DanielsDM 818R

[DanielsDM]

Hello everyone,
I'm finally getting around to starting my build thread. Almost two years ago I decided to seriously look at build an 818R and started cruising this forum, asking questions and learning as much as possible. My kit arrived Dec. 1, 2015. Progress has been slow due to some of my plans, which I'll explain later, and I had to have surgery on my shoulder which sidelined me for 2.5 months.

The car will be built to race NASA Super Touring 2 and Western Endurance Racing Championships E0 (since ST3 cars run in E0 we will detune it to meet ST3 wt/power specs for enduros). BUT... with this years changes to ST3, went from 9lb/hp to 10lb/hp, I may rethink trying to fit in E0 and may end up in ES.

Our race team consists of myself (Daniel) and two of my friends (Steve and Andrew) who are helping with the build and will also drive/crew. Here is a quick background on each of us:

Daniel: I am a mechanical engineer by profession for the last 21 years. I've worked at companies that made turbine engine components, semiconductor equipment, and biomedical robotics. My first job out of college was more of a manufacturing role than mechanical design, in addition to fixture and process design I also did the CNC programming of the mills, lathes, grinders and edm's. That experience served me well when I moved on to a design engineer job since understanding how a part will be made is very important when designing.
I really enjoyed the machining and have acquired machine tools for my home shop over the years. Now I have a side business, Daniels Design and Machine, designing and fabricating one-off prototypes (no production runs, after the first few parts I get bored and it starts feeling like work). I have done a lot of design and fabrications for Davidson Racing's Norma and Eagle.
Racing experience: I went through NASA's HPDE program to get my racing license and raced Spec Miata for a few years. I sold the car and put racing on the shelf for awhile because of family commitments.

Steve: A mechanic by profession, Steve worked for Davidson Racing for several years as the Norma Car Chief, including when they won the Overall at the 25 Hours of Thunderhill in 2014. He has also built Spec Miata's that have won two NASA NorCal SM region championships, a PTE NorCal championship and a PTE Western States Nationals. Steve also holds a NASA racing license and has races several seasons in Spec Miata.

Andrew: Also an engineer, Andrew was a certified welder before going to school for mechanical engineering. He has built a 24hours of Lemons car and races a few times a year.


The project started with adding a recessed mid height scissor lift to the shop.IMG_2216-1.jpg
A 2007 WRX donor.IMG_2219-1.jpg

The Kit arrived!IMG_0014-1.jpg

Weighed the chassis, just to know what we're starting with.IMG_0015-1.jpgIMG_0016-1.jpg

Removed the X under the seats and welded in plate. This allows the seat to set a little lower. IMG_0058-1.jpgIMG_0060-1.jpg

That's it for now. I'll post more after I take some more recent pics.
Cheers,
Daniel

[FFRSpec72]

you might want to consider addressing the potential frame issue before you get it powder coated, the issues are documented in my build thread and in Chad Plavan's thread

[mikeb75]

Welcome, looking forward to following this build! I expect lots of 1-off goodies based on everyone's CV's.

Can you show a bit more detail of your under seat steel plate? I did something similar, but I'm reconsidering how I welded the steel to the frame.

[AZPete]

Welcome. I look forward to following your build. It's interesting that chassis weighs 457 lbs., with some aluminum panels but not the radiator frame. Good info. Thanks.

[Mitch Wright]

Welcome to the club, looking forward to your build.

[DanielsDM]

you might want to consider addressing the potential frame issue before you get it powder coated, the issues are documented in my build thread and in Chad Plavan's thread

Thanks for the heads up. I've been following the issue here. Steve pointed out the problem with the main hoop sitting on a tube when we first got the kit. I have a plan, I'll post it when I actually get to it.

[Mechie3]

What kind of machine tools?

[longislandwrx]

every time I see a new build I'm like... oooooh nearby??? nope.

welcome. good luck with the build!

[DanielsDM]

Welcome, looking forward to following this build! I expect lots of 1-off goodies based on everyone's CV's.

