Stressed Engine On the street

[rjwoods77]

I have been looking through a bunch of supercar stuff in my own fasination of doing a car after I graduate like everyone on here has at one time or another. I like the idea of a stresses engine/trans/suspension bolting to the firewall like formula cars have been doing for 50 years. The carerra gt does it as well. My question is what part of the car do you build in a failure mode into so when you stuff the thing into a curb or get hit in the rear that you dont crack the engine/trans case. I know on f1 cars there stuff breaks apart easy(carbon shatter) by how do they keep the trans and/or carbon tub from getting fried in the process of do that have that many spares laying around they dont care? I cant image that they are all just throwaways with how expensive they are and the frequency of coultard driving over people(big joke).

[rjwoods77]

I have been looking through a bunch of supercar stuff in my own fasination of doing a car after I graduate like everyone on here has at one time or another. I like the idea of a stresses engine/trans/suspension bolting to the firewall like formula cars have been doing for 50 years. The carerra gt does it as well. My question is what part of the car do you build in a failure mode into so when you stuff the thing into a curb or get hit in the rear that you dont crack the engine/trans case. I know on f1 cars there stuff breaks apart easy(carbon shatter) by how do they keep the trans and/or carbon tub from getting fried in the process of do that have that many spares laying around they dont care? I cant image that they are all just throwaways with how expensive they are and the frequency of coultard driving over people(big joke).

[Brian Evans]

They use an attenuator for rear impacts that is sacrificial. The bellhousing/oil tank often cracks. All of the suspension is mounted on shear plates that often break. The engine/gearbox should detach from the tub if the impacts get large enough. Those cars are not about how to save stuff, more about how to go fast by spending insane amounts of money...

[js10coastr]

...must stop temptation... must resist... must hold back... stay on topic... stay on-


YOUR MOM IS STRESSED ON THE STREET!!!!

boo-yah!

[rjwoods77]

Dude your such an asshole. How else is she gunna make money? http://fsae.com/groupee_common/emoticons/icon_smile.gif

[Garlic]

Typically the engine is mounted through the valve cover and sump. These parts do often break in a crash (especially the valve cover) but are more easily replaceable than the heads or block.

[KU_Racing]

I know for sure that on an
F1 car, any accident bad enough to separate the engine from the car will result in the engine going into the dumpster. I would suspect that the Carrera GT is the same way. When you are talking about a race car that costs $100 million dollars, a $200,000 engine is not a big deal to replace.

The way that the tub is shielded from damage is by the use of a secondary mount. What i mean is that the engine does not bolt directly to the tub- there is an intermediate piece between them that is designed to fail under certain conditions, preventing damage to the tub.

[Frank "Ruska" Roeske]

Rob,

the CGT engine isn´t full stressed. Yes, it is bolted to the MC. But Suspension Pickup points and the whole pushrod system is located on the Carbonfibre rear frame. This is also bolted to the MC. All loads goes in the subframe not in the engine/transmission as like as a formula car assembly. Also a lot of subsystems are located on the rearframe (Oilcooler, etc).

[kwancho]

http://www.seriouswheels.com/2006/2006-Porsche-Carrera-...utaway-1920x1440.htm (http://www.seriouswheels.com/2006/2006-Porsche-Carrera-GT-Cutaway-1920x1440.htm)

[murpia]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Rob Woods:
My question is what part of the car do you build in a failure mode into so when you stuff the thing into a curb or get hit in the rear that you dont crack the engine/trans case. </div></BLOCKQUOTE>
For curbing I would stress it such that the suspension will fail completely before the engine or transmission is stressed to the yield point (with a safety factor of course). For rear impact you will need some form of attenuator, if I recall correctly the McLaren F1 road supercar mounted the exhausts, silencers and catalyst behind the rear axle line as a crush structure, that way no extra weight needed to be added just smart analysis of tha energy absorption characteristics.
Regards, Ian

[Scrappy]

Wouldnt this be better suited for the off topic forums? Seriously, there have been so many Off Topic posts in Open discussion it has been ridiculous.

[Boston]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Scrappy:
Wouldnt this be better suited for the off topic forums? Seriously, there have been so many Off Topic posts in Open discussion it has been ridiculous. </div></BLOCKQUOTE>

What are you talking about? Rob's recent posts on:

This post
Meth injection on a turbo
Illest CNC maching ever
My 8 piston calipers (for a truck)

have everything to do with FSAE

[NetKev92]

I don't recall exact figures, but I think the Ferrari F1 budget for a year is $174M and Toyota spends $134M.

I'd make a wag that the cars are about $1M each. The engine might be a decent bargain to just throw out at $250k. They were throwing out engines every race until the rules changed, requiring them to run an engine for two race weekends. With F1: If in doubt, throw it out.

[KU_Racing]

No offense Kevin, but you might want to rethink your budget info. F1 Magazine does a feature every year were they estimate the budgets of the teams. these are guys in the sport that know the sport, and I would bet that they are pretty close to the actualy figures. The only one i can find right now is 2003, but they estimated the ferrai total budget per year at about ~450 million. Average that over the 10 or so chassis get produced...... thats 45 million each.

That 250 thousand dollar engine doesnt seem so major anymore.....

[drivetrainUW-Platt]

scrappy, go away, all you are doing is posting in every post you dont like, say something worth a damn or find a new forum to bitch in!

[Dr Claw]

45 million each...thats how much each of the 10 chevy SSR's, that GM built, should have sold for then. When you have a 400 million dollar program for any car, and you only build 10 or so vehicles you get 40-45million each..

But F1 teams dont JUST build race cars...they design them, they have buildings that they build them in, they fly their cars places (let alone their suport teams), pay drivers, and test and break stuff.

i cant see an out of the box F1 car costing the team more than 3 million dollars.

[BrendonD]

The cars themselves don't cost upwards of 3 million a piece as Claw said, it's all the R&D behind them, the parts cost next to nothing compared to all the research, testing and engineering that goes on all year round, when they decide to manufacture a part, they can make as many as they want pretty cheaply provided they already have a machine setup to do so. The entire car is a sacrificial piece as far as I am concerned. The drivers are worth so more to the race teams than their entire budget.

As far as stressed engines go, think of guibos in BMW's, I would try and take that approach if I were building a project, and then if I was bold enough to be casting my own shortblocks and transmission housings, make everything rear of the firewall attach to the engine and transmission. That may not be very practical for street use though. The CGT rear CF subframe is a work of art... I'd grab one just to put it in my garage and look at it.

[Mike Flitcraft]

For myself:
I'm really eyeballing the GTM Supercar from Factory Five Racing. Kit car yes, but a beast of one.

Now to get the dragger done, and the truck done first.