Hayden's Cars- Annual update!

[Hayden]

Attention people who know aero! If you see me say anything that isn't scientifically accurate, please correct me! I won't be embarrassed, I'm genuinely trying to wrap my head around this stuff

The topic of aerodynamics has always interested me, and with the few work-free days I had over the holiday period, I decided to look into it more deeply. My end goal was to learn the very basic theory, then design and refine ideas that could potentially be applied to the 300c.

I started by doing some basic research into the theory and the ways that motorsport engineers past and present have learnt to minimise drag (allowing higher top speed, acceleration and fuel economy) and maximise downforce (allowing higher cornering speeds.) With the very basic theory sort've figured out, I downloaded a basic 300c model from the sketchup warehouse, copied it, made a small change, copied it, made a small change, etc, etc, etc. Until I had about 20 different designs incorporating everything from spliters, air dams, side ducts, cannards, diffusers and vortex generators to wide bodies, NASCAR spoilers, roof wings and a couple different basic racing wings. I then purchased a one month license for AutoCAD flow design; (a Computational Fluid Dynamics (CFD) wind tunnel program that costs $50 a month) and got to work.

I'll point out now that Sketchup isn't the perfect program for the editing side, and I am not a physicist or designer. It is however an apples to apples comparison on an advanced CFD program, so I feel the results are fairly indicative of the real world. Tests were carried out on all 20 models with each slight variation looked at carefully. For the sake of my sanity and yours, I've just included the results I found to be most significant and interesting.

Here are some pictures of the standard car, as it was when downloaded from the Sketchup Warehouse. (Created by user 3design.)

I loaded it into Flow design to get some results that could actually teach me something. I decided all tests would be ran at 46 M/S (160kph/100mph) because it's a pretty fair average speed for a race track. These pictures show the 3D air flow from side on, the rear angle (to show circle wake), the front angle (to show pressure on bodywork) and the side in 2D to show pressure around the car. These angles, display methods and settings are consistent in all tests. Drag coefficient of this model was 0.44.

Notice the graphs on the upper left hand side of each image and the velocity and pressure numbers next to it. The colors stay the same from model to model but the numbers they represent do not. (There is slight variation on the three images of each model but it's not significant.) A red zone on this car doesn't necessarily mean the same amount of pressure or velocity as a red on another.

I know this stuff is complicated but i'll do my best to explain it as we go!

These next images are of what I call the NASCAR design. The spoiler on the back was designed exactly to NASCAR regulations, as I figure they work pretty well on the race cars so the idea should carry over. The car also sports a front splitter and air dam with air blocks in front of the front tyres. The fake ducts and foglights on the front have been removed to make a simple flat surface. I then added an inset area which would be the theoretical placement of an intercooler. It's also received a flat floor and rear difuser. Drag coefficient of this model was drastically improved. A fair chunck of that change was achieved by lowering the car and adding the splitter (0.29), then adding the diffuser and air dam (0.25), before adding the NASCAR wing to get it to 0.24. These numbers may not be real-world accurate but it is fair to compare them to each other as apples vs apples.

A few things are obvious when looking at these images compared to the ones of the stock car. The circle wake following the car is far more tight, and tidy, reducing drag. The red zone around the grille of the car is a fair bit smaller and there is a good amount of high pressure on the top face of the front splitter. When combined with the low pressure underneath it, the car is effectively sucked to the ground, producing downforce. Due to the changes at the front, there's a far bigger high pressure zone in front of the car that's visible on the 2D picture. Precisely what effect this has, I am not sure. There is also a significantly higher amount of pressure on the boot, where on the stock car produced negative 717 PA of pressure while the NASCAR wing cuts that to be positive 52 PA, producing a little bit of downforce. The fact that rear end lift can be eliminated with a 4 inch tall flat piece, at a 70* angle (as stated by NASCAR regs) is simply amazing.

This next model is a slight evolution, the car now has front canards, a proper inverted wing with end plates and a small roof spoiler. I was curious if the popular JDM style upgrades that people put on their street cars made a significant difference to the big american sedan. I decided to keep the NASCAR spoiler on this model to see how it interacted with the racing wing.

