ace37

I just picked up a 1997 986.1 Boxster 5 speed. I plan to use it for DE/TT for a year or two while I turn some laps and earn my race license. Over that timeframe I'll develop the car into a PCA Spec Boxster / NASA Spec 986. My current thinking for car development is right now I just get the car and get it trackworthy on street tires. This winter I'll make safety and reliability/cooling improvements, and the following winter I'll do the suspension and whatever is left to complete the SPB build.

My donor car came with an OEM hardtop, an great sounding exhaust system, and an extra set of wheels. It's a well maintained driver level car with 70k miles, so pretty good shape overall with just enough blemishes to keep the price reasonable. In the two days I've had it I've changed the oil and gutted the trunks, inner doors, and about half of the cabin. I need to do more gutting, pull the top, put fresh brake fluid and pads and rotors on the car, and check the other fluids to see what can stay and what goes. I've also got a 997 shifter laying around that I'll throw in the car. This is going to be fun.



But I'm running into an issue. I've essentially spent what I planned to spend on the basic car and upgrades for this initial season. But there's a lot more to do, and the car needs to be reliable and durable. The rules allow for an extra radiator, coolers for the oil, transmission, and power steering, brake cooling ducts, and a deep sump and accusump. That's all good and well, and on the spec tires I expect the bulk of it is necessary or strongly recommended. But while it's being used as a DE car on street tires, I'm thinking the must-have list might be quite a bit shorter. The car came on Hankook Ventus V12 evo2 tires in 205/50-17 and 225/40-17 that I planned to use this year before switching to something like NT-01s, and my local track is Utah Motorsports Campus = Miller Motorsports Park, so high desert at ~4400 ft altitude.

What do I need to get on the car right away, and what do I need to get sooner rather than later? I'll probably only get out for a short ~six DE day season this year. That's not a whole lot of track time, but I want to make sure I don't have to short shift the whole time or end my sessions early because I didn't slap a cooler on the car. (I previously owned a 370Z nismo that couldn't make it 20 minutes until I added an oil cooler.)


Thanks, and I'm excited to join this community!

ace37

Also, while this is certainly no big deal, can the upper dash be removed and replaced with a custom one? Reading the SPB specific rules section leaves me thinking yes as I don't know what would be the difference between the "instrument cluster" and the "instrument pod," but most cars have the full stock upper dash shell in place. Maybe I'm misinterpreting "dashboard instrument pod," maybe there's a general rule saying leave it in there, or perhaps there's just a pretty good reason to leave it in there so everybody does. In any case I think I'm missing something.

968workaholic

#1 rule in any spec class, if it doesn't say you can then you can't, with regards to your dash question. Fresh and quality engine and trans oil, new re-packed wheel bearings and track pads are a must. You won't be driving the car hard enough to need any of the other stuff right now. You are going to hate the soft stock suspension on the track, maybe put the tarett sway bars on at least for now

ace37

I appreciate the input!

I hadn't thought of wheel bearings so I'd better find some. And from a few street drives I must say you're right about the suspension, very soft with a lot more roll than I was thinking. A sway makes a lot of sense.

I just pulled the soft top out of the car. This is fun

mmuller

I would add a deep sump pan. Cheap insurance in my mind the really helps with oil pickup.

Greg Holmberg

None of the extra cooling is necessary. I don't have any of those on my Spec Boxster, except the larger Boxster S oil/water heat exchanger. Which you wouldn't use if you eventually go to an external oil cooler, so maybe just wait for that, if you have oil temp problems.

The accusump is useless, don't bother. Get the deep oil pan and baffle. EBS has a good one.

For the engine, you should replace the IMS bearing, and the rear main seal.

The transmission is a weak point. If you cut out the rear bumper, you can get airflow over the transmission. And/or get a transmission oil cooler. Some people say just change the transmission oil really often and don't bother with the cooler. In any case, don't slam the shifts.

Personally, with the lack of structure in a convertible, I'd put my money first in a rollcage, seat, harness, and removable steering wheel.

Regarding the anti-roll bars, many racers use the stock one on the rear. So just replace the front one. The Bilstein PSS9 struts and 450/500 springs will make the biggest difference in handling. When you get the Toyo RR tires, you will need 3 degrees camber, and then you need the lower control arms. On street tires, not so much.

As someone said, good racing pads (like Pagid Yellow) and new rotors are a good idea. Also, SS brake lines don't cost too much.

Here's a link to a spreadsheet I developed of the build costs for Spec Boxster: SPB Build Costs

ace37

Thanks for the further comments!