Can you show a bit more detail of your under seat steel plate? I did something similar, but I'm reconsidering how I welded the steel to the frame.

Yes, there are several 1-off parts in the plan.
The bottom of the plates are flush with the bottom of the frame. Tack welded from the top for now. We will seam weld the bottom after we take it all back apart and we can flip the chassis over.

[DanielsDM]

A few more details on my approach to an 818R:
Front Suspension: When I got my first look at an 818 in person the front suspension design gave me some concern and some things I wanted to do different.
1) The short upper A-arm design is unconventional, not necessarily a bad thing, but something to make you go hmm...
2) The design hangs the weight of the car on a ball joint that was not originally intended to carry a heavy axial load. I don't know the axial load rating of the factory ball joint so it may or may not be fine. None have failed yet that I know of so perhaps it's ok. Still something I don't particularly like, and if it did fail there is nothing retaining the bottom of knuckle. Could be ugly at race speed.
3) The front WRX knuckles are pretty heavy. Great for a 3000+ lb front end heavy car that can be rally raced. But alot overkill for a <2000lb rear heavy road racer.
4) I want to eliminate all rubber bushings in the suspension.
5) Also want more adjustment: Anti-dive, roll center location, camber, bump steer and ackerman.

To address these issues/goals I chose to completely redesign of the front suspension.

So first we assembled the WRX/FFR suspension on the car (minus springs). Then leveled it at my intended ride height of 3". I then marked a reference line on the floor parallel with the chassis and began the slow process of measuring the chassis. After all the suspension pivot locations were determined the data was entered into a SusProg3D to study how it behaves.
818-Measured 12-13-15.jpg
Analyzing the geometry showed that the short, high mounted upper a-arm layout behaves better than I expected. My design keeps a similar layout and uses the Factory Five attachment points to avoid major chassis rebuilding.

Here is one of the front uprights assembled with a hub. Note the hub has a 4x100 lug pattern. I'm running 15" wheels in the front to allow for a lower ride height without rubbing (and save about 5lb/wheel). There are alot more choices of 15" wheels in 4x100 than 5x100.
IMG_0243-1.jpg
Starts with a 25lb billet
IMG_0215-1.jpg
Let the chips fly!
IMG_0218-1.jpg

IMG_0226-1.jpg

[mikeb75]

Yay! I was hoping someone would mill custom front knuckles. Did you research the MSI replacement uprights, or is your design based entirely on your measurements?

Either way, AWESOME. Can't wait to see what's next (this is car pron, you need an age appropriate warning. )

[Canadian818]

Those are sick! Any plans to sell them?

[Mitch Wright]

Nice work, also fun to see someone doing what many of us would like to do.

[DanielsDM]

Yay! I was hoping someone would mill custom front knuckles. Did you research the MSI replacement uprights, or is your design based entirely on your measurements?

Either way, AWESOME. Can't wait to see what's next (this is car pron, you need an age appropriate warning. )

I have seen the MSI uprights, but my design is based on my own data. These are not drop in replacements for the Subaru parts, but part of my front suspension design which also includes Lower Control Arms, Upper Control Arms, rear LCA mounting bracket (replaces the subaru one with the giant rubber busing), UCA mounting bracket that replaces the FFR setup. I'll post more as I get it done.

Those are sick! Any plans to sell them?

Maybe someday. For now I have to finish and test it. Once it is a proven setup I may consider making more to sell.

[DanielsDM]

Progress Update.
Almost done with the front suspension and brakes.
IMG_0478_1.jpg
Billet Aluminum UCA and mount.
IMG_0477_1.jpg
Billet aluminum upright and fabricated steel LCA
IMG_0479_1.jpg
Floating rotor/hat

On the rear I'm using the WRX uprights with a caliper mount that replaces the steel caliper mount/parking brake setup. Saves about 4lbs per side.
IMG_0476_1.jpg
IMG_0475-1.jpg

[ben1272]

Nice machining, your experience shows! As I understand it, there is a bumpsteer issue with the front suspension as designed by FFR, so you will want to make sure and address this if you see the same issue.

