Shifting the 915 gearbox
#16
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all good advice.
I was the second and now fouth owner of my 85 911. after buying the car back I eventually had to have the tranny rebuilt at 85k miles due to clear synchro issues.
a new clutch and having replaced the bushings and fluid with Sepco helped delay the rebuild. in hindsight I suspect the need for the tranny rebuild at that point was due to my and previous owners not fully understanding how to work a 915 properly. patience and feel when shifting are keys with the 915. and having driven enough to become familiar with it. First time I ever drove a 911 (83SC) I thought the shifting was horrible. but then a 911 will grow on you if you give it a chance ;-)
my dad is an 'old' drag racer and both of my brothers are drag racers. they keep trying to press me into taking the 911 to the drag strip to 'see what it will do'. NO WAY.
after the rebuild by a great porsche mechanic, it shifted good but was tight and took a few K miles to loosen up. car now has 120k miles and still shifting great.
i current have a 'factory' short shift kit installed and I also installed a kit 'like' the seinesystems but not sure it is that one. I found the seinsystems spring loaded kit helped me a lot. I do a lot of PCA DE and autocross, and hitting 3rd cleanly was a challenge before the seinesystems kind of kit. track time is very demanding of your attention and getting hung up between gears is a big, unwelcome distraction. as noted above, I have reached a level of confort where I tend to trail brake but that took a while to become a good enough driver.
I have been looking into the following shift system, link below, which raises the shifter to a better location and has the same kind of 3/4 plane spring loading. I have seen a similar system as the link below from fabcar?? but does not have the 3/4 plane spring loading.
I have heard very good things about the Wevo from a couple guys at the track, but they installed not only the shifter but the gateshift kit INSIDE the tranny when they rebult them.
good luck.
http://www.hargettprecision.com/
I was the second and now fouth owner of my 85 911. after buying the car back I eventually had to have the tranny rebuilt at 85k miles due to clear synchro issues.
a new clutch and having replaced the bushings and fluid with Sepco helped delay the rebuild. in hindsight I suspect the need for the tranny rebuild at that point was due to my and previous owners not fully understanding how to work a 915 properly. patience and feel when shifting are keys with the 915. and having driven enough to become familiar with it. First time I ever drove a 911 (83SC) I thought the shifting was horrible. but then a 911 will grow on you if you give it a chance ;-)
my dad is an 'old' drag racer and both of my brothers are drag racers. they keep trying to press me into taking the 911 to the drag strip to 'see what it will do'. NO WAY.
after the rebuild by a great porsche mechanic, it shifted good but was tight and took a few K miles to loosen up. car now has 120k miles and still shifting great.
i current have a 'factory' short shift kit installed and I also installed a kit 'like' the seinesystems but not sure it is that one. I found the seinsystems spring loaded kit helped me a lot. I do a lot of PCA DE and autocross, and hitting 3rd cleanly was a challenge before the seinesystems kind of kit. track time is very demanding of your attention and getting hung up between gears is a big, unwelcome distraction. as noted above, I have reached a level of confort where I tend to trail brake but that took a while to become a good enough driver.
I have been looking into the following shift system, link below, which raises the shifter to a better location and has the same kind of 3/4 plane spring loading. I have seen a similar system as the link below from fabcar?? but does not have the 3/4 plane spring loading.
I have heard very good things about the Wevo from a couple guys at the track, but they installed not only the shifter but the gateshift kit INSIDE the tranny when they rebult them.
good luck.
http://www.hargettprecision.com/
#17
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PS. I still drive my 911 on the street occasionally to keep it exercised between track events. but with many track upgrades it is harsh on the street and mainly a trace car. I am in process of getting a full boltin cage before the next season.
recently bought a nice 84 928S auto for daily driver when I do not need my 4X4 truck due to nasty weather.
recently bought a nice 84 928S auto for daily driver when I do not need my 4X4 truck due to nasty weather.
#18
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Great stuff!
I appreciate all the advice i can get, as a computer nerd gone car enthusiast some of this can be quite over whelming. One step at a time. After i get the motor sound the next project is the tranny. I will be sure to take all of these things into account.
rusnak, I cannot thank you enough for such a generous offer. As i have a few hurdles to tackle before i get to that step in the restoration, I will be sure to keep you updated. Do you belong to a central valley PC? Regardless I am always visiting friends in Southern California and I would be more than willing to let you take her out for a spin.
I appreciate all the advice i can get, as a computer nerd gone car enthusiast some of this can be quite over whelming. One step at a time. After i get the motor sound the next project is the tranny. I will be sure to take all of these things into account.
rusnak, I cannot thank you enough for such a generous offer. As i have a few hurdles to tackle before i get to that step in the restoration, I will be sure to keep you updated. Do you belong to a central valley PC? Regardless I am always visiting friends in Southern California and I would be more than willing to let you take her out for a spin.
#19
I haddah Google dat
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Hi Nikkoa,
I think joining a Porsche club is an excellent idea. I was a member of PCA central california region. I think we are called Yosemite or something. I sort of let my membership expire - I need to renew!! Anyway, some of the nicest people you would ever want to meet are Porsche air cooled people, especially the 912 and 356 guys.
You should join the Pelican Parts board as well, subscribe to Excellence magazine, and buy the Bentley worshop manual. Another source of tech advice is Gabe, owner of Strasse in San Luis Obispo, Ca. Tell him Russ is Fresno told you to call him. Otto at Ottos Venice is also very knowledgeable if also very curt and to the point.
Just keep your 911 in safe working order that's the main thing. Please keep me in mind if you need some help in the future. I will help you if I can and hey, I'd love to have an excuse to drive up to Sacramento. I love Old Town Sac.
