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So as I am new to the Porsche world I was wondering if Porsche uses the same transmission across more than one car. I would be very interested to know if any other models share the same design final drive. If so what are the ratios. I was thinking since the GT4 one is 3.89 something around the 4.1 range would work great. Any ideas?
The Cayman GT4 has the same ratios and final drive as the S and GTS models. This has come up in a few other threads already, but the opinion of people like GTGears is that increasing the final drive is not desirable because the core problem isn't too-tall gearing across the board, but rather improper spacing between certain gears, which a shorter final drive would do nothing to solve, but it WOULD for example potentially make 1st gear useless. Additionally, GTGears in particular already has gears in various ratios for 3rd through 6th depending on the owner's application, but he can't do replacement rack and pinions (which are prohibitively expensive due to the machinery required to produce them) and he's also seen reliability problems with aftermarket R&P setups, whereas solid gears are solid even in endurance racing settings. I may be slightly off on a few details here and there, but that's the gist of the discussion that's already happened.
Welcome to the Porsche world, I'm new myself -- well I will be come early November.
@manthey trackday at Nurburgring last friday I had a long chat with http://richard-lietz.at/?lang=en Porsche works driver. Among other things we spoke gt4, as he just driven mantheys / Porsches gt4 development car. To me I have no issue on gt4 gearing, its great at nur and I find no accual problems on other tracks eighter. Lietz did agree in that, he found no issu on the gearing around nur. Manthey had a different rear diff on the gt4 and Lietz Said it was way to aggressive, hence advice to put stock in. Then again Porsche will not allow manthey to change rear diff, hence they most likely will keep these parts stock on their gt4. I Asked to drive the Old development gt4 that manthey now have their hands on developing chassi etc on. Close call, but in the end Porsche still owns the car so I was not allowed. Bummer as its on kW 3 ways race suspension and aggressive camber, -3,2 front and -2.5 rear. Would For sure cut a few second of My laptime at nur on that setup on My car.
Porsches old development gt4, any one will tell if look at the rims:-) look close and you spot them pirellis trofeo R, there is a reason For that I guess and thats Why they are on this car, sticky tires:-)
The BMW is way shorter in gears 1-2-3 but also has a (slightly) longer 6th for cruising. In gears 1 and 2 driving around town it's a difference of over 20%! That's a 20% more torque to the wheels if the GT4 were geared similar to the BMW. I don't think it's a question of performance so much as the driving experience, especially here in the US with our speed limits. When I swapped the final drive ratio in my last car to a shorter ratio it totally woke up the car - so much more responsive, you could use the top end without going to jail, and the additional shifting actually made the car more fun and engaging.
Would shorter gearing be slower at some tracks? Probably.
Am I competing for the HPDE world cup? No.
Would it be way more fun? Definitely!
Given that there isn't a cost effective solution for the 1-2 gears since they are on the mainshaft, maybe a combination of 20%-25% shorter final drive and potentially longer 4-5-6 gears would be interesting?
Manthey had a different rear diff on the gt4 and Lietz Said it was way to aggressive, hence advice to put stock in. Then again Porsche will not allow manthey to change rear diff, hence they most likely will keep these parts stock on their gt4.
Did you mean rear limited slip differential, or rear ring and pinion (final drive ratio)? I'd heard rumors Manthey was working on the latter. If so I'd be very interested.
Much like 997 GT3 gearing I know it's decent at faster tracks. On the autocross, back roads and at lower speeds, however, I find the tall ratios a serious issue, and I'd much prefer a shorter R&P like the 997.2 GT3 RS.
My friend has a 987.1 with a 3.8S engine swap and a couple mods. We did some side by side pulls and found his car and my GT4 essentially equally fast, the advantage going to whoever starts at better revs due to the different gearing. At the autocross, however, his shorter 2nd gear is a huge advantage, so much so that a regular 987.2 S accelerates nearly as hard as the GT4 despite having 65 fewer horses. Thus I'd be very interested in a R&P potentially with a taller 6th.
So far Manthey is I believe the best hope. The hypoid gear has proven very difficult for many manufactures to make for some reason.
I always felt that Porsche kept the gearing the way it is cuz it worked well on the 'Ring.
'Ring lap time was a big part of GT4's marketing IMO. No pun intended, the performance settings were geared towards having a very good lap time around the course.
I always felt that Porsche kept the gearing the way it is cuz it worked well on the 'Ring. 'Ring lap time was a big part of GT4's marketing IMO. No pun intended, the performance settings were geared towards having a very good lap time around the course.
Emissions. Again,it's all in the highlights of AP's interview at Rennsport.
