Spectre Seven

After completing my first season of autocross and a few track days, I thought I would post my scratch built toy here. I am calling it a Spectre Super 7. Spectre meaning "fearsome apparition or ghost" in an effort to intimidate my competition.

It will never be "completed" but here is the info and build pics as well as pics as it sits today. I have about 600+ hours into it including my welding classes I took at the local community college. It is my first build of any kind. I did this in 1/2 of a 2 car garage at home. BTW, I also have a very patient wife who did not mind occasional small fires in the garage.

Chassis • Custom scratch built “Book” sized Mig welded with Std Mig Mix Argon/CO2 • 1” 16ga mild steel square and round tube with 16ga stitch welded floor and various extra strengthening tubes. • 1½” .095 wall DOM Seamless Roll hoop front and rear integrated into frame per SCCA Solo rules and SCCA GCR rules • Two 2” x ¼” steel drive shaft hoops (required for Modified SCCA rules) • Completed bare frame is 240 lbs

Body • Handmade .040 half hard aluminum sheet panels • Nose cone fiberglass S2 repoduction • 10” Front cycle fenders from Coveland • Rear fenders handmade .040 aluminum with integral rear spoiler/boot deck • Dash Gauge Plate 1/8” 5052 aluminum plate • Aero Belly pans .040 aluminum

Suspension • UB Machine Front lower strut type with spherical bearing mounts to chassis and upright (Asphalt stock car type design) • Speedway Front upper wishbone swedge tubes with spherical bearing mounts to chassis and std ball joint to upright. (Asphalt stock car type design) • Mustang II spindle/uprights • Front coilover aluminum single adjustable shocks with 350 lb springs • Rear custom 3 link trailing arm live axle with swedge tubes, panhard bar and spherical bearing mounts to chassis • Rear coilover aluminum single adjustable shocks with 90 lb springs • Diamond spun steel race wheels custom offset 13” x 10” rear and 13” x 8” front • Hoosier race slick tires rear 22” x 10” x 13”, front 20.5” x 8” x 13” R25B compound

Driveline • Mazda 12A stock port rotary with carb • 2” Custom 2 primary header design .180 wall mild steel and titanium wrap • Stainless Racing Beat 3” presilencer, to 3” Racing Beat stainless muffler • Oil system with 2 qt Accusump with factory oil cooler and manual valve all AN braided stainless lines • Cooling Honda Civic 3 core radiator with manual electric Spal fan • Mazda RX-7 stock 5spd gearbox & clutch • Custom driveshaft fabricated by Action Machine, South Bend, IN • Mazda RX-7 GSL live axle with LSD

Steering • Coleman 2.5 quick ratio manual rack & pinion • 10” steering wheel with Coleman quick mount

Brakes • Front Ford stock car type vented disc with GM metric calipers from Speedway • Rear Mazda RX-7 stock disc • Dual Wilwood master cylinders with remote cockpit adjustable balance bar. • Neal CNC pedals • Combined Nylon and braided steel lines • Hawk Pads

Ignition/Fuel • Weber 48IDA downdraft mounted on Racing Beat intake • Holley electric fuel pump with high capacity filters and fuel pressure regulator • 3 gallon RCI aluminum fuel cell • All braided stainless lines and AN fittings • Mallory HyFire 6AL dual CD ignition for trailing and leading wasted spark set up with rev limiters. • Innovative Tech LC-1 Air Fuel sensor mounted in header with heat sink and digital A/F gauge • Lightweight battery mounted in boot • 8 circuit basic electrical harness and fusebox

Safety/Interior • Kirkey aluminum race seat • G Force 5 point SFI harness with camlock • AutoMeter & Rebco Pro Comp gauges and water resistant switches & Master switch • Two .25” x2” steel driveline hoops & SFI Flexible safety blanket/scattersheild

VERY nice!

I almost forgot to post a pic with the GRM sticker visible!!!

Awesome ride!

COOL! good job man!

Looks the muffler setup! Imperative with a rotary that has a 4 ft long exhaust. Have fun!

RacingBeat was good help with exhaust tech info. Had to balance the performance design with reasonable sound limits. Tough to do in a package that will fit on such a small car. It works well.

locofinn wrote: RacingBeat was good help with exhaust tech info. Had to balance the performance design with reasonable sound limits. Tough to do in a package that will fit on such a small car. It works well.

I know that feeling. I had a streetported turbo II motor in the back of a 911 with a 3 ft exhaust into a supertrapp muffler. It was absolutely deafening and I like loud cars.

What is the total weight on this thing or did I miss it?

Wow nice, you didn't miss doing anything right on this car. Have you thought about changing the front fenders though? If you cover the front of the tire you'll cut drag and lift.

Total weight is 1,490 with driver. I have to shed about 100 pounds to get down to class minimum. I can loose about 50 lbs in front brakes and spindles with some changes. The stock car stuff is heavy and more than I need for a light car.

