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NASA ST4 - U build thread - engine swapped
Hello everyone. Fellow ZN6/road racing enthusiast here, hoping to bring some visual and verbal enjoyment for everyone as I go through the process of building and developing my BRZ for W2W fun.
Small backstory of myself and the car/cars to get us going! I have been racing and engine swapping cars for about 20 years now for fun and for work. Most recently I ran a NA Miata in ST4 with a Ecotec swap with decent success. That car was chosen as a very good friend ran midgets years ago and wanted to start racing with me but didn't want anything high powered, so 200 whp and 2400lbs later we have this... https://www.ft86club.com/forums/pict...ictureid=12861 https://www.ft86club.com/forums/pict...ictureid=12862 So, after several years of beating that thing up and my teammate having some changes in life I let the Miata go to a nice couple in STL, MO. Wanting to get back into a higher HP car but have the ability to move up and down in the NASA classes I did some hunting/researching thus leading me to this 2017 BRZ PP..... https://www.ft86club.com/forums/pict...ictureid=12828 https://www.ft86club.com/forums/pict...ictureid=12827 Having a "little" damage she needed some loving from a good friend of mine before the fabrication begins... https://www.ft86club.com/forums/pict...ictureid=12829 https://www.ft86club.com/forums/pict...ictureid=12830 https://www.ft86club.com/forums/pict...ictureid=12831 https://www.ft86club.com/forums/pict...ictureid=12832 https://www.ft86club.com/forums/pict...ictureid=12833 https://www.ft86club.com/forums/pict...ictureid=12834 https://www.ft86club.com/forums/pict...ictureid=12835 So after getting it repaired I drove it around for a few months while working on customer cars, quite enjoyable stock I have to say, before beginning tear down. (everything is sold btw) Beginning of tear down and cage fabrication. https://www.ft86club.com/forums/pict...ictureid=12836 https://www.ft86club.com/forums/pict...ictureid=12838 https://www.ft86club.com/forums/pict...ictureid=12839 https://www.ft86club.com/forums/pict...ictureid=12840 https://www.ft86club.com/forums/pict...ictureid=12842 https://www.ft86club.com/forums/pict...ictureid=12843 https://www.ft86club.com/forums/pict...ictureid=12844 https://www.ft86club.com/forums/pict...ictureid=12845 https://www.ft86club.com/forums/pict...ictureid=12846 Still need to finish things on interior (belt loops, dash mount, fire bottle...list is long)but for the most part its done. I just need more parts to arrive and more time. So on to the fun stuff!!! Horsepewrs...... https://www.ft86club.com/forums/pict...ictureid=12848 https://www.ft86club.com/forums/pict...ictureid=12847 https://www.ft86club.com/forums/pict...ictureid=12849 https://www.ft86club.com/forums/pict...ictureid=12850 https://www.ft86club.com/forums/pict...ictureid=12851 https://www.ft86club.com/forums/pict...ictureid=12852 https://www.ft86club.com/forums/pict...ictureid=12853 https://www.ft86club.com/forums/pict...ictureid=12854 https://www.ft86club.com/forums/pict...ictureid=12855 https://www.ft86club.com/forums/pict...ictureid=12856 https://www.ft86club.com/forums/pict...ictureid=12857 https://www.ft86club.com/forums/pict...ictureid=12858 https://www.ft86club.com/forums/pict...ictureid=12859 So a bit of an avalanche of pics from the last couple months but it pretty well gets us up to date! As she sets at this moment, with the two stock seats in it and a little under a 1/8 of a tank of fuel left in it..... https://www.ft86club.com/forums/pict...ictureid=12860 So without seats its about 2140lbs.... not as good as i hoped but pretty close. Numbers are little skewed left to right as the right rear shock is bent from the earlier impact, so its like a bad corner balance haha thus really light on that wheel (its about 2 inches higher than the left when in free air!) I'll get deeper into spec's as we go and feel free to ask questions, I enjoy bench racing/bench building as much as the real thing! |
Ah, another Miata convert. What weight / tires are you targeting for 4?
