2.4L S Engine Case: 5R vs 7R?

[yopurp]

"pg. 136 "The 901.101.102.7R magnesium crankcase with the 92mm cylinder spigots was introduced for use with the 2.4 liter engines in midproduction."

Shawn - make sense. I have the COA from Porsche on my car (yeah, I forked out the $110 - unbelievable. No wonder they are the most profitable car cmpany on the planet - pisses me off in light of their position on racing these days). Anyway, my engine case matches my CoA engine #. My car (and engine) are certified '73S, chassis #1100 (more than mid-year). The Birth date on my car was (no joke) April 1, 1973. So, Beginner- maybe some guy on the assembly line decided to put one in an S-car for fun. If mine is the only S car w/a 7R case, I'd be stoked (doubtful). Consider question asnwered - thanks Shawn (replied to your PM)

[Chuck Miller]

Chris,

So you don't feel alone...

My April #1099, has a 7R mag case..

[ttweed]

Originally posted by beginner
Any 911 fitted with aluminium case will always be tail-nervous, even LWB. 911 is meant to corner well; it's not a drag car.

If you believe this, you really are a "beginner". You do know that the mag cases stopped being used in 1978 with the introduction of the SC and have NEVER come back, don't you? Do you really think that the extra few pounds of an aluminum case will always make a car "tail-nervous" compared to the overwhelmingly greater influence of suspension and setup? It's not ALL about the F/R weight distribution, or Porsche would never have continued with a rear-engined design for so long.

The changes made to the suspension in the later 911s has completely dialed out the inherent oversteer of the early cars.
All you have to do is drive one of the later 911s and feel it push like a pig with the factory setup and you will see that an aluminum case is NOT going to make a car loose automatically, even with a big fat heavy 3.6 and G-50 tranny in the back.

TT
(never even taken my 911 to a drag strip)

[yopurp]

Chuck,

Thanks for not leaving me out there. BTW, last time we emailed, I'm not sure I had my CoA. I was curious. If #1100's birth date is April 1, 1973, then what's #1099's BDay? Are you an April fools too?

PS- Shawn - yup, found the info right my Bruce Anderson book on the pages you marked. I must have not had my coffee when I looked it up.

PS - I'm pretty bummed that I can only now drive my car on a drag strip. ;(

[Shawn]

Chris, your CoA has a born on date (what like the beer). I don't have that on mine.

Dang it , mine gives the (nice folder BTW) vin#, model type, engine#, trans#,paint code, interior material and color.

Then optional equipment: 1 antenna, 1 speaker, chrome wheels, and wood steering wheel.

That's it. Nothing more. No born on date. I guess my car has gone bad.

I guess I will have to toss it out with the trash. Shawn.

[Chuck Miller]

I'm with Shawn, Chris, no birthday date on mine either
... sup-wit-dat?

Some time in April ... dats-about-it

Hey ...I like talkin-like-dis

[yopurp]

Chuck,

Dunno? Mabe das de reason dose german fellas in Atlanta upped da price from $75 to $110. But seriously, mine has a "Birth Date: April 1, 1973" in addition to all the other stuff Shawn mentioned. So, if I had to guess, if your BD is not April 1, it was probably a March baby. Wouldn't it be cool (I'm such a geek) if we got these two cars together again after 30 years if they in fact were one behind the other on the assembly line?

[beginner]

Originally posted by ttweed
All you have to do is drive one of the later 911s and feel it push like a pig with the factory setup and you will see that an aluminum case is NOT going to make a car loose automatically, even with a big fat heavy 3.6 and G-50 tranny in the back.

That's because later 911's have rear wing, which makes a huge difference. Without rear wing, it would be tail-nervous. We are talking about pre-74 911's, i.e. no rear wing....

Without aerodynamic aids, weight distribution is important.

[ttweed]

Originally posted by beginner
That's because later 911's have rear wing, which makes a huge difference. Without rear wing, it would be tail-nervous.

Nope. I am talking about the low-speed push in the new cars, at less than 40 mph, where aero factors do not yet come into play. It is all in the factory setup (suspension and alignment), not F/R weight distribution (which is nearly the same as the early cars) or aero devices.

Without aerodynamic aids, weight distribution is important.

Yes it is, but it is only one factor, and the rear engine Porsche is still going to be pretty dang close to 40/60 front and rear weight distribution whether you have an aluminum OR a mag case.

In changing the handling balance of a car there are so many other factors having an influence, such as rear tire size in relation to the fronts, tire pressures, relative F & R spring rates, ride heights, swaybar sizes and settings, chassis stiffness and alignment, especially camber and toe settings, F&R. Any of these factors can effectively eliminate or overshadow any imbalance caused by an extra 25 lbs. of case weight. You're barking up the wrong tree.

Sorry,
TT