Question for anyone who's driven a 4 speed 930

[93097004xx]

Interestingly this thread is relative to a December 1975 panorama article on the first turbo carrera stateside.

Incase you are wondering I have every panorama from 1969 to today..












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[93097004xx]

The 4 speed, the turbo lag (the lag IS the experience in these early turbos) and the HARD hitting turbo are the reason for owning a 930 to me.

If you want 5 6 7 speeds no turbo lag and a linear boost delivery..

You can get that in any turbo porsche from the mid 1990s on..

For that matter ANY turbo car from 1990s on..

[Rawknees'Turbo]

^^^

Each to their own, but the absurd turbo lag, non-linear boost, and boost that falls on its face shortly after it peaks (about a 2K RPM usable range), are major design flaws that any right-thinking owner would want to remedy - fairly easy to do, does not cost a fortune, and then you have a very cool, vintage car that actually works well.

None of which matters for garage queen cars, however - might as well have a Leggo engine in those.

[Matt Monson]

Originally Posted by 93097004xx

Has nothing to do with “improving” although I would like to call into question the quality and soundness of these “mods”...

It has everything to do with maintaining a historically significant porsche that is historically correct as possible.

You are trying to be a modifier and that is a slippery slope.. really easy to end up with a project that is all wrong .

You can question all you want. Not many can claim to have been an oem supplier for Ruf, 9ff, Mosler, Singer, and even Porsche Motorsports themselves. If you want to insinuate that I have an agenda or that I am presenting anything that's not race proven and time worn, I would just say it's another of your unfounded opinions based on your feelings. I am not a modifier. I am a motorsports manufacturer and the best in the world come to me for my parts and my advice and then use them to win races and titles the world over.

Raw, you can tell D I'm acting 16 again...

[clutch-monkey]

Originally Posted by Matt Monson

Porsche put a 4spd in the 930 because it was what they could fit. They were a small company without deep pockets. They had started racing turbo rsrs with 915s and couldn’t get them to last a 24 hour race. They needed wider gears, and in order to fit the gearbox in the same space within the existing chassis it could only have 4 of them. It was a practical decision, not a performance driven one. The 917, 908, 910, and everything else was 5spd. The 930 was a compromise based on nothing more than the chassis.

this

Originally Posted by 93097004xx

Has nothing to do with “improving” although I would like to call into question the quality and soundness of these “mods”...

It has everything to do with maintaining a historically significant porsche that is historically correct as possible.

I have recently spent the past month studying the 4 piston calipers and have learned that the casting changed from early to late model 930s as did the manufacturers..

I’m saying that I am trying to be the best historical steward I can be..

You are trying to be a modifier and that is a slippery slope.. really easy to end up with a project that is all wrong .

porsche didn't care about the road cars, that's why the 4spd 930 started off so crap.
they just wanted to race and needed a turbo and the stronger 4 speed homologated.
deluded if you think the stock car is ideal or how it should be for street.

[Rawknees'Turbo]

Originally Posted by Matt Monson

. . .
Raw, you can tell D I'm acting 16 again...

Can I tell him that you're acting like a bisch, too?!??!

[Matt Monson]

Originally Posted by Rawknees'Turbo

Can I tell him that you're acting like a bisch, too?!??!

Only if you can catch me and get me into the ball gag.

[Rawknees'Turbo]

Originally Posted by Matt Monson

Only if you can catch me and get me into the ball gag.

First I'd have to figure out how to get it back from Deez!

[Ollies930]

Let us not forget that 930s originally were intended as nothing more than a limited production homologation car, where the factory was hoping to sell enough cars to be able to register their group 4 and 5 cars with the appropriate modifications already in place. As such, the cars were modified to work on the street with a limited amount of design/engineering spent on making them a street car. By happy coincidence we ended up with a car that was able to compete and beat the top sports cars of their time, but I do not believe that was Porsche's intent at the time at all. It is just a happy example of unintended sales success, that Porsche had to keep building 930s for the street. Consequently we ended up with a somewhat quirky car, that responds extremely well to modifications.

