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I am ruined, aero is too fun.
Things that were new at Chuckwalla: G-Loc R18 front. 4" splitter and new airdam. APR GT250 Singular AeroWing kit. Brakes were awesome. I have fallen in love with the R18 pad in Snoopy and Bullet. Waited for my R10s to wear out before switching over. I love the added bite. I have a stock 1.8 non-sport brake system for NASA points, so the higher mu means I have to stand on the pedal less to get the same bite. That allows easier modulation since I am not flexing my leg, firewall, etc so much. https://cimg0.ibsrv.net/gimg/www.mia...7e04a3ac02.jpg https://cimg1.ibsrv.net/gimg/www.mia...d696eb4f36.jpg https://cimg3.ibsrv.net/gimg/www.mia...5765d988e2.jpg The car is still on 1000/500 springs, stock bars. I am going to drop down to 900lb fronts and add back the RB 54107 and 14mm SPM bars to make it even easier to drive/fine tune. I also want to cut some mor eout of my doors and look over the car for other weight. |
Yas. Everything is just better with that aero package, I still feel like I haven't gotten used to how hard I can stand on the brakes at higher speeds now.
I'm on 1000/500 right now with the SuperMiata bar kit, anything in specific that prompted you to want to go back down to 900 in the front? |
Originally Posted by Arca_ex
(Post 1453109)
Yas. Everything is just better with that aero package, I still feel like I haven't gotten used to how hard I can stand on the brakes at higher speeds now.
I'm on 1000/500 right now with the SuperMiata bar kit, anything in specific that prompted you to want to go back down to 900 in the front? |
Chuckwalla CCW video chopped. First time driving Counter. Would love some tips from the bros.
Big bobble entering the front straight is obvious, cost .200. I pushed wide through the bowl, cost me .165. Still my fastest lap. second session golden conditions. Got hot and windy later. No other major deltas to other laps. I ran a bunch under 2:02 so I have lots of comparison sectors. https://cimg0.ibsrv.net/gimg/www.mia...4b024b151b.jpg |
the track looks so different for some reason. I know its counter but the angle or POV or something makes it look odd.
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Originally Posted by doward
(Post 1453106)
I also want to cut some mor eout of my doors and look over the car for other weight.
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Originally Posted by ThePass
(Post 1453865)
Sorry :p
Things on on the chopping block: headlights wiper system trunk webbing/latch/hinge hood latch/webbing door innards(keep crash beams for w2w) switch to lighter Supermiata Crossflow rad I think I can get well below 2200lbs with driver pretty easy. Also on the menu is a safety gear refresh: -Halo seat. My Sparco Evo is well past due. I added a back brace in 2016 to get up to NASA tech minimum. Considering Sparco Circuit II and OMP HTE-R400. Waiting on Vegas to get back so I can see/test the seat fitment in that car. (It’s also an NB set up for a rearward seating position for Emilio. He and I like similar recline and leg-pedal distance, I just need more steering wheel spacer.) -Fire system: 2 nozzle system mandatory for Supermiata 2018. Good idea anyways. -Relocate my master kill switch and maybe add a secondary activation. |
I love my OMP HTE-R. The material is very breathable, and the dimensions are perfect for the miata.
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Originally Posted by doward
(Post 1454079)
-Relocate my master kill switch and maybe add a secondary activation.
Take a look at the Cartek battery isolators: Battery Isolators | CARTEK Motorsport Electronics |
NASA ST5 rules dropped.
Most of of my guesses were spot on. Targeting 15.5:1 was good. The class max is 14:1, but miatas get a couple hits due to superior suspension design(upper A arms +.7) and light weight(+.3 or .4), bumping them to 15.0 or 15.1. Adding a 4” max splitter costs another .5. My plan is to run light, since I don’t have much horsepressures. This means I’m allowed a max section width of 226mm. So I made a Go/No go gauge from the NASA template. https://cimg8.ibsrv.net/gimg/www.mia...319c56c04.jpeg Looks like im good to run 205 R7s under 2400lbs as long as I mount them on 8” or narrower wheels. So that’s what I’ll start with. 14:1 base +.7 A-arms: 14.7 +.4 under 2450lbs: 15.1 +.5 splitter, 4" max: 15.6 2250lbs(Less than this gets another .1 P:W hit) 144 average whp (I make 143 peak now, might add a BP5A cam to reach ~148 peak, 144 average) 205/50/15 Hoosier R7 15x8" wheel to pinch them down to 226mm. Otherwise I have to run over 2400lbs. GT250 wing 900-1100/500 Xidas RB 54107 front, 14mm SPM rear sway bars. 1.8 Brakes, GLoc R18/R10 4.3 Torsen lap time expectations: Chuckwalla 1:58 Buttonwillow CW13 1:54 ACS Roval 1:56 |
Wouldn't you want 1000+ front springs? I thought that was the hot setup now for an "aero" setup?