The front fenders are a compromise for autocross. I don't always miss those damn cones. I am going to add a front splitter and a rear diffuser within the rules.

I know this car! I've seen you at the SBR autocrosses at tirerack. Great looking and sounding car. I'll be following this.

If you were doing it all over again would you choose the rotary or would you go zetec or ?

Similarly, would you do the solid rear over again over an IRS?

I have been looking at someday building a DM locost and have been weighing the pros and cons of each package.

(pipedream, 1.0L Ecoboost, but needs an engine management solution)

What mufflers did you use?

Nevermind, found it. Stainless Racing Beat 3” presilencer, to 3” Racing Beat stainless muffler

Is this Grissom?

Yes the pic above is Grissom at the Hoosier Challenge event last year. I got my ass handed to me by Jeff Cashmore. Everybody did. I think he took index.

Apexcarver wrote: If you were doing it all over again would you choose the rotary or would you go zetec or ? Similarly, would you do the solid rear over again over an IRS? I have been looking at someday building a DM locost and have been weighing the pros and cons of each package. (pipedream, 1.0L Ecoboost, but needs an engine management solution)

If I was starting over I would go with F20C Honda power (S2000). These motors can be had complete with ECU and tranny as JDM swaps for under $3500 to $4000. Not cheap but about half the price it will cost me to get 250hp out of a 12A rotary. I see an engine swap in my future. I'm only pushing about 150-160hp now. It still will scare you when driving it. Some co-drivers come off course shaking a bit. But it is a good kind of scary.

For the rear end on a track/autocrosser, I think the solid live axle is the way to go. MUCH less complicated and cheaper to design correctly. For a street car an IRS is good. For a flat out race car, I would stick with simple and fast. Here is a few pics of my 3 link set up. I think a lot of the first gen RX-7 road racers used a 3 link? Eventually I will go with a quick change light weight rear end like a Winters.

locofinn wrote:

Apexcarver wrote: If you were doing it all over again would you choose the rotary or would you go zetec or ? Similarly, would you do the solid rear over again over an IRS? I have been looking at someday building a DM locost and have been weighing the pros and cons of each package. (pipedream, 1.0L Ecoboost, but needs an engine management solution)

If I was starting over I would go with F20C Honda power (S2000). These motors can be had complete with ECU and tranny as JDM swaps for under $3500 to $4000. Not cheap but about half the price it will cost me to get 250hp out of a 12A rotary. I see an engine swap in my future. I'm only pushing about 150-160hp now. It still will scare you when driving it. Some co-drivers come off course shaking a bit. But it is a good kind of scary.

Why not bridgeport 13B? You can certainly have one together for $4,000 and make more power than the stock F20c.

DaveEstey wrote:

locofinn wrote:

Apexcarver wrote: If you were doing it all over again would you choose the rotary or would you go zetec or ? Similarly, would you do the solid rear over again over an IRS? I have been looking at someday building a DM locost and have been weighing the pros and cons of each package. (pipedream, 1.0L Ecoboost, but needs an engine management solution)

If I was starting over I would go with F20C Honda power (S2000). These motors can be had complete with ECU and tranny as JDM swaps for under $3500 to $4000. Not cheap but about half the price it will cost me to get 250hp out of a 12A rotary. I see an engine swap in my future. I'm only pushing about 150-160hp now. It still will scare you when driving it. Some co-drivers come off course shaking a bit. But it is a good kind of scary.

Why not bridgeport 13B? You can certainly have one together for $4,000 and make more power than the stock F20c.

Only a streetport 13B or bridgeport 12A is an option in D Mod. A bridgeport 13B will put me into E Mod. At that point you run a turbo anyway like Jeff Keisel's E Mod National Champ green sprite. I heard he has somewhere around 450hp!!!

250hp is PLENTY of power in a 1,360 lb package including driver.

What did you use to paint your chassis, and how did you apply it? The time is nearing for me to paint mine...

bgkast wrote: What did you use to paint your chassis, and how did you apply it? The time is nearing for me to paint mine...

Machinery Gray Rustoleum. A wise old Mod car builder said to paint with light colors so you can see weld or frame cracks easier than black tubes. Applied with a 2" roller and brushes. I etched the bare metal first with Metalprep. Stick good and easy to match. I threw on some safety red for bling factor.

Because racecar, and it doesn't see salt except for the occasional margarita in the garage.

Great, thank you. The finish turned out well for brushing. I want to brush mine too, so that I can cover every nook and cranny but was worried about the finish.

I would thin the paint before using it out of the can. It will flow a little better and dry quicker. Straight out of the can, Rusroleum is very thick stuff. I mixed 1/4 to 1/3 mineral spirits in a seperate can as I used it.

In reply to locofinn:

Re: your 3 link rear suspension setup. Are all three links nearly the same length?

The three links are the the same length. The top link mount can be adjusted to increase antidive.