a particular event. Just did Evolution autocross school this past weekend and all the instructors said it was the most fun car to drive.

As mazdaspeeder says lower settings work great around town. For example car handled downtown New Orleans roads (horrible) this weekend with no issues.

Yeah, shiped/taxed to europe, where talking 2500$, that's around 2300€ on a country with <500€ minimum waige, that's not a pay and forget type of buy to us.

I was on Federal 205/50 RSR possible with less than desire tyre pressure. Hitting bump stops is a possible cause, and i disconected rear ARB that problably made it worse. New RB hollow 1,25" bar is on the way and 9/6 (7/5 before) longer springs have just harrived. Now i can increse coil "pre load" on the rear without coilbiding that was limiting my rear suspension bump travel and possible connect rear FM arb on the lowest setting (should be similar to 14mm Emilio recomends).

I would also go to 225s, and up the spring rates. A blackbird fabworx rear wing will help with the overseer if you don't mind a giant wing/ducktail/thing on the back of your car. hehe