Or do you have enough sway bar to make up for the 900lb springs? |
1100/500 would be the go-to setup on 205 R7s on an ST car.
My car is an S2 Supermiata, with S1 aero added for nasa. I still need to look at what events with each series I want to drive. Not chasing anything other than fun. I like the ST rule book and have tires laying around. Not making a serious effort unless something flips and I decide to build a motor and tow to Austin, so I’ll have some compromises built in to allow double dipping back to SPM S2. 225 RC1 will hate me for running the current 1000s and adding a big front bar in S2 trim. |
"We are going to revise the +0.3 Mod Factor from 200 TW non-R compounds tires to just 100 TW or higher."
This is pretty huge, and again helps a Supermiata cross over. lol Getting .3 P:W credit back for running 225 RC1, NT01, Rival, RE71R, etc is a good thing. It completely pays for the comp weight penalty if you run at >2450lbs... Lets look at 2250lb options first: 14.0 P:W Base A arms +.7 >2250lbs +.4 100TW+ -.3 14.8 P:W allows 152 average Splitter +.5 makes it 15.3 and 147 average. Hoosier R7s +.3 makes it 15.6 and 144 average If I decide to build a higher power motor and run at 2450+: >2450lb options. 14.0 Base +.7 A arms +.3 >2450 -.3 100TW+ 14.7 P:W allows 166.7 average. Splitter +.5 brings it down to 15.2 and 161 average Hoosiers +.3 bring it down to 15.5 and 158 average I am still not sold that .3 P:W is worth giving up Hoosiers, but it is interesting. |
BTM aero credit(-.4) and 100TW(-.3) credit pays for the .7 A arm hit....
>2450lb with BTM aero gets back to the base 14:1 P:W and is allowed 245/40 RC1/RivalS/RS4. add .3 for 2450lb 171.4 average whp. |
That's cool to them actually make changes for 100tw. I still think the delta between RC/Rival-S(-0.3) vs R7 to A7(-1.0 in ST4) isn't quite real-life accurate.
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Originally Posted by doward
(Post 1455977)
BTM aero credit(-.4) and 100TW(-.3) credit pays for the .7 A arm hit....
>2450lb with BTM aero gets back to the base 14:1 P:W and is allowed 245/40 RC1/RivalS/RS4. 175 average whp. if it's go 175, could you take a trackspeed kit and get it to produce a 175hp plateau? Like a no aero supermiata s1 car on 8" 225 RC1? |
Originally Posted by Neversatisfied
(Post 1456249)
With your experience does it make sense to go the Hoosier / aero / low hp route or no aero, rc1, 175hp dyno curve for st5?
if it's go 175, could you take a trackspeed kit and get it to produce a 175hp plateau? Like a no aero supermiata s1 car on 8" 225 RC1? Over 2400lbs, ST5 allows 257mm of tire. Thats a 225 R7, or a narrow 245 like RC1/RS4. I think that fastest car is a 2451lb, 225 R7, with aero. This build runs at 15.5:1 and 158 average. I don't know the best/easiest way to get 158, but it's probably simple cams in a healthy NB motor. |
Originally Posted by flier129
(Post 1456020)
That's cool to them actually make changes for 100tw. I still think the delta between RC/Rival-S(-0.3) vs R7 to A7(-1.0 in ST4) is quite real-life accurate.
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Originally Posted by Bryan Z.
(Post 1454082)
I love my OMP HTE-R. The material is very breathable, and the dimensions are perfect for the miata.
https://cimg3.ibsrv.net/gimg/www.mia...ffa4968b2e.jpg https://cimg4.ibsrv.net/gimg/www.mia...d9647ad8e5.jpg |
Originally Posted by doward
(Post 1456286)
Andrew thinks an alternate wast-gate spring will allow his 6258 kit to make 175 average. (If it only gets down to ~180, you can shape the curve to bring the average down to 175, so there is some flexibility in ST. In PT you have hard peak caps, so we almost always left 2-3% on the table.)
