Honey Badger's Completely Off-the-Rails Race Car Build and Track Adventure Thread

[honeybadger]

Composite is definitely a strong material.for vibration damping then steel. Good luck

Fortunately, I shortcutted it and went to a dry sump and CPC. problem solved

 

[DougS550]

Fortunately, I shortcutted it and went to a dry sump and CPC. problem solved

What was involved to switch to a DS?

 

[mavisky]

I'm using an Einstar scanner. its the only one I have experience with and I'm still very new with it - but its been pretty darn good. I can see why the more expensive ones are better, but the Einstar isn't particularly hard to use and its accurate enough. the more expensive ones appear to get more accurate scans with less work.

Whatcha' planning on modeling? Are you using Fusion 360?

Im probably going to start with some new endplates and tunnels for my revised splitter as well as some dive plane designs. Mostly just to relearn 3d modeling in Fusion 360 and Blender after a 20 year hiatus of using it professionally. I had hoped to have more of the car scanned but there was some miscommunication and im not going to complain for an essentially free scan.

 

[honeybadger]

okay - I might have figured out the driver side. need to do some final checks tomorrow before ordering pipe. 10in of 1.875", 18in of 2.0" into collectors. Cylinders 5/8 and 6/7 are paired together to maximize scavenging.

Took a couple of hours collectively of playing around. used a combo of 2.5 and 3in CLR and straight blocks for the 1.875 section and then a collection 3, 4, 6 CLR and straight for the 2in section.

 

[honeybadger]

Okie dokie - sitll in a waiting period on the exhaust as I wait for the last of my materials to get in. In the meantime, I've started working on wiring updates. I've moved the PDM/Ecu to the front passenger a-pillar wall, so I am adding some new sensors and reconfiguring stuff.

Now that I've got a year plus of using the car under my belt, I have a better idea of what I want to measure. I'm really focused on measuring cooling efficiency and getting some more data points to predict early engine issues. Here's a comprehensive list of I've built (which help from ChatGPT to format/strategize)


Engine sensors used now

• MAP — main plenum
  • Use: Primary load signal for speed-density fueling, ignition, and baro-corrected torque modeling. Helps diagnose air leaks (idle MAP drift).
• IAT — plenum/runner, fast tip
  • Use: Air-density calc + temp-based spark trims. Heat-soak vs airflow diagnostics (IAT drop vs RPM/MPH).
• Oil pressure — remote filter/engine feed (post-filter)
  • Use: Primary protection: min-pressure vs RPM curve, staged trims/cuts. Trend bearing health (hot-idle P).
• Oil temperature — remote filter/engine feed (post-filter)
  • Use: Viscosity window (target 100–120 °C), warm-up logic, derates if oil too hot. Correlate with pressure to spot thinning/cavitation.
• Fuel pressure — rail feed/end
  • Use: Maintain ΔP_fuel = Rail − MAP at regulator setpoint. Alarms/cuts on drop; diagnose pump, filter, or pickup issues.
• Fuel temperature — Fuel return off rails (combined with ethanol sensor)
  • Use: Vapor-lock/hot-soak management, compensation for density; diagnose return-line heat.
• Ethanol content — Fuel return off rails
  • Use: Blend maps (fuel, spark, cold start) and failsafe if content swings suddenly.
• Cylinder-head water temp (L/R) — each head
  • Use: Spot bank imbalance/hotspots; protect against localized boiling; drive fan/pump bias if supported.
• Coolant temp (hot/outlet) — head Y-block
  • Use: True engine outlet temp for fans, pump duty, and over-temp protection. (This replaces swirl-pot temp.)
• Coolant pressure (hot side) — Y-block/upper hose
  • Use: Boiling margin & head-lift detection; look for throttle-correlated spikes. Use with cool-side P for ΔP_radiator.
• Lambda per bank (×2) — each collector
  • Use: Bank-specific fueling safety/trims, misfire/lean detection, lambda-target control.
• Oil tank temp (bulk) — mid-tank in moving oil
  • Use: Warm-up timing and trend logging (bulk thermal state). Not for protection.
• OEM CHT — passenger head (aluminum temp)
  • Use: Backup over-temp channel; great for rate-of-rise alarms if coolant sensor fails or de-primes.

