TurnerX19
TurnerX19 Reader
1/17/19 5:57 p.m.

For 12 lbs of unsprung weight I would try really hard to adapt the ABS tone ring and sensor from the iron knuckle to the aluminum one. Oh how I hate, Unsprung weight.

sleepyhead
sleepyhead Mod Squad
1/17/19 11:59 p.m.

I would to... 

but, it's almost the end of January... and in a lot of ways, getting 'big things' like this buttoned up and out of the way is important to get done now.  That way, only minor issues are left to sort through in March/April when life tends to ramp up.

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/18/19 7:30 a.m.

In reply to sleepyhead :

Yup. Getting solid working brakes with ABS that can handle the heat is (hopefully) the big mechanical thing to get sorted. I'd like to get that done, working and get several thousand miles of daily driving on the system as well as whatever test days I can fit into my schedule/$$. 

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/20/19 12:17 p.m.

Swapped the second rear knuckle and the ABS light was off by the time I pulled out of the driveway. Success! Drove it around the block and I'm happy with the brakes on the street. ABS works, gobs of brake. I'll need new rotors and pads all around before One Lap. The plan is to run something fairly mild in the rear, paint up the rotors with heat paint, go do a track day to confirm temperatures, and then decide on compound from there. 

Also, spent the morning yesterday driving back and forth to Austin to pick up these guys. 

They're heavy and ugly but the stock steelies don't fit over the new front brakes and the RS4's are getting low enough that I don't want to drive them in the rain even though they probably have 2 track weekends left in them. This the spoke clearance they have. None. 

Time to get out the washers and estimate spacers. 

One washer thick would clear the calipers by about one wavelength of light and two was plenty. Two stacked up was just over 6mm so I ordered 5mm spacers. I don't think I'm going to have enough stud left with the thicker rotor hats and the spacers, so I also ordered proper ARP wheel studs for the front. This also means that I'll probably need new lug nuts. The cascade of parts. 

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/21/19 1:44 p.m.

Lots of thinking about fender liners and bumper covers and splitters. Fender liners are necessary, at least in the front, to keep dirt and water and all of that off the back of the headlights and the rest of the unprotected areas. One of the pains of running a street car. Also there is the question about how to integrate the bumper cover and fender liners and the splitter. Lots of coffee. Lots of thinking. I did get dzus in so that the bumper cover pops off with four dzus and two phillips screws. I have plans to replace the phillips. 

While I was in there I relocated one horn and threw the other one away. They sit here, right in front of the radiator. I doubt they block much airflow now because of how the crash beam and bumper cover sit, but removing these was on my list. 

I put in a nutsert and moved the horn over to the drivers side frame horn where the big snorkel tube used to be. Need to secure that wire still. This is the high tone horn. It sounds adorable. 

Some re-looming to move the wire, replacing plastic loom holders and all of that and I'm horn free in front. Someday when I'm all carbon hood cool guy I'll pull the hood latch and cut away most of this metal to open things up even more. 

Dirtydog
Dirtydog Dork
1/21/19 2:54 p.m.

Nice progress. Can drilling 1 1/2 or 2 inch holes in the crash beam help with cooling and weight?  (oz. = lb.)

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/21/19 4:06 p.m.

In reply to Dirtydog :

It would certainly help with a few ounces, but it's behind the solid part of the bumper cover so no real airflow difference unless I drill matching holes in the bumper cover. 

I decided to play with the small battery again. Still won't crank if it's not completely charged. I think I need somewhere between the stated 130 CCA on the small battery and the 450 CCA on the big one. 

While I was in there I found this on the intake boot. That's probably not good. 

sleepyhead
sleepyhead Mod Squad
1/21/19 4:20 p.m.
mazdeuce - Seth said:

I decided to play with the small battery again. Still won't crank if it's not completely charged. I think I need somewhere between the stated 130 CCA on the small battery and the 450 CCA on the big one. 

ETX14 / PC625 ?  (220cca & 12-13#)

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/21/19 4:41 p.m.

In reply to sleepyhead :

That would be the logical way to go. Or.......I could go with this which worked great in my Mazda2. Zippy LiFePo4 1.2 lbs. and they hardly ever explode!

adam525i
adam525i Reader
1/21/19 7:30 p.m.

Having played with larger and larger Li-Poly batteries in RC helicopters and cars (up to 6s 5000mah) and using my 3s and 4s batteries to boost cars when needed I've always thrown around the idea of using one of the "safer" chemistries as a battery for my track car. Did you just wire yours in and hope for the best or did you use a BMS of some sorts to balance the cells and offer some protection?

