Challenge Boxster?

Thanks for all the replies. I was stressing too much about it.

Goals for the Challenge this year:

• Have fun.
• Keep it simple.
• Be safe.
• [and destroy this engine after I get a timed drag run.]

Here's a quick history of the engine for anyone who doesn't want to look back through the thread. I bought a cheap 2000 Boxster S that had this engine installed. Aside from being a 2.5L engine where a 3.2L engine should be, it was a complete mess; Oil leaking, missing vacuum hoses, bad AOS and water pump, no thermostat, and a poorly rigged set-up with the throttle body and intake. I think the coolant in it was dirty pond water. I flushed it out - oil and coolant, replaced AOS, water pump, thermostat, spark plugs and tubes, a couple coils, and more. The coolant tank in that car leaked and I replaced it with a new one. After all that, I found that it still had the problem of dumping coolant out the pressure relief valve whenever I drove it hard. I pulled the engine out of that car and left it in my driveway under a tarp for two years. I offered to give it away for free. It sat.

When i got the Challenge car with the bad engine, I figured I'd give this engine one more try. I flushed water thru the cooling system. I installed it as a hybrid with the harness, intake and fuel system from the 2.7L engine with modifications to fit on the 2.5L block. It had the problem dumping coolant still. I replaced the oil cooler. It seemed better at first, but when I took it out and drove it hard and hot, the problem was as bad as ever. That's where it is now.

I plan to bring it to the Challenge with the 2.5L engine now and not mess with the V8 swap until after. I have a 'Nitrous Express' wet kit for the car now that has jets up to 150 and a 10 Lb tank. My trailer has a winch.

After I took the convertible top off the car, I put a hard top on to keep the weather out. Hard tops for these run about $1,000 to $1,500, so that's not going to be on the car for the Challenge. No top at all is bad aero. Too much top is weight. I'm trying to build a compromise with the frame from a bad top (cracked rear window) and the aluminum hood from an Audi A8. It's still very much 'under development', but I'm starting to like where it's going.

I started out stripping the frame off the hood and cut it down to the basic shape of the roof.

Drill and rivet. Bend, drill and rivet. Cut.

At this point I was still thinking of working a lexan window in back and have it sloped similar to a Cayman. It wasn't quite going how I had envisioned it, so I stopped and let it rest for a day.

Eventually, after I trimmed it back a bit more, drilled out and re-set some rivets, I decided to keep it as a short, open top for some cover and reduced turbulence, but not add the weight to fully enclose it. It's still going to evolve for a while and can easily be removed if I want to go topless.

AngryCorvair said:

don't oil down the track early.

This. As much as everyone likes a big boom, no one likes having to wait 30 minutes for cleanup. It's just good form to wait till towards the end for the risky business. 

I like the DIY hardtop. 

AWSX1686 said:

I like the DIY hardtop. 

me too.   looks like a good start to a shooting brake.

Aero isn't going to be a concern in the event.  Just run it without a top.

I'll GLADLY let you borrow the $200 nitrous kit off my car after I make it to 12's. You can add it to the budget. It will be jetted to about 125, maybe more...

edit: just read up to the part where you bought your own kit. FYI my strategy is roughly the same. Make a soft pass, make a much harder pass, jet up until it blows. 

docwyte said:

Aero isn't going to be a concern in the event.  Just run it without a top.

That's what I originally thought. After pulling the top off I did some searches about the effectiveness of aero in autocross. To my surprise, most of the non-anecdotal info I found said that it does matter even at autocross speeds for tenths of a second.

Here's some of the discussion:

• https://tentenths.com/forum/showthread.php?t=124657
• https://www.miataturbo.net/race-prep-75/roof-no-roof-weight-v-aero-87692/
• https://grassrootsmotorsports.com/forum/aerodynamics-presented-nine-lives-racing/autocross-aero-and-a-challenge-miata/136411/page1/
• I watched some of Gray's Garage Videos. I think they were good, but I kept waking up with my head on the desk in a puddle of drool.

For me with little autocross experience, I don't think it will be significant - even if I knew how to do good aero.  There are many other factors that are more important. Tires, tires, and tyres are apparently what matter.

Why am I making the top? I've had the aluminum body parts from the A8 laying around and always wanted to give it a try. It's fun. I'm going to run the car with it and without it, but there will probably be enough other inconsistencies between runs that it won't be clear if there's a difference. In rain, or blistering hot sun it will be worth it's weight.

In reply to maschinenbau :

Thanks for the offer. I bought a $400 kit on Amazon that had a physical WOT switch to mount on the gas pedal or cable throttle. They sent me the wrong thing. What arrived was the "Fly-by-Wire" version that connects to the TPS and self calibrates for max throttle -possibly adjustable to a window. It took me a few hours to figure out what I had and find instructions for it.

