ND Miata Autocrosser Considering Making the Switch

[TarzanoftheApes]

Hey All,

Currently drive an ND Miata and autocross it regularly. I was intrigued by the updates to the 2018 GT so I took a test drive in a PP manual transmission. Pretty impressed. The transmission felt positive and the car had a "driver's car" feel to it. Interested in switching because the daily grind in the Miata is getting old. The GT Premium felt like a luxury car in comparison.

Anyway, my initial thought for autocrossing is to get a car with the Performance Pack and Magneride. I would also spring for the active exhaust. Car would be a manual.

Any thoughts on this? My biggest concern is the long gearing. I noticed first is good for like 45mph? Seems like this might be tricky in autocross. Also, will Magneride be stiff enough to compete with people running Konis?

Thanks all for the input

Sponsored

 

[BmacIL]

Not sure what your budget is, but maybe you want to look at the PP level 2. More track focused suspension, Recaro seats, 305 all around Sport Cup 2 tires, bigger splitter. Mag ride will definitely be competitive.

The new gearing with the manual and 3.73 axle will be a little better for autocross. A lot of guys were hitting the rev limiter in 2nd at decent size courses. With 3.31 and the old ratios I go to approx 70-71 in 2nd, which is enough for any course. The new gearing should be close to that. Remember, this engine has a much wider powerband than that I4. Anything above 4000 rpm and it's got plenty of rip. 3500 even.

 

[TarzanoftheApes]

Not sure what your budget is, but maybe you want to look at the PP level 2. More track focused suspension, Recaro seats, 305 all around Sport Cup 2 tires, bigger splitter. Mag ride will definitely be competitive.

The new gearing with the manual and 3.73 axle will be a little better for autocross. A lot of guys were hitting the rev limiter in 2nd at decent size courses. With 3.31 and the old ratios I go to approx 70-71 in 2nd, which is enough for any course. The new gearing should be close to that. Remember, this engine has a much wider powerband than that I4. Anything above 4000 rpm and it's got plenty of rip. 3500 even.

Thanks for the input. I'm hesitant to go PP2 because it looks like it might be classed out of FS, probably into AS with the SS 1LE.

I guess I'm just used to maxing out speed at top of my 2nd gear in the miata (50ish), and figured I'd hit that same speed in the GT. But sounds like the GT can easily push above that

 

[XPystchrisX]

So I've got a 2015 PP which I've had for approximately six months. I've done two events here in SWFL at Gulfcoast Autocrossers. I come from a history of hot hatchbacks and the odd Honda CRX or three.

I fell for this car for the same reason that you enjoyed the 2018. It took me two months to finally take the plunge and I dont' regret it. It is a big car (made worse by only being 5ft 7in tall... 5ft 7in and a half really...) but when you start to hustle it you forget the size. I can place the car much better than my Golf R and it responds extremely well for being all stock (except tires) at this point.

With the '15 I only have a 6800 redline, but the feeling is the same with 1st. I've found that even shifting into 2nd that the car has more torque than I'm used to, so I don't find any issues with being low down in the power band. I believe that the 3.73 rear end helps with that. I've also swapped all four corners to 275/40r19 Kumho PS-91's. Not extreme auto-x tires, but I'm waiting to get a second set of wheels for that duty. Putting 275's up front helped with some of the push that I had to fix with throttle.

Overall I don't regret it for a moment. It's more than 400 or 500 lbs heavier than anything I've ever owned but when it's time to party this thing makes me laugh like an idiot. I haven't even tuned it, yet, which I'm expecting will change things again.

 

[BmacIL]

Thanks for the input. I'm hesitant to go PP2 because it looks like it might be classed out of FS, probably into AS with the SS 1LE.

I guess I'm just used to maxing out speed at top of my 2nd gear in the miata (50ish), and figured I'd hit that same speed in the GT. But sounds like the GT can easily push above that

Yes that's a valid concern. We will probably see soon!

 

[DickR]

Do it!

