mark kibort

what the heck is the big bosch box (aluminum, looks like one of the LH computers) right above the dead pedal on the driver side? can it be removed?
it looks pretty serious, like something that keeps the engine running or something

Mk

AO

I believe on the latter cars it's the cruise control and/or seat & Mirror memory control board.

mark kibort

Thats what i was hoping for. so, i can just pull it out? (since i dont have any of the aformentioned luxury items )

mk

Jim bailey - 928 International

Mark get the Porsche 928 number off of it...that makes it easy

Ed Scherer

Are you sure it's not ABS? I think the location you're describing is where the ABS controller is on my '90.

AO

On the '90 the ABS should be located under the driver's seat. But remember Mark, your car is kind of a Frakenstein... who knows where they put stuff on that car. Get the p/n.

AO

Sorry, I'm thinking PSD... nevermind. I think Ed is correct.

Ed Scherer

So, if it is ABS, then I guess you could say that Mark is pulling out all the stops to get his racer lightened...

mark kibort

Ill see if i can get a number. sounds like its an ABS unit,as it sure looks like this picture andrew posted

mk

mark kibort

Here is the picture of it

mark kibort

I just plugged in the numbers for a google search and found something close was ABS, so thats what i bet it is.

thanks. I guess its not going anywhere, as i do leave the ABS on, most of the time.

mk

Jim bailey - 928 International

Ah suddenly the light goes on ...... No wonder you talk of "trail braking" into a corner the ABS is saving your Butt ! Too funny. Basic POC drivers training school day one driving a constant radius on the skid bring up to the limit what happens if you give it gas the rear end oversteers...let of the gas abruptly engine braking it oversteers..touch the brakes and the front end understeers.....add ABS and suddenly you can brake with no loss of control add Porsche Stability Management like a Cayman S and it is almost impossible to spin no matter what you do. I was trying to get the head instructor to pull the ABS relays on the students so they could see who was actually driving their car !!

mark kibort

Not really, I drove for several seasons without it. when the abs goes on, you can feel it. i use it like a saftey net for straight line braking to not flat spot a tire if i go too deep. I have had the relay blow for two races, and the ABS light came on for two others and at that point, it wasnt working. (remember you sold me the original relay after a season or two of racing the holber car, as i thougth i had other issues with it. the relay turned it right on....ThX again for that bit of advice) I can test it pretty easily on the track. (pulling the relay)
i have so little rear brake bias, that i still have the same set of rear pads from 2 seasons ago. and before that, i was using mintex street pads in the rears for 4 seasons prior. they do get warm, so i know they are working, but its all on the fronts.

as a side note about trail braking and getting the car bent out of shape, there was a race or two where i didnt get the idle cut off switch removed. in those cases, a real hot engine, after a slow gear downshift , the engine would die in the middle of a shift, and when the clutch was released, the wheels would be urged to lock a bit, and would toss the car sideways, but that was an extreme case. Ive trail braked other cars, like the BMW M3 the same way. Trail braking, like what is done in turn 2 at laguna, is only to go much deeper than going straight, and start a gentle turn in while still under braking, but not quite as hard at that point. (with a goal to urge rotation in some cases) . by the time . Here is a key point. If done right, you have put the car in a lower gear that is reving down under threashold braking. even if you trail brake, the rear brakes are being driven by the engine and dont have much of an effect.

I have never seen any lockup of the fronts or the rears without abs in this region of the turn. Instictively, i think most would take a little pressure off the brakes as they are shifting the weight of the car. more of a factor is how you toss the car around under braking and even just on the initial turn in. after my mishap at turn 9 at laguna in my old car, there is not one single turn in that i dont expect that rear end to come around when i am pushing hard, abs or not. our abs is so weak, and scan times are so long that when its engaged, it almost feels as though i am driving on snow. what is nice about it, is that the sound warns you to modulate, rather than the sliding feel or smell of a lock up.

Scot is doing the same type of technique with the 82 5 liter, and has never had a rear lock and disturb the car. he is down to a 1:41.4 right now, which is scooting right along.

mk

edit: added some additional points

Jim bailey - 928 International

Mark .." has never had a rear lock and disturb the car. " Why would the rears lock up ? it is the front tires which are being overloaded if braking and turning at the same time. It is the far right pedal which rotates a car either by accident if the engine RPM is too low throttle closed or intentionally with a bit of BWHAA ! Tight slow corners the front tires are working far more than the rears so there is some extra traction that can be used to accelerate ....The act of turning must use some of the stored energy to redirect the mass of the car so anytime you are turning the car is slowing down unless you are on the gas. I often have a student run onto the skid pad at good speed and tell them to NOT TOUCH the brakes just coast out of gear and make a series of quick left right turns just to show them how much the car will slow down. Try to teach them that if they are not HARD on the brakes they need to be on the gas ! Then I make them ride with me and I am on the brake and the gas at the same time with my size 14 , downshifting in corners all the things you do not want them to try just yet... Since I run the same size tire front and rear I have under hard braking going down hill transfered enough weight to the front end that the rear tires would chirp but that is unusual.

mark kibort

I thought you were saying that the rears without abs would lock. what you say is true.

part of the way i got around tiny brakes is doing what you talk about below. i go to the limit of the brakes (and the room i have to slow) and then no matter where i am, i start a turn in, the turn in is a more powerful brake than most people understand. you might have to wait a bit to get to the speed safe enough to start applying the gas, but until that happens, the fronts are taking a beating.

anyway, my use or not use of ABS doesnt effect much. I think the only time you can just stomp on the pedal and and use the ABS for an advantage is with real racing ABS like on a cup car. our 928 abs is 20 years old, and is only good either in the rain or as a safety net (warning device) in racing to stop a flat spot and tell you that you have just exceeded the tires capability to stop effectively so " get off the brakes quickly and try again )

mk