I am looking forward to following and hope you decide to make some of your creations available to the rest of us! That is, assuming they all perform as expected!

Keep up the great work.

-Ben

[DanielsDM]

Thanks for the compliment Ben.
Regarding bump steer, I modeled the suspension geometry in a program called Susprog3D. It allows you to see how everything changes through out the travel. In theory my design will have less than .010 bumpsteer with +/- 2" of travel, less in the +/- 1" range it will typically operate in. This with the wrx rack in the ffr location. There is adjustment in the design to account for the differences between theory and reality.

[Mechie3]

Nice work! Are you doing FEA on the parts to optimize them or just kinda eyeballing the strength? Haven't checked this thread in a while and I've missed some cool stuff.

[DanielsDM]

I have done FEA on all these parts. More of a verification process than optimization. I.e. design it to what looks right, calculate the load conditions, run the FEA. If the stress is below the fatigue strength of the material by a reasonable safety factor then move on, if not update the design and repeat the analysis. Several of the parts needed some tweaking after the first FEA run.

[Aero STI]

The suspension setup looks amazing. You should sell them.

[Mechie3]

I wish I had taken some automotive classes in school. I never had any guidance in fea of suspension parts and wish I had some.

[STiPWRD]

Sweet suspension setup! Did you already have front wheels selected and is that why you chose the 4 lug?

[DanielsDM]

My plan from the start was 15" wheels in front. A 1800lb car doesn't need big rotors so there isn't any performance benefit from 17" wheels. 15s are 5-7lb lighter, tires are less expensive and I will be able to have a lower ride height without reworking the fenders. There isn't much of a selection of race worthy 15" wheels with a 5x100 bolt pattern unless you go cu$tom forged. Since I'm making my own uprights I could use any hub I want. Lots of race proven 15" wheels in 4x100 so that is the way I went.

[DanielsDM]

I wish I had taken some automotive classes in school. I never had any guidance in fea of suspension parts and wish I had some.

Dynamics, Strength of Materials and Fundamentals of Machine Design are the same whether applied to industrial machines, robotics, cars or airplanes. The standard practices are different for sure. You can do things different when designing an industrial machine because the primary design factor is usually rigidity, whereas in a car or airplane minimizing weight is usually the primary design factor. Thus the stresses are higher and more attention must be given to avoiding stress risers and fatigue of parts seeing cyclic loading.

If you haven't already I recommend reading Carrol Smith's books: Tune to Win, Prepare to Win and Engineer to Win. As well as Bill and Doug Milliken's Race Car Vehicle Dynamics.

[FFRSpec72]

My plan from the start was 15" wheels in front. A 1800lb car doesn't need big rotors so there isn't any performance benefit from 17" wheels. 15s are 5-7lb lighter, tires are less expensive and I will be able to have a lower ride height without reworking the fenders. There isn't much of a selection of race worthy 15" wheels with a 5x100 bolt pattern unless you go cu$tom forged. Since I'm making my own uprights I could use any hub I want. Lots of race proven 15" wheels in 4x100 so that is the way I went.

There are some potential advantage of taller tires, but they have to all be taken in with the dynamics of the rest of the car, like final gearing, tire profile, etc.

[RetroRacing]

We had to make the move to 15" in the front, could not get the car to low enough ride hide for the underside aero to work. It was stupid hard to find a 15" wheel in 5x100, so I think you made the right choice, we use 15" on our EP cars, and there are a ton of them out there. As for strength, remember, we are only moving a 2000lb car around, and curbs are off limits due to ride height, so finding a super strong wheel was not our main concern, finding a light one was. You can bend a Kodiak but just looking at it the wrong way, but a lighter, higher quality wheel, you will not find. We do not have that budget as we need to have at least 5 sets of wheels....

Love what you are doing, please keep updating.