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Shooting for 2400lbs, 245 r7 tires. Nothing like running a v8 at half throttle all day 😄 Central st4 class is pretty decent here, normally 5-7 cars each event, when we head south we can have 10-12. When not enough car count for contingency I'll jump up to other classes for fun! |
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We got a little done over the past few days as some more parts arrived. Sparco grid-Q seat and Tilton pedals fitted (I am 6ft/215lbs for fitment reference) along with painting the bars/bare metal spots - using steel-it urethane paint for reference. We will do final paint of the interior and engine bay once everything is fitted in the car but for the moment we did the bars and such to prevent rust. Also fitted the strut bars to fit the new valve covers and to clear the fuel rails and coils.
More parts arriving this week such as the fuel cell from Fuel Safe along with the fire suppression system from Lifeline, the waiting game on parts is super frustrating at the moment :mad0259: https://www.ft86club.com/forums/pict...ictureid=12890 https://www.ft86club.com/forums/pict...ictureid=12891 https://www.ft86club.com/forums/pict...ictureid=12892 https://www.ft86club.com/forums/pict...ictureid=12893 https://www.ft86club.com/forums/pict...ictureid=12894 https://www.ft86club.com/forums/pict...ictureid=12895 https://www.ft86club.com/forums/pict...ictureid=12896 https://www.ft86club.com/forums/pict...ictureid=12897 Still need to patch up all the holes in the firewall and various other places as well but we'll get to that :cheers: |
Nice! I remember seeing your Miata at the Hallett nasa events a couple times. Welcome to the 86 club!
This should be a fun build to follow. Same car that was on FB for sale a while go in that area? I recall it was a pretty good deal if it's the same blue BRZ that I'm thinking of. Either way, do you have goals of having it ready by year-end? Would love to hear some more on your plans for the build and setup. |
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This car I got out of MO from 76 auto salvage. I hope to have it done before the season is over but we shall see, it will kill me to have it sit all winter being done, even if that is the case I'll load up and head south or south east for some testing. I am really trying to make a multi tool car so I can do some open road racing such as the sand hills open road run, NASA of course and maybe some SLB or GTA. It makes it more difficult to be on the pointy end for some of the events beside NASA but that's ok. I will be making some swappable aero components for various classes as well. The main goal at the moment is to build it as light as my wallet will take me basing it on NASA rules for ST4 and shape it from that point. |
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Yea, it's the bright blue one (previously silver, now with aero) we run it in TT5 with TX region.
I feel your pain on making the car a multi-tool it challenging to work with a bunch of very different rulesets. I'm constantly switching out stuff for TT/Autocross and making the car legal for both. Two trunks with and without a wing, removable splitter, etc. It can get exhausting and definitely plenty of compromises. But it's fun to go take it to multiple places. I think your setup sounds really versatile! Especially with tuning/detuning of you motor choice. |
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Chipping away as parts arrive!