The yellow visible on the Canards and wing indicate that they're doing their job and producing a good bit of downforce. The swirl in the wake of the car has grown slightly but is still quite tidy when compared to the random styled flow of the stock car. In the 2D image, it's clear that the roof spoiler is doing something. The green section over the boot has grown forward slightly and the pressure of that has moved up slightly. This means even less drag than before. The drag coefficent of this model was 0.23

With things going positively, I decided to step it up a notch. This car shows a skip of about 7 minor adjustments. The car now features a widened front splitter, along with an extra cannard each side that are joined to each other and the splitter with an end plate. The basic intercooler grille is gone, replaced by two functional ducts fed from a slight curve in the bumper. They run through an intercooler, into the front wheel well for brake cooling, then exit out through the fender. The wheel wells and side skirt have been widened to sit flush with the outmost edge of the tyres, to make sure they catch as little air as possible. The back bumper has been cut behind the wheels to allow air out from behind them, which runs over small wings to hopefully generate some downforce. The rear wing is now dual stage and the roof spoiler and NASCAR spoiler are gone, with Evo style vortex generators now lining the rear of the roof. Finally the car has tunnels running from under the car to exit through holes in the boot and over small wings.

There's a few things that jump out straight away. First is the wake which is now quite a bit messier. I put this down to the removal of the NASCAR wing. Next is the increase in red on the front of the car, with my newly designed front section not directing the air quite as I'd hoped. I feel that the slope may need to be removed or made far more severe to have a positive impact. The new dual step canards and wing are receiving pressure as I'd hoped which translates to a good increase in downforce. Worryingly clear on the 2D image is how much negative pressure is above the car. I feel that I need to make significant changes to the front of the car and bring back the NASCAR wing to try and calm this back down. Drag coefficient of this model went up considerably to 0.28.


Thanks for reading folks. I will point out now that this research is genuine and the ambition is to put what is learnt into place on the car. Judging from what's been found so far, that will include a front splitter and NASCAR style wing in the short term. As my understanding grows and the car develops, a full time attack set up (like that last model) definitely isn't out of the question. Unfortunately the CFD program doesn't show a total lift/downforce number (it's the most requested feature on the forum) but the colour zones do give a little bit of an idea.

If anybody with a good understanding of aero can help me expand on exactly what I'm looking at here it would be very much appreciated.

Cheers!

 

[Heldenzeit]

Maybe read though this guy's posts. He has some good insight on what works and what doesn't.

https://www.facebook.com/KazeSpecEngineering/?fref=ts

 

[Hayden]

@Heldenzeit- Brilliant link with some great analysis! Thank you very much for passing it on

 

[Hayden]

While I was playing around with CFD, dad was playing around with paint. Our great white Luxo barge is no longer white!

The finish is far from perfect and he's already started sanding it back so we can put on a few more coats. I honestly think it looks incredibly mean in flat black!

He also experimented with doing stripes. As it turns out, the matte base would "suck" all the gloss out when he sprayed it on top, making them nearly un-noticeable. What he did find though, is that by wet sanding the matte black we could get a pretty glossy finish. So he taped up a stripe over the bonnet and gaurds, gave them a quick wet sand and got this cool ghosted look.

We're still figuring out if we'll do Viper roof stripes, classic Mopar ones over the boot, something original, a combination or a proper livery. It's something we'll experiment with after we put on a few more coats of paint

Today my brother helped my dad and I take a look at the 300c and see if we could get it going on all 8. We had theorised that it was the standard MDS lifters not opening the valves that caused the car to only run on 4, so we pulled the engine down to find out. It's not the best photo, but it was pretty clear the lifters were the issue once we'd pulled the head off. The MDS system disables the outside two cylinders on one side (pictured) and inside two on the other. As you can see, the cylinders which are meant to deactivate have not fired at all.

We put in aftermarket lifters and cradles we'd ordered from the US and put the engine back together. We ran into a small issue with the drivers side exhaust manifold, with one bolt refusing to cooperate. It was eventually persuaded and we were ready for the ultimate test.

I jumped into the drivers seat, pressed the start button, and after a few attempts it roared to life... just to die immideatly. Which it then did three more times as we tried to figure out what it could be. Stumped, we poured some petrol in the tank and it finally barked to life and stayed there. Angry, deep and tough, yet not over the top, the sound was music to our ears.

It still wasn't perfect though. The car hunted for idle, died occasionally, had a bad exhaust leak and was very irresponsive to throttle input. We put a stock tune back on, which made it a little calmer and far more responsive, but it's still not right. Safe to say she'll be going back to the dyno man some time soon.

Man I can't wait to throw this thing around a track

 

[GDII]

This is an interesting choice of race car. From what I see on the surface starting with a big heavy car that is shaped like something that resembles a brick wouldn't be my first choice but then it's so different why wouldn't you do it. I have a nick name for these cars, Chrysler Brick. And the wagon is Chrysler Brick With A Brick On It. But that's just me poking fun at large American cars because of what I am used to with the small Japanese cars.

