fletch & son's build thread

[fletch]

This car’s going to be a handful.
Attachment 148919

2.5L from 2006 WRX
TD04-19T turbo and Grimmspeed EBCS
91 octane

Our tuner also remapped the DBW pedal inputs to make it much smoother at tip in. Very streetable—up to a point.

...and that very night, Dad insisted on installing the seatbelts.
IMG_4407.jpgIMG_4408.jpg

These are wagon belts modified per this post. https://thefactoryfiveforum.com/show...sedan-location

I realized the sedan location wasn't going to work for a number of reasons. The wagon spool mechanism would not fit in the FFR-provided sedan slot/bolt hole combo - maybe this was a difference in the wagon hardware itself. Even if we modified it to work, the webbing would exit the spool off-axis. To accommodate the mounting shown, we had to flip the seatbelts' webbing 180 deg in the buckle and the upper mount. Very happy with this solution for the time being.

There was a concern raised a while ago about retraction issues. When you pull the belt out all the way, a ratcheting mechanism engages requiring the belt to be retracted most of the way before it disengages. Other builders reported that their configuration wouldn't allow enough retraction to disengage the ratcheting mechanism unless they unbolted the outer mount point. We have plenty of travel in our belts so this isn't a problem.

[fletch]

You wouldn't know it from our build thread, because I've not done a good job keeping up with all our work, but we're planning a track day in the next week or two. This will be our first shakedown of sorts and we're looking for input. What would you do? What would you test? What would you measure?

The car will eventually be more of a daily driver, but we'd like to iron several things out first.
Top on our list is brake bias. We've got the Subaru ABS system installed and it works well. A few hard stops from 30-35 mph have produced quick, but even stops. We plan to disable the ABS and dial down the pressure to the rear wheels with the proportioning valves until it's closer to neutral. Then re-enable the ABS. We don't have our final wheel & tire setup so this will be a preliminary brake balance.

What else should we be considering?

If I understand correctly, we may be sharing the track with others, but should have enough space to do more or less whatever we need to. There's a skidpad, a road course and an oval.
Thanks for the input.

Me again, requesting more input. Thanks!

[blomb11]

Thinking off the top of my head here if I was in your shoes. I am not sure what kind of data logging abilities you have like a Cobb AP or something else.

1. Checking and adjusting the braking bias as you mentioned. Bedding the pads and bleeding the brakes after they get hot to make sure no air is in the system.
2. Measuring tire temperatures across the width of the tires to check your tire pressure, alignment, and suspension settings. This could tell you if you need to adjust the camber, shock stiffness, etc.
3. Keep it to 80% max power while shaking things down definitely hard to do as I would probably mash the throttle . Get it hot so running a session at 80% for ~10min or so to be able to look at all of your engine parameters oil pressure, oil temp, coolant temp, intake temps, DAM, knock, fueling, etc. This can tell you how things like your intake position is doing to get cold air into the engine and making sure your cooling systems are work as intended.
4. Checking the oil and fuel system to make sure there is no starvation under high G turns since this has been a complaint of many 818 builders.
5. Checking to see how your seat, steering wheel, and shifter all feel under HPDE driving conditions and if any adjustments are needed. This may be OBE if street driving is the main focus.
6. Post session full inspection of the engine and cooling systems to make sure there are no leaks or other issues.

Have fun! Can't wait to be in your shoes one day...still counting down the days to my delivery.

[fletch]

Thanks for the thoughtful reply.
1) Definitely step 1. ABS is wired & fully functional but we plan to disable when setting brake bias then reenable to keep ourselves from trouble.
2) Wve got a cheap IR gun for this purpose. We will probably also try the shoe polish technique as well to verify contact patches.
3) 80% - roger that. We have a Cobb AP and will be logging but we’re new to it. We also may have access to BTSSM logging via Tactrix cable to an Android phone. Not sure if that offers any benefits like increased sampling rates. We’re still at go kart stage so intake plumbing is not representative.
4) I’m not sure how to do this. I assume we may encounter The same oiling problems others have found because we are running an OEM oil pan without any baffling. Fueling will probably not be an issue because we have a front mount tank with fuel foam installed. I’d appreciate thoughts on how to monitor these things.
5) Thanks for this suggestion. We won’t be doing any HPDE events but checking ergonomics is an excellent idea.
6) is there anything other than a close visual inspection that you would recommend?

Again, huge thanks for the feedback.

