mark kibort

I'm dragging the car up to Thunderhill for the last race of the year. should be a nice weekend with temps in the mid 80s.
this will be my first time there on new tires, so it will be interesting to see the improvement on the lap times vs the dumpster tires I've used over the past 17years!

also added a couple of more vents to the nose to help with any possible overheating, as i had last year on that hot day with the air in the system. (same temp forecasted as last years race day )

IcemanG17

it will be interesting to see your lap times vs previous best

dr bob

Mark -- Front undertray in place?

SwayBar

During the off season, since you're having heat problems, perhaps you can install an external engine oil cooler. That will take a big load off/out of your radiator.

Besides that, it's good preventative maintenance with no downside.

mark kibort

yes, thats the difference between last seasons grand finale race and this weekend. (also make sure the system was burped ) temps are in the low 90s at race time. same temp as last year when it overheated due to the air in the system and subsequent boil out.

Car ran fantastic. below the middle the entire race, qual, and practice.
the weather was hot, and the race was a heated battle with some 600+ cars, but was hanging in there so there was no relaxing. engine oil was 260+, but the water never went above below, the middle. NEVER. always pointed down. you can see the primary S4 fan cycle on during the race. the 2nd fan never had to be used (manual). in otherwords, ran VERY cool.

same lap times as my previous best a few years ago . 1:58s (with hill) I ran my new tires in race, and my 8 heat cycle tires in practice and qualifying. 1:58s in qual.. the race had someone dump a lot of fluid on the crest of turn 9, so altering that line was a little slower through that section all race.
ill have video up shortly. Keep in mind, when i got some 5-6 heat cycle A6s from Darrel anderson, they were quite good. my 8 heat cycle tires vs the new ones were almost as fast. a little loose on the power on corners, where the new ones didnt step out at all. (mainly the rears were a little more slick)

there was no issues with temp this weekend . thought there might be a problem since i had that issue last year,and the laguna 110F weekend. BUT, i guess i just found the limit of the system. its possible the vents would help laguna, as the original vent design helped one 110F day at thunderhill, but the average speed is faster at thunderhill with much longer high speed straights (130mph+, 3 times a lap)
the cooler is on the agenda though over the winter.. certainly would make sense.

I think 110F was just over the limit for the speeds and power used at laguna. its the only time ive had a problem with outside temps with out causing a problem before hand with not bleeding system before the race warmup routine.

mark kibort

I have a pretty big "click" (movement) in the driverside tie rod ball joint. (tie rod end)
i think i replace it a while ago, maybe the holbert car. anyway, if i remember, you just bang it out with a picklefork and unscrew at the rack? count the threads (mark them) and you might get the alignment close, right?
the rubber boot , and plastic stuff seems to be coming out of it. definitely toast. i drove the last race wondering about it. on the early cars, is this the part that is aluminum??

mark kibort

Mid race pic. Holding close to the 650hp beasts.

Otto Mechanic

Mark; Thanks for all your efforts keeping the 928 in the limelight, best of luck at Thunderhill, I'd love to see your car up close someday when you're closer to the tracks I'm close to (Laguna Seca, Buttonwillow), I'll be there to root for you. Racing a 928 is challenging and I hope rewarding, I've only done a few DE events with mine and sort of wimped out and bought a 944 S2 as my track platform. It's easier since there's been so much more aftermarket support for the 944 and I ended up taking the low road, but someday I still dream about converting my '85 928S3 parts car to a race car. I've recently discovered Ken's chips for mine so I may get back in the game after I'm done with the 944.

Meantime, know we're on the sidelines and in the pits rooting for you guys!

Rob Edwards

Three 130+ mph straights per lap and you have a failing tie rod end that you know about but didn't fix? Has SCCA stopped doing any sort of safety checks, or are they no longer concerned about liability?


Are you insane, or just trolling us?

dr bob

Mark --

There's a cute little press tool that pops tie rods and balljoints handily. Better than a pickle fork as nothing gets bent or abraded (steering arm) as with that pickle fork.