New side view mirrors arrived, for $40.00 shipped these are built pretty nice and are suuuuper light weight , we'll see if they hold up W2W but if not for that price I'm good! Glass is clear, lightly tinted. https://www.ft86club.com/forums/pict...ictureid=12907 Finished up the pedal box and false floor. Positioning feels great and it has a lot of adjustability. I'm leaving it at the 6.9:1 ratio as I want as much leverage as I can. BTW all the hardware on things like this floor piece will be changed to stainless button head screws or something of the like when its put back together after painting. https://www.ft86club.com/forums/pict...ictureid=12908 EPS ecu and clutch/brake reservoir mounted along with the new steering wheel and adapters. Will be removing the cable emergency brake system for a hydraulic hand brake with lock. https://www.ft86club.com/forums/pict...ictureid=12909 https://www.ft86club.com/forums/pict...ictureid=12910 https://www.ft86club.com/forums/pict...ictureid=12911 Also started on fitting the fuel cell and the surge tank setup. Fuelab 49502 lift pump inside the Fuelsafe cell, cell has a 3 ball surge tank inside as well as using a Fuelab 61712 surge tank setup with with 52902 digital regulator. The regulator monitors pressure/flow to control pump speed on the fly which if anyone has tried to run big pumps or multiple pumps on anything long term - street or track - knows how nice this is as it keeps from over circulating the fuel which creates heat and can cavitate creating various problems. Will be making a box frame for the cell and of course new sheet metal around the tank to facilitate the mounting of all the fuel components. For those wondering a bulkhead/firewall is coming after all fun stuffs is mounted in the rear such as these items and the accusump. Also have to think about wing supports/mounts when fitting all this, may install a remote fill like a dry break for the cell but we will see how it lays out first. https://www.ft86club.com/forums/pict...ictureid=12912 https://www.ft86club.com/forums/pict...ictureid=12913 New radiator in and started designing the coolant system. https://www.ft86club.com/forums/pict...ictureid=12915 https://www.ft86club.com/forums/pict...ictureid=12914 |
Working on fuel cell mounting yesterday, got the frame for the cell done and started on the sheet metal. Fairly please, should look good once its all finished.
Next will be mounting the fire bottle, accusump and make the side filler panels for the quarters. Bulkhead/firewall will be last. Not super pleased with my rolling on this panel as the edges aren't real crisp and the corners are soft but it looks ok, just me being picky. https://www.ft86club.com/forums/pict...ictureid=12924 https://www.ft86club.com/forums/pict...ictureid=12925 https://www.ft86club.com/forums/pict...ictureid=12926 |
Not a whole lot of magic this week but our drive shaft came in! Love me some carbon!!
https://www.ft86club.com/forums/pict...ictureid=12931 https://www.ft86club.com/forums/pict...ictureid=12932 https://www.ft86club.com/forums/pict...ictureid=12933 Once of the customer projects this week. I built this car last year, finally convinced him to build a proper header since the old one we re-used was hot garbage. This one will be sent off to be cerakoted next in a high temp satin black. https://www.ft86club.com/forums/pict...ictureid=12934 Should be able to keep the momentum going this week on the BRZLS but we shall see. :cheers: |
Well for better or worse the firewall and filler panels are done. Tried to do the main firewall in two panels and bit off more than I could chew, my bead roller is only a 18" and I really needed a 24" or bigger, i couldn't quite reach the center on a couple of the beads :mad0260: I am really pleased with the design and the fitment but I might do them over as it really irritates me on those spots but then again the seats go in front of it. I'll keep progressing and come back to that later, I still need to finish the small filler pieces from the cage to the body to seal it off but that's not a huge deal.
https://www.ft86club.com/forums/pict...ictureid=12938 https://www.ft86club.com/forums/pict...ictureid=12939 https://www.ft86club.com/forums/pict...ictureid=12940 https://www.ft86club.com/forums/pict...ictureid=12941 |
Great project! What are your plans for the exhaust?
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I have been thinking about that one for a while, rules be damned I would run it out the quarter panel or rockers with a trim ring around the opening like a TA2 car but since I would have to take p/w hit for ST4 for any floor/rocker modification for exhaust I figure I will run 3" round at the collectors, transition to a 3" oval equivalent (ground clearance) and merge to a single 4" or 4.5" oval equivalent tube and exit to the passenger side just under the rocker panel, it will angle downward so you wouldn't really see it but it would be right at the edge of the rocker - since I have no fuel tank under the car - (hard to paint a picture). |
One other good note for this week, I received my shocks/springs, MCS 2 way with Vorshlag plates.
