Slow but Steady HPDE to ST/TT Build
#81
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If I didn't want over 145rwhp for consistent track use, I'd just stay with the BP. If I wanted more on track, the k24z3 is just really hard to beat for long-term use. For a cost reference, here's my on-going list that includes quite a bit of random parts: https://docs.google.com/spreadsheets...it?usp=sharing
#82
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Assuming 250+ whp is the goal, there isn't any option that is either a quick 20hr swap or fire and forget once installed. K24A2 requires a new subframe. Z3 uses OEM subframe. Unopened K24 on E85 can make a reliable 220whp or thereabouts but its not cheap or quick install. All the hours & $$ up front but once installed, it's pretty bombproof. The BP is cheaper and easier but above 250whp not as low maintenance as the K24. I know a few here have long, service free hours on turbo track BP's, but they are rare. Even the vaunted TSE turbo kit (NLA) required regular stud maintenance.
If simplicity and low maintenance were top priority, I'd lower power goal to be met by an junkyard K24Z3 on E85. 220whp is damn fun in a ~2300# NA/NB with good suspension and a little aero. Doesn't require massive cooling mods or F1 brakes, eats fewer tires than a 350whp build. Less stuff breaks.
We just got trigger info for the Z3 from Haltech and forwarded that to KPower. That precludes the need to swap in the A2 triggers. So outside of the oil pan stuff, it's an unopened $600 junkyard motor. The expense is in the KPower kit & ECU, the motor itself nearly free.
Junkyard BP's only stone reliable below 7,000rpm and about 145whp on E85 with bolt ons ($1000).
Forged, ported, big valve BP ($5000) maybe 170whp on E85 for 200 race hours.
Z3 ($500) more reliable than either at 220whp. Just have that $5k/40hrs up front to build the Z3.
If simplicity and low maintenance were top priority, I'd lower power goal to be met by an junkyard K24Z3 on E85. 220whp is damn fun in a ~2300# NA/NB with good suspension and a little aero. Doesn't require massive cooling mods or F1 brakes, eats fewer tires than a 350whp build. Less stuff breaks.
We just got trigger info for the Z3 from Haltech and forwarded that to KPower. That precludes the need to swap in the A2 triggers. So outside of the oil pan stuff, it's an unopened $600 junkyard motor. The expense is in the KPower kit & ECU, the motor itself nearly free.
Junkyard BP's only stone reliable below 7,000rpm and about 145whp on E85 with bolt ons ($1000).
Forged, ported, big valve BP ($5000) maybe 170whp on E85 for 200 race hours.
Z3 ($500) more reliable than either at 220whp. Just have that $5k/40hrs up front to build the Z3.
I got two K24Z3's for 700.
If I had a fresh racecar build and could go any direction I wanted I would still do a K24Z3. Fits in tons of fun classes, cheap and reliable junkyard engines, and fast enough to have some serious fun, can't really beat that. If for some reason I lost an engine at the track I would just load the car up, grab a beer and hang out, not a huge deal. If I lost a built BP that I spent like 4 or 5k building I'd be a lot more upset that's for sure.
If I had a fresh racecar build and could go any direction I wanted I would still do a K24Z3. Fits in tons of fun classes, cheap and reliable junkyard engines, and fast enough to have some serious fun, can't really beat that. If for some reason I lost an engine at the track I would just load the car up, grab a beer and hang out, not a huge deal. If I lost a built BP that I spent like 4 or 5k building I'd be a lot more upset that's for sure.
If I didn't want over 145rwhp for consistent track use, I'd just stay with the BP. If I wanted more on track, the k24z3 is just really hard to beat for long-term use. For a cost reference, here's my on-going list that includes quite a bit of random parts: https://docs.google.com/spreadsheets...it?usp=sharing
Thank you @emilio700 , @Arca_ex , and @flier129 for your thoughts. You've certainly gently pushed me in the direction I think I've needed to be pushed all along haha. As much as it slightly irks me that "K-swap the world" is very much becoming a real thing, I need to get that irritation out of my head and just commit to building a fun car that I will enjoy. Because my ~110whp I have now is certainly not cutting it.
