87-G-50 rebuild costs and considerations

[charleskieffner]

and yes i have "searched" on here and really didnt find anything specific to costs or the while yer in there considerations.

anything available to beef transmission up? for longer life? 118K on it now.

car will never see anything more than the 3.2 liter motor maybe a 3.4 in its life, so HP not anything to worry about.

differentials to consider? can i have my cake and eat it also w/going to aftermarket torque sensing diffy on the street and track?

or just replace pesky worn out 1-2nd synchro and slap a new clutch, pressure plate and call it good????


plan on keeping car til i croak, not bothered by dumping bucks now. mtr still runs like a raped ape!

[jbrinkley]

may i ask how you know that that is the problem? are there give aways or something?
sorry if this is stupid, but my 1 2 shift is difficult at best

[Bill Verburg]

Steel syncros are a stronger but pretty expensive upgrade.

PMS or Guard asymmetric LSD is a very nice track oriented option. The Quaiffe(torque sensing are more oriented to street or A/X use)

[charleskieffner]

the reason i know is we have tested both mobil 1 lube when i bought it, and then swepco after we experienced shift problemos at calif. mtr. speedway.

coming off the embanked turns 1 and then 2 you had to climb up to wall and make a 5th to 2nd shift and a hard LEFT or face splattering yourself against the really big thick ugly concrete barriers of sheer certain DOOM!

repeat this 5th to 2nd shift multiple laps for 3 days of time trials. all the shifter bushings have been lubed adjusted replaced.

my wrench and very brave navigator/instructor jim patrick suggested i change to swepco. i said what the hell. after getting back to phx. within 2 days we dumped tranny fluid. i was watching w/my fingers crossed that metal chunks didnt come pouring out.

much to my surprise ........none did.

patrick is pointing at the 1-2nd synchro. all other shifts any combination are fine. you just had to be spot on and baby the 5th to 2nd shifts. annoying to me, and once again another annoyance that will have its fair share of my wallet.



already on tap as mentioned by bill verburg are steel synchros. a clutch fork upgrade,and the clutch release shaft bushing upgrade.

but my question for just rebuilding a normal g-50............what are we looking at??? $3000-$3500???

i really am questioning a differential and how much bang for buck this will give.

the drill around here has become ......throw wads of money and time at car. take to track....run the snot out of it and see what lets loose, come back repair. take g/friend out 1-2 a month on some road trip to escape valley heat. thats it! and it sits in garage after being given TLC wash and wax -polish. it truly is babied until track days and then the evil race face comes on and all hell breaks loose!

the above combination has been really helpful in finding all the lil bugs that any car has and solving them. we pretty much feel if it can handle going WFO at the track it should be able to handle a spirited run thru the backwoods of arizona, for a coupla hundred miles with the a/c blowing ice cubes on my g/friends TAA TAA's!

and as we all know...........it dont get any better than that!

[Bill Verburg]

clutch fork upgrade,and the clutch release shaft bushing upgrade.

also good touches

last I looked steel 1-2 was well over $1000 in parts alone

[Zeke]

5th to 2nd? Is there no other way? That's a double clutch shift for the best of drivers and not one I would like to have to do. I don't know, if Patrick says that's the hot ticket, then I defer.

I hear you can buy G 50's for around 2K that you can drive before you buy. After selling yours, how much would you be out of pocket?

[charleskieffner]

if their a $1000 bucks ........oh well...........!

here we go again! thats the problem with these 20 yr old cars, everybug has been worked out and a better badder part has taken the place of the OEM part for a reason. 20 years of technological advances is great, except when it comes time to pay the bills. trick parts that last........ cost big bucks.