The paint with the hidden stripes is a nice touch.

 

[Dan]

While I was playing around with CFD, dad was playing around with paint. Our great white Luxo barge is no longer white!

The finish is far from perfect and he's already started sanding it back so we can put on a few more coats. I honestly think it looks incredibly mean in flat black!

He also experimented with doing stripes. As it turns out, the matte base would "suck" all the gloss out when he sprayed it on top, making them nearly un-noticeable. What he did find though, is that by wet sanding the matte black we could get a pretty glossy finish. So he taped up a stripe over the bonnet and gaurds, gave them a quick wet sand and got this cool ghosted look.

We're still figuring out if we'll do Viper roof stripes, classic Mopar ones over the boot, something original, a combination or a proper livery. It's something we'll experiment with after we put on a few more coats of paint

Today my brother helped my dad and I take a look at the 300c and see if we could get it going on all 8. We had theorised that it was the standard MDS lifters not opening the valves that caused the car to only run on 4, so we pulled the engine down to find out. It's not the best photo, but it was pretty clear the lifters were the issue once we'd pulled the head off. The MDS system disables the outside two cylinders on one side (pictured) and inside two on the other. As you can see, the cylinders which are meant to deactivate have not fired at all.
View attachment 622145
We put in aftermarket lifters and cradles we'd ordered from the US and put the engine back together. We ran into a small issue with the drivers side exhaust manifold, with one bolt refusing to cooperate. It was eventually persuaded and we were ready for the ultimate test.
View attachment 622147
I jumped into the drivers seat, pressed the start button, and after a few attempts it roared to life... just to die immideatly. Which it then did three more times as we tried to figure out what it could be. Stumped, we poured some petrol in the tank and it finally barked to life and stayed there. Angry, deep and tough, yet not over the top, the sound was music to our ears.

It still wasn't perfect though. The car hunted for idle, died occasionally, had a bad exhaust leak and was very irresponsive to throttle input. We put a stock tune back on, which made it a little calmer and far more responsive, but it's still not right. Safe to say she'll be going back to the dyno man some time soon.
View attachment 622144
Man I can't wait to throw this thing around a track

I've seen quite a few modified Chrysler 300s in the past and never liked the mods done by their owners (stock 300s are gorgeous IMO). This, however, looks extremely intimidating in a flat black paint. Even the blacked out grille which I didn't care for in the past looks excellent on your car. Keep up the good work, and update us when you can!

 

[Hayden]

@GDII Chrysler Brick with a brick on it . It's far bigger than I'm used to as well, but I'm really keen to see what it's like to drive. Literally the only race cars with a similar weight and size are V8 Supercars (& superstars), so depending how the dyno tune goes this thing could be quite a handful.

@Dan Thanks mate! It's a backyard job so we weren't really expecting it to get much praise.

Yesterday Dad & I got stuck into the car to fix what we could and have it ready for the dyno man.The exhaust leak was an annoying repair, with the bolt that was fighting us on Saturday proving the culprit. We had to pull the whole driver's side exhaust manifold off, line it up properly and put it on again, which is an extremely tight and fiddly job. Fortunately we got it done and the car is leak-free!

Dad also pulled his custom steering column out (for about the 6th time) to try and rectify a bad clunking we noticed while going for a slow drive around the paddock. A bearing moving in a housing proved the issue and after a few hours of welding and modification he thinks he's finally got it under control.

While he was doing that, I was sanding and masking the car for its final few coats of Matte Black. Nothing makes you realize how big this thing is until you have to go over the whole thing with a sanding block!

 

[Hayden]

It's been a while but annoyingly not much has happened.

The car's spent the last 3 weeks at this dyno shop. We decided to change from the other place for reasons neither dad or I can remember (I think they were fully booked for a couple weeks) and it probably wasn't the best idea. Basically they've been having major issues with the ECU, which responded well to them when they first started playing around with it, then suddenly shut the car down half way through a run and wouldn't let it fire back up. These guys (along with everyone else in South Australia) don't really have much knowledge or experience with the Chrysler computer so they posted the ECU to Melbourne in Victoria.

Apparently the entire thing has been wiped and it's completely bricked. The guys have sourced another ECU and we're looking forward to some progress early next week. If they have any further issues with the factory computer we have discussed the expensive option of a Motec or Haltec standalone ECU. This will be an absolute last resort but we are hoping to have it ready for an event in late march so it's a possibility.