The full build can actually be somewhat simpler and cheaper than I was originally expecting. I appreciate the build list as it really helps keep the complete project in mind.

I'm getting a new brake system on order shortly. Pads, rotors, fluid, ducts, and perhaps SS lines since I'm doing everything else. I'll also change the transmission fluid and fab up some door pull straps. Might also get at least a front bar in a few months as I bet the body roll gets annoying to me. (I also have a 997.2 shifter just sitting in a dark corner of the garage that I'll try to swap in - it might improve shift feel and it's free anyway.) Once that's all done I think I'll try it at the first DE and see if that's good enough for a short season!

The deep sump is something I originally wanted right off but I think it will have to wait for next season just to keep the wife on board with the car costs. I'm hoping cheap tires offset for the lack of it. After looking at wheel bearings I think the same story holds - I should be ok for a few DEs on lousy tires, but when I start getting out more and on better rubber I'll have to change them.

Over this winter I have a ~$10k bonus already earmarked for car development. I'll probably try to do an oil and transmission cooler with the IMS/RMS/clutch/flywheel/pulley etc all at the same time. That way I can just pay a shop to pull it all out one time, swap everything, and put it all back in. And the other key is to get basic safety equipment in with a cage, seats, harnesses, etc. And perhaps a decent set of tires so I can see higher limits, NT01s or something like that. That will about exhaust my development budget for next season, and I can add the suspension, data, and complete the build the following year.

This is a great project! I've already got my son helping...

mjj0000

If we are going to turn this thread into a kids in racecars, here is my entry.

mark boschert

Welcome to SPB! So far I am the only one at UMC but have heard Sam Kapp is building one, Otto may do one, etc. At other venues, run groups are 20+ cars.

As to build sheet, you could talk to Tatem Racing who did mine and JR Smith's cars. I would agree that custom cage, good cooling (I have usual extra radiators plus added a tranny cooler this winter plus should change fluid regularly), but disagree about comment on Accusump as it is needed at Miller or any hot fast track.

Another person in our region to talk to is Chris Cervelli in Denver who has built ~ 10 SPB and has a large stable of cars there he supports.

Mine has run flawlessly so far with only breakage being 1 rear axle which I have read can happen at 60-100k miles and likely should be replaced on both sides when you do RMS, tranny, etc to avoid issues. Gearboxes are vulnerable but cheap (3k) and available.

ace37

Over the weekend I pulled out the soft top and more of the carpet. Yesterday I ordered a full brake refresh: pads (Raybestos ST-43), rotors (Cquence slotted), lines (Goodridge), fluid (Endless 650), and the GT3 front ducts. Besides installing those I still need to pull a little more out of the interior, check on the transmission fluid, and I'll throw my leftover 997.2 shifter into the car just to see if it improves shift feel any. It's just sitting in the garage.

I'll probably run it like that at the first event and cross my fingers that I'm not short shifting at the end of each 20 minute session to keep the car happy.

Is a low temp thermostat worth a quick swap? Wondered if, assuming I need more cooling than I have, maybe getting the coolant flowing early would buy me a few minutes of lower temps. Maybe not, I could see that going either way. I'd like to cut out the rear bumper for cooling but I have a plate on the car so I'd have to figure out how/where to mount it.


Like Mark mentioned, Miller requires a lot more cooling than typical between the high peak speeds and the thin desert air making radiators less effective. I might not be able to get off as easy as others - guess we'll see soon enough.

Love it!
Hey Mark! I remember last year one of the NASA announcers was saying how you were out there racing a Spec Boxster alone, come on somebody go build a Boxster and join him! I took their advice, and although mine won't be built right away I'll at least start getting out there. Hopefully in time I'll get myself and the car good enough to keep up with you and give you someone to play with.

The fields are a lot smaller here than I would have hoped, but if Tatum gets their way that may change. I had forgotten about the Colorado guys; I hear they have a decent field of cars running. Good point on reaching out to them.

I was thinking I'd get Tatum involved next year and have them do the big stuff for me. Nice group of guys there. I'll ask them for their opinion on cooling/oiling/wheel bearings/axles to get another data point. Last fall I had signed up for a DE with my 911 GTS (my last event for the year) and the battery gave out overnight without warning. So instead of staying home, I made the mistake of renting a SPB through Tatum - I was hooked! They had it set up on Hoosiers for NASA and that was my first time on DOT slicks, so my grin was about a mile wide... and I started looking for a SPB donor as soon as the winter started to end.

ace37

Two quick questions:
1. Within the rules, what can I do to help water drain out of the cabin? 2-4 well placed ~3/16" drain holes seem like the ticket but I'd like advice as to where, if I need to coat the exposed metal edges, and whether I'll need to worry about being a "cheater."