but not to worry, we have an evil plan on the drawing board that has been in place for awhile. we started w/brakes and did everything we could w/in pca rules. then we moved to suspension and tires. did everything we could there. smart sway bars. turbo tie rods, all new bushings. monoballs,new CV's, bearings etc. then the body. we shed alot of weight going to RUF bumpers. then safety equipment. all the while replacing any engine wear parts. all we have done is focus on one component of the car at a time. for awhile it was hairy jumping from one fire to another but now after quite a few track hours and roadtrips, the bugs have been driven off w/a vengence and it runs like it was basically brand new.

so now we have to tend to the g-50. kinda knew sooner or later it was in the cards. so figure while we are in there replace anything that looks at us funny and upgrade where we can, within reason. the most HP the car would ever see while i own it is maybe a 3.4 liter motor. so nothing to worry about excessive horsepower.

driving the car on street i just baby 1-2nd shifts and thats all. not a big deal until track day...............and THEN IT IS A BIG DEAL!

patricks recommendation is the centerforce clutch kit. hey the one in there(OEM) has gone 118000 miles!!!!

milt...we gridded #43 on purpose so i could get the hang of calif. mtr. speedway before we were lapped by the full race winged im gonna kill you if yer in my way drivers!

coming off turn 2 you go high right within inches of wall on short straight........then downshift 5th to second, full straightline braking and then turn left and then right and off you go into infield roundy rounds and then onto turn 4 and then the straightaway WFO.

the 5th to 2nd shift was talked about for 3 days! if you didnt have it perfect you were gonna HEAR SOME NOISE!

the cars not a daily driver by any stretch of the imagination. just a toy and doing that 5th to 2nd shift here at PIR or FIREBIRD aint ever gonna happen due to both tracks being short. CMF is 2.8 miles long and yer going WFO coming out of turn 4 in 5th gear ALL THE WAY TO TURN 2! you are fer sure going WARP FACTOR SPEED!

but it did teach me a damn good way to come to almost a dead stop going 5th to 2nd and applying full brakes!

the guys up at carquip in denver quoted me around 3K-3500 to rebuild and then add on goodie parts like steel synchros. they even recommended(steel synchros) if i was just going to keep car forever let alone go scare myself silly taking it to the track when time allows.

i dont have to do this now.........but its in the future. since we got nailed by monsoon rains here(3.5 inches here-4 inches north of me) the roads are washed out and debris everywhere. i cant even get car out to the pavement. and if i did my RUF spoiler would be wasted by granite that has washed across low areas. so for now im just gathering my ducks for the day we drop the tranny and do the dirty deed and upgrade the HELL OUT OF IT!

[charleskieffner]

milt 2000 bucks for a tranny sounds pretty good. patrick quoted roughly 3000 for basic rebuild w/no surprises. he gets about 88 bucks an hour labor. somewhat cheaper if you bring beer every week on saturday afternoons.

how many manhours into doing a complete rebuild on a G-50?

[89911]

My brothers 87 and my 89 have both had our's regeared (2-5). The standard G50 is really a 3 speed if you look at it. 1st to get it rolling and 5th to save gas on the highway. Once we dropped the ratio's closer together, the car comes alive. Definitely the best upgrade I've done. Here's an example of the ratio's. (at least audibly)http://video.google.com/videoplay?docid=-4700035160174297055

[charleskieffner]

read a little into the changing of the gear stacks. apparently quite a few around due to racing efforts. not cheap mind you, but available. basically trannies are set up for the almighty EPA mileage rating and the average guy driving.

from what i read here not too many of us are average drivers by any stretch.

when you changed gear stacks did you do so for a specific track? or was the change due to autocross or any other specific racing??

can you be specific on what ratios are now? and who you bought them from and the price?

how does this do on the highway??

the only time my car is ever subjected to city driving is going to patricks about 40 miles away and just about all freeway to his doorstep or jeffs(CUL8R) down in awatuckee about 60 miles one way. other than that its open highway or the track.

doing a 6-speed entails torsion bar housing rework because g-50-6-speed is longer so thats out of the question. too much work.

[KFC911]

Originally Posted by 89911

My brothers 87 and my 89 have both had our's regeared (2-5). The standard G50 is really a 3 speed if you look at it. 1st to get it rolling and 5th to save gas on the highway....