P.S. - thank you @flier129 for that spreadsheet. Incredibly helpful. Now to try to go re-sell the K-swap idea to my wife...
#87
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Absolutely killer weekend at VIR. Weather was about as perfect as you could ask for: blue skies and mid-60's. Car ran great all weekend with it's usual quirks...there's still a phantom cylinder 1 misfire that keeps popping up and causes a stutter at paddock speeds, but at WOT there are no issues at all and the car actually felt relatively peppy. My stock replacement clutch now with three seasons of track-only abuse was not so happy however. On Sunday it started slipping really bad on quick 3-4 gear shifts and then started getting worse and worse, eventually slipping for a solid second or two between each gear change at WOT. Was still good for a new PB of 2:22:48 on 21 HC R888Rs though, so I'm very happy with that. Puts me right at 4 seconds behind Spec Miata with my unopened/unmodded BP4W. Slowly closing the gap!
Driving was improved as well. Braking now feels much more relaxed and natural as I have finally begun to trust that the car is going to stop. Since I don't drive this car on the street at all, it takes quite a bit of adjustment moving from either my 400 hp Mazdaspeed3, tow rig, or commuter car. Now that I know I can really trust the brakes I am way more comfortable braking later and harder. The goal this weekend was to condense some braking into turns 1 and 14, and I think I succeeded at least a little bit. Will have to go review video and data to confirm, but it felt better. Hoping to further improve next time out.
I think that is going to be it for this year though. I was planning on finishing up at Summit Point in three weeks, but with the clutch slipping as bad as it is and plans to pull the engine and swap everything over to the caged shell this off-season anyway, I don't see the point in trying to slam a new clutch in such a short time frame. Coupled with a promotion at work it's going to be quite the time crunch. So, I'll just be happy with a solid finish to the year and get a jump start on moving everything over to the new shell (with a few safety and reliability upgrades along the way) and keep saving for a potential K-swap down the line.
The current goal is to shoot for a 2:20:xx at VIR without adding power or aero. Still plenty of time in my driving and I haven't even messed with sway bar adjustments yet. I'll need to get to Summit Point again before I have a truly good benchmark there. But all in all a good (if not short) season. I'll document the build progress over the winter as I move everything over to the caged shell and finally get to removing things I don't need off the car to save a little weight.
Driving was improved as well. Braking now feels much more relaxed and natural as I have finally begun to trust that the car is going to stop. Since I don't drive this car on the street at all, it takes quite a bit of adjustment moving from either my 400 hp Mazdaspeed3, tow rig, or commuter car. Now that I know I can really trust the brakes I am way more comfortable braking later and harder. The goal this weekend was to condense some braking into turns 1 and 14, and I think I succeeded at least a little bit. Will have to go review video and data to confirm, but it felt better. Hoping to further improve next time out.
I think that is going to be it for this year though. I was planning on finishing up at Summit Point in three weeks, but with the clutch slipping as bad as it is and plans to pull the engine and swap everything over to the caged shell this off-season anyway, I don't see the point in trying to slam a new clutch in such a short time frame. Coupled with a promotion at work it's going to be quite the time crunch. So, I'll just be happy with a solid finish to the year and get a jump start on moving everything over to the new shell (with a few safety and reliability upgrades along the way) and keep saving for a potential K-swap down the line.
The current goal is to shoot for a 2:20:xx at VIR without adding power or aero. Still plenty of time in my driving and I haven't even messed with sway bar adjustments yet. I'll need to get to Summit Point again before I have a truly good benchmark there. But all in all a good (if not short) season. I'll document the build progress over the winter as I move everything over to the caged shell and finally get to removing things I don't need off the car to save a little weight.