[Kraftday]

Originally Posted by spuggy

'Coz I never have


How is the factory 4-speed 1st for moving off the line/around in traffic?

Does it need a little finesse/slipping - or basically fine?

Does it seem too tall once clutch is home and rolling at low speeds - eg transmission snatch, have to feather the clutch etc?

The 78-88 trans / clutch features a deep bell housing, heavy assembly. Originally a rubber center hub disc. Backdating the clutch with the MODE clutch adapters or shortening the bell housing will save you a lot of mass and lowering the moment of inertia. That requires a bit more clutch release finesse but everything is quickened.

[93097004xx]

930s have great low end torque. First gear from the line should be no issue. These engines seldom build boost around town driving. They produce plenty of torque and should happily take off with no issues.

I believe you are referring to the rather tall
2nd gear ratio which dose not work in traffic situations.

[93097004xx]

It will however approach 90 mph in second gear which I always though was cool as no other car in the world could do this until the last 10 or so years. Getrag I believe builds a very high performance transmission that has a 2nd gear ratio nearly as tall in their 200 mph application transmissions.


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[quattrorunner]

I happen to love 2nd gear around town.
And getting away from stop is no problem at all. 1st is perfect compared to a 915 short 1st.

[Rawknees'Turbo]

Originally Posted by 93097004xx

930s have great low end torque. First gear from the line should be no issue. These engines seldom build boost around town driving. They produce plenty of torque and should happily take off with no issues.

I believe you are referring to the rather tall
2nd gear ratio which dose not work in traffic situations.

The big torque you are referencing is during boost - there is almost no horsepower or torque produced from the measly 7:1 static compression ratio without the aid of the turbocharger.

That is why the engine performs so much better with basically any turbocharger than the one it was made with - you get big torque at a way earlier RPM, and can haul a lot more ass a whole lot earlier.

[Matt Monson]

Originally Posted by Rawknees'Turbo

The big torque you are referencing is during boost - there is almost no horsepower or torque produced from the measly 7:1 static compression ratio without the aid of the turbocharger.

That is why the engine performs so much better with basically any turbocharger than the one it was made with - you get big torque at a way earlier RPM, and can haul a lot more ass a whole lot earlier.

You can't argue with his feelings.

[kevinbodman930]

Rawnuts you are absolutely right I went from a slightly modded K27-3200 to a gtx3584rs.The K27 was no slouch but this new turbo along with all the other mods put me in my place.Last knight I sware It felt like I did a second gear wheelie.You sexy biatch.


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[rick conrath]

Tall first gear....no problem in traffic or between lights. Hardly any need to shift.
No complaint when I had my 930.
Rick

[WERK I]

Originally Posted by voitureltd

...................snipped for space...................
Also a 4spd with a 8:41 R&P is an improvement for our roads with a top speed of around 145 MPH. Sort of like a G50 without the 5th gear. Or just use the stock R&P and regear 3rd and fourth so it gets to around 120 in 3rd and 145 or so in fourth. A g50 is so much work and expense as the alternative and a converted 4spd to a 5spd by RUF is also very costly and rare.

Anthony,
I have an 8:41 R&P in the slant with what feels like stock ratios. First gear is almost useless. I would call it a great get out of the pits quickly gear. The engine redlines so quickly that the boost gauge never moves. With the k27-7006, SC cams and headers, the turbo is always "on-the-boil",so to speak. At 70MPH @3100RPM, it's a bit buzzy inside the cabin long distances. Overall, it's great for canyon carving but a bit undesirable in interstate driving. In a road course sense, it would be ok at Lime Rock, but woefully short at Road America. Another gear would be nice.

[full quack]

"930s have great low end torque."

Wow, that's drinking some real good kool aid right there.......

Mark

[911tracker85]

With the k27-7006, SC cams and headers, the turbo is always "on-the-boil"

good to hear. I will have the same on my build. project has a 7006 and wondered if I should consider a different turbo. got the recommendation to go with SC cams.

and the 930 gearbox I acquired has stock gearing. would love to regear 2nd and 3rd, but budget is saying get the car built first.....