Over 2400lbs, ST5 allows 257mm of tire. Thats a 225 R7, or a narrow 245 like RC1/RS4. I think that fastest car is a 2451lb, 225 R7, with aero. This build runs at 15.5:1 and 158 average. I don't know the best/easiest way to get 158, but it's probably simple cams in a healthy NB motor. Don't forget to have a '-10 HP' tune or a bunch of ballast handy for when you get put on the NASA MCE Dyno.. |
My spare motor went off to Keegan to get torn down and checked out.
Going pretty universal on the build, adhering to the 80/20 rule, focusing on low hanging fruit. Not too high compression, no CNC, no coatings. Stock crank, cams, valves, damper. Going to target 10.7:1 so I can run it on pump gas if desired, boost it in the future, etc. It'll get forged internal bits, valve springs, oil pump, ACL bearings and studs, a little blending, maybe some short side radius touch up in the head, along with Mike's typical blueprinting. 7800rpm. It won't make peak power there, but there will be times in TT where I can use the extra rpm to save a shift, so I want to be able to. |
Originally Posted by doward
(Post 1457951)
My spare motor went off to Keegan to get torn down and checked out.
Going pretty universal on the build, adhering to the 80/20 rule, focusing on low hanging fruit. Not too high compression, no CNC, no coatings. Stock crank, cams, valves, damper. Going to target 10.7:1 so I can run it on pump gas if desired, boost it in the future, etc. It'll get forged internal bits, valve springs, oil pump, ACL bearings and studs, a little blending, maybe some short side radius touch up in the head, along with Mike's typical blueprinting. 7800rpm. It won't make peak power there, but there will be times in TT where I can use the extra rpm to save a shift, so I want to be able to. Just curious over piston choice. |
Originally Posted by shuiend
(Post 1457952)
Are you planning on cali 91octane and boost? More then 220whp?
Just curious over piston choice. Current plans are ~165whp/e85 for ST5 with a restrictor plate added for 140whp/e85 Supermiata-ing. If I ever want to do an enduro, it'd be nice to switch to a pump gas map for economy. |
Do 9.5 or 10:1 and shave the head for compression. That way you can swap the head later and bring the compression back down if you ever decide to S1.
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Easier and cheaper to just add a bit of head gasket thickness to lower CR. Loses a bit of Squish and efficiency but for S1 there so much power to spare and E85 it won't matter.
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I'm so glad you're going this route :D. I really hope it works out, because it's what I want to do.... solid N/A build to run ST5 with the possibility of adding S1 + power down the road.
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I have had the same Sparco Evo through three cars and ~9 years of track use now. It has long since expired and does not have a Halo. Since it is/was FIA approved, I was able to limp it along with an I/O Port back brace for the last three w2w race seasons. In TT and HPDE, expired seats and harnesses are still legal.
I want to move to a Halo seat for 2018. Supermiata rules will require one by 2019, NASA rules currently require either a halo seat or center net, but will likely go Halo AND center net soon as well. Center nets and seat halos do two different things. Emilio picked an OMP HTE-R400 for Vegas, so we have one on hand. Sonny has a new Sparco Circuit II going into his car. Side by side a few things are evident: Product spec sheets are not 100% accurate for either seat. Sparco Circuit II halo is huge, 4-5" wider than the R400. Meaning, much worse cage/door/window/net fitment, but more head swivel room inside the seat. OMP base is actually wider, but shorter under the thighs. Meaning, the OMP will actually require more trans tunnel mods or be more off center. Shoulder wings are actually within 1/8" of eachother. Meaning that door panel fitment would actually be pretty similar if both seats are mounted in the same centralized location. For my body composition, the Circuit II is significantly more comfortable. The base is ~1" longer under the thighs with a much more linear pad. The OMP has a very pronounced knee lift pad that I find uncomfortable. I'd rather get my knee height by reclining the seat. The OMP also has more harsh ribcage bolster edges. They don't pinch per say, but I meld perfectly into the entire bucket of the Sparco. Whereas I can feel each important touch point of the OMP, the knee pad, rib cage bolsters, shoulder wing wrap angle, etc. I am 5'10" 185lb and on my way down from 225lb. I have some 'cushion' still, but wear 32/30 pants. I typically do not need to add any booster pads to Emilio's cars(he is over 6ft), but do need an extra steering wheel spacer. Luckily, my cage was built around my Sparco Evo which shares the same bottom width and shoulder width. I still need to test fit Sonny's seat in my own cage. If it fits, I am going with the Circuit II. https://cimg6.ibsrv.net/gimg/www.mia...1cb89bfcfe.jpg https://cimg7.ibsrv.net/gimg/www.mia...9a979c51fa.jpg https://cimg8.ibsrv.net/gimg/www.mia...ec78537312.jpg Circuit II in Sonny's early TC Design cage: https://cimg0.ibsrv.net/gimg/www.mia...1e9f4d4779.jpg |
Thank you for the direct comparison as I am currently in the Sparco or OMP debate myself. It was quite annoying having to search multiple threads for real world measurements when trying to imagine if a seat will fit. I'm looking forward to seeing the Circuit in your car if you can get it in there.