Originally Posted by Z356
Today Sunday Sept 27th at around 1:30 PM Andreas Preuninger, head of the GT program at PAG & Porsche Motorsports, gave a talk at the PCA Hospitality Tent at Laguna Seca as part of the Rennsport V event. There were several Rennlisters present (e.g. Zellamsee, Dunlopnick, etc), so I ask others present to add your interpretation of what we all heard at this meeting for the purpose to represent accurately what he actually told us...which I think was significant! Here are the highlights of Andreas Preuninger remarks as I remember it: 1) Natural aspirated engines will continue for all the gt3 & gt4 products into the foreseeable future. 2) There will not be a PDK version of the Cayman GT4 in this generation. The current GT4 is scheduled to continue for the duration of at least the MY2016 model year (so production until late Spring 2016 for sure). Reports to the effect that PDK would be offered soon on the GT4 were posted here on Rennlist and Andreas Preuninger went out of this way to say that he was not quoted correctly when words to that effect were attributed to him. I think he was referring to this thread: https://rennlist.com/forums/gt4/8909...-weissach.html Thus I want to make sure we correctly report what he told us today at the PCA tent! 3) The success of the GT4 in a manual version has helped make the case that there is a market demand for that type of transmission in the GT product line. And he hinted that the next base gt3 might well have a manual transmission as an alternative (option) to PDK. That manual transmission option might come as early as the .2 991 gt3, but that is only speculation on my part. 4) There will NOT be a manual offered on any future version of the gt3 RS. That is considered by Porsche as a track-oriented product whose mission is best served by a PDK transmission. 5) He hinted that there will be a .2 991 GT2 version coming...so there will be a turbo engine soon again in the Porsche gt product line (like it was in the 997 era)! 6) The .2 991 gt3 and gt3 RS will not be as different (or improved, if you preferred that word) from the current versions. The gains in performance will be less that from the .1 997 to the .2 997 because the already great advances made in the current version. Expect more differentiation to come in the interior (design & materials) to separate the gt models from the series production .2 991s. You have heard me say this before. Andreas Preuninger is one of the most eloquent speakers at Porsche today. He commands the subject matter of these discussion and...the audience that listens to his presentations. He inspires confidence in the products that he is affiliated him and I consider him one of the truly bright lights at the company...and one of the best I have ever seen & heard in my many years affiliated with Porsche as a loyal customer. Hopefully I will add and modify as I try to recall more details from Andreas talk this afternoon. But I wanted to start our conversation on this important subject which I think will be of interest to the readers of this forum! Saludos, Eduardo Carmel
IIRC he suggested none beyond planned forecast ie no increase in total global numbers (my interpretation) as vendors and parts are bottleneck. I suppose if they had already planned to dole out a few more as yet unassigned allocations from the start these would go ahead. But my recollection is that PAG planned around 2000 worldwide. And I suspect that that's it. AP said of current strong demand that they would love to build more cars, but they temper that with production realities and wishing to keep the GT cars somewhat more exclusive (ie. not 10000 cars built). So I doubt we'll see them flooding the market with a ton of unexpected allocations. The last thing he wants to see, he said, is unsold GT cars sitting at dealerships. Other bits I recall. He seems to recommend oil change at 1000-1500 km as part of break in. GT engines different from "normal" 911. With thinner Motorsport valve rings (?) and other components that really need proper break in. Discouraged 9k off the lot! He also feels current gearing on gt4 is best compromise (despite criticism gearing too long) to render acceptable emissions,autobahn high speed usage, etc. I also asked him to sign my manual a couple days ago. Plus his Motorsport boss and vp (Walliser) and vp customer centre (Frenkel) and about 30 past and present drivers (many of whom gave really great interviews) did the same! How cool is that of them to do!! Super awesome people, all of them!! Overall I'm super impressed by the generosity and time offered by these ladies and gentlemen. Apart from very interesting discussions we even got a few cool gifts like pens and notebooks, booklets, and a North American exclusive cars board / plate from Barbara Boeckenhoff, Florian Truffner, and the porsche tent staff. Big thank you to them! And of course it was so cool to meet many interesting people involved in making these cars. Big thanks to Eduardo for letting me in on some interesting conversations with Frenkel and designer Thorsten Klein and others. So many great opportunities to meet and hear from the real inner circle involved in creating the cars we love! Thank you RRV for an amazing few days!! PAG you guys rock!!
This will be a must have mod for my GT4. I could care less about the impact on MPG or a couple seconds on the track... I want to shift often and angrily.
This will be a must have mod for my GT4. I could care less about the impact on MPG or a couple seconds on the track... I want to shift often and angrily.
This reminds me of a few years ago when I first drove one of the local tracks in four 30 min sessions. Next day, my right arm and shoulder were very sore - never happened before after track days. Then I realized I had executed over 1100 shifts! but it was a fun 1100 shifts - either heel toed down or upshifted at a glorious 9000 rpm! the lap time did not matter. That's what I hoped the GT4 would be...
Remember the GT 4 is a parts bin car. It would not of been cost-effective to develop a new transmission with different gearing . The car was built to a price point. I had the same gearing in my last 981 MTs and they didn't have the power .One could argue fewer shifts saves on the clutch And gear box.In a perfect world I would like lower gearing but is nowhere near a deal breaker. Still. A fun car.carll
09-28-2015, 03:43 PM
GT4 final drive discussion
Saludos, Eduardo Carmel