Something we hadn't even thought of but was mentioned by a mate, is the possibility that the guys who tried tuning it before we replaced the lifters put an exclusive license on the computer, causing it to throw a tantrum when someone else tried tuning it. An annoying and pretty costly venture with the new tuner that could have been completely avoided if we'd just stuck with the other guys

Nothing against the new shop at all, these guys do great work and are really easy to get along with. It's our fault we're in this predicament.

 

[Katiegan]

Something we hadn't even thought of but was mentioned by a mate, is the possibility that the guys who tried tuning it before we replaced the lifters put an exclusive license on the computer, causing it to throw a tantrum when someone else tried tuning it.

Most likely the case. I know a lot of remapping companies here lock ECUs once they've tuned them to avoid tampering. Unfortunately, as you've found out, any tampering results in bricking the ECU! Hope you can get it sorted for not too much money.

 

[Punknoodle]

Interesting, I know with my Haltech when there is a password on there it is simply impossible to change any settings. The only thing you can do is set the channels for logging, and load a new map (which would clear the password protection but you would lose the previous tune). Doesn't brick the ECU though.

The new Haltech Elite is a bloody great ecu if you do end up needing an upgrade. I'm very tempted to upgrade my Platinum Sport to an Elite.

 

[Murcie_LP640]

Ah yes ECU licenses...I know all too well about that with ECUTek - most of the fee for tuning the stock ECU on Rexies is actually in the ECUTek license rather than the tune itself but it's added convenience I guess.

 

[Hayden]

Good news on the 300c front! It's back from the dyno shop after the new computer plugged in and worked first shot. The car made a very healthy 293RWKW. Calculators I've found online puts that somewhere around 520BHP at the flywheel which is more than a Ferrari 430 Scuderia.

Unfortunately, the tune revealed a couple issues. First was a problem with cooling, which we think we've fixed by switching to proper coolant from the water that was only meant for test firing; rewiring the Thermo fans too activate via switch and rerunning some coolant lines we don't think we had right earlier. All in all, it should now have no issues keeping cool.

Next we took the car to an exhaust shop, because the dyno man thought that the standard exhaust we were running and the 1 3/4 inch pipe we'd used to join it to our headers was causing some restriction. The guy at the shop did his job well and with the mufflers, H pipe, catalytic converters and narrow join pipes gone it's certainly breathing better. I have a video but it's not cooperating right now, so you'll have to take my word that it sounds awesome

The final issue, which is visible in that video, is a severe delay from releasing the throttle to the engine stopping its acceleration. It's about a 2-3 second gap while in neautral and while not as bad while the car is under load, we fear that if I try to lift and the car keeps accelerating, I'll end up in a wall.

Research told us that this is a problem with either the (brand new) throttle body or the tune, with most people recommending getting a US based tuner to write a program for us. We were able, however, to find another (3rd!) dyno shop on the other side of the city, whose owner promises he has a device that links the throttle body directly to the pedal, without confusing the computer. He says that if it doesn't work he'll even uninstall it and give us our money back. After so much uncertainty from these sort of shops, it's good to finally hear some confidence!

Other than that the car just needs a wheel alignment, a few more minor tweaks and some decent tyres! There's a hillclimb this weekend and all things going well, we will be there!

 

[Hayden]

Unfortunately the tuner's throttle device couldn't plug into our car due to him not having the right adapter and we had to give up on running the 300 at the hillclimb.

Not wanting to waste my entry, I decided to take the 86 down for the 5 hour each way trip to have a go at the twisty coastal roads. Upon arrival, I was greeted with familiar faces, as many of the entrants were people I'd met at last years Legend of the Lakes hillclimb, being as this "Twin Peaks" event was only half an hours drive from the Legends course.

After some electrical tape application and a quick reconnaisance run, it was straight into competition, with the 50 or so competitors lining up. Twin Peaks is different to most other hillclimbs, because it actually runs two tracks simultaneously. The first, a tight, complex affair filled with extremely difficult double apex and falling away type corners. The second, a long, relatively straight run with a chicane in the middle. Both courses required you to go down the hill, do a u-turn then come back up, with your best times from each track added together at the end of the day to rank the drivers.

My first run was slow and messy, with me trying to learn the tracks while in an extremely keen and eager mood, which just made for oversteer and constant fidgeting.

The second run is one I'd really rather not talk about. After doing the u-turn and on the way back up the hill on the first run, I lost my bearings, forgot the corner tightened up, locked my brakes and had a small off resulting in my front bumper contacting a bush and my car getting stuck in the beach sand. I would be lying if I said it didn't bring back very strong memories of the crash that wrote off my first 86. I'd also be lying if I said it didn't scare the hell out of me.