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Originally Posted by Quigs
(Post 1461311)
I'm looking forward to seeing the Circuit in your car if you can get it in there.
This is the Circuit II. |
Originally Posted by doward
(Post 1461314)
To clarify, the Circuit fits very easily. That is what sonny had before, in which I did not fit at the time.
This is the Circuit II. |
New custom seat brackets received and test fit yesterday. Key feature is that the rear floor mounts are moved back behind the humps. This allows the entire shell of the seat to pass down through the mounting bracket and sit on the floor. They are currently a one-off set of tall-guy specials made by a friend. I begged and pleaded for a set for myself.
I need the forward most mounting slot to reach my pedals. They can put the back of the seat on the rear bulkhead. https://cimg1.ibsrv.net/gimg/www.mia...34c8f89003.jpg While the brackets can clear the humps, you can mount the seat that much lower by removing them. So I removed them. https://cimg8.ibsrv.net/gimg/www.mia...4453ad95a3.jpgNB floor hump removal. Sparco Circuit II halo would fit inside a window if I wanted to drop one in for storage: https://cimg9.ibsrv.net/gimg/www.mia...9eef2812f6.jpg Side shot to show how low this ginormo seat is: https://cimg0.ibsrv.net/gimg/www.mia...1d2fd52180.jpg Shoulder wing clears the tub and door. My cage is mounted on the rear bulkhead, so there is plenty of room for the seat. https://cimg2.ibsrv.net/gimg/www.mia...48ea333e14.jpg Unrelated, and no shiny pictures, but I also got the PTE stock swaybar setup out and a pieced together Supermiata Sway Bar kit installed. In went my old Racing Beat 1 1/8" 54103 front bar, Supermiata endlinks and Racing Beat 54123 brace blocks. A fresh Supermiata 14mm adjustable rear bar went in with my old endlinks. https://cimg3.ibsrv.net/gimg/www.mia...66df31b009.jpg Still need: 4 nozzle fire system Cartek GT battery isolator APR GT250 foil class lettering ballast Still want: Paint interior install Aerocatches install/wire starter/switch panel new polycarbonate windshield |
Originally Posted by doward
(Post 1463672)
New custom seat brackets received and test fit yesterday. Key feature is that the rear floor mounts are moved back behind the humps. This allows the entire shell of the seat to pass down through the mounting bracket and sit on the floor. They are currently a one-off set of tall-guy specials made by a friend. I begged and pleaded for a set for myself.
I need the forward most mounting slot to reach my pedals. They can put the back of the seat on the rear bulkhead. https://cimg1.ibsrv.net/gimg/www.mia...34c8f89003.jpg While the brackets can clear the humps, you can mount the seat that much lower by removing them. So I removed them. |
First Socal NASA event in two weeks.
SoCal/AZ Crossover at Chuckwalla Valley Raceway. Pre-reg so far: One ST5 entry, Rx7 One TT5 entry, FRS 3 TTD(2 spec miata double dippers) 0 TTE/PTE/PTD I can drop down to TTD for contingency, but would rather run in TT5 specification for fun. |
My foil arrived today. APR GT250 as part of the Singular Aerowing kit. Stock APR end plates for minimal drag. I’ll also be removing the gurney. My white paper reading led me to the understanding that an endplate sized at 50% of the chord length in height is the most efficient, APR's base plates are nearly exactly that. Whodathunk. APRs own info also implies that the gurney shouldn’t be used until the foil is over 5* AoA. This mirrors the setup notes on the 1000 where they say to keep the main element at 5*, and do all of your tuning with the second element, from 10 to 52*. Ill be running the small plates, no gurney in an attempt to balance my 4” splitter with as little wing as possible. https://cimg7.ibsrv.net/gimg/www.mia...f3ae0c304.jpeg |
https://cimg2.ibsrv.net/gimg/www.mia...509a6c10c.jpegSparco Circuit II can juuuust squeeze into a Miata. Big seat, little car. This is the most comfortable I’ve ever been in a racecar. https://cimg3.ibsrv.net/gimg/www.mia...a4279570d.jpegNew bits. https://cimg4.ibsrv.net/gimg/www.mia...7c9893622.jpeg2325 with 3/4 tank and 65lbs of ballast plate. Allowed as low as 22050. https://cimg5.ibsrv.net/gimg/www.mia...d826cc545.jpeg205/50/15 Hoosier R7 is legal for NASA ST5/TT5 when mounted on 15x8. Meets “equal to or less than 226mm”. https://cimg6.ibsrv.net/gimg/www.mia...e3db1ee0e.jpegI had to buy new socks, but passed my annual tech for 2018. |
NASA Arizona, Chuckwalla, Feb 2018.