2. When I pull the top motor and transmissions, the rear clamshell won't be locked into place. Any issues with the rules on making a little sheet metal bracket to bolt it down to something?

968workaholic

Two small holes by the engine bulkhead on the floor will take care of the water, or you can relocate the alarm module under the dash. Leave the linkage intact so that the rear clamshell can still be lifted up by hand, minus the motors. What top are you using, factory or aftermarket?

ace37

Thanks, glad to hear that will work. Any sealant or corrosion protection recommended? I'll probably end up relocating the module as well. The issue was the car was parked outside in the rain, locked with the top on and windows closed, and the passenger floor still had a quarter inch of water in it. Driving it on a short errand I watched it slosh back and forth and realized it had nowhere to go. So in thinking to drill drain holes I was simply not wanting to break out the shop vac whenever we get rain and the car isn't sheltered.

I have an OEM hardtop - happily got it with the car. While I suspect it would keep the clamshell closed I though it would rattle around like crazy. I saw for a lot of the fiberglass tops people were welding in mounting tabs.

I appreciate the feedback!

Bill Lehman

I'm not Spec Box but ran Caymans for years. The deep sump is cheap and DIY project if you have any mechanical skills. Do it.

ace37

So an update!

Drainage:
For water drainage I made two small holes in the aft floor where the 20 year old water/goo residue was the thickest. Since then the car has been in rain a few times but hasn't had any standing water in the floor. (Before this a light rainfall left water on the floor.) I sprayed the holes with a bit of black epoxy and then CorrosionX to make sure I don't end up with rust. Success

Rear Clamshell:
Now that I've pulled the rest of the top parts, the rear clam seems like it's not going anywhere. I'm going to leave it alone and assume it's good to go for the time being. If anything is funny I'll just fab a small custom bracket and strap it in place. It's easy to open right now though so I'd like to keep it easy to open and close.

Factory Dashboard:
I found an old set of rules for the BSR class circa 2012-13 that shed a bit more light on my dashboard question. The last sentence is no longer in the rules.
Based on that, I think the interpretation that best represents the intent of the rules is "Factory dashboard and instrument pod must remain intact." I'll plan to make some aluminum straps and brackets to get the dash cover back on securely after removing the heavy metal brackets and such that the HVAC system and other under-dash accessories are mounted to.

Alarm and Door Locks Connected:
For the next month or two I'm planning to park the Boxster outside. For this reason, it stays locked and the windows are staying in. Pro tip: If you remove the alarm system components, the passenger door may no longer be lockable using the power locks. I tried the backup 'turn the key three times to lock everything' trick but the car just pauses and honks twice telling me it knows better and won't lock up.

Ah well - I'm in a nice quiet neigborhood and there's nothing to steal aside from the car itself. I ended up getting full coverage on the car as the cost was very low, so I won't be left high and dry if the worst were to happen. But to further deter any theft concerns, I'm looking into picking up a quick release.

Cooling and Reliability:
I'd like to do a deep sump and the install looks to be pretty easy but I'd want the 2QT kit from LN or mantis and would be looking at just under $1k for the parts. I'm thinking to just wait until next year. I can stay on street tires, cross my fingers on reliability issues, and focus on learning the platform. The other thing is I'm pretty interested in the dry sump that Chris Cervelli is working on - I'm hoping he'll have a kit available in a year or so. If that works out and eventually makes it into the rules I could skip the deep sump and accusump.

I did pick up a lightly used Boxster S radiator and shroud from eBay but I need the supporting plumbing and mounting hardware before I can install it. I saw how cheap good used ones are on eBay and I'll eventually need it so I clicked Buy It Now without thinking any further about it. They shipped fast and now it's sitting in the garage. I've got a suspicion the radiator may be necessary to run a 20 minute DE session up here; we'll see. If temperatures are ok as is I'll do it in the fall with everything else and if not I'll order the other pieces and put it in.

Suspension:
On the stock suspension, yeah, it's way soft. I think you're right on that a front sway to would be a low cost way to make DEs more fun - good suggestion. I just need to stop buying other stuff first. I'm getting too into progress and the problem of the day instead of seeing the car as a system. It will work out either way but you're right, that might make the DE part of the journey more enjoyable.