I thought it was just me ... Since I rarely get out on the highway (mostly twisty backroads for me), I can't remember the last time I was in 5th, and most days 4th isn't used either. Subscribing...

[89911]

My brother has all the data and I can try to retrieve it. He went with a 993 Diff, steel syncro's, lightened flywheel and all the other items you mentioned above for durability. I did the same, but all ready had the limited slip diff. We did some some estimate off the absolute achievable top speed of the car at redline (we both had engine rebuilds, his a high compression euro 3.2, mine a twin plugged 3.4) and set the top speed for 150mph which we can achieve at tracks like Watkins Glen. I think the 5th in a G50 is set for a maximum top speed of 175mph or something unachievable. It really is for low rpm's at highway speed. From there, we spaced the ratio's evenly, leaving 1st alone. Again, I'm generalizing and can give actually ratio's once I get the data. 5th ended up being a 1-1 ratio.
Driving the car is great. I can drive on the Highway in 4th or 5th with no problems. The engine is turning faster, but I like it because it is not lugging in the low rpm's. Around the town, it's just a better driving car. The money is the only "downside" to the change. A 6th speed would be even nicer if they had them then. It makes your car feel like it has an additional 50 hp and is 200 lbs lighter.

[JackMan]

89 911, I would like to get a copy of the rebuild specs of your tranny. I'm looking to rebuild my tranny in the future and am collecting data. Please email to wellborn_jackiii@ml.com.

thanks

wj

[charleskieffner]

hey thank you for the data. this will come in handy building the ultimate G-50 for highway and track.

hey these cars are 20 years old now, and the advances in technology are pretty much in place. its no longer rocket science. i feel that this is a good combination to build a tranny that grants the owner "the best of all worlds".

with enough web surfing, hanging around at tracks, you can pretty much source everything that works, and for sure hear about what doesnt work.

seeing the other G-50 post with milt welding the reinforcement torsion tube housing for the 6 speed, looks like a cool way to go if bucks are not a consideration.

these transmissions are pretty tough evidenced by all the abuse thrown at them from various forms of racing. rally, road racing, autocross etc.

our angle is lets do it RIGHT ONCE and never look back at the component and move on to the next problem presented.

hey im the first guy to go nuts over horsepower/braking/suspension upgrades. but staying to the letter of PCA rules for F-J-STOCK class has been an eyeopener to how well these cars work without dumping obscene amounts of cash into them.

having my car WIDE ******* OPEN 5th gear at calif mtr. speedway is a real eye opener to what they will do with the rules allowed. on scale of 10 for pucker power ........this rated a 100! and believe me the fun lasted quite a long time going from turn 4 all the way down straight away thru turns 1 and 2!

from what i have read so far its easily looking at $4000 bucks possibly more to build the ultimate G-50 for essentially a stock 3.2 maybe a 3.4 in its future.

at least it will be close to bulletproof barring any total mis-shifts on my part.

would love to hear anyones comments on upgrade differentials and how they like them. is there a happy medium when it comes to differentials for highway and track????

[89911]

I'll do my best to get the info. I'm battling a few situations. My unorganized brother has all the specs when he had his done and now it is "filed" somewhere in his garage. This was also done about 4 years ago. The mechanic who did this is excellent, but his operation is very relaxed to say the least. He works out of his house and basically gave me all the parts purchased on a tablet paper when I would pay him incrementally with cash. The rebuild was also tied in to me rebuilding my original 3.2 into a 3.4 with Mahle P/C's, twin plugging, changing cams and a few more tablet sheets of parts. Needless to say I was visiting him often after visiting the bank, so its hard to have an accurate price on the work. I think he preferred in that way. The good news is that he does excellent work and has done other G50's prior and after my brothers and I, all with excellent results. I don't think cracking open a G50 and regearing is an easy project and wouldn't trust it to anyone without experience. If your close to Pittsburgh Pa, I can give you his number.