We ended up having 4 ST5 cars, but no real racing battles. I was out front with a gap on my slower tires. I set Pole on Saturday. Won race 1 after a short 1 lap battle with Keith. His rx7 rolled me on all three starts. He was battling handling issues all weekend after upgrading/converting the car from PTD. Sunday Qualifying was a 2nd race based on race #1 finish position, but we had 2 more competitors. An ST4/Spec Boxster was moved down into our group, and an E46 BMW showed up with painters tape class letters. I won the qualy race with the ST/PT group starting behind Spec944 on the same flag. I had a blast ripping through traffic. 944 group weren't too happy with the traffic coming through tho. The boxter and rx7 both rolled me. Keith and I had an even more fun side by side battle for another lap or so. I picked the right 944 to follow through traffic and that was the pick I needed to get free. Race #3 I was placed on pole for our own green flag. I think I was in 4th going into T1. Eventually got by the boxter and Keith again as Keith spun his rx7 off in front of me. 3 race wins 2 TT wins Fastest race lap of all three races. Technically, 4 new track records. It was a fantastic new experience being the fastest car on track. During Sunday's race I passed 25 cars. That is not normal in a miata. In ST5 mode: 225/45/15 Maxxis RC1 2:03.048 CW Saturday. 2:05.619 CCW Sunday, hot/windy/dusty, everybody went slower in the afternoon. For TT I ran 205 Hoosier R7s and went 2.1-2.6 seconds faster. 2:00.983 CW Saturday, 4:40pm. 2:01.032 CCW Sunday. 8:50am. I would have finished 2nd(of 5) in TT4 on Sunday. 1.2s under the TTD CW record from 2012. ("Crusher") 1.1 off the TTD CCW record from 2014. 1.6 off the TTC records both ways. ST5 is a 14:1 class, but with modifiers for superior suspension design and light weight, I run at an "adjusted P:W" of ~15.3:1 My raw P:W was 16.3:1 this weekend, adjusted was 15.3 in ST5 on Maxxis, 14.7 in TT5 on R7s. I was ballasting the car for each wheel combo to try and stay within 50lbs on my Min Weight. 225/45 RC1 on 9" wheel vs 205 R7 on 8" wheels has a package weight difference of like 24lbs. Burning e85 ~40% faster than gas also makes it more difficult to gauge fuel weight sometimes. With the new engine, I'll be allowed to make an additional 30 horsepower and use bigger 225/45/15 Hoosier R7 tires if I run at 2400Lbs instead of 2250. I think the car will go 2-3 seconds quicker with the extra power and tire, despite the weight gain. https://cimg9.ibsrv.net/gimg/www.mia...7066a6785a.jpg https://cimg8.ibsrv.net/gimg/www.mia...775fb16dfb.jpg https://cimg0.ibsrv.net/gimg/www.mia...05e808db3f.jpg https://cimg1.ibsrv.net/gimg/www.mia...a9fc6265d3.jpg https://cimg4.ibsrv.net/gimg/www.mia...8f2bad8739.jpg https://cimg3.ibsrv.net/gimg/www.mia...21db13da6c.jpg |
Peter from Winding Road Socal took a couple snaps in grid from his vendor booth:
Thanks Pete! I purchased a new Black Armor Circuit Composite helmet, fresh Turn One/Oreca 6pt camlock belts, and Alpinestars FIA socks from them to prep for this season. In 2016 I used their TT Contingency program rewards to help pay for my Schroth HNR FLex head/neck device and my Schroth center net among other bits to prepare for wheel to wheel. Highly recommend. https://store.windingroad.com/articles/landing.htm https://cimg4.ibsrv.net/gimg/www.mia...230d5675e.jpeg |
Quickie video for Jeff @ JerfSpeed "jpreston" here on MT.
Hit him up for your seat mounts. |
Pulled the Maxxis contingency stickers, over to Hoosier for this event.