Sensors I am adding now

• Crankcase pressure (dry-sump vac) — cam cover/catch-can
  • Use: Ring seal & scavenge efficiency. Alarm if vacuum collapses at WOT; correlate with tank pressure.
• Coolant pressure (cool side) — radiator outlet
  • Use: Cavitation margin at pump inlet; with hot-side P gives ΔP_radiator (restriction/airlock indicator).
  • Action: Warn if cool-side P < ~3–5 psi at pace or ΔP_radiator > ~10–12 psi.
• Coolant temp (cool side) — radiator outlet
  • Use: ΔT_radiator = Thot − Tcold → cooling effectiveness; ducting/fan strategy tuning.
• Oil pressure (pre-filter) — pressure pump outlet
  • Use: With post-filter P gives ΔP_filter; rising ΔP hot = filter restriction. Early warning before gallery starvation.
• Oil temp (hottest) — scavenge-out or tank return jet
  • Use: Peak oil temp & cooler sizing check; ensures bulk/tank temp isn’t hiding abuse.
• Oil tank headspace pressure — tank top, away from return
  • Use: Vent health & NPSH for pressure stage. High +P = vent restriction; too much vacuum = cavitation risk.
• Exhaust gas temp on each primary — 100–150 mm from ports
  • Use: Per-cyl balance, lean-out/misfire detection, header leak diagnosis, timing limit validation.

Handy derived channels & how you’ll use them

• ΔP_fuel = Rail − MAP: maintain regulator setpoint; instant lean-risk flag.
• ΔP_radiator = P_hot − P_cool: restriction/airlock; guides ducting, pump maps.
• ΔT_radiator = T_hot − T_cool: cooling effectiveness vs speed/fans.
• ΔP_filter = P_pre-filter − P_post-filter: filter clog monitor.
• Crankcase_inHg: scavenge/ring seal; loss at WOT triggers check.
• Bank λ delta: injector/exhaust leak or sensor drift.

 

[honeybadger]

Wow - just realizing how long its been since I've updated this thread. Good lord this project has been more work than I anticipated and I'm STILL not done. Stopped tracking hours on the this exhaust - but well over 100 hours into the headers at this point. I've re-done quite a few parts now to get the fit and finish where I wanted. Learned a lot. Journey below.

As mentioned previously - I used the building blocks to do the routing and figure out what I needed. I'd say they get you 90% of the way there on fitment. Meaning if you take them and translate real tubing to exactly those bits, you'll be 90% accurate. Point I'm trying to make, at these lengths, the real tubing will need some additional massaging to work. This became very clear in two areas - the steering shaft and the starter. Even though I verified like 6x I had clearance, when I did real fit up, I had interference on both

[

Tacked real tubing

Lesson #2, the driver side was not in fact the harder side. I started with that one because I thought working around the steering shaft would be the hardest obstacle. It was not. Turns out I forgot that cylinder number 1 is physically a little further (about 1in) ahead of cylinder 5 due to the offset of the heads/crank. that was just enough to make a similar routing on the passenger unusable. Even with an absolute straight shot from #1, I was over my tolerance limit of +/- 0.5in for equal length primaries. To make it work, I had to rotate the orientation of the first set of collectors from stacked to side by side. Compare this side to above

I dont really have any pics between this stage and the final weld-up, but let's just say we were in revision hell. I think I re-did like 6 different primaries at some point. Long story short, I tweaked passenger side until I got it right. Then I went back over to the driver side and re-did that one because it would have driven me insane having one set of collectors stacked and one set side-by-side.

So the primaries are all welded and ready to go. Time to weld them on the flanges! This part was the most fun. Very satisfying welding. To ensure they didn't warp, I got an 18in long, 4in wide, and 1in thick aluminum bar and drilled holes into to make a manifold. The block acted as a heat sink and manifold for distributing purging gas. Can post more if interested.

Once done, I put them on the engine and test fit in the car. We're all done now, right?!?! Lesson #3 incoming.

Despite verifying endless times, I proved to be an absolute muppet and literally put a primary directly in the way of the steering. UGH. This is where I stopped taking pictures of progress. Work and life got too busy and I was stealing time in the garage here and there for some me time. so i focused on that. But I did make a ton of progress. I ended up fixing the above by cutting into the frame rail a bit and adding more clearance to shift the shaft over. I also ended up moving the primary tube over towards the head. Will post a pic once I get the engine back in the car. My k-member and motor mounts still needed to be painted.

