Detroit_Bill

The Atom has always intrigued me. Are you getting a roll bar of some type? Does that pass the broomstick rule?

X25

Atom talk
Yes, it has a roll bar option that significantly increases the bars right behind you, and it is removable (though I'd never remove it). There was no full roll cage option available from the factory, but the whole car is more like a cage than anything else. I should also note this is the first Atom that is also designed to pass European crash standards for a special low volume license (for easy registration within Europe, Australia, etc.).

I got the following options:

• 2019 Ariel Atom 4
• Brake Upgrade - 2-Piece Rotors
• Brake Upgrade - Track Compound Pads
• HANS Specific 6-Point Harness (Full Set)
• Removable steering wheel
• 1-way adjustable Bilstein dampers with track valving
• Standard Chassis Color - Satin Black
• Standard Color Package - Center Section:
• Select Bonnet/Airbox (Center Section) Color: - Ariel Red
• Decal/Emblem Color Selection: - Black
• Standard Wheel Color - Silver
• Lexan Side Panels
• Carbon Fiber Wing Package - Front & Rear
• Track Package - Stage 1
• Removable Full Roll-Over Bar
• Battery Master Switch - FIA Approved Master Switch
• Fitted Car Cover - Outdoor
• Reversing Camera System
• LSD (it's normally only included in performance package)

Track pack includes:

• Cockpit Adjustable Brake Bias
• Fire Suppression System
• Tow Eye Kit Front/Rear

The most expensive upgrade was the front and rear wing package ($6K), but I think it's worth it. There's no pic of Atom 4 with this package yet, but here is an Atom 3S with a similar package:


A quick update on Z06
I've been driving with the SS lines pretty much whole day, and as suspected, there's not much difference at all in brake pedal feel. Perhaps it would make a bigger difference on an older car with the rubber that's no longer as stiff, but no noticeable difference at the street on my account.


I put on the new wheels with brand new Toyo RRs at 315/30/18, 345/30/19, set them to 36 PSI (I have my reasons), and measured height at full tank (with no ballast).
LF, RF, RR, LR (in mm)
693, 693, 726, 724


Updated my RaceChrono lap timer screen to include Coolant and IAT temps. I actually see the coolant temp on the dash as well, but it wouldn't hurt to see it from here, too : )

X25

I've tried RRs on both my Miata and Z51 before, and in both cases, I was not impressed like how R7s impress you. That said, whenever I read about it, I hear drivers being able to hit lap times very close to, or on par with R7s, especially after the first few sessions/HCs with R7s are over (end of so called purple crack).

R7s are great, but I think the stock suspension cannot keep them alive long enough, since there's uneven wear at the edges, even with -3 camber. I know others with DSC controller also destroy tires in 2 track days at the same track, so that's not a solution, either. I flipped the tires on their wheels, and will try the R7s on 7/13 track day (will bring RRs as backup), and we'll see if they last longer like that. Anyhow, if RRs can provide double the life, and last 4-6 days, that would be a massive improvement, and I'd be ok with losing a second, if that's all the impact.

In short, yes, I'm also looking forward to seeing how RRs will fare, and my big wonder is about how long they will last. A friend of mine, who is actually a faster driver than me, will also attend the very same event with his C7 GS and identical tires/wheels/brakes. He will be my 'control group', and we will compare the data at the end of the day. He seems to be missing certain parts of human brain that pertains to self preservation, so I'm sure his data will be 'exciting'. As such, looking forward to the dinner we'll have after the event : )

fatsport

Thanks for the knowledge on the RRs. Do you think the rubber compound is similar to the R888R? I think the tread pattern of the R888R is what reduces their overall grip and extends the life - so much surface area in the voids. With the minimal rain grooves of the RR, footprint and therefore traction should be greatly improved.
I’m missing some brain parts too. Last Saturday at Sebring I went into a hole before the rumble strips at the entrance of turn 14. Hit it at 105. Blew a tire. Was on a runflat, so it held up well enough to not shoot me into the wall. No excuse for me not knowing that hole was there.
A couple friends call me Mr black flag, as I like to push the limits. I plan ahead to be aggressive in spots on the track that are generally safe. Not uncommon for me to be in the sand.


On my way to the beach in turn 1. Hit a bump mid-turn that sent the car wide.




Setting up the entrance of turn 14 a little too wide. Didn’t know there was a hole there. Should have, was my 3rd day at Sebring

badhabit_wb

You're really lucky that hole didn't throw you into the wall. There are a few spots like that at VIR and I've seen people hit them with disastrous results.

X25

Wow that's a big hole; I'm surprised it doesn't get fixed!