Oh, and fresh 15x8 TiO2 6ULs. https://cimg0.ibsrv.net/gimg/www.mia...9df11f40fe.jpg https://cimg1.ibsrv.net/gimg/www.mia...8748c8fff0.jpg https://cimg2.ibsrv.net/gimg/www.mia...860553c59e.jpg https://cimg3.ibsrv.net/gimg/www.mia...87e3f4ac16.jpg |
Forum software won't let me give you more than one cat, sorry dude.
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Originally Posted by emilio700
(Post 1478370)
Forum software won't let me give you more than one cat, sorry dude.
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At Chuckwalla I was a mess swapping wheel sets between classes. 225 RC1s on 9"s for ST, 205 R7 on 8"s for TT. HUGE swings in weight between the wheelsets, so I was way overweight with the RC1s. For Buttonwillow I mounted up my last set of freshies on a second set of 15x8, this time in our new TiO2 finish. https://cimg8.ibsrv.net/gimg/www.mia...52466cc154.jpg https://cimg9.ibsrv.net/gimg/www.mia...d547ad4570.jpg New layout for me, 13CCW. I've driven 1 and 25 CCW, as well as 13CW, so it was pretty easy to put together. For warm up i scrubbed in the stickers to let them cure overnight, with plans to race them on sunday. Ran a 2:02.9x, good for p2 grid spot for qualifying. Back to the scrub 2016 championship tires for qually and race 1. They've by now got 10-12 cycles on them after the Chuckwalla weekend and 2016 champs. Confusion on qualifying logistics, I showed up early to get gridded by laptime. 2 HC4 cars buzzed around me and zipped right up to the end of the pit wall. Apparently SoCal region has a first come first serve qually policy, where the grid cones are ignored... Every other region I've run with uses warm-up times to set the qually grid. (SoCal has a few peculiar customs I really dislike. No Supersize offer for TT double dipping being the big one, no tech after qually, not a single ST car got compliance dynoed this weekend, etc.) So myself, Nik, Erin and Adam get jumped in line by a couple slow hondas for qually. They end up ruining both Nik and I's first flyer, so we coast around for a lap, letting Erin and Adam by, among others, before banking another flyer. Nik squeezes out a 2 flat. I find 9/10ths from my warmup time for a 2:02.0. Still p2. Tire data from warm up and qually was odd. 205 R7 on 8" wheels like a lot of air. RF corner was getting roasted so I ended up with a totally asymmetric pressure setup for the race. I was classed at 2250lbs to give me P:W cushion to MCE, claiming 138 average whp. I voluntarily weighed after qually and was 2289 empty. So I pulled the wiper arms, wiper motor, and about 30lbs of ballast from the passenger side, before adding 5 gallons of fuel. Going for broke and targeting exactly 2250 +/- 1 gallon after the race. The race was amazing. I got a great start and we were side by side entering T1. I quickly got by Nik in Sweeper with great traffic management through the esses and into sweeper. He and his car were very fast, very early. Once we were free of traffic, there wasn't much I could do to keep him behind me. I squeezed him to the inside of every turn for about 2 laps, but since we were both parked down on the apex, he was able to motor right by me following Sunset/T1. Took me a while to reel him in, but my car was very fast mid/late, while his car was cooking the tires from my pressure. It was the best duel i've ever had. I really enjoyed it. https://cimg3.ibsrv.net/gimg/www.mia...6dad0411e0.jpg https://cimg9.ibsrv.net/gimg/www.mia...cd6038ec23.jpg https://cimg0.ibsrv.net/gimg/www.mia...40db6437b2.jpg On lap 12 I suffered a broken throttle return spring, causing the throttle to stick wide open entering Sweeper. 4, waaay, off the outside. A 2:16 lap and the battle over. I was able to get the car around a few more times before Erin caught me to hang on to 2nd place. I was there at the end with great tires applying pressure at every opportunity. I rolled across the scales at 2258, about a gallon over. I feel like I nailed the setup and that was my best drive ever, I had a blast and came away pretty satisfied with a P2 and a lap record, even after the mechanical. Sourced a replacement TB on sunday morning from an E2 enduro car, but I didn't like the way the car was running during my paddock test drive. Upon inspection of the broken TB, I found one of the throttle plate screws missing, the spring seat broken and the throttle shaft able to walk side to side about 8mm. Fearing throttle screw ingestion, I decided to load it up and diagnose it properly back at the shop. really poor idle and a stumble on part throttle tip in. Need to run a leakdown test. __________________________________________________ __________________________________________________ _____________ Going forward: Power rules. Get more of it. I don't think the splitter is worth the .5:1 P:W hit. I could probably remove the splitter and the gurney flap, retain good aero balance, and drop another 66lbs at my current power. Down to 2184lbs/138whp. I think 2184 is achievable for just time, no money. Ultimately, the goal is 2400/153 or 2450/158 to allow 225/45/15 R7s on wide wheels, with an airdam and wing. Further optimization in the form of Supermiata OsGiken, 6spd, more rpm will be bolt-on speed too. |
Awesome work, congrats.