It was a true amateur mistake, with me pushing far too hard for only the second run of the day when I didn't even know the course yet. Very luckily, the car came out of it pretty much unscathed, with some slight surface scratches I'll be buffing out sometime this week. It was a humbling reminder that this thing isn't a race car and I really can't afford to do 🤬 like that. Afterall, I needed the car to drive the 5 hours home after the event and to work every single day of the week.

After getting towed out and pulling back in the pits, everyone was quick to make sure the car and I were ok before telling me stories of offs and crashes they've had at this event. The guy in the commodore above, completely wrote a car off by hitting a concrete barrier at 140kph last year, with the only thing that survived- a storm trooper bobble head- now residing on the dash of his new race car. There is serious consequences when you are racing on a course that doesn't have run off areas.

I went out for the next run with the ambition of driving clean, careful and calm- constantly telling myself "you need to drive this thing home." I took it very easy and surprisingly set times far better than my first run. As the day went on I slowly regained my confidence and while staying careful, pushed to try and improve my time. On the second to last run of the day I changed my lines in a couple corners, used different gears in others and braked later and harder on the high speed track to knock 3 seconds off of my best combined times. I was stoked and knowing there wasn't much time left on the track for me, I took the last run as a relaxed excuse to do a couple handbrake turns and have a bit of fun.

I hadn't been paying too much attention to the time sheet throughout the day, with my off taking any thought of me being competitive off the table and mere survival becoming my focus. To my absoloutley shock though, come presentations, I'd actually managed to catch and beat the FB RX7 who'd started the day with runs 7 seconds faster than mine. My time of 2.02.77 was actually good enough for 25th/42 overall. Very surprised, I accepted the first trophy I've ever won in my entire life, thanked the track workers for pulling my stupid ass out of the sand and drove the 5 hours home, arriving just before midnight with something to put on my mantle.

This was the last competitive event I will enter the 86 in, with the 300c very near completion, it simply isn't worth the risk of me putting it in a wall. It feels good though, knowing that it's retiring a champion

Full photo credit to Turn 8 Photography- https://www.facebook.com/turn8photography/

In the rush to leave to the event I forgot my camera and go pro. I'll add any other pics that get put up and somebody else's onboard video to this thread later in the week.

 

[Katiegan]

Congrats on the trophy! Hopefully the first of many once the 300 is up and running.

 

[Hayden]

Finally. After 9 months, countless dollars, many hours and endless roadblocks. It lives.

Dad & I took the 300c down to Mallala on the weekend for its very first shakedown. We decided that with no walls in close range, it'd be a good opportunity to test the throttle lag, along with the engine, gearbox, our custom steering setup, the chassis and the brakes. Getting it ready was pretty easy, with just a few stickers applied; two of which were a pair of custom racing numbers I'd had made with the family's business name on them, the fire extinguisher pulled out of the 86 and installed, a switch for the thermo fan put in place and a good wash inside and out being required. We also sourced and fitted some Nankang NS2R Semi Slicks in 245/40/R18. They lowered the car a bit and don't fill the guards like the road tyres did, but we thought the scraping while putting it on the trailer was a small price to pay for having good rubber

We arrived late because of work commitments and by the time we had it off the trailer, my first run had already begun. I quickly threw on dad's old racing suit and drove from the pits to the track. With the Marshall telling me I had 5 minutes until the end of my session, I entered the track, put my foot down and smiled. The car span the semi slicks effortlessly into the 1st corner and barked eagerly as it's speed climbed and the tail wagged. I got just two laps in before my group was called off the track, but with a smile from ear to ear, I knew we'd built something pretty special.

After a quick going over, and the longest hour of my life waiting for my next session, it was time to head back out. I struggled keeping the car idling on the way to the track, due to our throttle delay issue and big cam, but once the car was out there and under proper load, you wouldn't even know it had a problem. The car felt so eager to accelerate, and to my absoloute shock, I realized that in my first session I had been shifting by sound alone and hadn't looked at the RPM meter. I had an extra 2000 revs to work with and as I found out, that is where the 5.7 really wanted to be.

I already knew the track from the drift days i'd done at Mallala in the Skyline, but I had to completely relearn the lines and flow because I obviously wasn't there to drift.
Despite that, I started pushing a little harder in that session and really got the feel for the car and how it handled. Coming from the 86 and Skyline, I fully expected something the size and weight of the 300 to be an absolute nightmare to drive but I could not have been more wrong. It was simply brilliant. Agile, responsive, predictable and just plain right. The Falcon's rack, coilovers, low height, roll cage and semi slicks really transformed this thing into a corner carving monster. Don't get me wrong, you can tell its a big, heavy car with 500+ BHP, but it didn't detract from the experience or make it hard to drive. It just made it feel like an event and made the whole experience all the more special.

