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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.
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.
Are you planning on cali 91octane and boost? More then 220whp?
Are you planning on cali 91octane and boost? More then 220whp?
Just curious over piston choice.
I'm not currently planning on either, but would like to leave the door open for one of them.
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.
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.
I'm so glad you're going this route . 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.
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.
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.
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.
While the brackets can clear the humps, you can mount the seat that much lower by removing them. So I removed them. NB floor hump removal.
Sparco Circuit II halo would fit inside a window if I wanted to drop one in for storage:
Side shot to show how low this ginormo seat is:
Shoulder wing clears the tub and door. My cage is mounted on the rear bulkhead, so there is plenty of room for the seat.
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.
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
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.
While the brackets can clear the humps, you can mount the seat that much lower by removing them. So I removed them.
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.
Sparco Circuit II can juuuust squeeze into a Miata. Big seat, little car. This is the most comfortable I’ve ever been in a racecar. New bits. 2325 with 3/4 tank and 65lbs of ballast plate. Allowed as low as 22050. 205/50/15 Hoosier R7 is legal for NASA ST5/TT5 when mounted on 15x8.
Meets “equal to or less than 226mm”. I had to buy new socks, but passed my annual tech for 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.
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
12-20-2017, 07:22 PM
2
. 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.