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Are you running the stock TB?
Also, for the air damn to work well it needs an under tray to keep it from getting pushed in/keep laminate airflow under the front of the car right? So you would only be dropping the weight of the splitter that protrudes from the airdam. Would you be able to extend the bottom of the dam forward to reduce drag? Or do rules prohibit? |
Originally Posted by MiataMan00
(Post 1478793)
Are you running the stock throttle body?
Originally Posted by MiataMan00
(Post 1478793)
Also, for the air damn to work well it needs an under tray to keep it from getting pushed in/keep laminate airflow under the front of the car right? So you would only be dropping the weight of the splitter that protrudes from the airdam. Would you be able to extend the bottom of the dam forward to reduce drag? Or do rules prohibit?
The weight loss isn’t from any physical differences in splitter vs undertray, it’s the .5 p:w hit I take by having it on the car. Honestly, my Alumalite splitter is probably lighter than my birch plywood undertray. deleting the splitter from the build sheet would allow me to pull the remainder of my ballast and a couple other tricks like gutted headlights and skinned doors and trunk. Rules have a 5* tolerance to vertical for the airdam. |
Originally Posted by doward
(Post 1478796)
I was. I won’t again.
Originally Posted by MiataMan00
(Post 1478793)
Are you running the stock TB??
Reading your write-ups on ST5 gets the motivation going! ST6 pending I know, but I feel like I'll be copying your car...... as usual :laugh: |
Codorus also injested the oem throttle plate screw fwiw |
After breaking a throttle shaft and ingesting a throttle screw on my freshly build high compression motor a few years ago, I'll never run a stock throttle body on a track car if the rules allow alternates. Either Skunk2 or the one Emilio keeps teasing.
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Originally Posted by doward
(Post 1478773)
Going forward: Power rules. Get more of it. I don't think the splitter is worth the .5:1 P:W hit. I could probably remove the splitter and the gurney flap, retain good aero balance, and drop another 66lbs at my current power. Down to 2184lbs/138whp. I think 2184 is achievable for just time, no money. Ultimately, the goal is 2400/153 or 2450/158 to allow 225/45/15 R7s on wide wheels, with an airdam and wing. Further optimization in the form of Supermiata OsGiken, 6spd, more rpm will be bolt-on speed too. Back to this thought. So splitter isn't worth it because you're down on power for 2251lbs. Or are you thinking no splitter and just airdam/rear-wing will always be the way to go for aero balance for ST5 na/nb miata? No splitter at 2251lbs puts us around 148rwhp AVG and ~153rwhp peak. That also sounds like a riot and still not too far off to detune for S2 :party: |
Originally Posted by flier129
(Post 1479022)
Back to this thought. So splitter isn't worth it because you're down on power for 2251lbs. Or are you thinking no splitter and just airdam/rear-wing will always be the way to go for aero balance for ST5 na/nb miata?
No splitter at 2251lbs puts us around 148rwhp AVG and ~153rwhp peak. That also sounds like a riot and still not too far off to detune for S2 :party: With zero dyno cushion I could go as light as 2167lbs with splitter. Giving myself a few horsepower cushion leads me to 2250 to save that extra .1 weight factor. Delete the splitter and zero cushion leads to 2111lbs, taking a -.6 weight factor. LOL Unless the momentum car with a splitter has 2 second advantage on raw pace, it's REALLY hard to defend against a car with 60 more whp AND a large ratio advantage. I squeezed Nik to the inside of every corner, parking him. My 1 move was a very formula 1 race start style drift across the track from corner exit to cover/squeeze him down to the entry point of the next corner. I was able to hold position for about 100ft following those corners before he simply walked right by me. Once I was behind him in his draft, I could have sipped a coffee. The car was so much faster with a tow down every straight. I had grip to spare in every corner, so his tow allowed me to present a few times, but he had enough power to squirt back to the front on exits. The only place I could pass on merit and not his mistakes was Riverside, the super long sweeper where he had to tiptoe through while I was power limited and had my choice of lines around him. Running a 16.3 P:W car in a 14.0 class is tough. I am only competitive because of razor edge min weight management and 'good' driving. Removing the splitter to gain the .5 P:W is a step in the right direction. Running heavy to gain another .1 or .2 is a step in the right direction. Reaching 2400lbs also unlocks a big tire size allowance increase. This would keep the current key trait of being on happy tires late in races, while the heavy sedans and FWDs have roasted their tires. Comp weight pound per tire millimeter: 2250lbs on 205s = 2.74 Current setup 2400lbs on 225s = 2.66 Tires even happier late in the race than they are now. 2450lbs on 225s = 2.72 3020lbs on 245s = 3.08 (Nik's IS300) |
All of that makes perfect sense! Any clue on Nik's/IS300 power from this event? There's a local here in a E36M3 that should be in a similar setup.