https://www.ft86club.com/forums/pict...ictureid=12953 I was pretty impressed on the adjustment range and a quick test shows it will go pretty close to -7* on the front :thumbup: I plan on starting at -4*F/-2.8*R and will go from that point, I feel that will be a good baseline setting to start from. Initial spring set up is 615lb front 504lb rear - figuring wheel rate it should be what I want, not figuring sway bar numbers. Will be starting with a 25mm Hotchkis front bar and stock 15mm rear bar. I may end up making a splined speedway bar for the front but we will see how this is first. I ended up doing that on my last mac strut race car and it worked very well but the off the shelf bars available were shite at the time. I shouldn't have sold that car, miss it a lot. Pic also gives a glimpse of where this one is going, no widebody or picnic table splitter due to class rules though :thumbdown: https://www.ft86club.com/forums/pict...ictureid=12954 |
More work complete! Finished up the fuel cell area top and bottom. Media blasted, painted and installed billet bushings in the rear subframe. Fuel filler neck and hose is done other than changing a couple clamps i'm not happy with looking at :lol: .
https://www.ft86club.com/forums/pict...ictureid=12962 https://www.ft86club.com/forums/pict...ictureid=12963 https://www.ft86club.com/forums/pict...ictureid=12964 https://www.ft86club.com/forums/pict...ictureid=12965 https://www.ft86club.com/forums/pict...ictureid=12966 https://www.ft86club.com/forums/pict...ictureid=12967 |
So cool. Thanks for sharing.
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Few side notes and some more sheet metal work done this weekend.
As I was working on the new differential, pulling the gears to send off for REM treatment, I did some comparison shots of the internals versus a 8.8 ford diff I have, quite the material difference! If the factory diff dies I'll fab up a 8.8 using a newer aluminum housing from like a 2018 mustang gt but for now I'll try the factory torsen, REM treat the gears and use a knock off cusco diff cover for some added fluid capacity. Gear's are from a 2012 is250 (3.727 ratio) https://www.ft86club.com/forums/pict...ictureid=12975 https://www.ft86club.com/forums/pict...ictureid=12976 https://www.ft86club.com/forums/pict...ictureid=12977 Sheet metal wise I finished up the firewall but still need to do the harness loops for the center net and main belts on the center bars of the cage. https://www.ft86club.com/forums/pict...ictureid=12973 https://www.ft86club.com/forums/pict...ictureid=12974 https://www.ft86club.com/forums/pict...ictureid=12972 |
Plugging away as I get time, thankfully the racing season is ending so people will hopefully stop breaking stuff for me to work on :lol:
Got the gears back from REM treatment and the diff is assembled with billet bushings. (bushings are from salasko racing) For people wondering why the polishing, it's to help reduce friction so less heat in diff and more power to the ground. https://www.ft86club.com/forums/pict...ictureid=13009 All painted up and new cover installed https://www.ft86club.com/forums/pict...ictureid=13010 https://www.ft86club.com/forums/pict...ictureid=13011 Started working on the coolant pipes as well, kind of off track a bit but I really wanted to see some progression in the bay a bit, motors are my favorite part. https://www.ft86club.com/forums/pict...ictureid=13007 https://www.ft86club.com/forums/pict...ictureid=13008 |
Great build. I'm curious, it looks like you blocked off the rear compartment. No rear view mirror? Are you going to use a camera system?
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I will attempt to mount it up high on the cage near where the factory mirror was as naturally your eyes move that way but worst case it will be down on the dash in line of site. I drove a few cars with this style of camera and it works beautifully. |
Just saw this thread! looks like an awesome build. You don't have a template for the side windows you could share do you?
https://www.ft86club.com/forums/pict...ictureid=12941 |
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I don't have a way to scan the templates so I'm not sure how i would do that really. I use construction paper from hobby lobby to make the templates and then transfer to main material if that helps. |
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I have played around with taking a picture of something and tracing it in Fusion360 and then getting it laser cut from sendcutsend.com but its hard to get a straight on shot and be perfect. |
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BTW, this build is kick-ass, can't wait to see it hit the track. |
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Had some more time to get work done! Engine bay is finish painted along with the firewall being welded up and gutting the hood. Finished shooting the interior yesterday, ran short on paint so the insides of the doors need finished (used far more paint than I anticipated) I forgot how much I hate painting interiors, places like the bottom of the back deck and just all prep work in general, but she's all pretty now!