The car survived it's first shakedown day with an unexpectedly small list of issues. The brakes, obviously, were rubbish. After just two laps they started to fade and by the end of the day I'd covered the wheels in brake dust and warped the rotors to the point that the whole car physically shuddered under heavy braking. This is pretty much the only aspect of the car we didn't touch in the 9 months of build time we've had so far; so Lets just say we weren't surprised that the combination of 2 piston fronts & 1 piston rear calipers with no cooling, pressing ancient pads onto worn out old discs with cheap and nasty fluid doing the work just wasn't up to the task. We've already looked into and priced SRT8 Brembo brakes before, but after the weekends performance, I think that'll be the very next upgrade we do.

The next problem was oil related. The car pushed a small amount out through the pod filter and burnt some through the engine, creating white smoke from the exhaust. Research on Chrysler & Dodge forums tells us that this happens if you fill the oil up too fast, due to a weird design kink in the 'new' hemi engines. Dad recalls using a funnel to fill it so we'll be draining the oil this week, refilling it slowly and hoping the smoke and leak go away.

As i mentioned earlier, the throttle delay problem wasn't that noticeable on track, but it was a massive pain in the pits and when loading the car on the trailer. After doing some research on how we could make more power without a turbo or supercharger, we've bought a 6.1 Hemi's intake manifold and intend to fit it and have the car tuned in the next month or so. It'll be interesting to see just what numbers it will put out next time.

For now though, I'm just super excited for the next time I'll get to jump into this thing! Thanks to all of you for tagging along for this build and I'm looking forward to sharing this car's future with you! That includes the build video that I've been hinting at for months now, and i'm glad to say that it's very nearly finished and GTPlanet will be the first place I post it.

For now though, here's a video of a lap from the weekend. It's a far from perfect lap and by this point, the brakes were well and truly past their prime. You can get an idea of what the 300c is like from the drivers seat though


In the spoiler below are a few pics I took of other cars at the track day. I've never experimented much with photos of moving cars before so I was pretty happy with how some of these came out

Spoiler

 

[Dan]

Man, that 5.7 sounds absolutely evil. Glad to see the car finally up and running. Did you have a chance to speak with the other drivers and hear their opinions on the 300?

 

[Katiegan]

So happy to see the car finally out on the track! Looks like all that hard work has really paid off. The car looks and sounds absolutely brilliant. Looking forward to seeing more clips of it in action!

 

[Anathema]

Very, very nice. That noise it makes is glorious.

 

[homeforsummer]

I fully expected something the size and weight of the 300 to be an absolute nightmare to drive but I could not have been more wrong. It was simply brilliant. Agile, responsive, predictable and just plain right. The Falcon's rack, coilovers, low height, roll cage and semi slicks really transformed this thing into a corner carving monster. Don't get me wrong, you can tell its a big, heavy car with 500+ BHP, but it didn't detract from the experience or make it hard to drive. It just made it feel like an event and made the whole experience all the more special.

Definitely a lot to be said for the more-power-than-grip, slightly wayward setup of something like this. Drove a new Mustang GT on track the other week (on both standard and uprated suspension) and it was great fun. Wasn't a car you could hustle like something lightweight and with something like this you tend to go a bit easier on the brakes unless you're running a pretty serious braking setup, but the long wheelbase and big power make cars like this feel wonderfully adjustable.

Dunno what brakes you're running (edit: helps if I read your full post!), but I'd be trying to squeeze something as big and powerful as possible behind those wheels, with as much cooling as possible and some heavy-duty pads. Going fast is only half the fun at a track day - the other half is giving the brakes death lap after lap and never losing confidence in the pedal!

Man, that 5.7 sounds absolutely evil.

^ What he said. Few more revs at the top end and it'd almost sound like a stock car.

 

[Hayden]

Man, that 5.7 sounds absolutely evil. Glad to see the car finally up and running. Did you have a chance to speak with the other drivers and hear their opinions on the 300?

