Carl Fausett

here's the tags off my car. This little '78 has had quite a life!

Carl Fausett

Carrera51 - It has a Tremec T56 6-speed in it.

Here's the shift pattern

Carl Fausett

Kibort - I'll bounce your idea off of Ross Bentley. I do see your point.

Imo000

That huge oil tank where the passenger seat used to be should go outside of the cockpit. Imagine if that rips open during a crash. There has to be better spot that isn't much of a compromise than where it is now. Sorry to hear you crash but at least you are OK and the car isn't damaged too bad.

Carl Fausett

Its an air-oil separator and its empty. Not an oil tank. I do agree with you however, and my Accusump (which IS an oil tank) is outside the cockpit for just that reason.

mark kibort

Great... I hope you see it....I'm just trying to help and trust me, if you change that one thing, your lap times and safety will increase immensely.
when ever you are off line, the wheel has to be straight if you are going to do a rapid reduction of speed. there was more than enough grip and time to do so. (you heard the tires squeeling which indicates tons of grip) but , like you said, your instincts might be there to old your hands out even, but if the wheel is pre turning 90 degrees and you lay on the brakes, it will feel like you are on ice skates.... its happened to many others, trust me. but the good news is there is a cure. no shuffle steering. next year when you master that, you will be thanking me!! Btw.. you dont need to bounce this idea off Ross.. He will 100% agree. this is racing fundamental 101. (well, maybe 201)

mark kibort

thats good news... even though there is a lot of damage which sucks. thankfully you hit tires and it wasnt terribly fast. Keep us posted on the rebuild and the removable front section. good idea.

mark kibort

watch this video carefully.... picture yourself in the driver seat... if you can picture you drivng this car with the hand position you use, then you are able to find the limits of your car safely. if not...... then practice practice practice until you get it right. its the easiest way to get faster. hands hand hands!

http://www.facebook.com/HistoricRaci...type=2&theater

Carl Fausett

Mark.... thank you for your input and please stop. I got this.

mark kibort

good... I hope you can focus on this as much as you have on the awesome engine build! I think it will pay huge dividends!
good luck!
Mk

Carl Fausett

So... back to the big questions:

Can a 928 make big horsepower? YES
If a 928 makes big HP, will it survive? If built right, YES
How long can it survive? We've gone 3 race seasons before needing a refresh.
Will it pound the bearings out the bottom? NO
Will it crack the block? NO
Is it amazing to drive? YES

mark kibort

I think if driven slightly differently, I bet the stock transmission can survive as well. Ill be able to prove that when i get a intake.. maybe you can make one for me for my racer to get it to 450 to 500rwhp with intake and a cam.
(pre -revs heal toe, etc)
Your engine is wet sumped, correct? hmmmmm.

Now, let's get that thing dialed in handling wise and really beat the stuffings out of the club racers.... NASA championships ST1, GTS5, etc!

Carl Fausett

Mark Anderson and I have broken drivetrain components, and oddly, we broke them in different places.
He broke 5th/input gear and I never did, and I broke 3rd gear and I dont think he ever did. I think we have both broken LSD spider gears. We have both broken the driveshaft too.

These tend to be fatigue failures, so they are not immediately apparent. That is, don't run one race and then say "see? it survives!" because it won't forever. At my worst - road racing at about 750 WHP/882 BHP, I was braking a G28.13 every 3rd race. That's why the T56 trans swap had to happen for me. Couldn't afford the Porsche parts.

Yes - I am wet-sumped, but with modifications. I do have an Accusump installed, our crank scraper and windage tray, pan-o-vacs to evacuate the crankcase and a dry-sump-type air-oil separator installed with a Tilton pump to put the oil back in the motor. And Total Seal piston rings running on ductile iron cylinder walls to reduce blow-by absolutely as far as possible. We use Brad Penn 20w--50 semi-synthetic race oil. This combination is working very well. Took many years to sort it all down to what works. I literally can go a complete race and have the oil on the dipstick clean and clear and exactly where it was before the race. Almost no consumption at all. This at up to 18 pounds of boost. Rev limiter is set to 6600 although I balanced the engine to run to 7000. Many different tracks, many carousels and off-camber high-speed corners.

So as you can tell... I am quick to say "YES" to wet-sump, wet-sump absolutely can work without bearing failure; but I would never agree that it is stock.

mark kibort

So, its modified with a scraper and an additional pump.
I dont think your experience should discount the stock transmission though. even though you have and had a boat load of HP, it doesnt mean the stock stuff cant survive.. anderson ran his for many years and it was fine. it broke the input shaft, but a lot of people have done that. keep in mind, one bad downshift can cause that failure ( 4th to 3rd, mis rev type, NOT a wrong gear selection). that force can exceed your forces on the 700-800hp engine at WOT.
the fact that you broke 3rd gear and mark never did is interesting, expecially since the gears with the most muliplication will have more significant forces, but 3rd does get used the most. i broke the 5th gear as welll (in the gear box) and the input shaft as i said. ( the '84 box, but on the dyno with a partial ebrake engaged that vibrated enough to cause failure it seemed)
as far as spider gears, that also is a function of tire grip and nothing on the engine side. what ever it takes to be at the edge of grip of rear tires will be the same at any speed you can break the tires loose.. so, how you apply power on each shift, or if you are doing standing starts like a dragster, will effect how long the spider and half shafts last. road racing is much easier on those than drag racing , for obvious reasons. a 300hp autoX car that runs 1-2nd gear will be harder on the CV joints than a 600hp road race car in 3-4th gears .
(i.e. 9-7:1 for 1st and 2nd gear vs 5-3:1) ...... However , nothing wrong with going to the Vet/viper transmission. then , suddenly its alot stronger and can take whatever you can dish out (generally)

As far as proof, i think Fan was wetsumped as well. (albeit with accusump). scots, mine and Brians all were stock oil systems with no real mods, (none on mine) and they worked well.

Your lap times are putting a lot less G forces than we would put on the engine, so i think the stock engine is pretty safe in most cases at those speeds. sure some have seen failures, but there are a lot of factors to those as i have seen. I dont think its the tracks fault, with the exception of open road racing. (as GB and others have noted regarding long duration at 6000rpm can pump all the oil up in to the heads. ) But for road racing I think if you treat the equipment well. ( good shifts, etc), the stock stuff can work for many seasons of full WOT , redline fun!

James Bailey

So there you have it Carl...stuff never breaks unless you abuse it . The Trans swap was not needed. It is all about being the perfect driver, with the perfect setup, with perfect gearing, and an Ego so large that stuffing it into a helmet must be a challenge....
Now Kibort does know something about crashing 928s on track....two down thus far Oh right not really his fault ......imagine that