[blomb11]

I have only used the Cobb AP for data logging so you can just go in a select all of the ECU parameters you want. I am not sure about sample rates probably just comes down to how much data you want to collect.

Yea true #4 is kinda hard you would probably feel it while driving around the track at speed. You could also verify by looking through your post run data logs to see if there were any sharp changes in oil/fuel pressure.

I was thinking 6 would just be a visual inspection to make sure there are no oil leaks, coolant leaks, or brake fluid leaks. Just a visual to see if there are any issues after pushing the car a bit. Kind of all things I would check, but maybe someone else has some clever tricks.

[Bob_n_Cincy]

Brian,
I think the normal stuff you already know.
Keep an eye on fuel, oil, and coolant fluid levels and temps.
Double-check hose clamp tightness after heat cycles. I blew a radiator hose off during the 4th session of the day.
Watch lug nut torque. I have snapped off quite a few of the OEM types.
Watch suspension and body roll.
This video shows how much engine movement and how much front suspension travel. The more cameras the better;

[Frank818]

Brian,

On top of what was said, watch for
1- Clamps loosening up
2- Bolts (any!) loosening up
3- Wiring, any weird signs, heat, sounds, electrical issues, rubbing
4- All suspension parts
5- Exhaust, leaks, loosening up
6- Spark plugs
7- Check your seats anchor points to make sure bolts didn't loosen up, I guess you used bolts there


Are we going to get a video of that track day?
Just saying...

[Sgt.Gator]

Most tracks have a broomstick test for open top cars. Also depending on the organization hosting the event they may have their own broomstick test. Enforcement of the rule varies greatly. Be sure to check both the track and the organization's rules about convertible top cars. So asap have the tallest driver sit in the car with a helmet on and do the broomstick test. Compare the results to the requirements.
You don't want to go all the way to the track to be told to go home because you don't pass their requirements. Do a google search for HPDE Convertible Rules and you will find how different they can be!

Example, HPDE at NCCAR with the Tidewater Sports Car Club:
"All convertible/open top vehicles must be able to pass the broomstick test. The broomstick test involves laying a wooden dowel/broomstick/etc across the windshield frame and the roll bar with the driver seated in their normal position and wearing their helmet. The driver must have 2in of clearance between the dowel and their helmet. NOTE: If you have a non-production-based vehicle/kit car and cannot prove that the windshield frame is a structural item (letter from the manufacturer stating so), the broomstick test will be performed to the front shock tower/structural chassis point instead of the windshield frame."

My Note: If they require 2" above the helmet for kit cars like our 818 running from the roll bar to front shock tower/structural chassis point there is no 818 that will pass that test unless the driver is 4' tall.

Example BMW Car Club Boston: "Convertibles: have a retractable top, whether soft-top or folding hard-top. Convertibles additionally require:
1. An approved roll bar or roll cage where both driver and instructor sitting up right with helmets are below the top of the roll bar.
2. A 5- or more point harnesses for both driver and instructor, with belts properly routed.
3. Arm restraints."

Example: Lime Rock Driver's Club: "For members and guests protection, The Club does not allow convertibles without rollover protection to participate on-track. Factory fitted rollover systems including pop-up systems, such as those on the M3 convertible, Mini Cooper, Boxster, Carrera TT, S2000, Audi TT, 350Z, Z4, Z8, etc are allowed. All factory fitted systems must meet the “broom handle test” which measures whether the head, and helmet fit below a line formed from the top of the rollover bar to the top of the dashboard. For convertibles without factory rollover protection, a four point, structural roll bar that meets SCCA GCR guidelines for Solo 1 is mandatory."


And separate from whatever the track or organizational rules say, my personal opinion is you have to pass the broomstick test period. To perform the broomstick test have the tallest driver sit in the car in driving position. Lay one end of a "broomstick" on the roll bar, the other end on the top of the steel dash hoop. If the stick contacts the driver's helmet it's a fail.

[JimLev]

Fletch, you should be fine. A friend that has been to this track a few times has a TVR convertible. He’s a big guy, his helmet is way above the top of the windshield frame. No roll bar in his car either.

[fletch]

Gator,
Thanks for the reminder. Our track time won’t be a sanctioned event, just some test and tine time when we get to sort things out. As JimLev said, the regulations at the track are lax regarding test & tune. I’ve already cleared our setup with the owner so we shouldn’t run into problems. The experiences you and others have shared here allowed me to ask all those questions up front.