Regarding compounds, I think they're different. Regarding thread, I remember discussions during R888R's introduction that the bigger chunks a la NT01 provided better cooling than the previous design (R888), which was one of the main factors in how it overheats less/slower than R888.

X25

Just came back from the track day at Ridge Motorsports Park.

• Tires: The Toyo RR tires performed well. They do bark quite a bit at the limit, and the ultimate cornering traction seems to be less than R7s, but I believe one can do great lap times with it, as long as they use the strengths of this tire (consistency, braking, etc.). These tires provided excellent traction in the first few laps, not much different than R7s, but then they lose a bit of traction. I'm not sure if it's due to heat or increased pressure, but they provided amazing traction when they're cold(ish) at 27 PSI, in the first few laps.
• Lap times:
  • Long story short, I missed the morning of the event, where my friends did their best times (tarmac got much hotter in the afternoon), and I was not able to put a clean lap due to a few reasons: so much traffic in most laps, and I did make mistakes in clear ones, since I'm still getting used to these tires. I've also had an oil leak issue, which distracted me.
  • That said, my optimal lap time per sector times was vastly improved to 1:46.3, which is even below my best lap so far with R7s at 1:47.02. Looking forward to trying it again with less traffic!
• Oil leak issue: I spotted oil on the passenger wheel, and after a bit of tracing, it seems to come from one of the breather hoses of the dry sump system. See below for the pic.
• Updated track video layout: I've updated my track video layout with more information, better throttle graph, brake zones identified on track map, as well as a (temporary) 2D graph to track the coolant temps.
• Temps: Speaking of which, I did stabilize at 232 degrees F coolant, and <270 degrees F oil.
• UNCUT video: I've put the whole last session, and added a graph for coolant temp. I'll do the same after I install the DeWitts AUX cooler as well.

I've highlighted the hose that seems to have spewed a bit of oil during the track day (1/3 quart or so). It seems to have leaked right from the spot where I drew a *****.

You Tube

I did not get to drive much today, and this is the video of the best lap of the day. If I removed sector 3 (on RaceChrono) from this lap, and replaced with that sector's time from any other fast laps, this would be 1:46.3. Sigh..

You Tube

Here is the UNCUT video of the last session from the paddock exit. I was not really focusing on lap times, but rather wanted to play along with the C6 Z06, which was just as fast at the straights (unknown modifications, but it had a cam for sure, and it was very stinky : ) )
Observe the coolant graph, and how it settles. It moved from 228 degrees to 232 degrees in the last few laps. Considering ambient temp is pretty low, it's a pretty high temp.

tiborrules

What display is that on your PDR screen? Mine is the standard PDR display and doesn't look like that. I also heard you talk about IAT's in an earlier post. Where do you get those measurements?

Detroit_Bill

That is a cool looking track lots of variety there.

X25

You should've realized it's not the sucky 720p PDR camera : )

I do not have PDR. I log all the data on my phone from OBD2 using a Bluetooth dongle, and also have a (Bluetooth) GPS dongle for more accurate GPS/GLONAS data. I've made the layout you see using RaceRender on my PC.


Indeed it's a great, fun track. Since it's very close to bigger cities and B.C. (Canada), though, it's always crowded, as you can see from the traffic.

X25

Just installed the DeWitts AUX cooler!
Simple modifications (explained later):

1. Used plastic retainers that I've recovered from OEM deflector instead of rivets.
2. Used the OEM plumbing, and just connected to them with 2x 5/8" hose connectors (not provided).
3. Also needed 2 more hose clamps (kit comes with 4)

These are the contents out of the box. There were a few things missing for me; I'll get to that later.


We start by removing the bottom covers.


Here's the OEM AUX cooler in its full glory.


Once I removed it, I was greeted by all this crap trapped by the bottom of supercharger HX. Cigarette bud? The car is only at 3500 miles!


The area is now cut per instructions, and it's now time to install the deflector. Modification 1: Instead of using rivets, I just drilled two small holes by the deflector's sides, and used plastic retainers that I've removed from OEM deflector. This way, I can easily remove it if I need to.


New core is now installed. Here I put the OEM cooler on the top to show the difference in size. No, my hand is not that long; it's the fisheye effect of the wide-angle lens.



Modification 2: The OEM plumbing beautifully brings the lines all the way to the driver side. Instead of removing them completely, I just connected new hoses to these hoses. For that to work, you'll need 2x 5/8" heater hose connectors, like Gates 28604. These connectors did not come with the kit, but they were readily available at my local car parts store.


Here is the new core installed, with the first hose connected. This core looks like a symmetrical design, so I don't think it matters if you connect the hotter hose to one or the other.