Ok where's the video at?!? |
Originally Posted by flier129
(Post 1479076)
All of that makes perfect sense! Any clue on Nik's/IS300 power from this event? There's a local here in a E36M3 that should be in a similar setup.
Originally Posted by flier129
(Post 1479076)
Ok where's the video at?!?
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Originally Posted by doward
(Post 1479079)
Good question. Ask my Gopro. SD error. All I have are warm up and qually, which are both boring and not a 1:59.
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Originally Posted by flier129
(Post 1479076)
Ok where's the video at?!?
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EDIT:
Now with data overlay. Driving Marcus Lutrell's (Flier129) TTE car to a win at VIR during Hyperfest 5/20/18. I flew in from CA on Saturday. Long, early travel day, after a long night at the Taylor Swift/Camila Cabello/Charlie XCX show in the Rose Bowl. First time back at VIR in several years. I probably ran a 2:40 in my street car in ~2007? First session, green track, still damp in spots from overnight rain. 2:16.0 Second session, much warmer, but more comfortable with the track. 2:15.8 Third session, even warmer, but even more comfortable. 2:14.8 with a a big bobble onto the back straight, and a pass onto the front straight, both cost me time. Pretty good everywhere else i think. Marcus' car continues to improve. I drove it last at Mid O in 2017. It has since been gutted/caged/ballasted, a Halo seat added, along with a fresher used motor. 137whp 2438lbs after session #3 +1 Intake +5 Header back exhaust +5 800/500 Xida +2 RB front bar, SPM rear. +3 4.3 Torsen +3 205 R7 |
Finally found motivation to tear into Button’s throttle body/diagnosis. To recap: Throttle plate screw ingested through engine. The second broke tonight during disassembly. Throttle return spring guide bushing failed. Broke into 4-5 pieces. Throttle return spring broken, causing throttle to stick open. (Sent me way off track, I managed to limp home 3 more laps for P2) https://cimg9.ibsrv.net/gimg/www.mia...2dda929b8.jpeg Compression and leakdown are happy. Camera scope only found one little nic in the middle of #4. Nothing at the sides that indicate squished throttle blade screw between piston and cylinder head. https://cimg1.ibsrv.net/gimg/www.mia...5e119431e.jpeg https://cimg2.ibsrv.net/gimg/www.mia...a22bff9bb.jpeg https://cimg7.ibsrv.net/gimg/www.mia...7395fccfd.jpeg So, I’m thinking an oil change and a set of tires makes it ready for Sonoma with Speed Ventures in september. I’ve had that event circled all year, and I’m really excited to finally drive that track. Lets send it. |
That gives me cold sweats from when I ingested a throttle screw on my fresh high-compression VVT build. Glad you were lucky enough to get a through and through.
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July and August off track. Late August Birthday, the last two years I've flown to Ohio to drive Mid Ohio during a NASA TT/PTE weekend. Probably sitting that out, so I've targeted Sonoma for my next event. I'm skipping NASA Nats at CotA, so the final NASA event will be back at Buttonwillow, hoping for CW13 this time.
Sep 29-30 Sonoma Speedventures/Supermiata Oct 13-14 ButtonWillow NASA SoCal Nov 3-4 Auto Club Speedway Speedventures/Supermiata Nov 17-18 Chuckwalla Speedventures/Supermiata At one of these, Jpreston is flying out to co-drive or double dip. Publishing for posterity and public ridicule if he backs out. |
Originally Posted by doward
(Post 1493515)
At one of these, Jlpres2 is flying out to co-drive or double dip. Publishing for posterity and public ridicule if he backs out.
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Yeah yeah... I'm a bum, I know.
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