Frank,
There will be data logs and multiple camera angles on board. We should have at least two cameras running and maybe a third. Some of our mount points shown here.
7D063873-6EAC-4253-8B44-02C06D25CC25.jpg

[Frank818]

Brian, your rear lower lateral links painted in blue, do you like them?
I'm asking cuz my fore one is extremely hard to adjust and tighten the nuts properly cuz too close to the mounting points. I see yours have nuts right in the middle of the links or so, making them super easy to adjust, am I correct?

If yes and they work well (might wait after that track day just in case), I'm gonna source a set, probably not in blue as I think you painted them but that's fine.
They are the same all 4 or have different specs?


tnx

[fletch]

Brian, your rear lower lateral links painted in blue, do you like them?
I'm asking cuz my fore one is extremely hard to adjust and tighten the nuts properly cuz too close to the mounting points. I see yours have nuts right in the middle of the links or so, making them super easy to adjust, am I correct?

If yes and they work well (might wait after that track day just in case), I'm gonna source a set, probably not in blue as I think you painted them but that's fine.
They are the same all 4 or have different specs?
tnx

Hi Frank,
All four lateral links are the same design. Here's a link to them. https://www.spcalignment.com/compone...AFrom&to=USATo

I pressed out the bushings & powder coated them blue.

[roadrashrob]

Hi Frank,
All four lateral links are the same design. Here's a link to them. https://www.spcalignment.com/compone...AFrom&to=USATo

I pressed out the bushings & powder coated them blue.

Frank: Check Rock Auto. Mine are Moog but look identical and were about half the price: https://www.rockauto.com/en/moreinfo...=10401&jsn=769

[Frank818]

Hi Frank,
All four lateral links are the same design. Here's a link to them. https://www.spcalignment.com/compone...AFrom&to=USATo

I pressed out the bushings & powder coated them blue.

Hmm, something just not add up... On your pic, which are the real deal I know, the nuts seem quite way off the rotating joints (forgot the name!) on each end, your nuts (lateral links' nuts!!) seem to be way off the mounting points, making it easy to fit a wrench. But on the pic from your link (same goes with radrashrob's pic), those nuts seem to be very close to one edge. Is it just that the pix on the links aren't truly true? That's common on car parts, just want to make sure how yours really are.

Brian do you have other pix of your lateral links on one of your threads?

I should have taken a pic while I was in the garage, but my problem is on one rod the nuts are so close to the rotating joints that fitting a wrench interferes with either the trailing arm or the FFR mounting brackets. On the engine side I cannot fit a wrench and need to stick a big screwdriver while I twist the rod in order to tighten the nut, that doesn't make any sense and it's quite inefficient.

Frank: Check Rock Auto. Mine are Moog but look identical and were about half the price: https://www.rockauto.com/en/moreinfo...=10401&jsn=769

Ha you're right, they look identical at half the price! Tnx for that! Makes them a no-question-purchase, dependent on my above question.

[fletch]

Frank,
Maybe this will help.
26ED5851-B3C1-484E-A98F-BCBF42646D9F.jpg
The adjustment nut + 2 jam nuts are about 6.25 inches. My starting length (before alignment adjustments) was 16-13/16” center to center.

[fletch]

If you want to watch Isaac driving around our neighborhood for 30+ minutes using a variety of camera angles, you just got your wish!
https://m.youtube.com/watch?v=KE-EuT...ature=youtu.be

[Frank818]

Your son must be thrilling as hell driving such a go-kart!
What are his impressions, actually?

[Frank818]

Frank,
Maybe this will help.
26ED5851-B3C1-484E-A98F-BCBF42646D9F.jpg
The adjustment nut + 2 jam nuts are about 6.25 inches. My starting length (before alignment adjustments) was 16-13/16” center to center.

That is a wonderful pic Brian! Clearly the jam nuts are located much more towards the center of the rod rather one nut close to the rotating joint as we see on the website pictures, but that's fine, often website pix have illustrations that vary a little from the real deal.

I may buy just one set and replace my front arms only, those are the ones very inconvenient to adjust with my current arms and had loose nuts too often already.

Thanks a lot!!

[FFRWRX]

If you want to watch Isaac driving around our neighborhood for 30+ minutes using a variety of camera angles, you just got your wish!
https://m.youtube.com/watch?v=KE-EuT...ature=youtu.be

Very cool video. I love how everything is strapped to the dash. There is something bouncing around the drivers side shock; looks like a large washer.

