Pricing help

[Matt Monson]

Originally Posted by JMS935

These hot rods are always missing the turbo transmission. Why do they all spend the money for all of this work and not finish it off with the proper tranny? Maybe they prefer the 5 over the 4, and the G50/50 5 speed is just too expensive, that could be part of it. I personally prefer the 4 speed, and yet still never see any of these builds with that tranny either. They always have either the 915 or the G50, both non turbo tranny’s.

You've read too many threads on the internets. There's so much rubbish out there about the gearboxes. The ONLY reason the 930 4spd gearbox exists is homologation rules. When they started running the turbo carreras in 1974 with the 2.1l engine they still ran the 915. The engine made 400ft/lb of torque, and by season's end they realized that they had exceeded the capabilities of the gearbox.

For 1975 the 930 gearbox was released. But in order for homologation they needed 400 road going cars to qualify. At 260hp, the 3.0l turbo street car didn't actually require the new gearbox. Keep in mind, the 915 wasn't even introduced until the 911ST started hitting 250hp in NA form. Carrera 3.0 RSRs of the era were 300hp cars and did just fine in the 73 and 74 race seasons with the 915. It was the turbo racecar that mandated the gearbox change.

As for the G50 NA gearbox? There's not as much difference as people think. Internally the gearsets are IDENTICAL on a G50/01 versus a G50/50. The NA box has a 7" ring gear, whereas the turbo has a 9", but it doesn't really matter that much. We've built 1000hp cars around the NA gearbox. When Eddie Bello blew up his G50/52, he put a G50/03 gearbox in the car. He made 1200whp on his car.

Given how much better the shifting is with borg-warner synchros, I would take a G50/01 car over a 930 car any day of the week. Ruf agreed and was putting NA gearboxes in their cars a couple years prior to Porsche putting the 50/50 into the 930 in 1989.

Over the years, many people have put turbo engines into cars and kept the 915 gearbox like puddy's car. If it's a stockish 3.3l why not? At 304ft/lbs, I personally wouldn't stress too much about it if it's driven maturely. rarly8 and others around here have driven these kinds of cars on the street and track for many years without incident.

[pmax]

Originally Posted by Matt Monson

...
At 304ft/lbs, I personally wouldn't stress too much about it if it's driven maturely.

Groan.

Is that like having a hot girlfriend you can't touch ?

[JMS935]

Originally Posted by Matt Monson

You've read too many threads on the internets. There's so much rubbish out there about the gearboxes. The ONLY reason the 930 4spd gearbox exists is homologation rules. When they started running the turbo carreras in 1974 with the 2.1l engine they still ran the 915. The engine made 400ft/lb of torque, and by season's end they realized that they had exceeded the capabilities of the gearbox.

For 1975 the 930 gearbox was released. But in order for homologation they needed 400 road going cars to qualify. At 260hp, the 3.0l turbo street car didn't actually require the new gearbox. Keep in mind, the 915 wasn't even introduced until the 911ST started hitting 250hp in NA form. Carrera 3.0 RSRs of the era were 300hp cars and did just fine in the 73 and 74 race seasons with the 915. It was the turbo racecar that mandated the gearbox change.

As for the G50 NA gearbox? There's not as much difference as people think. Internally the gearsets are IDENTICAL on a G50/01 versus a G50/50. The NA box has a 7" ring gear, whereas the turbo has a 9", but it doesn't really matter that much. We've built 1000hp cars around the NA gearbox. When Eddie Bello blew up his G50/52, he put a G50/03 gearbox in the car. He made 1200whp on his car.

Given how much better the shifting is with borg-warner synchros, I would take a G50/01 car over a 930 car any day of the week. Ruf agreed and was putting NA gearboxes in their cars a couple years prior to Porsche putting the 50/50 into the 930 in 1989.

Over the years, many people have put turbo engines into cars and kept the 915 gearbox like puddy's car. If it's a stockish 3.3l why not? At 304ft/lbs, I personally wouldn't stress too much about it if it's driven maturely. rarly8 and others around here have driven these kinds of cars on the street and track for many years without incident.

You are correct, I know very little when it comes to transmissions and gearing ratios, but it has nothing to do with reading internet threads. If so, I might actually be more educated on the matter. My opinion is solely based on my experiences driving my own cars, and I much prefer the 4 speed transmission over any of the 5 speed tranny’s. Maybe that is why I prefer the ‘turbo’ transmission, since it is the 4 speed gearbox, which is my preference. This is why I always think (imo) these conversions are lacking the proper tranny, not because they can’t take the power, but because I simply prefer the 4 speed gearing, which is only offered in the turbo gearbox.

Do these all end up with a 915 or G50 tranny because those converting these cars are trying to keep costs down? Or is it because they all actually prefer the gearing of a 5 speed tranny? I guess that’s the question...