BTW, we have 0 bump steer. Strongly suggest you look aftermarket for a rack, or go electric power steering. I see trouble lasting 2.5 hours in the car.....

[Hindsight]

We had to make the move to 15" in the front, could not get the car to low enough ride hide for the underside aero to work.

Did you just test this with the seat of your pants? I'm not even sure I'd be able to tell, going by feel, but I'm very inexperienced with that.

Also, your comment about curbs caught my eye. Do you really stay off the curbs at all times due to ride height? Won't this be a real disadvantage to corner speeds? Genuinely curious about this.

Daniel, great looking build! I am looking forward to seeing how the custom suspension improves things.

[RetroRacing]

Our splitter was 3" off the ground, our center pod 2" with the front tires rubbing. We are being told we need to get the center to closer to 1".
As for curbing, we can touch a low curb, but need to be very careful we don't split one. Now with the new lsd in the car, we can't wait to test. We were getting a ton of power on understeer in the car, so making some adjustments to tighten up the rear, and now with some available clearance, drop some spring rate out of the front. We are also going to put some compression toe out in the rear to help it turn a bit later on, once we do some more testing. Right now the car is super safe to drive, but way to conservative. 30-40 more hp and an LSD for next test session IF we can finish fixing the fire damage in the next 2 weeks!!!

[Hindsight]

Nice, good luck and keep us posted in your build thread!

[DanielsDM]

There are some potential advantage of taller tires, but they have to all be taken in with the dynamics of the rest of the car, like final gearing, tire profile, etc.

I agree that there some potential advantages to taller tires as well as shorter, stiffer sidewalls. In my opinion, the benefits of a lower ride height (lower CG=more mechanical grip and potentially improved aero grip) are more important on an 818R.

[DanielsDM]

BTW, we have 0 bump steer. Strongly suggest you look aftermarket for a rack, or go electric power steering. I see trouble lasting 2.5 hours in the car.....

What rack and electric power steering are you using?

[DanielsDM]

IMG_0522 (640x480).jpg
To eliminate the rubber bushing in the rear upright (knuckle) I made a bushing that holds a spherical bearing.

IMG_0523 (534x640).jpg
Installed.


I didn't get any work done on the car last weekend because I went to Vegas for the Nascar race. One of our suppliers at work is owned by Rheem, who sponser a car in the Xfinity series.
IMG_0540 (640x250).jpg
The sales rep got us garage and pit passes and we got to sit in the pit box with the crew chief and race engineer. Awesome experience!

[RetroRacing]

Something like this http://www.ebay.com/itm/02-07-SATURN...RYhXke&vxp=mtr or for a Cobalt is an easy install, just use the same rack.

[DanielsDM]

Cool. Thanks.

[UnhipPopano]

I would not consider putting in the Electric Power Steering unit an easy install. Where are you going to fit the unit?

[DanielsDM]

I suppose "easy install" is a relative term depending on fabrication skills, equipment available and the scope of the project. As for placement check out Jeff's build thread (Retro Racing) as they have already installed one. I plan on staying with manual steering at least until I get some track time on the car and determine that it is needed. I am planning on endurance racing so when doing 1 hour+ stints it may help with driver fatigue.

[biknman]

How's the build going?

[DanielsDM]

It's coming along. Slower than I want it to of course. Just about finished with my dry sump setup. Will post pics when it is installed.

[DanielsDM]

Time for an update.
Been working on the dry sump system. Pump is a Johnson's HTP 4 stage (3 scavage + 1 pressure). Just barely fits in the AC compressor locations.
IMG_0638-1.jpg
Billet pan machining.
IMG_0640-1.jpg
IMG_0652-1.jpg
IMG_0654-1.jpg
IMG_0651-1.jpg
My design extends the hose connection to the front of the motor so the hoses stay further away from the exhaust.
The filter will be moved to remote location the factory heat exchanger removed.

Next is temporarily mount the body to figure out where to put the DS tank and oil/water heat exchanger, and well... everything else.

[biknman]

Excellently! You sir set the standards for all others to follow!