[fletch]

Your son must be thrilling as hell driving such a go-kart!
What are his impressions, actually?

Oh, he's happy. He tries to drive it every day now. More Friday once we go to the track.

Very cool video. I love how everything is strapped to the dash. There is something bouncing around the drivers side shock; looks like a large washer.

Yeah, the dash needs lots of clean up. I'll take care of that this summer. The white washer is some sort of plastic split ring. I'm not really sure of its purpose. There's one on each Koni, but front left is the only one that bounces around.

[fletch]

We have 3 ways to log ECU data.
1) Cobb Accessport V3
2) Tactrix cable to Android phone with BtSSM app via on-the-go cable
3) Cheap Amazon OBD2 to USB cable to Android phone with BtSSM app via on-the-go cable

I took a little time tonight to compare performance of the 3 configurations. Really, just 2 data points. Below are the average sample intervals in milliseconds

Logging 17 data fields:
Cobb: 96ms
Tactrix: 71ms
Amazon: 74ms

Logging 7 data fields:
Cobb: 43.8 ms
Tactrix: 45.9 ms
Amazon: 47.2ms

I found the results interesting. During the first test the Cobb was showing "10 Hz sampling" on the screen. During the second it showed "20 Hz sampling" which makes me think Cobb does some sort of nearest integer math to schedule requests to the ECU. I was expecting the Tactrix cable to win this comparison in all cases, but that's clearly not my experience. Given the ease of use of the Cobb setup and the fact that the USB-C port on our phone is intermittent, I'm not going to bother with either Android phone setup on Friday.

If anyone has an interest, here's a link to the OBD2 cable I'm using.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
And here's the OTG cable.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Bob_n_Cincy]

Brian, Thanks for doing this test. To add another data point to your testing.
Running my Bluetooth BtSSM OBDii module to my Galaxy S7 phone running BtSSM, I datalog 25 data fields at 13HZ or 77ms.
Bob

[aquillen]

These last two posts need to also be on the electrical/engine threads for easier to find ref. I know of guys on the forum who rarely read down into individual builds, but would more than likely look for this in the dedicated groups. Good stuff to know about.

[fletch]

These last two posts need to also be on the electrical/engine threads for easier to find ref. I know of guys on the forum who rarely read down into individual builds, but would more than likely look for this in the dedicated groups. Good stuff to know about.

I will combine and repost later today.

[fletch]

Way back on June 11 we went to our local track to get some practice.
Too much detail to recall. Funny how the mind gets flooded when adrenaline kicks in.

We got to the track around 8 and began our first lap around 8:30. Temperature was 80F and heading to 95F so I wanted to be done by noon.

Tires - 22 psi all around, nearly even tread at 7/32"

Bedded the brakes - no drama, but it was fun to see how quickly this thing moved us. It stops quicker than anything we’ve been in outside of a roller coaster.
Adjusted bias by dialing down the rears quite a bit. We have the 2006 WRX front brakes (293mm, 4-pot calipers) and the 2004 forester front calipers mounted to the rear backing plates with DBA rotors (316mm rotors, 2-pot calipers) so we knew the rears were going to lock up first... and they did. It took us 5 or 6 tries to get them roughly balanced. At which point we turned ABS back on and felt 2-3 wheels pulsating during heavy braking. I figured that was about as good as we were going to get it.

Spent some time exploring what happens when the rear tires lose grip. I had Isaac driving around a turn attempting to get the rear loose. He learned pretty quickly how to make adjustments. But we both need some more time to feel where the edge is. It’s an unsettling feeling when the car starts to rotate out from under you. We need more opportunities to make it happen safely. We don’t have much video from our first track day because after a little while, I put it into the weeds. Unfortunately our sideways slide through the loose New Mexican soil produced what Isaac called a “dirt wave” - a veritable breaker of dust, dirt, and rocks. Afterward we vacuumed what must have been >30 pounds of dirt out of the car. We had to take numerous bits apart to get as much out as we could.

Some choice photos:
IMG_4439.jpgIMG_4440.jpgIMG_4442.jpgIMG_4443.jpg

Despite the mess, we had a fantastic time. And learned that the loose nuts behind the wheel require the most attention. The car worked wonderfully.

