A Porsche 928 competes at Pike's Peak in 2007
#138
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Carl, The car looks great. You've put a lot of work into that car and it shows, I wish you the best of
luck at the Hillclimb. You'll have to take some "after" photos of the dust and dirt all over that clean
engine bay and undercarriage.
luck at the Hillclimb. You'll have to take some "after" photos of the dust and dirt all over that clean
engine bay and undercarriage.
#140
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I'm not that much of a polisher. Its built for racing. I always thought a race car looked better after battle than before... I'll have it all clean and pretty for you before our "928s Run Road America" event on Labor Day at Elkhart Lake. We are sponsoring that one - you be sure to make it!
Last edited by Carl Fausett; 07-05-2007 at 01:20 AM.
#141
Three Wheelin'
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Originally Posted by ibkevin
Any news on when the Denver group will be driving down for the race?
#144
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Originally Posted by Carl Fausett
They perform 2 aerodynamic functions: a) they depressurize the cabin and reduce drag, b) they increase downforce of the rear spoiler making it more effective.
Analogy: Imagine you are holding two buckets in the wind. One bucket is normal, on bucket has big holes in the bottom. You know which one will have more drag.
You may have noticed in your garden-variety 4-door sedan that the noise caused by driving with the driver's window only down is deafening, but if you also crack open a rear window, the noise (and turbulance and drag) is much lower and better. Same thing.
The car, with the windows down for racing - is the bucket. The air curls into the cabin on the 928 just in front of the B pillar, but cannot exit. Its like going down the main straight with the drag parachute extended ( a slight exageration, but an effective visual aid). If we let the air out of the back of the 928, then we reduce drag, and we cool the driver better too as we have improved air exchange in the cabin.
We simply aim the outlet below the spoiler to lower the air pressure beneath the spoiler, therby increasing downforce.
My design - I have not seen it yet anywhere else. I can't be the first to have thought of it - so I 'm sure I'll see it somewhere someday.
Analogy: Imagine you are holding two buckets in the wind. One bucket is normal, on bucket has big holes in the bottom. You know which one will have more drag.
You may have noticed in your garden-variety 4-door sedan that the noise caused by driving with the driver's window only down is deafening, but if you also crack open a rear window, the noise (and turbulance and drag) is much lower and better. Same thing.
The car, with the windows down for racing - is the bucket. The air curls into the cabin on the 928 just in front of the B pillar, but cannot exit. Its like going down the main straight with the drag parachute extended ( a slight exageration, but an effective visual aid). If we let the air out of the back of the 928, then we reduce drag, and we cool the driver better too as we have improved air exchange in the cabin.
We simply aim the outlet below the spoiler to lower the air pressure beneath the spoiler, therby increasing downforce.
My design - I have not seen it yet anywhere else. I can't be the first to have thought of it - so I 'm sure I'll see it somewhere someday.
Michael
#145
Captain Obvious
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Very nice work Carl and crew!
Your explanation of how damaging the crushed granite is sparked an idea in my head. I remember seeing on vast majority of WRC cars, in addition to the conventionally located mud flaps (behind each tire), some sort of a heavy duty mud flap/s running transversely between the front and the rear wheels.
Any plans to install anything like this or is this not really practical for Pike Peak race?
Your explanation of how damaging the crushed granite is sparked an idea in my head. I remember seeing on vast majority of WRC cars, in addition to the conventionally located mud flaps (behind each tire), some sort of a heavy duty mud flap/s running transversely between the front and the rear wheels.
Any plans to install anything like this or is this not really practical for Pike Peak race?
#148
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Thank you for all of the good replies and support everyone. The car is running great and pulls very hard. We have not had time to get the car to the dyno but it is definitly making some good power as the boost is now at 12psi at redline! On top of that this is using the largest pulley we have for the supercharger.
There should hopefully be some pictures up soon as we just put the finishing touches on the interior and the front part of the undertray is on and the second half should be on sometime tomarrow.
On a side note I have something in the works for Carl that will allow him to go even higher then 12psi in the future if he desires and have a consistant A/F ratio all the way through the power band (still using K-Jet).
There should hopefully be some pictures up soon as we just put the finishing touches on the interior and the front part of the undertray is on and the second half should be on sometime tomarrow.
On a side note I have something in the works for Carl that will allow him to go even higher then 12psi in the future if he desires and have a consistant A/F ratio all the way through the power band (still using K-Jet).
#149
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Just came in from Powercom Park ½ mile clay oval. They let me in to practice before Pike’s Peak a tad.
Plenty of power, in fact, in the straights, I could not get more than half my throttle down without throwing a rooster tail. On the next lap, I could see a pair of stripes in the dirt where I had lit them up.
The bad news was they had not groomed the racetrack since the Sunday night races were held. The ruts in the turns were 4 to 5 inches deep in spots – keep in mind I only have 2” of ground clearance!
I wanted some dirt track time to see how these tires bite or drift – but I just had a sense that instead of track time I was really just beating up the car. My first clue was when the rear view mirror came tumbling down off the windshield! I kept going…later, the engine jumped on its mounts enough to tear off the power steering hose from the pump to the reservoir. That’s when I figured I was beating up the car more than I was gaining by practicing here – so we packed it up.
The dirt track boys have soft suspension and about a foot of suspension travel. I am still wearing my 850 pound front springs for tarmac, and do not have that much suspension travel, either. With this setup, I could not get anything going in the corners.
Yet – it was still a good practice. I wanted to know if I could throttle steer these Goodrich KDW tires on loose material, and I can. I wanted to know if they were predictable when they break sideways, and they are. The G-Force meter showed I was pulling .5 G in the corners. With Hoosiers, I have done 1.3 G’s lateral on pavement. Not today!
It was a good test (and probably more severe than most) of the newly-installed 928 International engine belly pan! Worked great!
We leave for Colorado Springs on Saturday afternoon.
Plenty of power, in fact, in the straights, I could not get more than half my throttle down without throwing a rooster tail. On the next lap, I could see a pair of stripes in the dirt where I had lit them up.
The bad news was they had not groomed the racetrack since the Sunday night races were held. The ruts in the turns were 4 to 5 inches deep in spots – keep in mind I only have 2” of ground clearance!
I wanted some dirt track time to see how these tires bite or drift – but I just had a sense that instead of track time I was really just beating up the car. My first clue was when the rear view mirror came tumbling down off the windshield! I kept going…later, the engine jumped on its mounts enough to tear off the power steering hose from the pump to the reservoir. That’s when I figured I was beating up the car more than I was gaining by practicing here – so we packed it up.
The dirt track boys have soft suspension and about a foot of suspension travel. I am still wearing my 850 pound front springs for tarmac, and do not have that much suspension travel, either. With this setup, I could not get anything going in the corners.
Yet – it was still a good practice. I wanted to know if I could throttle steer these Goodrich KDW tires on loose material, and I can. I wanted to know if they were predictable when they break sideways, and they are. The G-Force meter showed I was pulling .5 G in the corners. With Hoosiers, I have done 1.3 G’s lateral on pavement. Not today!
It was a good test (and probably more severe than most) of the newly-installed 928 International engine belly pan! Worked great!
We leave for Colorado Springs on Saturday afternoon.
#150
The Lady's Man
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2" of clearence?? You do know there are some big rocks that get thrown on the course, right?? Best of luck to you. I wish I could be at the Devils playground watching you run. It has been a while since I was lat there. IN fact it was when Robbie unser and arie L. ran for Peugot. Great time. Enjoy the ride.