[BLACK3.2]

Pretty sure you're an outlier, JM. Most prefer driving with a five speed.

[Matt Monson]

Originally Posted by JMS935

Do these all end up with a 915 or G50 tranny because those converting these cars are trying to keep costs down? Or is it because they all actually prefer the gearing of a 5 speed tranny? I guess that’s the question...

I think a lot of it is a run what you brung approach. To put a 930 gearbox into a G body requires shortening the gearbox or getting an early short one. The problem there becomes only 86+ ones can easily be shortened. Any 78-85 930 gearbox doesn't work. So, you get a 3.3 swap out of one of those years and it doesn't have a usable gearbox.

OR, you put a 3.3 swap into an 87-88 3,2 Carrera that already has a G50. Or, and here's where the cost and hassle comes in, you have to put G50 torsion tubes into a 915 car to make the gearbox fit. When it comes down to it, doing a gearbox swap on a car that is getting a turbo engine added isn't a simple affair in most instances.

Plus there is the 5spd thing. As was mentioned, most people prefer 5spds to 4, and see putting the 930 gearbox in the car a downgrade even though it's stronger.

[puddy]

If i'm going to keep the car, as per my AMAZING wifes wishes i'm going to have to go for bigger horsepower and upgrade the tranny. Does anyone have a simple 930 swap list they can link, showing what is required?

I have a 1975 chassis with an 915/68 gearbox. Would a SBH 930 fit right in and use my existing axles? I understand shifter and link / rod would have to change. Does clutch cable remain the same?

[Matt Monson]

This one is a steal. It's got $7000 worth of my parts in it. I think he's got the year wrong because it has continuous bosses. It could be shortened.
http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/1007685-1983-930-4speed-close-ratio-trans-guards-diff.html#post10186014

EDIT: looked it up. It's an 87.

[puddy]

Originally Posted by Matt Monson

This one is a steal. It's got $7000 worth of my parts in it. I think he's got the year wrong because it has continuous bosses. It could be shortened.
http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/1007685-1983-930-4speed-close-ratio-trans-guards-diff.html#post10186014

EDIT: looked it up. It's an 87.

OK, thanks but wouldn't this be good value too?? I doesn't need to be shortened.

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/1006645-fs-porsche-930-sbh-transmission-lsd.html

[Rawknees'Turbo]

Originally Posted by BLACK3.2

Pretty sure you're an outlier, JM. Most prefer driving with a five speed.

The five speed boxes really become four speed when a little power is added to a 930 engine - 1st becomes basically useless.

[JMS935]

Originally Posted by Rawknees'Turbo

The five speed boxes really become four speed when a little power is added to a 930 engine - 1st becomes basically useless.

That is exactly why I dislike the G50/50 transmission! First isn't only uselsss, but if you want to use it, you've got to have the skills of a pro race car driver to be able to switch into 2nd gear without topping out 1st if you're giving the car any sort of gas off the line. My 5 speed is highly modified, however, so it's probably harder to drive than most. It's DP's equivalent of a street legal race car, it's not even close to being a tame 930. Maybe my opinion probably wouldn't be as harsh if it were stock, but stock is fairly lame.

I really don't get why I'm so in the minority preferring the 4 speed over the 5 speed. It's less rowing and more enjoying! Isn't that what Porsche eventually evolved to? Less manual movements for efficiency and effectiveness (and enjoyment). To me, the 4 speed is the best of both worlds, it allows you to row through the gears yourself, but it also allows you to enjoy driving without being held hostage to shifting gears so often. I also prefer the softer clutch pedal as well, so that's another thing. I prefer my leg workouts coming in the gym, not the car.

[Matt Monson]

Originally Posted by puddy

OK, thanks but wouldn't this be good value too?? I doesn't need to be shortened.

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/1006645-fs-porsche-930-sbh-transmission-lsd.html

That box is insanely overpriced. It still needs $1500 of labor t put it back together which is more than the cost of shortening a box.

[Rawknees'Turbo]

^^^

I really like the 4 speed box, for the reasons you mentioned - add some power, and a turbocharger that is earlier spooling, more linear, and pulls harder and the wide gear spacing becomes a non-issue, too (for those that often mention the gear spacing to be a negative).


Hey PullinMyPuddy, Brandon/quattrorunner did the 930 gearbox conversion within the past couple of years - reach out to him and I'm sure he can give you some direction and/or some tip(s), just the , on that.

[JMS935]

Originally Posted by Rawknees'Turbo

^^^

I really like the 4 speed box, for the reasons you mentioned - add some power, and a turbocharger that is earlier spooling, more linear, and pulls harder and the wide gear spacing becomes a non-issue, too (for those that often mention the gear spacing to be a negative).


Hey PullinMyPuddy, Brandon/quattrorunner did the 930 gearbox conversion within the past couple of years - reach out to him and I'm sure he can give you some direction and/or some tip(s), just the , on that.

