Q&A Porsche discussion

[lakatu]

Originally Posted by st-anger I think you are giving me too much credit here st-anger ....no i don´t, definitely not, i think we all know - at least I KNOW - that ur general knowledge on Porsche is up to mine

Sorry to tell you this but I'm just a good bluffer. Your the real deal.

Glad to see you back safe and sound and I hope you had a great time.

Edit: I just learned that there was an X51 option on the 997S. Had no idea...see what I mean.

[nthfinity]

o someone telling he has a GT3RS imported in the US and driving it on public roads = bullshit ?

i am fairly sure that Ruf imported the 'gt3 rs' but not in name... slight interior modifications likely add some weight... but they called it the RGT. its more complicated then that; but this is the closest you'll see to a GT3 RS in the us.
http://www.rufautocentre.com/newcars/RUF_RGT.asp

also, there are a few MKII gt3's around the US that have every GT3 RS option installed visually, except one... the porsche crest is still a badge.

hope that helps

good to hear from you lakatu, and st-anger

i really havent read much on the CTR, do you happen to know if the 4 valve heads were from the 959, or the 956? both obviously have huge potential, with the 959 heads having greater reliability with 2 heads vs. 6 individual heads.

[Wutputt]

Originally Posted by lakatu First I went and reviewed the discussion in the WYST and most of it is correct as I understand it but let me add a little detail. Was there a regular CTR and a Yellowbird version? And if so, what's the difference. Well the term Yellowbird was given at the infamous R&T test by Paul Frere and the name just kind of stuck. The term is used in two ways, which makes it kind of confusing. First it refers to the original Ruf that Alois brought to the R&T test. That car is a one of a kind and is still occasionally brought out to show. The second way it is used is to refer to the G-series bodied CTR. I guess if you were to ask Alois he might say that the original is the Yellowbird and all others are CTR's. Both the Yellowbird and the CTR are twin-turbo and they used the 4 valve heads used in Porsche's racing versions of the 911. I have heard that the production models of the CTR were different than the Yellowbird but I couldn't tell you exactly how that is. I have also heard differing accounts as to the extent of the lighting of the Yellowbird. Some reports say the bonnet and doors were made of aluminum and that the interior was stripped out. Others have indicated that the quarter panels were also made of aluminum and that the fit and finish on these panels was not very good…and so when production CTR’s were made they didn’t have aluminum quarter panels. How many of these cars were built? Sorry but I just don't have the time to research that but I had read it somewhere and 20 full CTR's sounds about right. Surprisingly to me since the Yellowbird has received so much attention. Some CTR's have air ducts on the rear 'shoulders'. What's the reason behind this, and why don't all CTR's have this feature? These ducts are referred to as NACA ducts. The original Yellowbird had them to increase cooling to the oil and intercoolers. However, they actually didn't work. ops: It was later discovered that the air from inside the engine bay actually was forced out through those ducts and so they didn't feed any air into the engine compartment. Therefore, customer models where created without the ducts. Instead on the customers CTR the angle of the intercoolers was changed and the slots in the rear bumper were added. I believe that the air flows in through the rear spoiler vents to the new angled intercoolers and out the rear bumper slots. If you have a copy of the old R&T test you will notice that the Yellowbird doesn't have all those slots but has a few slots under the license plate. IMO the CTR looks better without the NACA ducts. The same is true for the 996 Ruf you can order the car with or without rear panel NACA ducts. For me the simpler the look the better, I don’t like ducts, wings ect. If you are interested in more details st-anger posted an excellent article from GT Purely Porsche on the Yellowbird. The title is Absolute Power and can be found at this link http://www.motorworld.net/forum/show...=261025#261025 Also check out this wonderful index that st-anger has spent so much time creating and maintaining. 8) There are a lot of other articles about the CTR there. http://www.motorworld.net/forum/showthread.php?t=16472

Thanks a lot for the reply. That's about the info I needed, I learned some new stuff today And st-anger, that's a wonderful Porsche index you made there!

[st-anger]

^u´re welcome - unfortunately due to lack of time it´s MORE than uncomplete i´m afraid

[yg60m]

Originally Posted by st-anger Originally Posted by yg60m Just a question for st-anger : do you think that the X51 option (engine "tuned" to 381 bhp on the Carrera S ) is worth the buy ?? On several magazines I read that it is too expensive for what it brings the 997S X51 is - when speaking of lap times and pure performance - as fast as a 996TT imho a MUST HAVE for the "S" when u´re a sporty driver, of course also because of the PSE and i think i can tell - ALL X51 engines are running at +/- 400hp and not 381

Thanks for your answer

[lakatu]

Originally Posted by nthfinity i really havent read much on the CTR, do you happen to know if the 4 valve heads were from the 959, or the 956? both obviously have huge potential, with the 959 heads having greater reliability with 2 heads vs. 6 individual heads.