Hose connectors connected to the OEM hose side. Modification 3: The kit came with 4 hose clamps, but if you do what I did, you will need 6 of them. I already had a few clamps laying around.


Here, the hoses are connected. Be careful not to keep the hoses too long, or they might kink.


Next up, cutting the 4 center ribs of the under tray. My long-handle dykes worked the best, and I was done in a few minutes.


How it looks (before I bolted down the bottom cover.



Done!! I did a test drive on the highway. I kept the car at 2nd gear, and kept revs at 5K+. This eventually increased the oil temps to 235 or so during my short drive, but coolant stayed around 212. Later I kept the car on first gear doing 50-55 MPH at my local state road (55 MPH speed limit), and I was able to hit 245 degrees F oil. and coolant got to 212 again. Well these lame tests don't tell much since I have OEM thermostat, but at least it seems to be working. The real test will be on Saturday at Oregon Raceway Park. 2300 ft elevation (think air) and expected 82 degrees F temps; almost identical to my last attempt, so I'm hoping to have a great comparison. Final Note, I did not open any holes on the bottom cover.

X25

In other news, I also noticed that I've been wearing down the splitter bolts by the sides at the track.




This is the driver side. The bolt wore down to the point that I was not able to remove it with a screw driver anymore.


Drill is your friend.


All impacted bolts. I've decided to not put any bolts on those two sections, since there are already quite a few other bolts, and I don't want to deal with bolts with no heads to turn them.



I've ordered a new passenger side PCV hose (what was leaking at the track), but until then, I need to keep this one on. I found an o-ring that fits, and fit the nipple with it in hopes of having a better seal. We'll see if it works!!

X25

Finally did my first testing with the DeWitts Aux Radiator. Below are my notes:

• OBD2 ambient temp reading is initially correct: The outside temp gauge shown on the entertainment system is not the ambient temp. Perhaps it's something related with the cabin temps? What I can read as ambient temp from OBD2 is correct, until the car starts getting heat soaked. More on this later.
• First attempt with no holes: I did not drill any holes at the bottom for venting during this first test.
• Short day: I stabilized at 237 degrees F coolant at 79 degrees F ambient, during my time right before lunch break. Considering afternoon would be even hotter, and I did not want to exceed 240 degrees F coolant, I cut the day short.
• ORP climate: This track has inland climate. As such, the mornings usually start substantially cooler, and the temp variance throughout the day is significant. This gave me the opportunity to find and match two sessions from before the DeWitts aux rad, and after, with pretty much identical temps.

This is one of the sessions from today. Notice the ambient temp recorded during each lap stays at 79 degrees F for a while, but just as the coolant temps start to pick up as well, it starts creeping up all the way to 87 degrees. This reading is false. The sensor is right by the radiator ducting, and I presume as all the radiators get hot, the sensor gets heat soaked. By the way, this was my last session out before the lunch break, and I've decided to call it the day, since it stabilized at 237 degrees F, and the afternoon would be even hotter.


Since I let it go when it's about to exceed 240 degrees F coolant, I needed to find a lower ambient temp to compare before and after with more stabilized temps. This is a session from a pre-upgrade at the same track (but clock-wise and with R7 tires) with identical ambient temp. Max coolant temps have stabilized around 235 degrees F with 68 degrees F ambient. The lap times are a bit faster (with R7 tires), and average RPMs is about 100 higher.By the fourth lap, I'm at 232 degrees F.


This is from today. By fourth lap, I'm at 228 degrees, 4 degrees lower than before the upgrade in similar conditions.


Results and next steps:

• Results with no vents: I've seen similar drops in different temps, too. In short, I see about 4-5 degrees of drop in coolant temps after the upgrade.
• Next test: At this point, I plan to cut the holes as shown in instructions, protect them with a screen, and see if it helps (and I think it will!).

I am thinking of attending a track day on next Friday to test it out.

BrunoTheMellow

Different coolers but I used a 1 " spade bit to make these. I put my fans infront of the car and I can feel air through them. I couldn't feel air at the stock exhaust location (by the intercooler pump and reservoir).

I can tape over it easily if anything.

also I learned a spade bit with a driver, although messy, cuts through plastic much faster than a round hole cutter bit (the hole cutter melts the plastic and kills the drill with friction)

X25

Did you test the impact before those holes? I'm currently thinking about opening 2-3" diameter holes, covered by 4x8 mm oval mesh grill I've ordered online. Is the location same, btw; 6" from the front of the covet?

BrunoTheMellow

Nah. If i feel like it should be running cooler I'll tape the holes off and try. But hell I've never drive the stock '15 Z on track, and I've done a butt load of cooling mods at once.