Then I moved on to the secondaries and final set of collectors. This is where lesson #4 comes in. I had, naively, assumed that once the collectors were in the right general location, I could figure out a routing that worked between the first set of collectors and second. Wrong. I ended up needing to tweak two primaries once again to get them bit more parallel with each other. And then I still had to get creative with the secondary routing. So unfortunately, they're not symmetrical. But they're close enough for me. I thought the secondaries and final collectors would be a night or two to button up. Nope. About 40 hours worth. Good thing no one is paying for my slow ass. ha.

I also welded in bungs for EGT sensors. So I'll be able to track temps of each cylinder for tuning optimization and catching bad cylinders (i.e. clogged injectors, etc.) early.

Despite the struggles, I think they came out awesome. I'm finalizing the engine mounts and k-member. I ended up getting the engine another 1/2in lower and 1in back, so I'm excited about that. Will share more in the next 2 days or so. Start a 3 week long vacation Wednesday, so hoping to get the beast buttoned up and ready for 2026.

 

[wingnutt]

…where’s the “holy crap” button in here

 

[Strokerswild]

…where’s the “holy crap” button in here

This.

A friend is a rather accomplished fabricator, and he built a similar set of equal length tube headers for a drag car of his. Countless hours into them, they were beautiful also.

He fabbed an H-pipe for me once as custom was the only option, and it was almost a shame to hide it under the car.

 

[ZX3ST]

Kevin, I recently heard about some substantial shifts to the ownership situation at COTA. Any word on how this is going to affect your driving there?

 

[TreeFiddyAre]

Wow - just realizing how long its been since I've updated this thread. Good lord this project has been more work than I anticipated and I'm STILL not done. Stopped tracking hours on the this exhaust - but well over 100 hours into the headers at this point. I've re-done quite a few parts now to get the fit and finish where I wanted. Learned a lot. Journey below.

As mentioned previously - I used the building blocks to do the routing and figure out what I needed. I'd say they get you 90% of the way there on fitment. Meaning if you take them and translate real tubing to exactly those bits, you'll be 90% accurate. Point I'm trying to make, at these lengths, the real tubing will need some additional massaging to work. This became very clear in two areas - the steering shaft and the starter. Even though I verified like 6x I had clearance, when I did real fit up, I had interference on both

[

Tacked real tubing

Lesson #2, the driver side was not in fact the harder side. I started with that one because I thought working around the steering shaft would be the hardest obstacle. It was not. Turns out I forgot that cylinder number 1 is physically a little further (about 1in) ahead of cylinder 5 due to the offset of the heads/crank. that was just enough to make a similar routing on the passenger unusable. Even with an absolute straight shot from #1, I was over my tolerance limit of +/- 0.5in for equal length primaries. To make it work, I had to rotate the orientation of the first set of collectors from stacked to side by side. Compare this side to above

I dont really have any pics between this stage and the final weld-up, but let's just say we were in revision hell. I think I re-did like 6 different primaries at some point. Long story short, I tweaked passenger side until I got it right. Then I went back over to the driver side and re-did that one because it would have driven me insane having one set of collectors stacked and one set side-by-side.

So the primaries are all welded and ready to go. Time to weld them on the flanges! This part was the most fun. Very satisfying welding. To ensure they didn't warp, I got an 18in long, 4in wide, and 1in thick aluminum bar and drilled holes into to make a manifold. The block acted as a heat sink and manifold for distributing purging gas. Can post more if interested.

Once done, I put them on the engine and test fit in the car. We're all done now, right?!?! Lesson #3 incoming.

Despite verifying endless times, I proved to be an absolute muppet and literally put a primary directly in the way of the steering. UGH. This is where I stopped taking pictures of progress. Work and life got too busy and I was stealing time in the garage here and there for some me time. so i focused on that. But I did make a ton of progress. I ended up fixing the above by cutting into the frame rail a bit and adding more clearance to shift the shaft over. I also ended up moving the primary tube over towards the head. Will post a pic once I get the engine back in the car. My k-member and motor mounts still needed to be painted.