Yep. The euphoric high of the boost is both longer and more enjoyable with a properly set up 4 speed. And that's what it's all about!

[puddy]

OK, fellas you're making me a believer in the 4 speed!

I"ll reach out to Quattrorunner.

[JMS935]

Originally Posted by puddy

OK, fellas you're making me a believer in the 4 speed!

I"ll reach out to Quattrorunner.

I've got both a totally stock US 930 4 speed, as well as a few other modified 4 speeds. If you plan on modifying it, you will love the 4 speed. I guarantee it. I'm not even talking crazy numbers, anything in the 350-375 range and it's phenomenal. That's the sweet spot for street performance for a 930 Imo, you don't need much more than that.

If you want a stock 282 hp motor, than as Matt has pointed out, either of the NA 5 speeds will be fine. So it really depends on whether you want stock turbo or modded turbo imo. Once you make that decision, then go from there. That's my two cents...

[Matt Monson]

Originally Posted by Rawknees'Turbo

^^^

I really like the 4 speed box, for the reasons you mentioned - add some power, and a turbocharger that is earlier spooling, more linear, and pulls harder and the wide gear spacing becomes a non-issue, too (for those that often mention the gear spacing to be a negative).


Hey PullinMyPuddy, Brandon/quattrorunner did the 930 gearbox conversion within the past couple of years - reach out to him and I'm sure he can give you some direction and/or some tip(s), just the , on that.

On a heavily modified car the gearbox I linked is a great fit. People always go on about short ratio this and that. But as you’ve mentioned 1st becomes too short with power, and that’s also true on the 4spd. We replace a lot of 2.25 FAI 1st gears with the 1.833 Hx in that modified box.

[JMS935]

Originally Posted by Matt Monson

On a heavily modified car the gearbox I linked is a great fit. People always go on about short ratio this and that. But as you’ve mentioned 1st becomes too short with power, and that’s also true on the 4spd. We replace a lot of 2.25 FAI 1st gears with the 1.833 Hx in that modified box.

I don't feel my 1st is too short, but then again I don't think any of my 4 speeds would be considered heavily modified. Matt, at what hp would 1st also feel too short in a 4 speed?

For my 5 speed with the short 1st gear I dislike, how much work is it to lengthen that gear? Or is it a bigger project than that, needing to address all of the gears at the same time?

[Matt Monson]

Originally Posted by JMS935

I don't feel my 1st is too short, but then again I don't think any of my 4 speeds would be considered heavily modified. Matt, at what hp would 1st also feel too short in a 4 speed?

For my 5 speed with the short 1st gear I dislike, how much work is it to lengthen that gear? Or is it a bigger project than that, needing to address all of the gears at the same time?

500-600whp+/- but it's really subjective. Most people with mildly modified cars go shorter than stock on the 930. Stock 1st goes to around 55mph. On an 89 with 50/50 it only goes to 45mph. There is a big difference there. guys in 300-400 range would prefer the kind of gearing of the G50. For them, we put a 2.53 or 2.83 1st into their 930s.

That 1.83 is super popular in vintage racing because it goes to 67-70mph depending on redline and tires. You would use a 1st gear like that in the International Horseshoe at Daytona or into a lot of slow hairpins around the country. Doesn't even require a high powered car for it to be useful in that situation.

Whereas someone running standing mile or 1/2 mile races might find even the 1.83 too short. I make firsts all the way up to 1.600, which is really a 2nd gear ratio in most instances. These are guys who would be changing 2 or 3 gears and maybe even all 4.

Changing out first on a G50 is expensive because first is on the mainshaft. So you can't just buy a gear like you can on a 930. One of my tall mainshafts runs $3k plus $1000-1200 in labor to install. That's bench time. It doesn't count R&R from the car. The 3.154 ratio that would be coming out is popular and is the same as used in the 964RS. It would be an easy resale in good used condition, but is generally only worth $1000+/- You can still get them new for around $2k,

[JMS935]

Originally Posted by Matt Monson

Changing out first on a G50 is expensive because first is on the mainshaft. So you can't just buy a gear like you can on a 930. One of my tall mainshafts runs $3k plus $1000-1200 in labor to install. That's bench time. It doesn't count R&R from the car. The 3.154 ratio that would be coming out is popular and is the same as used in the 964RS. It would be an easy resale in good used condition, but is generally only worth $1000+/- You can still get them new for around $2k,

Thanks for the info Matt. That sounds like a lot of work and money for just one gear replacement. At those prices I’d probably be more inclined to just buy a 930 4 speed gearbox and swap it out. It would cost more money that way, but you’re also getting an extra transmission out of it as well. The dollars are better spent that way. This isn’t the first Porsche project on my list, so I’ll table it for now. But that’s what I’m leaning towards if/when I end up addressing this after seeing how expensive it is for a single gear change on a G50/50.