My aux cooler is much larger, 9 inches deep vs 6.75" , so your location would be different. Take both parts off. Measure from the bolt holes forward for location and bolt both trays together to drill through.

X25

I added the vents for the aux rad, today:


Used this mesh made specifically for car grilles. It has 8x4mm openings.


I was able to flex the bottom covers down enough to make the holes without endangering the radiator core. I decided to use 7" from the tip of the deflector cover. The instructions manual sent with the kit asked for 4" off, and Tom's manual he's shared online asks for 6". Looks like 7" would be perfect with 2" diameter holes to cover the rear 1/4 of the cooler core, so that's where I did it. By the way, I wanted to check with latest instructions, but THE LINK TO INSTRUCTIONS AT DEWITTS.COM DOES NOT WORK!


Zip ties!


It looks nicer in person. I was not able to put the mesh inside, since the inside of the splitter support does not have a smooth interior.


While the car is on the lift, also changed the diff/transmission fluids

• The transmission fluid on my Z51 never leaked with the original fill, but started leaking once I replaced it. I later learned that it actually needs to be filled a bit below the fill line, not by the fill line. My Z06 actually leaks with the factory fill! I opened up the fill plug, and no wonder, fluid started leaking. Looks like it was a bit overfilled from factory.
• Diff fluid was a bit cleaner this time, but the magnets still caught quite a bit of metal. This time, I've switched to Amsoil Severe Gear 75W-110 diff fluid. This fluid has a much higher tolerance in high temps, and yet still approved for any diff where a 75W-90 is required. Sounds great to me!

I've also changed the front mud flaps with the wide OEM versions. I know, it won't be enough, but I know from experience that it significantly reduces hits, which is good enough for me.

Initial testing with the vents
I did the same test I did when I installed the aux rad, and went out to highway, driving 60-70 MPH at 5-6K RPM on second gear. Ambient was 2 degrees cooler than last time at ~68 degrees F. Last time, I hit 235 degrees F or so during my short highwat drive, but coolant stayed around 212. This time, the car did not exceed 226 degrees F oil, and coolant was around 208.

Later, on my way home, I kept it at 1st gear, hitting 5-6K 45-55 MPH on first gear. I waited until oil hit 250 degrees F, and coolant hit 216 degrees F. I think last time I hit 245 degrees F oil while coolant was 212 degrees F.

Anyhow, my hunch is that the vents will help for another 5-10 degrees at the track, which is all I'd want if it becomes reality. I intend to test it out at the track on Friday, at RMP.

rico750sxi

Good stuff, I really enjoy this thread. Do you happen to have a part number for the wide OEM mud flaps please? Thanks!!

X25

Thanks! Fronts are 22935635, and rears are 22935639. I found best prices on eBay.

X25

I finally tested out the AUX cooler with vents.

Let's start by looking at the snapshots from logs:


It was a nice day today, at RMP. The temps during my sessions ranged from 66 to 73 degrees F ambient. Clouds also help since RR tires don't like too hot tarmac.


This is the first session. I tried to not have any cool-downs mid-session to ensure everything keeps boiling.


The following sessions saw higher temps, with 73 degrees being the max. Coolant temps settled at ~225-226 degrees F max.


... and this is the session from just two weeks ago, right before I installed the AUX radiator. The difference seems to be about 7 degrees. This is the impact from both new AUX cooler (which seems to have improved by ~4 degrees by itself) + vents. Cool!!


Remarks:

• Improvement: So, there you have it; 7 degrees drop!
• Ambient temps: Due to unusual summer we're having here, these tests were conducted at relatively low temps. I don't think it would be hard to imagine the gap would likely increase between OEM AUX and DeWitts' AUX with vents as the temps increase. I have a bit of data from 80-85 degrees. I'll see if I can come up with comparable data at those temps, too, in same tracks.
• OEM AUX with vents?: This whole experiment also begs the question: how would stock AUX cooler fare if it had the same vents? Would it drop by a few degrees, too? This is not something I'll get to test, but I might convince one of my local friends with C7 GS to do so for testing : )

Next track day will be in Area 27 in Oliver, Canada on Aug 2nd. The current forecast is 88 degrees F, so if the temps stay high, it will be interesting to see how the car fares!



-------- In other news ---------


LF rotor. Still quite thick, but quite a bit of small cracks. I've been using these rotors since I started going to track with this car. The pads are also still holding up.


RF rotor. A bit better in shape.


Rear rotors have no cracks, and the pads are also twice as thick at the rear.


Washed the car after a long day; looks amazing (to me).