I autocrossed a 2015 GT PP for three years at Pro Solo's, Tours, and Match Tours and just traded it for a 2018 GT PP with MagneRide and the 10 speed automatic. I stayed with the standard exhaust because we prefer "stealth" and I was concerned that the system might force "track" exhaust (despite what the manual says) in "track" drive mode. If so this might exceed sound limits at some sites. FYI the 18's standard exhaust is significantly less "stealthy" than the 15's was.

With 420 lb-ft of torque and 460 HP what would be "long" gearing in a Miata will seem like "very short" gearing in an 18 GT PP despite the weight. You will be "traction limited" a lot even with RE-71R's, especially off the line at a typical dirty autocross start line. The 15-17 GT PP gearing was too short. Top speed on 285/35x19's was only 58 mph which caused us to hit the 6800 rpm limiter a LOT on all but the slowest courses.

The biggest adjustments will be size and weight and amount of full throttle time compared to the Miata. Not as bad as when I went from 20 years of a CM Formula Ford to a 2012 Mustang but it will result in a lot of cone hits and braking too late until you learn how big the car is, how much faster it accelerates and how much slower it corners than a Miata. Note that most of the "slower than a Miata" is due to the much greater width making off sets slower. Cornering grip is similar but wide cars have to move side to side more.

 

[NightmareMoon]

The '15-17 manual GTs w/ 3.73 gears would top out at <60 mph, which is awkward for longer nationals-style courses, and puts us at a disadvantage against some of our FS competition. Even at local events I'd often occasionally the rev limiter in 2nd.

The higher top speed in 2nd the 18s is a good thing.

With the Pony cars, you're going to be a bit slower through the corners and need to make up the difference with speed on whatever qualifies as a 'straight' in an autox course. In other words, you'll probably be hitting higher maximum speeds than you were in the Miata.

Coming from owning two NB miatas which I autox'ed a bit, the Mustang is a real pleasure to drive. Sure its got a wide track (chicago boxes suck) and not quite as nimble as the Miatas, but whoa putting power down out of a wide sweeper is really a pleasure in the 'stang. You just don't get to use that bottom part of the traction circle in a lower hp momentum car like you do with 400+ hp on tap.

 

[jdub.csu]

The 2018 hits 73 in 2nd now with 285/35r19 re71r tires. This is a huge improvement over the 15-17. It improves a lot of the deficiencies of the 15-17. Don't worry about the top of 1st you will not want to ride out that gear much unless you have VERY good throttle control which coming from a miata is going to take some practice.

 

[Static_LV]

Don't hesitate, the gearing on the 2018 is much better than the 2015-17. The clutch is improved, magnaride is a big jump, and the power is increased. They took what was an already fun car and improved it a lot for the mid cycle refresh.

 

[SVO MkII]

Hey All,

Currently drive an ND Miata and autocross it regularly. I was intrigued by the updates to the 2018 GT so I took a test drive in a PP manual transmission. Pretty impressed. The transmission felt positive and the car had a "driver's car" feel to it. Interested in switching because the daily grind in the Miata is getting old. The GT Premium felt like a luxury car in comparison.

Anyway, my initial thought for autocrossing is to get a car with the Performance Pack and Magneride. I would also spring for the active exhaust. Car would be a manual.

Any thoughts on this? My biggest concern is the long gearing. I noticed first is good for like 45mph? Seems like this might be tricky in autocross. Also, will Magneride be stiff enough to compete with people running Konis?

Thanks all for the input

Not sure if you ever pulled the trigger on the GT, but you may also want to consider a 2018 Ecoboost with Performance Package. You can probably pick one up for around $25K (6sp). It's a pretty good performance car value at that price, and 170 lbs lighter up front than the GT. I used to autocross a Miata back in the mid '90s and I've been doing PCA HPDE for over 20 years. The 2018 EB PP reminds me a lot of a 944 Turbo, which is a good thing, a very good thing.

Obviously, if you want the V8, the Ecoboost will not be a substitute. But if you're looking for a fun car to toss around the track at a great price, maybe give it a try?

Sponsored