I think joining a Porsche club is an excellent idea. I was a member of PCA central california region. I think we are called Yosemite or something. I sort of let my membership expire - I need to renew!! Anyway, some of the nicest people you would ever want to meet are Porsche air cooled people, especially the 912 and 356 guys.
You should join the Pelican Parts board as well, subscribe to Excellence magazine, and buy the Bentley worshop manual. Another source of tech advice is Gabe, owner of Strasse in San Luis Obispo, Ca. Tell him Russ is Fresno told you to call him. Otto at Ottos Venice is also very knowledgeable if also very curt and to the point.
Just keep your 911 in safe working order that's the main thing. Please keep me in mind if you need some help in the future. I will help you if I can and hey, I'd love to have an excuse to drive up to Sacramento. I love Old Town Sac.
Last edited by rusnak; 01-09-2009 at 02:44 PM.
#20
Race Car
Click on the 'Thunderhill' link to see a fairly-abused 915 being put through 5-4, 4-3, 3-4, 4-3, 3-4, 4-2, 2-3 and 3-4-5 each lap. Aside from the long throw, a 915 shouldn't require all that different an effort from any other manual transmission. Considering the work it does, my magnesium-cased transaxle has been given the Wevo components. But it shifter pretty well even with the stock components.
#21
Basic pointers. When starting from a stop, rest your heel on the carpet, and pivot your foot from your ankle until you engage and are moving. At this point you can draw your whole leg back. This will give you some finesse. When shifting, hold the shifter with the tips of your fingers. When shifting, move the shifter quickly but gently to the next gear. Follow the pattern, but get the shifter to the next gear as the revs fall, and offer the shifter to the next gear with very gentle pressure on the syncros. If your revs haven't dropped too much, you will feel the pressure lessen on the lever, and you may pull the lever into the next gear without any difficulty. I usually double clutch when down shifting, and you should always rev match the engine to the gear being selected, usually about 1000 rpms more than the next higher gear was pulling. If you have a rally cranky box, sometimes it is possible to slightly over rev, and offer the gear lever up in the same manner as an upshift. The lever will again fall in, when the box and the engine are spinning at the same speed.
I would see if you can get anyone to drive your car before you start doing a lot of repairs. As has been said, the car may be normal, or it may need some attention. Head studs are a serious matter, so do have a care and don't drive the car to ruin.
Another tip. Often we do not adjust 911s to our liking as much as we adjust our driving style to the character of the car. However, when tracing shifting problems, make sure you do not over look a dragging clutch or pilot bearing. These are often overlooked sources of shifting difficulty. Good luck with your new Porsche.
I would see if you can get anyone to drive your car before you start doing a lot of repairs. As has been said, the car may be normal, or it may need some attention. Head studs are a serious matter, so do have a care and don't drive the car to ruin.
Another tip. Often we do not adjust 911s to our liking as much as we adjust our driving style to the character of the car. However, when tracing shifting problems, make sure you do not over look a dragging clutch or pilot bearing. These are often overlooked sources of shifting difficulty. Good luck with your new Porsche.
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silverlock (07-25-2023)
#22
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Just drive the car more (it has only been two weeks). As you become more familiar with the clutch and the way the 915 shifts, your shifts will be come more seamless. Also don't rush your shifts, take your time and be precise with your throws. In time you will not event think about shifting it will just come naturally.
#23
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I think it's all been covered on the mechanical side....one more thing I'd highly recommend is getting with PCA or another organization and try out a track weekend. You'll get a chance to explore your car a bit further in a safe environment and you'll get some help with your questions on braking or not for turns. You'll probably help to ensure your 911 stays nice and shiny should you get out and explore its capabilities as it seems you're doing, by know more about a 911's unique and effective handling characteristics.
You don't have to turn into a race car driver or go off the deep end, but it is valuable experience getting onto a racetrack. And you have some great ones in NorCal.
You don't have to turn into a race car driver or go off the deep end, but it is valuable experience getting onto a racetrack. And you have some great ones in NorCal.
#24
Hey, you can adapt to anything. My first Porsche was a 1973 914 back in college. That type 901 transmission seemed HORRIBLE, you had to feel for each gear. But I finally got used to it to the point that I never even thought of it. Of course I later found out that the car had NO bushings in the shift linkage going back to the tranny. lol She seemed like a different car once I installed new ones.
#25
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There's really nothing to adapt to....provided the thing is internally OK, and as you point out (and others above) the bushings and coupler are good. These things did pretty darned good on the world racing stage, and still do, for many years.
#26
Rennlist Member
I agree with some of the suggestions at hand, especially Steve Weiner's and the Swepco #201 gearbox oil. The single most important thing you can do on a 915 shifter/gearbox is to not put your hand on the shifter until the clutch is all the way to the floor. It can be VERY damaging to the internals of the gearbox to try and move the gearshift lever when the clutch is not fully to the floor. Other than that, you may want to have a professional take a test drive to see if all is OK to start with and also just give yourself sometime, these are not like any other car you have driven.
#27
I reread the posts and don't think this was mentioned. I noticed when I shifted the transmission in the 914 (I also use this technique in 911's with the 915 tranny, and even my 964) that it was very helpful to use my fingers more when shifting; not grab the shift-**** in the palm of my hand. As has been stated you need to use a little finesse with these transmissions. I will often still use this technique when driving an unfamiliar car to get a better "feel" for the shift linkage. This method might not work for you, but I found that it helped me. Just wanted to throw it out there.
#29
Agreed. Just meant that it was helpful for getting used to an unfamiliar transmission. Tracking wasn't a factor in my 914; it had 165/(70?) bias-ply tires on it when I first purchased it in 1980. lol And since I was putting myself through college at the time there wasn't any money avail to upgrade.
#30
A lot of people will tell you that a 915 box is quicker than a G50. Most of them are track hounds who have a lot of stick time.