Greg Holmberg

Over on apexspeed.com I've been conducting a survey of operational costs for each racing class.

Here I'm only looking at the predictable costs that vary between the classes.

Some costs are more or less the same between classes, such as towing, hotel, food, entry fee, and so on. I am ignoring those costs.

Some costs are personal choice, and not inherent in the class, such as how much you choose to spend on your tow vehicle or RV, or paying people to support you. I am ignoring those too.

Some costs, while having some correlation to the class, are unpredictable and so difficult to quantify, such as crash repairs or engine failures. I am ignoring those too.

That leaves me with:

• tires
• engine rebuild (by a professional)
• fuel
• brake pads
• other, depending on the class

"Other" could include, for example, gearbox replacement if your class has a weak gearbox.

I guess there are other smaller but predictable maintenance costs, such as oil changes, brake rotors, brake fluid, etc. If you think Spec Boxster has above or below average expenses in these areas, let me know, and I will include them.

Drivers from many of the classes have responded with data for their class, and the result is:

a spreadsheet in Google docs.

Here's what I have for Spec Boxster. If you have changes, please reply below, and I will update the spreadsheet.
Thanks,

Greg Holmberg

katmeho

From my SPB experience:

Engine replacements vs. rebuild are more expensive and $5000 is not enough for a new one. $7000-$9000 for a competitive engine.

Tire costs listed don't include mount and balance, and few of us do that on our own.

20 heat cycles is fiction, but that seems to be hotly contested, so lets just say 8-16 to give outsiders a fair view.

Normal maintenance should be fluid flushes on a regular cycle. Thats dependent upon personal tolerances, I choose to do oil every 3-4 full days of usage. YMMV. But it might be good to capture an average of costs for engine and transmission oil itself and spread it across your weekend cost.

It might also be interesting to capture the average sanctioning body event costs and maybe even highlight it by region. NorCal races seem cheap compared to what I paid for the COTA event for example...and PCA costs vs. NASA costs? If there is a meaningful difference....

968workaholic

Wheel bearings- $100 each plus installation for the re packed bearings, they last at least a season

audipwr1

Brake Rotors - 150ish - 2 sets a season
Brake fluid 150ish 2 flushes a season
Car setup - every 2nd day of operation - string it yourself or pay 350ish

Bottom line is its pricey - I sent you in the group what it cost me to win the west coast series and podium for nationals - the car needs to be tip top and never have a mechanical failure which means you are constantly replacing things the minute they appear sketchy

MAF - 185 once a year if racing dusty tracks etc etc

hf1

How many hrs shop labor?

mjj0000

I'm curious what items were replaced preemptively and, more importantly, how did you determine that replacement was necessary?

I sometimes can tell something is failing between events through inspection, but mostly I find out at the track.

audipwr1

All this stuff has hours / measurements on it - I am not a wrench expert - had help in that department

Bearing - 20ish
Rotors - any warp trash em
Pads under 50%
Oil 2 weekends
Never had a control arm snap but I started with new and did 40 hours on the car - maybe every 3 seasons?

Unknowns
Trans
shifter cable - though pros replace them on conti caymans like every 10 hours
Gas pedal linkage - they just fail occasionally and annoying

mmuller

I do the inner part of the control arms every year. I had one split in half a few years ago and cost me $10k fixing bodywork as a result. I found Cup teams timed out the same part after 30 hours because they saw the same failure I did. Mine had 40 hours on it. I now do them every year like wheel bearings.

The inner part of the control arm is around $80. Much cheaper than $10k in bodywork.

CTS

I have not seen this particular failure. Do you have any pictures of the failed part?

Thanks,

Chris Cervelli
Cervelli Technical Service

mmuller

I don't, although I did keep the part and with some searching can find it and take a photo. It basically split across it top and bottom in the same place. Was at VIR and just straighening the wheel on the exit of a corner at the bottom of the esses when it broke and sent me backwards into the wall at 105mph.

Interestingly, that same part on a 997 GT3 control arm is forged, but just cast on a 996. Unfortunatly, the 997 part is not legal for SPB

RennPart

Eric from SSF informed me about the inner control arm issues, if you drive 10/10ths its probably smart to replace as mentioned. Thanks for sharing Matt, I had a control arm brake on me twice in my old Spec Race Atom and it wasn't a fun experience, no damage other then my underpants.

CTS

So the cylinder of rubber was left around the bolt and the cast aluminum broke which allowed the control arm to detach from the subframe?

mmuller

Correct, that's exactly what happened. It was a clean, straight break top and bottom.

hf1

This seems ripe for a rule change proposal. A cheap mod, all about safety and nothing to do with performance. Has the door closed for change proposals for next season?

katmeho

How many of these have we actually seen? Is it a systemic issue and do we have data to prove it? If so, then yes, rule change.