Adam

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/22/19 6:18 a.m.

In reply to adam525i :

When I used one in the past I just plugged it in and rolled. It seemed to work fine, but ignorance is also bliss. I have a proper charger now that I bought to re-fresh the Insight cells so I should be able to monitor things better. Also, now you can buy things like this that it looks like you can just leave hooked to the battery that will keep things happy. For about $100 you can buy a motorcycle LiFePO with a claimed CCA, or an RC battery that is likely the same thing in a different wrapper for about $50 and be experimental. Strongly considering experimenting. 

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/22/19 12:37 p.m.

Lots of stuff to think about when designing a splitter for One Lap. First, no rules. laugh But it has to be able to be driven on the street for about 6k miles. There's also about one catastrophic splitter failure a year, so we either need to be able to make a new one on the fly from stuff we can grab at HD, or we need to be able to abandon it and have the front end of the car hold up. Preferably both. Also, since my co-drivers for One Lap live between a couple hundred and several thousand miles away, all of this work is done by me, alone, so on and off has to be a simple one person affair. 

I started the process by cutting these keyholes in the bumper beam. 

An eyebolt can slide in the big hole but not out the slot. 

From here, you lay the splitter under the car with the bumper cover on and slot the bolts home. 

Then you pick up the rear of the splitter and put in the two bolts the go in the nutserts that I put in before. The rear bolts hold the whole thing in tension so that the bumper beam eyebolts don't slide out. In theory. Seems to work well so far. 

From there it was time with the plumb bob, dots, and a line two inches out. Trim to shape. We don't want to get tooooooo crazy even with no rules. At least not for this go round. 

This is just the template to make a better template. Things should look better by about the third try. I still think it looks cool and utterly impractical and considering the car would occasionally hit the plastic on driveways before the splitter, it's going to be absolutely terrible to live with. Horrible. I love it. 

 

 

captainawesome
captainawesome Reader
1/22/19 1:32 p.m.

I'm excited to see the build and evolution of the splitter as it's relevant to my interest.

spacecadet
spacecadet Reader
1/22/19 1:57 p.m.

Very nice! cross posted the last image to the One Lap Accord Facebook page. 

FunkyCricket
FunkyCricket Reader
1/22/19 2:56 p.m.

plans for giant WINGZ?

#winglife

#getyouraeroon

sleepyhead
sleepyhead Mod Squad
1/22/19 3:25 p.m.
mazdeuce - Seth said:

This is just the template to make a better template. Things should look better by about the third try. I still think it looks cool and utterly impractical and considering the car would occasionally hit the plastic on driveways before the splitter, it's going to be absolutely terrible to live with. Horrible. I love it. 

If you're worried about being able to clear speed bumps, and driveways... we could always cut the front back to match the bottom of the bumper, then "add some span" by making the splitter stick out from the side 3" instead of 2", and then add some vertical fence similar to loosecannon's mgb... up to ~ the wheel centerline

would also have the advantage of potentially creating a vortex outside the wheel to help pull post-brakecooling air out from the wheel well

standard caveat... I'll bow to any suggestion stafford1500 comes in here and lays down wink

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/22/19 3:31 p.m.

In reply to sleepyhead :

Agreed. Hadn't thought about going out beyond the wheels. I'll be sure to leave a couple of extra inches. Easier to trim than make it longer. 

stafford1500
stafford1500 HalfDork
1/22/19 4:04 p.m.

Yes, Add vertical fences where you have the blue tape at the ends. Maybe even make those at slightly more than 90 degrees to the length of the car (sloping out and back away from the wheel opening. Dont go any higher than wheel center.

If you want balance tunability and possible street clearance, place a piano hinge just ahead of your 2*4 mounting blocks. Raise the leading edge to get more street clearance and tune from flat toward nose up for balance at the track. You will find a happy spot quickly. Also adds some bending strength across the span.

For your key slots, plan to put something like a carriage bolt in behind your eye-bolts with a wing nut or regular hex nut. Tighten it down after you get the eye-bolts set. This will be insurance against the eye-bolts sliding out at speed and allowing the splitter to fod under the car (not a preffered way to get you your adrenaline up).

Maybe add two more cable braces from your eye-bolts to spots closer to the corners of the splitter. Let them slide thru the eye-bolt so they can keep even tension. Whatever you use to attach the cables to the splitter, make sure you have extras. If the splitter leading edge wears thru they will not be worth re-using.