To be honest I don't know the answer to that. To be really honest when I was writing what I said I thought that it didn't have 4 vavles but rather twin plug ignition but the R&T article listed it with 4 valves. I can tell you this for sure the heads were lifted off a Porsche racing model.

St-anger can correct me if I'm wrong but I think that many aftermarket tuners will try and use Porsche's racing parts to improve the perfromance of their tuned cars. So my guess though would be that Ruf pulled them off from the 935 parts bin. I believe that the 935 was 4 value but if I recall they also used water cooled heads so maybe that isn't it either.

The more I think about it the more I think that R&T is incorrect and that it is a SOHC with twin plug ignition. Sorry about the confusion...it is hard to answer questions about cars that where made by a tuner almost 20 year ago.

[nthfinity]

Originally Posted by lakatu Originally Posted by nthfinity i really havent read much on the CTR, do you happen to know if the 4 valve heads were from the 959, or the 956? both obviously have huge potential, with the 959 heads having greater reliability with 2 heads vs. 6 individual heads. To be honest I don't know the answer to that. To be really honest when I was writing what I said I thought that it didn't have 4 vavles but rather twin plug ignition but the R&T article listed it with 4 valves. I can tell you this for sure the heads were lifted off a Porsche racing model. St-anger can correct me if I'm wrong but I think that many aftermarket tuners will try and use Porsche's racing parts to improve the perfromance of their tuned cars. So my guess though would be that Ruf pulled them off from the 935 parts bin. I believe that the 935 was 4 value but if I recall they also used water cooled heads so maybe that isn't it either. The more I think about it the more I think that R&T is incorrect and that it is a SOHC with twin plug ignition. Sorry about the confusion...it is hard to answer questions about cars that where made by a tuner almost 20 year ago.

it would make more sense that the 2 valve 935 heads IMO... they were hugely powerful... 49mm inatke/41.5 mm exhaust, twin plug... same as the 2.8 RSR head, except in gasket design, which is a nieresist head gasket. it was definately air cooled, but oil cooled valve guides on the exhaust side.

again, that was a individual head per cylinder... im pretty sure you're right about tuned porshes running racing equipment.

also, it wouldn't be the first time that a magazine article quated tech incorreclty
edit:
http://www.supercarworld.com/cgi-bin...eneral.cgi?265 says that 25 were built... but it also says that it was a 6 speed... when all 964's were 5 speed, only the 959 had a 6 speed...
i cant seem to find any info on the heads

[Wutputt]

^^^
I was searching for further info as well. But came to the same conclusing: no reliable info about the heads

[lakatu]

Originally Posted by nthfinity http://www.supercarworld.com/cgi-bin...eneral.cgi?265 says that 25 were built... but it also says that it was a 6 speed... when all 964's were 5 speed, only the 959 had a 6 speed... i cant seem to find any info on the heads

Well you are right nthfinity the Yellowbird only had a 5 sp transmission, which was rather amazing at the time as Porsche was only selling a 4 sp transmission with the 911 Turbo. However, the CTR was produced past Porsche’s change to the 964 model. CTR models past then carried a 6 sp transmission. So depending on the year that the CTR was made it could have a 5 sp or a 6 sp transmission. There is an article that compares the 965 to Alois’ personal CTR that I posted and it has the 6 sp transmission. The link is here http://www.motorworld.net/forum/show...=176924#176924 again sorry about the last page but it was the best I could do.

[nthfinity]

Well you are right nthfinity the Yellowbird only had a 5 sp transmission, which was rather amazing at the time as Porsche was only selling a 4 sp transmission with the 911 Turbo. However, the CTR was produced past Porsche’s change to the 964 model. CTR models past then carried a 6 sp transmission. So depending on the year that the CTR was made it could have a 5 sp or a 6 sp transmission.

hmm....
well, im not an expert on porsche transmissions... but i wasnt aware that a 4 speed was all that was available through (most?) of the 964 time period... i ran into a '84 964 Carerra that was running a 5 speed, so i figured that since the 964 series was simply all 5 speeds? i guess not.
i for some reason havent ever looked closely at 964 turbos interiors to notices a 4 speed... definately tall gearing would be nessisary for such immense torque levels for the single turbo design.

nice chatting with you lakatu 8) im learning some definately relevant infos here

[lakatu]

^^^ Not sure but I think that I might have generated some confusion so let me make an attempt to clarify. Almost all Porsche 911's from the beginning have had at least a 5-speed transmission. There are some strange exceptions having to do with a clutchless manual transmission but we'll ignore those.