I've laid it all out in the car and done most of the wiring. Tip: Even if it's just one 'hot' wire you are splicing and you "know what you are doing" DISCONNECT the battery first. (Luckily it was just a 15A fuse this time)

The best position for the tank is a fore and aft alignment. Due to space and access for mounting bolts, I went longitudinally. With this mounting, I need to keep the tank rolled about 45 degrees forward to optimize the pick-up tube position.

That is the most rad. I love this project, can't wait to drag race you.

Haha this is crazy, I love it!

AngryCorvair said:

AWSX1686 said:

I like the DIY hardtop. 

me too.   looks like a good start to a shooting brake.

I like it as well! Cool!

Learn me tyres and wheels for this thing.

For my goals and intentions, spending a ton of money on tires doesn't make sense.

I think that my best plan for tires is to use a set of stock 17" Boxster wheels and some Toyo R888s - I have two new unmounted and plan to buy two more to replace two old, worn ones.

I don't know drag racing at all. For the drag race I'm wondering if I should use 18x10 wheels (instead of 17x8.5) on the rear with some old, Very worn (practically slick), but not corded R888s and run at a lowered pressure. The 18" wheels are about 8 lbs heavier than the 17s.

Looking to be firmly in the "not last" position of the autocross and drag race, this is more about learning the theory and practice rather than actually trying to Have the best possible set up on the car. So taking it further, if I wanted to win it all, what would I want to do?

I should be sleeping right now, but I need to unwind. I'm going to just ramble a little here. I don't think I'll rant, but it will be a disorderly ramble. ...ignore:

I don't think I did anything significant on the car last week. It's in the garage and the HVAC stuff will all be coming out soon. I have pulled a lot if parts off. I am running out of room for it all. Where did it go? Into the Hearse mostly. So glad I got that, great storage space.

I work 7 days on and 7 off. I've been off work since last Wednesday. I caught up on lawn and house stuff then flew to New Hampshire. Birthdays. My stepdad just turned 96 and my father turned 85.

Don, at 96, just quit driving this year. Still has a license, but can't see well enough at night to feel comfortable. Amazing man, World War 2 vet, glider pilot, and nuclear engineer. I had a great visit with him, lunch and a car show/air show in Concord.

For my dad's birthday, there was a dinner at the Top of the Hub in Boston (fancy restaurant at the top of the Prudential Center). Amazing view, great food (strange salads and appetizer thingies). Good family visit. I drank enough, but not too much.

Today I was supposed to fly home. I'm not home. I'm in Chicago and my motel room smells like wet death and dirty socks. It started out nice. As I left to go to the airport this morning there was a super-clean CRX. I love CRXs. Don bought a new CRX in the late 1980 s and I borrowed it whenever I was in town.

I got to the airport 2 hours before my flight and relaxed with an audio book (The Expanse Series, Persepolis Rising). I didn't hear the announcements, but noticed my flight was late. Eventually I went to the counter and figured that it was going to miss my connection in Philly. Rebooked for 2 hours later thru ORD. That aircraft arrived late, then had a minor maintenance problem. ...1 hour delay. Overbooked. I offered to give my seat, but they didn't have another flight for me, so I stayed on.

Finally arrive at ORD. I figured if I ran a half mile thru the terminal, I'd make my connection. Then another delay - there was no gate for us to de-plane at. Twenty minutes on the taxiway. No longer any need to run.

No more flights available to get me home tonight. They offered to fly me to Springfield, Mo, but that would be about a 4 hour drive home. Plus the 4 hours for my wife to drive there to get me. No thanks. Booked for 0630 to XNA now. Yay. One counter person said I could sleep on a cot in Terminal 2. Really. "Um, no." Next guy says, "Here's a motel voucher, call that number and give them this code." I thought it was all good and went out towards the ground transport. Called the number. $100 for a room? Discount? No other choices? Berk' that.

Orbitz app. Room booked for $64 incl tax and shuttle. Super, right? Not quite: Wet death and dirty socks. Airport shuttle leaves at 0400. Thanks for letting me ramble.

Oh, and I'm supposed to report for Jury Duty at 8 am in Oklahoma tomorrow.

Good night.

Oh man that really sucks! And jury duty when you get home? Wow...

In reply to Billy_Bottle_Caps :

It wasn't smooth travel, but it all worked out. I arrived at XNA (Northwest Arkansas Regional airport) at about 8:30 and called the courthouse. They said that I wouldn't be needed for a Jury this week and excused me from having to go. The drive home through pouring rain and flash flood warnings was the perfect wrap-up for my travel.