Last edited by Quigs; 10-07-2020 at 10:12 PM.
#91
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Good lap! That really sucks about the clutch, would drive me insane on track too. I've had great luck with ACT 1.6 discs on a 1.6 7lb Fidanza flywheel, you can get the whole sha-bang from Good-Win-Racing. The Supermiata clutch is also a really great value if you're sticking with 1.8. I was about to buy an ACT 1.8 4-puck, then looked at the SPM unit and noticed it had higher tq capacity and was less expensive by a good margin, win-win. Fix the clutch and add more power?
I think you already know most of the spots to get time out there. I can add my $0.02 if you want.
I think you already know most of the spots to get time out there. I can add my $0.02 if you want.
#92
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Good lap! That really sucks about the clutch, would drive me insane on track too. I've had great luck with ACT 1.6 discs on a 1.6 7lb Fidanza flywheel, you can get the whole sha-bang from Good-Win-Racing. The Supermiata clutch is also a really great value if you're sticking with 1.8. I was about to buy an ACT 1.8 4-puck, then looked at the SPM unit and noticed it had higher tq capacity and was less expensive by a good margin, win-win. Fix the clutch and add more power?
My primary focus this weekend was turn 3 and this was the first time I've tried shifting into 4th instead of riding the limiter in 3rd, so I definitely know there's work to be done there. I definitely over slowed and have plenty of track outside the gator at the exit I can utilize, I just need to figure the extra downshift out while getting back to a better line track right before turning in. I'm already flat in 4-9 but can brake a little deeper/harder going into 4. 10 I think I can carry maybe another MPH or two (or maybe more). Oak Tree is always a struggle but I think I've at least gotten a consistent line now. Trying to inch closer and closer to the arrow for my braking reference into 14.
#93
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Finalized plans for the off-season and into next year:
Biggest goal of course is to move everything over from my current blue chassis with rollbar (and rust!) to new green chassis with full cage. In the process of doing that I'm planning on upgrading the following:
- SadFab bronze bearing retrofit for my poly bushings
- Racing Beat header and probably exhaust because my stock exhaust is riddled with leaks and about to fall apart
- DIY intake with enclosure behind driver headlight and intake ducting through the lens
- New clutch, probably the SuperMiata organic, possibly with light flywheel as well depending on funds
- Miata Roadster tall angled shiter for better shifting (hopefully)
- Cutting out any and all unnecessary weight and wiring
- Redo radiator ducting
Additional upgrades depending on Black Friday sales and/or available funds:
- Coolshirt setup, either DIY, Coolsuit, or ChillOut if I'm feeling extra baller
- Fire suppression system
- Right side net and battery cutoff switches
- MiataHubs
- Second set of wheels with RA1s to use as rains/emergency backups
Plan for next year is to shake down the new chassis and check ride into TT for better quality track time. Can possibly be regionally competitive in TT6 with 125 HP at 2300 lbs due to very low car count, but I really just want the better track time to keep developing since HPDE3 has become quite the clusterfuck. Car will be mostly prepped for transition into ST safety-wise though, so if all goes well with shaking down and better driver improvement I may try to shoot for Comp School at some point, we'll see.
Long term plan still undetermined regarding BP vs K-swap and what class I ultimately want to shoot for. Right now focus is just on being a better driver and having a safe and complete car.
