GUMBALL

and why you seem to need so much wheel in the corners ??

I have always used aluminum bushings/mounts in a race car.

mark kibort

I think you might be right here! im now excited to change it out. i never really thought much about it and just assumed it was normal. ill be pretty stoked if this reduces the steering input needed!! placing the order today for the nylon bushings!
thanks

mark kibort

ha ha ha. i know.... it like the show "LOST". but it changes when i go to Laguna.
thanks!

Thats the interesting thing about race cars.........where to most draw the line about what is really the same race car, or what is just a relative? many of the historic race cars have been re-tubb'ed. then, throughout their lives,engines area rebuilt, transmissions are changed out, heads are exchanged, ecu's swapped.... in the end, i wonder how many original parts ever are on the claimed " historic " race cars... a body panel here and there?

Good to be back Jim.. thanks!
As far as the holbet car, yes, the chassis was changed......earlier, we changed the short block. before that , the cams and transmission (but still can fix the trans and put back) broke and were replaced.... alternator updated after failure, water pumps changed....... But, the heads, all the brains, (ECU) , the intake, all hoses, fluid mounts to the engine, MAF, rear suspension (spindles, cross members etc) are all from the original holbert car. some in racing would still call it the original, but i tend to lean to the "X-Holbert" classification.

as far as "same car being raced".... depending on the above and your definition of "same car". Ive been racing since 1998. (about 20 years) all with the 928, rarely missing a season race weekend. sure, chassis. my 84, the holbert and the re-tub. But that was 3 years, 8 years, and another 8 years for the current racer!

Thanks Bob! that doesnt sound good for the delrin.. i seemed to remember replacing the bushings many years ago ..... where do you get the aluminum? can you give me a refresher on replacement. alll ive seen (tough to find any thing on my searches) is that you need to drop the rock.. but if the bushings are totally blown out, like mine are (no seemingly visible attachment) will they come out without the rack removed? just remove that plate and pull them out... putting the new ones in, from the Pirtle site, just looks like you bang them in with a block of wood. thoughts?

Daniel5691

Welcome home !
There are leftovers in the 'fridge !

Chris Lockhart

Not sure if Roger at 928'sRus carries the aluminum steering rack bushings, but 928 Motorsports does if Roger doesn't.

rjtw

Great to see you back, Mark, and love those new videos!

mark kibort

hahaha!! thats funny . STILL my kids talk about the 928 with all the laser beams and the verbiage..... so funny..... thanks!

thanks! still fun making them.. cant get enough of that car and its sounds!

Thanks...im doing research now. as always, i want a simple solution, but want to make sure i do it somewhat right!

James Bailey

By your logic then there are now two cars....the wrecked chassis 1986 moded to look like an S-4 and the replacement car.
If your current car was to get stolen and recovered by the CHP...If you showed up with the title for the original 1986 you would never get the car or the engine back ......all the wrong serial numbers !! And yes converted street cars all should have titles....
And are you really running 30 year old original hoses ??? That makes you a risk to yourself and others.

dr bob

Mark--

Choices are aluminum (recommended) or Delrin. Delrin is almost as slippery as Teflon but has much better cold-flow capability. There's a small amount of isolation/dampening in them. The aluminum... none. Aluminum is a much better choice for your application. Cost difference is none. Get the right ones.

dr bob

I think that transferring the rear suspension from the Holbert car does not make the replacement car 'the Holbert Car" or even the "X-Holbert car". That designation belongs with the Holbert car. The one you are driving now is the Kibort car, and sort of inherits your race history.

The aluminum bushings: Come from Roger or Carl. Mark & Tom may have them but I can't guarantee. Phone call??

To change them, the rack needs to be unbolted out of the cavity in the crossmember. Untie the electrical harness from the hoses so you can move the rack down. the original bushings are metal with rubber sandwiched between. You'll be able to push the rotted rubber out with the inner sleeve. Then the outer sleeve needs to be twisted, chiseled, distorted and extracted. I use a small chisel to roll the mushroomed ends of the outer sleeve, then continue so it collapses slightly in the hole. Once it's collapsed, you can grab it with good pliers to twist it smaller then pull it out. The new bushings are a zero-interference fit in the rack ears. Push the rack back up so the bolts are through the bushings and the ears, then the bottom plate, then the nuts and the bolt.

Look carefully at the power steering hoses. If you truly have Holbert hoses in there from 30 years ago, replace them (and the banjo washers) now. A leak there equals a fire when they spray on hot headers. A leak there also makes the track incredibly slippery. The old hoses can usually be rebuilt at a hydraulic hose shop like Pirtek. Just make sure the fittings are clocked correctly. Add some heat sheathing down by the headers WYAIT.

Charley B

Installation will be a snap, Mark. You'll knock it out in 20 minutes. One of the few jobs I have done on a 928 that didn't include anti-social behavior.

mark kibort

Thanks Charley.... sounds good and very encouraging. Ive lost a lot of motivation for jobs like this.. however, looking forward to the possibility of doing the intake project.

Ill keep this note to assist me! thanks! as far as the hoses... i think i mentioned that the engine hose mounts, not the actual hoses.. the steering rack was replaced when it blew out back in 2005. all new washers and hoses. just replaced one line, that blew at willow springs. covered my entire engine bay with fluid . not fun and almost ruined the race. (the race at Willow springs when my help put the one rear 13" tire up front and the 12" tire in the rear. . then, the steering hose blew and i had no power steering. limped along to finish the race.

good points.... ill see if i can get them.. as long as they are easy to mount as well. you dont think a little damping might be good for the rack longevity? (leaning toward the delrin?)

good points...... but there are historic cars that have been retub'ed. maybe when the old tub is totally junked the legend can live on? since mine is still in circulation, i call mine the "X-Holbert" car.. but, maybe the "Holbert replacement car", might be more appropriate.

Now, no, you know as welll as i do , hoses dont last that long, so all rubber hoses were replaced, and a few times in between. ( i had that one expode at the SCCA Runoffs at laguna when i pulled in from qualifying . opened the hood and it was like an M80 water bomb went off. i was referring to the customized engine hose inlets to the engine. ( intake, water and oil, hose mounts, not actual hoses) but all the breather lines are 30years old, as well as the maf and maf adapter

dr bob

Mark --

The aluminum mounts are as easy to install as the Delrin. And, interesting as any "damping" from the Delrin might be, the aluminum will do a better job for you. The bushings are sandwiched between the rack and the crossmember, rack and the bottom plate, to keep the rack located vertically. The early "fix" for the originals in race cars was to put a few flat washers in there with the rubber parts, so the rack would be clamped tight vertically. Thanks to the hard angles that the tie rods see in cars like yours that are way below spec ride height, the small changes in the rack's vertical position translate into toe change and less precise steering. Think of the aluminum bushings as a step up from stacks of washers, as the aluminum bushings do a much better job of locating the rack laterally too. The bolts fit snug in either bushing. And again, the Delrin has some cold-flow characteristics under higher pressures, something the aluminum doesn't. Go With The Aluminum. They are made specifically for your application.

mark kibort

those are some great points Bob, thanks!
i do remember putting this "cone" washer in for a temporary fix, just on one of the blown out bushings about 10 years ago.. what a difference that was, and t was only 1 of them! i was just concerned with the shock load being applied directly to the old steering rack. I was always thinking the rubber made it a little easier on the rack itself.

thanks again for the help and the installation tips! got 2 weeks to get'er done.

Mark

9two8

Fantastic Mark, many thank's for posting a great video of the race, awesome !!!!



Ken
80 928 S
5 Speed

UK