I can't speak for everybody at the event, but everyone we spoke to thought it was pretty awesome. People kept coming up to us to have a better look at it and get the story behind the car. The consensus was definitely that it was a cool machine and everybody there (just like on here ) loved the noise it made. One bloke with a skyline told us we should take all the stickers off, black out absoloutley everything, put some bullet hoes in it and call it the mobster . On the way home we were overtaken by a large group of bikies and they were staring at the car on the trailer and giving us the thumbs up as they drove by

So happy to see the car finally out on the track! Looks like all that hard work has really paid off. The car looks and sounds absolutely brilliant. Looking forward to seeing more clips of it in action!

Thanks! It's been a really long road and it's great to finally have the car useable. Don't worry, there will be plenty more clips in the future

Very, very nice. That noise it makes is glorious.

Thanks! It's deafening from the inside but soooo worth it!

Definitely a lot to be said for the more-power-than-grip, slightly wayward setup of something like this. Drove a new Mustang GT on track the other week (on both standard and uprated suspension) and it was great fun. Wasn't a car you could hustle like something lightweight and with something like this you tend to go a bit easier on the brakes unless you're running a pretty serious braking setup, but the long wheelbase and big power make cars like this feel wonderfully adjustable.

Dunno what brakes you're running (edit: helps if I read your full post!), but I'd be trying to squeeze something as big and powerful as possible behind those wheels, with as much cooling as possible and some heavy-duty pads. Going fast is only half the fun at a track day - the other half is giving the brakes death lap after lap and never losing confidence in the pedal!

^ What he said. Few more revs at the top end and it'd almost sound like a stock car.

I'd never driven a car like this in anger before but it was definitely an eye opener. It just seemed to react so positively to everything I did mid-corner and felt so controllable. It's mighty tempting to get some extra stock wheels for the back and see what it's like to drift it, but I really don't wanna put it in a wall

SRT8 Brembo Brakes are definitely looking like the go. The only thing we're worried about is clearing them with our standard wheels. Unfortunately, semi-slicks for anything larger than 18" are only available from the expensive brands and we'd have to track down some expensive SRT8 20" wheels to put them on. Fingers crossed it all clears as is

 

[Hayden]

Finally finished the build video on the 300c. You guys know most of this already, but now it's in a stripped down, narrated, 9 minute and 15 second video

There's been a fair bit of work in this so I hope you all enjoy!

 

[GDII]

Thoroughly enjoyed. Well done to both you and your Dad.

 

[Katiegan]

Great work on the video, can't wait for more!

 

[Hayden]

I'm working on some very exciting things, but I'm just going to leave this here for now

 

[Dan]

I'm working on some very exciting things, but I'm just going to leave this here for now View attachment 648463

Can't wait!

 

[eiriksmil]

Insane how smoothly it pulls all the way to the top..!

 

[Hayden]

10 points to anyone who guessed what im up to by the vague, flag wielding fellow above, but for everybody else... I'm building an aero kit!

I've spent months researching this idea, as regular readers will remember from my virtual wind tunnel testing. I've been looking into the practical side of it too, by reading this brilliant thread on MiataTurbo.Net front to back over the last few weeks. So come last Monday, I had a head full of ideas and thanks to countless people playing with MX5s, a fair idea of how to make them a reality.

I started out with a piece of plywood I found laying around at work and bolted it up to the underside of the Chrysler using the standard mounting points for the slash shield...


Then I traced a line straight down from the front-most part of the bumper, measured 6 inches forwards of that and drew the rough shape of what the splitter should look like. I then cut roughly around the outside of that to get rid of some unnecessary material and make my workspace bigger


Next, I turned my attention to making an airdam. I went to Bunnings and bought a 2.4m x 1.2m sheet of corflute and cut a 15cm wide, 2.4m long piece of it. I then cut 5 cm deep cuts every 5 cm along the length of it. I found this to be the best way to make the corflute both easy to shape and easy to stick down. I bent all the cut flaps 90* in the same direction than stuck it down to the splitter and up to the bumper using masking tape. You can see the outwards bent corflute makes a small lip where it connects to the splitter. I kinda like the lip to be honest


Very long time readers of this thread may remember my last foray into fibreglass. About 3 years ago I began but never actually finished building a fibreglass hardtop for my 300zx convertible. That's still on the list of jobs I want to do, but I just wanted to mention it because I learnt a lot back then and i carried the techniques into this project. .... (Full story here)


So anyway, like I did back then with the vert, I covered up the surrounding area of bumper, along with what I'd made from the corflute with masking tape. I then went over the top of that with duct tape. Basically, the duct tape protects the car from the resin and the masking tape protects it from the duct tape. I then traced along the edge of the corflute on top of the tape so I would know where to stop applying fibreglass.