[charleskieffner]

im in arizona but still am interested when you have time, seeing what components you used and a rough guess how much it cost.

w/out even looking at bentley im sure there are a few tranny specific tools you need to rebuild a g-50 and as always any specific tool costs big bucks.

i dont have a problem in the least pulling the motor or tranny. and more than likely from what i have seen here on pelican and some of the damage incurred, i would more than likely pull both at the same time. this way i can replace anything that is on top of engine that shows any wear. fuel lines,gaskets,etc.

i plan on milking my motor as long as i can. 118K miles on it now. P.O. took average care of it(took it to local shop) for being a lawyer who didnt ever get his hands dirty. i've put 8000 miles on it in 2 years now. and they havent been kind miles as far as baby shifting it and using it as a daily driver. but my level of care to it, is light years ahead of an "average owner". as mentioned 2 days after calif. mtr speedway we dumped tranny oil to see if anything was amiss. in 1459 miles of flogging it, like it would never SEE on the street, i used a 1/4 of a quart of oil!!!!!!!

so dumping the bucks here on the tranny, in the near future, isnt really a concern at all. reliability is the main concern and only doing it ONCE! come on ........118K miles on a clutch!!!!!! LOL! that aint half bad for any vehicle, let alone one that has been flogged at the track!

hell this months excellence had a letter stating 7000 miles a year is low mileage on these cars and 9000 miles is high mileage per year! im at 4000 a year and thats a PITA, just doing that w/all the other crap going on in my life. and believe me..........if i could drive it everyday.........i would!

the recent porsche commercial during ALMS race, "there is no substitute" with the lil kid asking the salesman for his biz card and telling him " i'll see you in 20 years" fits me to the "T"! i worked for johnson bozzani porsche here when i was a kid and fell in love w/911's, when i was 16...........do the math! im 50 next month going on 16!!!!! LOL!

[Bill Verburg]

'87-89 US Carrera models used a G50/01
here is what it looks like stock


From a performance perspective it's pretty dismal.

JMO but if you don't trailer the car a top of around 160 is as low as I would want to go. For performance you want decreasing splits as you go up through the gears

For comparison here is a Row 964 RS, which is pretty good



I reposted this because the data for the 964RS box that I posted previously was in error

[KTL]

The 964 RS gearing can be almost achieved by replacing 2nd and 3rd only in a 87-89 G50 box.

The ratios I calculated to insert a 2nd and 3rd without goofing up the rpm drops (besides 5th) are

2nd = 1.94 or 1.88
3rd = can stay stock or 1.45 gives a little more accel.
4th = not too bad stock IMO at 1.125

1st doesn't matter since it never gets used. If you never run on long tracks then neither does 5th. Hence the reason I mention replacing 2nd and 3rd. My 3rd choice is a compromise since 4th is not being changed. I understand the change from 1.409 to 1.45 is probably negligible, but since my 3rd is crunchy i'd try to gain something by doing the repair anyway.

[KTL]

Originally Posted by charleskieffner

read a little into the changing of the gear stacks. apparently quite a few around due to racing efforts. not cheap mind you, but available. basically trannies are set up for the almighty EPA mileage rating and the average guy driving.

from what i read here not too many of us are average drivers by any stretch.

when you changed gear stacks did you do so for a specific track? or was the change due to autocross or any other specific racing??

can you be specific on what ratios are now? and who you bought them from and the price?

how does this do on the highway??

the only time my car is ever subjected to city driving is going to patricks about 40 miles away and just about all freeway to his doorstep or jeffs(CUL8R) down in awatuckee about 60 miles one way. other than that its open highway or the track.

doing a 6-speed entails torsion bar housing rework because g-50-6-speed is longer so thats out of the question. too much work.

Good prices here since they're on closeout for whatever reason.....

http://www.autotech.com/quaife/porsche/g50gears.htm