[Rob T]

I feel your pain. Early in my 818R experience, I used my car as a bulldozer at Buttonwillow where the track turned sharply right and I kept going straight. No damage, save to my pride, wounded even more as I looked like Pig Pen from the Peanuts driving back to the paddock. I too, got good use out of my vacuum. One small advantage was that the body was on my car....

I'm happy you are both OK, but happier you now have more track fun to look forward to.

[J R Jones]

Fletch, You might also check the tires for debris. My tires have ingested dirt sliding sideways without losing all the pressure. Rock and Roll and rattle.
jim

[fletch]

After a thorough vacuuming, including removal of the heat/AC unit, we took the car back to the track. This time we brought some cones and kept it below 40 mph, mostly. It was a very fun and very informative day. We feel much more comfortable driving at the limit now. However, when the boost pressure starts to ramp up things get out of hand quickly. By keeping it below 40 we avoided most of the drama. The car was rock solid, though the body roll was very obvious to us when watching each other drive. So much roll that the fronts and rears both go into positive camber - not good. We'll be looking for stiffer springs soon.
Me:
https://youtu.be/WX3-rY2v_mI
Isaac:
https://youtu.be/tQ7KnpqJPbQ

[Rob T]

Glad you had a successful day and won't be needing the vacuum . Seeing Sandia brought back some memories....

[Jetfuel]

Great video of you two, sure looked like a lot of fun
Will the added weight of the body minimize the roll???

Jet

[fletch]

Great video of you two, sure looked like a lot of fun
Will the added weight of the body minimize the roll???

I suspect it would make the roll worse, increasing the moment of inertia about the longitudinal centerline.

[JimLev]

Can you add sway bars? That would help reduce the body roll a lot.

[fletch]

Can you add sway bars? That would help reduce the body roll a lot.

That definitely would help, but that ship sailed when we chose to use a front gas tank for more cabin room.

[J R Jones]

Fletcherson, breathe and realize the voids in the space frame, open your mind. Be one with the anti-roll bar.
Actually making the rear anti-roll bar fit the front is clever, but like the steering geometry, it is a compromise and a greenfield for improvement.
BTW Isaac has no fear of cones.
jim

[roadrashrob]

Fletch, as you know I followed you and went with a front mounted tank as well. I haven't had the chance to drive mine to the point yet of determining roll, but I did leave the geometry such that a "straight" anti-roll bar could still hit the FFR mounts and pass just above the tank. My thought was that if I decide I need the extra roll control, they make them with splined ends and arms for the links so it is not out of the question to add. I'm definitely studying your videos as we should be go-karting ours in another week or so. I'm assuming ours will perform identical to yours. We were all ready to go when our brand new wideband O2 sensor died. Not giving me the warm and fuzzies for Innovate Products given all we've done so far was laid down the base tune. At least it stayed functioning for that.

[Sgt.Gator]

What are your static camber settings? What springs are you running?

[fletch]

Ride height 4.5"
Rear:
Toe: 3/16" total
Camber: -0.5 deg

Front:
Aluminum LCAs in outer mounting holes
Toe: 1/16" total
Camber: -1.0 deg
Caster: R 5.1 deg, L 5.5 deg

275# springs front
350# rear

[Sgt.Gator]

Those suspension specs are not going to work well on the track. No wonder you think it rolls too much and the camber goes positive!
Many of the track focused R builds don't use sway bars. I ran with a front bar for awhile, then removed it. Mitch has the front bar and likes it. Here's Mitch's setup for comparison:

"2.6 front camber
6* caster
0 toe
350# spring
3/4 OD .095 front sway bar
3.5" ride height
2.75 rear camber
3/16 toe in
500# springs
3.75 ride height
A number of other R's that are running have been using higher spring rates 400-550 front and 600-700 rear without sway bars with success. Personally I have found the softer spring rates and front bar work well for me. "

Hobby & I run very similar setups but with higher spring rates, 500 F, 700R.
Bob-_n_Cincy runs 350F, 600R.

And finally:
Dave Smith's FFR 818R at UTCC VIR setup and driven by Wayne Pressley:
500 fr springs, 750 rear
Front:
-3° camber
+6° caster
0 toe
.015 bump out per side
Rear:
-2.8° camber
3/16 toe in
.015" roll steer in
No sway bar.
225/40/17 and 255/35/18 Hoosier A7's on 17x9 and 18x9.5" wheels

[fletch]

Thanks for the feedback. Lots to think over here.

[roadrashrob]

Thanks for the feedback. Lots to think over here.

Ditto from me!