With the core complete, I went to get some supplies. I had a lot of difficulty finding someone that could get me the quantity of stuff I wanted for a reasonable price. I got lucky when I saw a ute with "fibreglass repairs" written down the side and decided to follow it to their workshop. They were a nice couple guys that were more than happy to point me in the direction of their supplier. While there I bought plenty of fibreglass chopped strand mart, cloth, resin, catalyst and the quite expensive contents of that mystery black roll...


What followed was the tedious process of cutting up the chopped strand mat, mixing up the first batch of resin and getting to work. The mat soaked up a huge amount of resin and as a result, I ended up spending a good couple of hours laying down the very first coat of fibreglass. I then added an extra layer on the upwards curve of the airdam and along the edges to add strength.


When I came back 24 hours later, it was all dry and after undoing the bolts and some gentle prying, the splitter and air dam came away from the body in one solid piece. Unfortunately the duct tape had lifted slightly on the passenger side and created some waves in the glass. To fix that, my next step will be using some filler to shape the air dam to look how I want it, then covering the entire thing with a good few more coats of firbreglass.


The splitter and air dam that I've created should be easy to remove, strong enough to survive an off track excursion, and be reasonably light.

There is more to the aerodynamic package than just the front end though, and I'll keep you updated while the kit starts taking shape

 

[INEEDNAWZZZ]

Love that render, makes it look like a V8 Superstar spec car:

 

[Hayden]

So with the front taking shape, I turned my attention to the rear. My aero research told me that a NASCAR spoiler would be beneficial, so thats where I decided to start. I looked into regulations and in hillclimbs, they use the same classes as proper racing and our current mods put us in group 3J. In CAMS 3J Improved Production, spoilers like this are allowed but they mustn't be further than 125mm from the decklid at any point.

Slightly off topic but my tired brain is struggling with the wording of the below rules. According to these, I feel like the splitter and airdam I've already made may actually be illegal. My understanding is that nothing can stick out further than the front bumper's front most part and that pretty much rules out a splitter all together. If that's the case I'll cut the splitter off and redesign it so it can be easily attached and removed depending on specific event regulations. If you are good with regulatory wording feel free to help me out on this one!

So anyway, with the rules in mind, I got some cheap metal brackets from a hardware store and went to work on the back of the car with corflute and masking tape. The idea was a vertical 90* wall at the maximum height allowed to catch as much air and eliminate as much lift as possible. I cut the rough shape into the corflute then glued the brackets to the front of it and put a flat piece in the middle on the rear side. The main job of these is to reinforce the spoiler but they'll also act as its eventual mounting points.

I then took a good look at it and realised I didn't really like how it looked. I tried a few different things but ended up settling on this design, with the spoiler stretching over the side and following the taillight before terminating with the body line. I choose this look because I felt like it best tied in with the car's bold body lines and I saw it as a bit of a throwback to racing muscle cars of the past.


. For mobile data (and bad puns) sake, there's more pics of the spoiler in the uh... Spoiler

Spoiler

It was interesting trying to turn the 90* angle on the boot to the far sharper line of the tail light. A couple small brackets came to the rescue!

When it's all said and done it should fit flush with the front of the tail light and terminate with the body line.

Picture this photo with no masking tape and more carbon fibre and you're on the right track.

There's two brackets on each side of the boot and I'll have fibreglass joining them. These panels will cut in exactly in line with the inset part for the number plate in the middle of the rear bumper. It's hard to explain but the Xs mark the side where there will be no fibreglass

With the basic shape figured out I then coated it with duct tape before having to leave suddenly without getting to apply any fibreglass. This could be a good thing though, so if you hate how this looks, please let me know now or forever hold your peace!


On a somewhat related note, I got to see some of Australian Motorsport legend, Peter Brock's most famous cars a couple weeks ago at an exhibit while I was on holiday. The museum had a priceless range of cars he used over the years, and if you're ever near Dreamworld on the Goldcoast of QLD, you should check it out.

The rows of awesome cars presented a great opportunity to see first hand how aerodynamics developed at the top tier of Aussie Motorsport. Everything from the simple duck tails on the Toranas (look familiar?)...

...To the boot spoilers on the early Commodores...

...the more familiar wing on the early V8 Supercars....

... All the way to a current spec Supercar show car they had near the exit.

Just thought you might find that a little bit interesting . Thanks for reading folks

 

[SVX]

A technique I found when I was working on my JTCC design is an entire bottom piece lip -

Attaching on to a second half of the bumper with the lip as one piece. Perhaps that could work, because it could be considered a piece of body work as opposed to an attached splitter?