Drop me a message if you want to pick my brain. Also, Sleepyhead knows whats up.

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/22/19 4:18 p.m.

In reply to stafford1500 :

Assuming we have no rules, becasue we don't, how far out from the tire edge would you want those fences to be? 

Also, good thought on blocking the slot. Will do. 

Thinking about the rest as well. I've quit drinking coffee after noon so my ability to create complex though tapers grandualy after lunch. Tomorrow morning will be better. Still have your card in the truck. Waiting for the proper "phone a friend" moment. laugh

stafford1500
stafford1500 HalfDork
1/22/19 4:25 p.m.

Dont run the fences out past the wheel opening edge more than about 1" because the drag adds up fast. If you had more motor then you could get by with more extension. More extensionwill get you front grip pretty fast too, just draggy grip.

docwyte
docwyte UltraDork
1/22/19 4:37 p.m.

You gonna add a rear wing to go with that front splitter?

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/22/19 4:55 p.m.

In reply to docwyte :

We've been discussing how to deal with the rear of the car chatting off the forum. A wing is the super cool choice, but only if a spoiler won't do the job. 

First I need to figure out if I can reasonably drive around with it, then I need to figure out how out of balance the car is, then I need to bring it back in balance. 

klodkrawler05
klodkrawler05 Reader
1/22/19 6:03 p.m.

I'm not sure if they'd work with a slot like that but my mind immediately thought quick release push pins to plug those holes and prevent the eye bolts from falling out.

I really like that method for securing the front of the splitter, it's much simpler and easier to attach than what I have, in fact I may steal the idea if I can come up with a good way to duplicate it with my kevlar crash beam.

edit: also, do you have anything in  mind for sealing the splitter to the bumper? from the little I know that's supposed to be a fairly important bit.

sleepyhead
sleepyhead Mod Squad
1/23/19 2:52 a.m.
mazdeuce - Seth said:

In reply to docwyte :

We've been discussing how to deal with the rear of the car chatting off the forum. A wing is the super cool choice, but only if a spoiler won't do the job. 

First I need to figure out if I can reasonably drive around with [the front splitter], then I need to figure out how out of balance the car is, then I need to bring it back in balance. 

There's a very real, non-zero chance that all you need is a rear diffuser, and we balance with what we can get out of the front.  no wing, no spoiler necessary... unless we want to try and have "all the downforce" for the skid pad and autocross...

stafford1500 said:

If you want balance tunability and possible street clearance, place a piano hinge just ahead of your 2*4 mounting blocks. Raise the leading edge to get more street clearance and tune from flat toward nose up for balance at the track. You will find a happy spot quickly. Also adds some bending strength across the span

[...]

Dont run the fences out past the wheel opening edge more than about 1" because the drag adds up fast. If you had more motor then you could get by with more extension. More extensionwill get you front grip pretty fast too, just draggy grip

this, with my comment above brings up the question of whether we want three configurations...

- Low Drag - Brainerd Long, NCM Full, Road America, and Drags  (places where we'll get into 5th, or where weight/drag is a penalty)
- Medium Downforce - Nelson, Blackhawk, Hastings and the shorter Brainerd/NCM courses  (courses mainly in 3rd/4th)
- AllTheDownforce - Skid pads, autocross (shorter courses mainly in 2nd/3rd)

that's part of why I'm thinking of going "short" to the bumper in the front, and wide on the sides... then we may not need as tall of a rear "flap" / "gurney" to get the flow turning we need.  I.e. more area, less camber = less drag for same downforce.

stafford1500 said:

Drop me a message if you want to pick my brain. Also, Sleepyhead knows whats up.

I do, and I don't.  Most of my past coursework, was around much simpler flow environments... and my former job was less aerodynamics.  Although, there is some irony that I wrote a paper as part of my senior design about flat-bottomed airfoils in low-RE environment... and now I'm playing around with constant thickness "flat airfoils" in a similar RE environment.  So, in some regards, I'm bumbling around loaded with enough information to be dangerous, but not enough practical experience to be confident (not that anything is particularly 'certain' when it comes to Aero).

mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/23/19 6:44 a.m.

The plan was to do this development over 3-4 years at a leisurely thought inducing pace. Trying to cram that into 6 months means that I'm going to leave things on the table for this year. We've certainly seen people vary their drag levels on One Lap between the drag race and different courses. Something for the future. This year I just want it to work and not fall off. Dream medium dreams. 

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