I had all day yesterday to rest and recover. Now I'm back at work, on night shift this week. Night shift means that I sleep most of the morning and have the afternoon to play with my projects before going to work at 7 pm.

I finished pulling the dashboard out, then removed the guts of the HVAC system.

I'm going to use a half dash cut from a parts car. That car had an engine fire and although most of the interior didn't burn, it's sooty with some small scorch marks and not useable for a 'normal' car. Not sure how to do it on the budget, or that it really matters. In this case, I took a good dash out ($250 value) and put in a dash that was otherwise unusable and would cost money ($10) to drop off at the dump.

While the dashboard is out, I see a lot of extra wiring that I can cut out. Probably not worth the time it takes to do it, but I expect that I will at least clean up all the loose ends. The dashboard bracing will probably all go back in. It's not very heavy and it probably adds a slight degree of stiffness to the car.

The Challenge is [almost] tomorrow and my car is completely torn apart.

This hasn't been a week for a lot of progress  (weeks run from Wednesday thru Tuesday for me). I left the interior a mess and moved on to the radiators and condensers up front. Boxsters have a radiator/condenser/fan unit in front of the front wheels. I pulled both sides out and routed the pluming into the 'frunk' tub. I have a junkyard Toyota radiator in there that fits perfectly between the frame rails. It was easy to re-purpose the original plumbing to reach the radiator, but I still have work to do under the belly of the car where the pipe splits to feed both sides and adapt it to the single radiator. Air will flow in the front of the 'frunk' tub to the radiator and out through the hood. I didn't need to do any of this, but it gets rid of some weight and I have been curious about how it will work out for a long time. Soon I'll know if it works.

I didn't take any good pictures yet, but this diagram should clear up any questions:

So... I was going to work on it in my afternoons this past week and have it on the road by now. Didn't happen. Excuses: Super busy week at work. My usual night shift 4-5 hours of sleep at work, turned into a week of all-nighters (such is the life of a Superhero sometimes). Rather than working on the car in the afternoons, I slept and rested all day, being a little less resilient than I was a decade ago.

To top it all off, our Dachshund had a little run-in with a snake. I awoke to the sound of my wife shouting at Kevin to get back outside. A moment later he was on the bed with me shaking his head and slinging blood everywhere. He was covered in blood. There was a trail and splatter from the porch through the kitchen and up to the bedroom. It was about 10:30 am. I didn't get any more sleep, or work on the car. It was a ratsnake just under 4' long. Now dead, but it had ripped Kevin's ear and for the rest of the day, it started bleeding any time he shook his head or had a chance to scratch.

Today I went to Tulsa for an annual flight physical and while in the city,  stopped at Grand Prix Auto Sports to get my nitrous oxide bottle filled. I start a week off tomorrow. On my first day off, I hope to get around to registering for the Challenge and sorting out most of my budget spreadsheet. I'm going to be tired and should probably stay away from major work on the car. Thursday & Friday I hope to get it back together and running again, then clean up some of the mess and drive it on the weekend. Lots of stuff I still want to do to the car and I'm not sure I have the time to do it all. Whatever happens, I'm going to have fun with it.

Can't say I'm not a little disappointed the v8 swap didn't happen for the Challenge this year, but I understand. And spraying the 2.5 till it pops is just about as cool. Looking forward to seeing how you do at the Challenge.

Hope the pup heals up quickly. I know how much time goes into taking care of an injured dog.

I’m looking forward to this challenge entry a lot.  I’d love to try my own Boxster challenge car if I can find one priced right.

Best of luck, will be following close

Love the updates, however little they are. 

I'm just picking up my kid every day in the S.  1000% convinced my HG is done.  It works fine for the drive, but I'm not at a point I can put the money into a new JY swap just yet. (from another S). and JY's want insane money for the 3.4 or 3.6...

My only request, and i say this as someone using the other lane because i have drag tires, is if you do plan to spray till it blows please wait till about 10 minutes left in the drag session so you don’t shut down the track

Patrick said:

My only request, and i say this as someone using the other lane because i have drag tires, is if you do plan to spray till it blows please wait till about 10 minutes left in the drag session so you don’t shut down the track

there you go, sharing my brain again.  that's what i said about 2 weeks ago.  ;-)

We're gonna need a meeting to determine the "nuke-it" run order at the end of the night.

maschinenbau said:

We're gonna need a meeting to determine the "nuke-it" run order at the end of the night.

You probably should put someone in charge to check with the guys with "fast" cars to make sure they are satisfied with their results. I still feel bad for making a mess on track at last call when Ed, was trying to get up for one last pass, if I would have known I would have waited. 

And by the way super jelly of the Challenge Boxster.