In 1976 Porsche introduced the 930 or 911 Turbo. Because of the immense torque the gears had to be stronger and the transmission casing would only allow enough space to fit 4 gears. So from 1976-1988 the 911 Turbo had a 4-speed transmission. Even the 934 the racing version of the 930 used a 4 speed transmission. Porsche claimed that due to the immense torque that acceleration times were very similar for the 4 speed vs. a 5 speed on the 930. The problem was the 930 had a lot of turbo lag and the longer gear ratios of a 4-speed transmission meant that the car took longer to come into the boost, which happened at roughly 3,800-4,000 rpm.

Ruf decided that to improve the drivability of their 930 variants that they needed a 5-speed transmission so they introduced a specialty 5-speed transmission in the early 80's around 1981. I think they sold it at the time as a separate part for around $9,000. You also have to remember that a lot of things were going on at Porsche at this time. The 911 had been slated to die and was to be replaced by the 928 and 944 so R&D dollars weren't spent on the 911. They 930 was initially a special homologation car and wasn't intended to be a permanent model and Porsche was struggling financially in part due to the energy crisis.

Well everyone knows that the 911 didn't die and ended up being the model that kept the company alive. The CEO at Porsche was replaced and refocused R&D on the 911 hence the 959 was born. In 1987 Porsche outsourced their transmissions to Borg&Warner and they created a much improved 5 speed for the 1987 911 which btw is referred to as either a G-series because of the body with the front and rear bumpers or it is also referred to as a Carrera or by its engine size 3.2L. I use engine size because the Carrera name was used by Porsche several times before as far back as the 356.

This new Borg&Warner transmission was much stronger and had better defined gates. Anyone that has driven an older 911 prior to 1987 can't tell you what a difference that made. The stronger transmission was able to support the hp and torque of the 911 Turbo or 930, so in 1989 Porsche finally introduced a 5 speed, this was also the last year of the 930/911 Turbo model to be replaced in 1991 by the 911 Turbo/964 Turbo/965 (they all refer to the same car).

The next 911 model was the 964 which was also available starting in 1989 and had the 3.6L engine. A few years later in 1991 the 964 Turbo or some refer to it as the 965 was introduced and again Porsche had a 5 speed on that car. The 993 saw the introduction of the 6-speed transmission for both naturally aspirated and turbocharged engines.

So I hope that clears up the confusion I created. So to recap in 1984 if you bought a 3.2L Carrera it came with Porsche's less than ideal 5 speed :roll: but if you bought the 911 Turbo in 1984 it came with a 4 speed.

[nthfinity]

So I hope that clears up the confusion I created. So to recap in 1984 if you bought a 3.2L Carrera it came with Porsche's less than ideal 5 speed but if you bought the 911 Turbo in 1984 it came with a 4 speed.

naw, not too much confusion just reminding me of stuff i ought to know ... what years of model designation ought to have been near the front of my thoughts regarding porsche ops:

anyway, i was unaware that Alois had a costom 5 speed tranny as a separate part fairly pricy... but it would seem an ideal component for somebody who would track their 930 turbo.

thanks again lakatu

[st-anger]

...nice and enjoyable to follow your conversation guys, appreciate both of your efforts

[lakatu]

anyway, i was unaware that Alois had a costom 5 speed tranny as a separate part fairly pricy... but it would seem an ideal component for somebody who would track their 930 turbo.

Yes it was a definite must have item but those prices are/were 1980 prices when you could by the 930 for $45k so the Ruf transmission was about 20% of the cost of a new 930.

BTW in the end Porsche was right the 1989 930 with the 5-speed transmission had basically the same acceleration times as the previous years 4-speed. Also another side note...the 4 speed transmission was the off the racing division parts so it could handle huge increases in hp. Many 930 owners ended up having their engines modified and were running 400-600 hp and opted to stay with the 4-speed transmission because it was so bulletproof. Imagine a car weighing 2850 lbs or less if stripped and having 500 hp.

[nthfinity]

Many 930 owners ended up having their engines modified and were running 400-600 hp and opted to stay with the 4-speed transmission because it was so bulletproof. Imagine a car weighing 2850 lbs or less if stripped and having 500 hp.

ive read similar accounts... and im not sure if a fully encompasses it... mabey its better to put it this way: the dead pedal is no longer an unmovable foot rest on the left

400-600 is a massive range, and i cannot imagine what the lag would be on the 600 range under single turbo conditions...

i suppose i havent been checking, but for the last 4 months, ive been lacking my monthly reads of GT, and Excellence... often they carry some great articles on some of these wonderful one-off highly tuned machines.