The Technical Questions Thread

[RacingManiac]

At the same token Porsche should really be putting the engine in front of the rear axle...but I don't see them doing that anytime soon neither with the 911...

V8 or flat 8 will just make the rear engine issue worse...

[Commodore GS/E]

At the same token Porsche should really be putting the engine in front of the rear axle...but I don't see them doing that anytime soon neither with the 911...

V8 or flat 8 will just make the rear engine issue worse...

Besides there is nothing wrong with Porsches RR layout, engine weight shouldn't be a problem at all. The Ruf-developed V8 weighs less than Porsche's B6.

[RacingManiac]

RR doesn't gain you anything though.....If a MR and RR shares the same front/rear weight distribution the RR will have the issue of more polar moment of inertia due to the overhanging weight. Porsche is really only gaining an unusable rear seat and legacy layout. The Ruf V8 may weight less, but if the V8 is longer it'll still shift engine's CofG rear ward, and a DOHC V8 is likely going to have a higher CofG than a boxer 6. And on the use of modern aerodynamic the RR layout puts the engine in where a diffuser can occupy....RR seems fine now, but then any car will be with 40 years of development on a single model....

Porsche knows full well themselves, the only real reason why Cayman is not faster than a 911 is because of Porsche's own product placement.....

For a car like 911, the brand baggage ultimately is more important than making something as good as it can be....

[culver]

The rear engine has one other advantage over a mid engine setup. It's easier for Porsche to make an AWD 911 than an AWD Boxster. To make an AWD 911 you add an output shaft to the tail end (the end that faces forward in a 911) of the gear box, add some sort of slipping type clutch/viscous system to act kind of like a center dif, the you have a clean shot up to the front of the car. Compare that with the Boxster were you need to get the drive shaft around the engine.

[Commodore GS/E]

Apart from that, the RR layout has some serious traction advantages. With all the weight in the back, the 911 brings it's power better to the ground than a comparable MR/ FR car. If you combine that with Porsches serious knowledge about the RR setup, you could see why the stick with it. Making the Cayman their new flag ship would cause them to move to a whole new niche which is conquered by marques that have way more experience with the MR layout. The GT3 isn't about the most successful factory race car in the world for nothing. I too would appreciate a more hardcore Cayman, but for myself, i would prefer the 911 because of it's well thought-out concept.

[culver]

The traction advantage of RR also applies to mid engine cars. It's a factor of weight distribution, not so much engine placement though of course engine placement has a big affect on weight distribution.

[RacingManiac]

Apart from that, the RR layout has some serious traction advantages. With all the weight in the back, the 911 brings it's power better to the ground than a comparable MR/ FR car. If you combine that with Porsches serious knowledge about the RR setup, you could see why the stick with it. Making the Cayman their new flag ship would cause them to move to a whole new niche which is conquered by marques that have way more experience with the MR layout. The GT3 isn't about the most successful factory race car in the world for nothing. I too would appreciate a more hardcore Cayman, but for myself, i would prefer the 911 because of it's well thought-out concept.

Hence what I said in the beginning, if they share the same weight distribution between the MR/RR layout, the traction advantage of the RR is nullified. Like Culver said, the traction thing is affected by weight distribution on the axle....

Will be interesting to see if 911's weight distribution has steadily moved more forward over the years though....

[Ferrer]

Will be interesting to see if 911's weight distribution has steadily moved more forward over the years though....

I'm sure it has, maybe not by a spectacular amount, but they must have worked in that direction.

Nonwithstading four wheel drive 911s.

[Commodore GS/E]

Yep... me again I have a little problem. If you remember, i said that i wanted to restore our '57 Jawa 350. It's a beautyful bike (at least from what the fotos tell) which my father bought in 1970. It was also the bike he drove when he first met my mother (and also his only motorized vehicle for many years). In conclusion: many good memories are connected to it.
However, I've done a lot of talking with my father to find out more about the drivingcharacteristics, the gas mileage, the ride etc. He told me that the Jawa has a significant problem: if you drive with a constantly high speed (high does in this case mean about 70 mph), it could happen that the inefficient cooling system (two cylinders in one block cause a lot of heat for air cooling) would cause the pistons and the engine block to overheat which could lead to a piston seizure. My question: could i do something to improve the cooling (like shortening the front fender to improve the air flow to the cooling fins) or am i doomed to drive slowly?

[johnnynumfiv]

Could you install an oil cooling system and perhaps an external oil tank to aid in cooling? Oil is really the only way porsches stay cool, so why couldn't it work with the bike.

[pimento]

This is a guide to adding an oil cooler someone did for a Honda CT90, if you could find a way to do that to the Jawa you should be set.

[Commodore GS/E]

Thank you very much. I hope this works

[mike.brown]

Recently Honda has called its Civic model cars for some Software upgrade to prevent the batteries from burning out fast. how is software related to these batteries? how can they consume batteries and how can they be fixed by just a software update?
I am not able to understand any thing.

[Sledgehammer]

Recently Honda has called its Civic model cars for some Software upgrade to prevent the batteries from burning out fast. how is software related to these batteries? how can they consume batteries and how can they be fixed by just a software update?
I am not able to understand any thing.

Basicaly their are four reasons a battery dies
- left electronics running for a long period of time
- battery fails to charge
- electrical drain from or to the alternator, or a short
- old battery that will nolonger hold a charge

new software will only touch the first. By changing how long electronics are on after shutdown will extend battery life, or reducing power to computer systems could also reduce the electrical load. Also the sleep time of different modules may keep them from powering down when the car is off.

Hope this answers your question.

[Commodore GS/E]

Two things. First, i have baaaaad news . I've excessivly discussed the whole Jawa restauration thing with my father (who is the original owner) and unfortunately, he suddenly decided that he doesn't want me to resore it. Which means it will stand in the shed for another 10+ years. Still, thank you for your suggestions. Maybe i will be able to finally finish the project some day.

Secondly, I've heard very interesting news from the N/A front. It's said that Porsche will possibly bring the Über-GT3 with the end ofg the 997 Generation. This car is said to be powered by a monster 4.0 flat 6 developing 500 (!!!) hp. 500. Out of an N/A 6.
Even if it's just a rumor, it got me thinking. Could this be the most powerful N/A six ever? I would be very happy if anybody could find an answer.