Rear diff and refreshed subframes are installed. I have the drivetrain out so I'm making the shifter linkage and shooting all the drivetrain mounts. I think thats about it for now. Few little side notes as parts are being made and slowly coming in. Wheels are being made by KOYA in AUS, 17x10 +40et, only 17x10 that wouldn't cost me a small fortune to have made that is a quality wheel, could have just gone with a smaller size or some cheap xxr's but didn't feel that was right way to do it. Rear wing is being built by TOP STAGE composites in AUS as well, I just didn't really like the designs here in the US. Very excited for both to arrive, probably at least a month or so out though :cry: https://www.ft86club.com/forums/pict...ictureid=13019 https://www.ft86club.com/forums/pict...ictureid=13018 https://www.ft86club.com/forums/pict...ictureid=13015 https://www.ft86club.com/forums/pict...ictureid=13016 https://www.ft86club.com/forums/pict...ictureid=13017 https://www.ft86club.com/forums/pict...ictureid=13014 Lots of suspension pieces inbound as well, looking forward to just bolting so stuff on for once haha. :cheers: |
paint looks great! what did you pay for the wheels? I have also been looking for a decent 17x10
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I am also interested in the wheels. I have also been looking at Augment wheels in Canada.
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Thanks man, that is a huge help! Not sure why its such a rare spec with 5x100 especially with the silly stretched tire trend. |
also are you doing any flares or "widebody" to help with the tire fitment?
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No flares or widebody, at most rolling fender edges. I run wheel to wheel so contact is inevitable and I don't want high-cost body parts to deal with. With my measurements and a minimum of -3.5F and -3.0R these fit perfectly under the stock panels. |
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This is huge. I spoke with Apex and they didn't seem to have any interest in producing a 17x10. Thanks for bringing this up! |
I love this project. And it's cool you're doing some things differently than many others. I'm looking forward to seeing the wheels.
I'm surprised you went through all of that to get a 17" x 10" wheel though, when you said Apex is appealing, and you could get a 9.5" wide wheel from them. Why were you so set on 10"? When racing W2W I'd think replacement wheel accessibility would be a significant consideration. |
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Multitude of reasons on the wheel. Its closest to optimum for the tread width of the tire I am running in my class, steering feedback, tire wear, response. Also when I choose to run a bigger tire when playing with higher power outputs, it makes it easier to do so. As to accessibility it is very significant, I will have three sets of wheels though, 2 drys and one wet. |
Finished up the doors last night and did the quarter window panels and trim. Just using SEM trim black to make them kind of look like moldings and more or less disappear. Another piece of the puzzle done!
https://i.imgur.com/THttvX9.jpg https://i.imgur.com/YjgFKP2.jpg https://i.imgur.com/BGdD4nK.jpg https://i.imgur.com/oP1jXev.jpg |
Getting some things assembled, painted and fitting/building new parts. Shifter and linkage is built and drying currently, used the base plate from the factory boot and the rubber portion for a gasket, turned out really good. The shifter is from amazon for a bmw e36, best $35 bucks I've spent in a while :D Made brackets for the factory door handles so they just go away. Seat belt mounts are all done on the driver's side, need to finish the passenger side but its no priority as it will require another $800 seat which I don't feel like buying at the moment, ride alongs can wait a bit :bellyroll: Drivetrain is back in so I can start building on that along with the accusump, fire bottle and surge tank to plumb those in as well. I will get the dash made this week also if all goes as planned.
It's starting to feel like a racecar! https://i.imgur.com/nGhXPFy.jpg https://i.imgur.com/UdEXLdK.jpg https://i.imgur.com/WeTxNwM.jpg https://i.imgur.com/SwkRgsm.jpg |
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