Then I moved on to the secondaries and final set of collectors. This is where lesson #4 comes in. I had, naively, assumed that once the collectors were in the right general location, I could figure out a routing that worked between the first set of collectors and second. Wrong. I ended up needing to tweak two primaries once again to get them bit more parallel with each other. And then I still had to get creative with the secondary routing. So unfortunately, they're not symmetrical. But they're close enough for me. I thought the secondaries and final collectors would be a night or two to button up. Nope. About 40 hours worth. Good thing no one is paying for my slow ass. ha.

I also welded in bungs for EGT sensors. So I'll be able to track temps of each cylinder for tuning optimization and catching bad cylinders (i.e. clogged injectors, etc.) early.

Despite the struggles, I think they came out awesome. I'm finalizing the engine mounts and k-member. I ended up getting the engine another 1/2in lower and 1in back, so I'm excited about that. Will share more in the next 2 days or so. Start a 3 week long vacation Wednesday, so hoping to get the beast buttoned up and ready for 2026.

UFFFFF… this thing is going to sound absolutely bananas and pull like it’s got a personal vendetta. Outstanding work, Mr. Badger

I was really hoping you were adding EGTs, and as I scrolled through the post and saw that you did… not gonna lie, I felt a wave of relief. That was a chef’s kiss moment.

My 8–4–1 Concept setup lands in April (maybe sooner if the stars align), and I’m seriously considering plumbing it for EGTs before ceramic coating. Since the car is going to be force-fed, I just don’t see how tuners can perfectly manage rear-cylinder fueling without that data. Feels like there’s not only power to be gained, but a whole lot of safety as well. Even though of doing a direct port water/meth with larger nozzles where they are needed to get things consistent ..

Maybe I’m overthinking it — maybe tuners have already mapped AFRs and EGTs across multiple manifolds — but what I’ve personally seen on an NA Coyote was a 1.0 AFR delta. Under boost? Yeah… that number isn’t getting smaller.

Also — please bless us with lots of sound clips once this thing is finished. What mufflers are you planning to run? X or H? Resonators or full send?
And while we’re here… ever think about running 7075 tubing to shave a little weight? Because why stop being extra now?


Seriously though — killer setup. Can’t wait to hear this thing scream.

 

[Lorne34]

Wow - just realizing how long its been since I've updated this thread. Good lord this project has been more work than I anticipated and I'm STILL not done. Stopped tracking hours on the this exhaust - but well over 100 hours into the headers at this point. I've re-done quite a few parts now to get the fit and finish where I wanted. Learned a lot. Journey below.

As mentioned previously - I used the building blocks to do the routing and figure out what I needed. I'd say they get you 90% of the way there on fitment. Meaning if you take them and translate real tubing to exactly those bits, you'll be 90% accurate. Point I'm trying to make, at these lengths, the real tubing will need some additional massaging to work. This became very clear in two areas - the steering shaft and the starter. Even though I verified like 6x I had clearance, when I did real fit up, I had interference on both

[

Tacked real tubing

Lesson #2, the driver side was not in fact the harder side. I started with that one because I thought working around the steering shaft would be the hardest obstacle. It was not. Turns out I forgot that cylinder number 1 is physically a little further (about 1in) ahead of cylinder 5 due to the offset of the heads/crank. that was just enough to make a similar routing on the passenger unusable. Even with an absolute straight shot from #1, I was over my tolerance limit of +/- 0.5in for equal length primaries. To make it work, I had to rotate the orientation of the first set of collectors from stacked to side by side. Compare this side to above

Are you a Packers fan? Love the "Green and Gold" LOL

 

[MAGS1]

Are you a Packers fan? Love the "Green and Gold" LOL

Sorry Lorne, but

 

[honeybadger]

Kevin, I recently heard about some substantial shifts to the ownership situation at COTA. Any word on how this is going to affect your driving there?

It’s a super unfortunate situation. It’s been confirmed that this is the last year for us locals that don’t have the cash to buy a membership (which is supposedly $1M initiation fee and $250k annual dues).

there’s a bunch of drama - they raised rates 18% this year AND took away running during the lunch hour so they can run hot laps. So the orgs lost 1/9 of their track time and a rate increase of 18%.