Remember that there is an inner tie rod and a tie rod end on each side. Since you'll be in there and will need an alignment when you are done, good idea to replace them all now. Having the tie rod out means those torn/leaky rack boots can be renewed too, and you can find the source of the wear fragments you mention. Do All Of Them At The Same Time, and be sure to record the work and the alignment settings in your maintenance logbook. I just can't imagine that you don't know if/when the tie rods were last replaced. Logbook replaces memory cells for this stuff, freeing up those cells for important things.

My too sense...

mark kibort

Bob, its the end ball joint. the tie rod end. the other one is solid. no , I don't usually align the car after messing with racks . I can check and make sure nothing moved as far as toe very easily and adjust the toe to make sure its 1/16th inch, toed in.

where is this little "cute" press you talk about? I don't like bending steering components by wheeling a hammer!

as far as records. we replaced the rack when the chassis was built up after the Holbert car. I know I replaced one before, but YES, I do have the record of it. ill look. it doesn't really matter, if its bad, It needs to come out. the other side is very solid and looks good. the bad one clearly is blowing out the internal bushing.... but the steel structure looks intact. the boots look brand new and there are no leaks or oil marks.

thanks for the note!

Mk

mark kibort

Race car's wear. you do this long enough and you understand what is urgent and what needs to be kept an eye on. everything wears. the trick is knowing when to replace. I watch everything. small hairline cracks in the rotors, suspension looseness, etc. remember the steering rack bushings? eventually, when it gets bad, I replace. the tie rod I just noticed when I was moving the wheel around. felt like a wheel bearing, but it was the tie rod end. the bushing was compressed in the joint and had a few people look and give assessment. all said for one race it would be ok. so I ran it. (plus it was on the less loaded side for the track). SCCA gives an annual tech, and then YOU are responsible during the year to make sure everything is safe. they don't check things like suspension slop............no sanctioning body does more than a wiggle on a loaded tire . mostly they check for leaks and other obvious safety issues as well as cage compliance and expiration dates of equip.

Thanks for the support!! yes, its a fantastic car, for many reasons! but the main one is the group here and how unique it is. one thing that is nice, is that I can go to a race like this, and not even use a wrench on it all weekend. (cept for wheel changes and adding oil) such a great car!!!! watch the video , and see how funny it is to see something so old running against and be so competitive to cars 10x its value!

mark kibort

Here is the Race video. 1st place in a pretty small field. but still a good time chasing the Racing Ambition 600+ hp NSX and Joe Montana Nascar.
at the end, there is a quick clip of hitting the rev limiter down into turn 2. never had that happen before. (thanks to some new tires and some faster exit speeds of turn 1)

No overheating, but some curious AFR readings . if you look down the main straight, the gauge normally would be pegged at the blue light. instead it hunts a little and I don't know why. seems to be running fantastic.

the vibration I was feeling at 120 plus , it think was caused by the loose ball joint on the tie rod end. getting that ordered ASAP! (easy fix)


rear cam view on the 1st lap of the race

mark kibort

Here are some pics of the weekend at Thunderhill
Great weather (a little warm) Pics also of the Tie rod end. you can see its still in the casing, as I removed the busted up rubber seal. it was moving inside the ball socket. probably the cause of some nasty vibration I had at 120+mph . the steering rack side joint looked and felt fine along with the rubber boots (which were new when the car was re-tubbed)
Also shown is the passenger side which seems nice and solid with no signs of problems

mark kibort

Bob,
you made me scour my record book for the Tie rod installation, and i thought you should know, i found it. I dont think you fully understand my racing effort, but yes, i have docuumented everythign ive done to the car, anything ive seen or measured on the car during a race weekend, over 20 years in a big notebook. finding one thing out of 1000s of notes can take time and i dont remember everything as maybe, you might. I even have engiine build notes showing the exact time and procedures.

anyway, the tie rod assembly that i do remember replacing was on the holbert car and was due to the inner ball joint being loose. it was replace don the driver side in 2007 and a manual alignment was done. (level on F/R of rim, marks on ground, trig technique).

as far as knocking the tie rod end ball joiint apart with a pickle fork, you think that steering knuckel can be bent by a few wacks ? I know the ball joiint and seal might be damaged, but that is junk now anyway and is what is being replaced. if you have a picture of this "little tool" or know where i can find it, that would help.
thanks.

Mark