Biggest goal of course is to move everything over from my current blue chassis with rollbar (and rust!) to new green chassis with full cage. In the process of doing that I'm planning on upgrading the following:
- SadFab bronze bearing retrofit for my poly bushings
- Racing Beat header and probably exhaust because my stock exhaust is riddled with leaks and about to fall apart
- DIY intake with enclosure behind driver headlight and intake ducting through the lens
- New clutch, probably the SuperMiata organic, possibly with light flywheel as well depending on funds
- Miata Roadster tall angled shiter for better shifting (hopefully)
- Cutting out any and all unnecessary weight and wiring
- Redo radiator ducting
Additional upgrades depending on Black Friday sales and/or available funds:
- Coolshirt setup, either DIY, Coolsuit, or ChillOut if I'm feeling extra baller
- Fire suppression system
- Right side net and battery cutoff switches
- MiataHubs
- Second set of wheels with RA1s to use as rains/emergency backups
Plan for next year is to shake down the new chassis and check ride into TT for better quality track time. Can possibly be regionally competitive in TT6 with 125 HP at 2300 lbs due to very low car count, but I really just want the better track time to keep developing since HPDE3 has become quite the clusterfuck. Car will be mostly prepped for transition into ST safety-wise though, so if all goes well with shaking down and better driver improvement I may try to shoot for Comp School at some point, we'll see.
Long term plan still undetermined regarding BP vs K-swap and what class I ultimately want to shoot for. Right now focus is just on being a better driver and having a safe and complete car.
#94
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I haven't liked the tall-angled MR shifter nearly as much as the OEM sized MR shifter. It's kinda floppy and easier to miss-shift at first. It's OKAY after you get use to it, but the OEM sized MR was way better than just OKAY.
#97
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Finalized plans for the off-season and into next year:
Plan for next year is to shake down the new chassis and check ride into TT for better quality track time. Can possibly be regionally competitive in TT6 with 125 HP at 2300 lbs due to very low car count, but I really just want the better track time to keep developing since HPDE3 has become quite the clusterfuck. Car will be mostly prepped for transition into ST safety-wise though, so if all goes well with shaking down and better driver improvement I may try to shoot for Comp School at some point, we'll see.
Right now focus is just on being a better driver and having a safe and complete car.
Plan for next year is to shake down the new chassis and check ride into TT for better quality track time. Can possibly be regionally competitive in TT6 with 125 HP at 2300 lbs due to very low car count, but I really just want the better track time to keep developing since HPDE3 has become quite the clusterfuck. Car will be mostly prepped for transition into ST safety-wise though, so if all goes well with shaking down and better driver improvement I may try to shoot for Comp School at some point, we'll see.
Right now focus is just on being a better driver and having a safe and complete car.
Ain't nothing wrong with that! I miss driving on track :(
I haven't liked the tall-angled MR shifter nearly as much as the OEM sized MR shifter. It's kinda floppy and easier to miss-shift at first. It's OKAY after you get use to it, but the OEM sized MR was way better than just OKAY.
I haven't liked the tall-angled MR shifter nearly as much as the OEM sized MR shifter. It's kinda floppy and easier to miss-shift at first. It's OKAY after you get use to it, but the OEM sized MR was way better than just OKAY.
#98
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If you end up still coming down to VA and the TT/ST6 class gains some entries I'd probably be perfectly content sticking with the BP and taking the money savings from not K-swapping and using it for nicer parts for increased reliability throughout the life of the car (IE MiataHubs and ChillOut vs going for the cheaper versions).
#99
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If you end up still coming down to VA and the TT/ST6 class gains some entries I'd probably be perfectly content sticking with the BP and taking the money savings from not K-swapping and using it for nicer parts for increased reliability throughout the life of the car (IE MiataHubs and ChillOut vs going for the cheaper versions).
#100
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If you end up still coming down to VA and the TT/ST6 class gains some entries I'd probably be perfectly content sticking with the BP and taking the money savings from not K-swapping and using it for nicer parts for increased reliability throughout the life of the car (IE MiataHubs and ChillOut vs going for the cheaper versions).
As for the swap, if you've got car counts in classes that you can be competitive in with the BP then stick with the BP as long as you can. Wait until you either feel like you really want more power, or if the increased power can get you into classes with better car counts. For me, there's no one locally to compete against in ST5 or ST6. But ST4 has pretty good potential to get some people racing, so that was the largest motivating factor. As well as being able to run at GLTC events, where a naturally aspirated BP is just not up to the task.