I’ll probably run COTA 1-2 times this yesr just to try and beat my PB. It’s $1300 for a weekend, so I can drive to Road Atlanta for a weekend for the same cost. I’d rather visit other tracks than support management like COTA’s

UFFFFF… this thing is going to sound absolutely bananas and pull like it’s got a personal vendetta. Outstanding work, Mr. Badger

I was really hoping you were adding EGTs, and as I scrolled through the post and saw that you did… not gonna lie, I felt a wave of relief. That was a chef’s kiss moment.

My 8–4–1 Concept setup lands in April (maybe sooner if the stars align), and I’m seriously considering plumbing it for EGTs before ceramic coating. Since the car is going to be force-fed, I just don’t see how tuners can perfectly manage rear-cylinder fueling without that data. Feels like there’s not only power to be gained, but a whole lot of safety as well. Even though of doing a direct port water/meth with larger nozzles where they are needed to get things consistent ..

Maybe I’m overthinking it — maybe tuners have already mapped AFRs and EGTs across multiple manifolds — but what I’ve personally seen on an NA Coyote was a 1.0 AFR delta. Under boost? Yeah… that number isn’t getting smaller.

Also — please bless us with lots of sound clips once this thing is finished. What mufflers are you planning to run? X or H? Resonators or full send?
And while we’re here… ever think about running 7075 tubing to shave a little weight? Because why stop being extra now?


Seriously though — killer setup. Can’t wait to hear this thing scream.

My tuner is super excited about the EGTs. He had to go conservative to ensure we didn’t lean out the back cylinders (and he didn’t want to run them artificially rich to be safe). The egts should allow us to optimize each cylinder and pick up some more power purely from efficiency - so it’s essentially free power.

and system is be straight back with some resonators. Plan to be able to swap in my big mufflers when I need to tone it down. V bands for the win.

as far as 7075, I chose to go with 18g stainless for this iteration (collectors back is titanium). My 18g headers that are like 20in longer my ARH headers were weight the same since they were 16g. Weigh savings was huge

 

[TreeFiddyAre]

It’s a super unfortunate situation. It’s been confirmed that this is the last year for us locals that don’t have the cash to buy a membership (which is supposedly $1M initiation fee and $250k annual dues).

there’s a bunch of drama - they raised rates 18% this year AND took away running during the lunch hour so they can run hot laps. So the orgs lost 1/9 of their track time and a rate increase of 18%.

I’ll probably run COTA 1-2 times this yesr just to try and beat my PB. It’s $1300 for a weekend, so I can drive to Road Atlanta for a weekend for the same cost. I’d rather visit other tracks than support management like COTA’s




My tuner is super excited about the EGTs. He had to go conservative to ensure we didn’t lean out the back cylinders (and he didn’t want to run them artificially rich to be safe). The egts should allow us to optimize each cylinder and pick up some more power purely from efficiency - so it’s essentially free power.

and system is be straight back with some resonators. Plan to be able to swap in my big mufflers when I need to tone it down. V bands for the win.

as far as 7075, I chose to go with 18g stainless for this iteration (collectors back is titanium). My 18g headers that are like 20in longer my ARH headers were weight the same since they were 16g. Weigh savings was huge

Niceeeee, will you share how much leaner (hotter) the rear cylinders are and how much fuel is needed to get them all balanced ? Cant wait to hear this thing with you new setup should sound like little miracles going off when at full tilt

 

[WItoTX]

It’s a super unfortunate situation. It’s been confirmed that this is the last year for us locals that don’t have the cash to buy a membership (which is supposedly $1M initiation fee and $250k annual dues).

there’s a bunch of drama - they raised rates 18% this year AND took away running during the lunch hour so they can run hot laps. So the orgs lost 1/9 of their track time and a rate increase of 18%.

I’ll probably run COTA 1-2 times this yesr just to try and beat my PB. It’s $1300 for a weekend, so I can drive to Road Atlanta for a weekend for the same cost. I’d rather visit other tracks than support management like COTA’s

I obviously know less than you, BUT there has to be some serious MFG money coming in to offset the lost revenue from all the events. And it goes beyond that. The hotels I stay at, the food I buy, the gas I buy, the gas station I hit up 1-2 times a day, it's just a huge impact to the community.

Isn't there some sound restriction discussions around CotA as the area builds up too? (Nevermind the morons that move next to a race track and don't expect to hear people having fun)

I seem to recall an ordinance discussion some time around Q3 of 2025 revolving around noise.