Why the 914-6 Floor Throttle Lever?, ....just askin'! Options

[Tom_T]

Not a Sixer myself, but just curious as to what the purpose was for providing a floor mounted throttle lever within inches of the gas pedal on the 914-6s?? (IMG:style_emoticons/default/confused24.gif)

[IronHillRestorations]

Carburated Porsches of that vintage do not have a cold start warm up, which is why there is a hand throttle, that can also be used as sort of a analog cruise control of sorts.

[Tom_T]

Carburated Porsches of that vintage do not have a cold start warm up, which is why there is a hand throttle, that can also be used as sort of a analog cruise control of sorts.

So Perry, it sounds like it functions as an old style manual choke!? ...yup, I'm old enough to remember them - had one on my 68 Opel Kadette!

I presume you pump the pedal a few times, then pull it up a bit as you would in cold starting a Cessna 152/172 - to cold start a 6??

Don't know if I'd want to be leaning down to adjust that "cruz control" (IMG:style_emoticons/default/sad.gif)

For both purposes, you'd think Porsche/VW could've found room on the expansive dash for a more convenient pull knob throttle/manual-choke.

[Pat Garvey]

Carburated Porsches of that vintage do not have a cold start warm up, which is why there is a hand throttle, that can also be used as sort of a analog cruise control of sorts.

I used to understand why these are there, but have lost the knowledge. Know that my '70 911E (MFI) had it. My '73 911t CIS has it. Particularly confused as to why the "T" has it, since it has a cold start injector?
Pat

[IronHillRestorations]

It doesn't change the fuel mixture, it's just a manual "fast idle".

[zymurgist]

My "Frankenporsch" has one... it's useful for getting the engine warmed up.

The day I drove the car home, I didn't realize what that was for and I thought it was part of the heater control (it was rather cold at the time). I got the car home and the first thing I did was to call the PO in a panic asking why the car he just sold me was idling at 2200 rpm. D'oh!

[Tom_T]

It doesn't change the fuel mixture, it's just a manual "fast idle".

Thanx Perry,

IIRC - a manual choke on carbs doesn't change the mixture per se, but rather limits (chokes down) the throat area with the choke-flap - thereby leaving the accelerator pedal travel to operate through the full range.

It sounds like this operates to increase the throttle speed itself - thereby increasing the fuel component mixture in the opposite action (same as pressing the gas pedal a bit), but would limit the lower end of the accelerator pedal operation.

....ergo, Ken's 2200 rpm "free idle"

The function is the same as the cold start device in my 73 2L's D-jet system, kicking up the idle a few 100s rpm while cold, but done manually.

IMHO - they still could've put that sucker on the wide-a** dash for easier access. (IMG:style_emoticons/default/dry.gif)

Maybe I'll find a nice 914-6 for myself one day, and actually have some dough left over to buy it after restoring my 73 2L! (IMG:style_emoticons/default/smile.gif)

...either that, or take another 914-4 & do Raby upbuild to 2270 or more, for more HP/TQ at less weight than that 6, for fun DD! (IMG:style_emoticons/default/biggrin.gif)

....but I'm sure the wife will put the kabash on that plan! (IMG:style_emoticons/default/dry.gif)

[r_towle]

Its a mechanical extra set of linkage that goes to the carbs.
It pulls on the carb linkage and its purpose is to allow the owner to hold idle at say 1500 while they wait for the car to warm up.
Once driving, you need to push it back down.

Rich

[Pat Garvey]

Its a mechanical extra set of linkage that goes to the carbs.
It pulls on the carb linkage and its purpose is to allow the owner to hold idle at say 1500 while they wait for the car to warm up.
Once driving, you need to push it back down.

Rich

Yeah Rich, it does that on carb's cars, as well as MFI and CIS cars. Helps a lot when it's working properly.

Back in the late 70's, I had a sporto 911E, and was living in Kentucky - working in Cincinnati. Came accross the bridge into KY at about 110 - KY trooper waiting! Stopped me about a mile up the hill. Told him I lived 5 miles away & the throttle was stuck. Just needed to nurse it home to fix it.

Looked at me dubiously & asked that I fire it up. Reached between the seats & pulled the lever up, started it, and the engine fired up to high rpm's. Shut it down quickly & told the officer "stuck linkage - I can fix it at home, but not here".

After a couple of minutes, he offered a tow. Told him it would wreck the front pan.

So, he told me to go home, but keep my foot on the brakes to keep the speed down, and turn the motor off & on when I got onto side roads. He followed me until I left the freeway, while tapping the brakes regularly to ease him.

Once I left the freeway, and he was gone, I drove the rest of the way at 30 mph.

True story!

I'll bet it would still work today. Who would know an old Porsche has a hand throttle between the seats?

Still don't understand why they have them on CIS motors - never used mine.
Pat

[r_towle]

I thought we were talking about 914/6 cars which are all carbs.

Rich

[Tom_T]

I thought we were talking about 914/6 cars which are all carbs.

Rich

Well Pat....being the Guru he is (IMG:style_emoticons/default/pray.gif) ....has expanded this to the tail-draggers with the floor throttle levers too! (IMG:style_emoticons/default/biggrin.gif)

My same question applies in any case, as does my comment of why not put it on the dash where it's more accessible!? (IMG:style_emoticons/default/dry.gif)

Hey Pat, did you ever fix that paint chip on your 914? (IMG:style_emoticons/default/confused24.gif)

[Cap'n Krusty]

Its a mechanical extra set of linkage that goes to the carbs.
It pulls on the carb linkage and its purpose is to allow the owner to hold idle at say 1500 while they wait for the car to warm up.
Once driving, you need to push it back down.

Rich

Yeah Rich, it does that on carb's cars, as well as MFI and CIS cars. Helps a lot when it's working properly.

Back in the late 70's, I had a sporto 911E, and was living in Kentucky - working in Cincinnati. Came accross the bridge into KY at about 110 - KY trooper waiting! Stopped me about a mile up the hill. Told him I lived 5 miles away & the throttle was stuck. Just needed to nurse it home to fix it.

Looked at me dubiously & asked that I fire it up. Reached between the seats & pulled the lever up, started it, and the engine fired up to high rpm's. Shut it down quickly & told the officer "stuck linkage - I can fix it at home, but not here".

After a couple of minutes, he offered a tow. Told him it would wreck the front pan.

So, he told me to go home, but keep my foot on the brakes to keep the speed down, and turn the motor off & on when I got onto side roads. He followed me until I left the freeway, while tapping the brakes regularly to ease him.

Once I left the freeway, and he was gone, I drove the rest of the way at 30 mph.

True story!

I'll bet it would still work today. Who would know an old Porsche has a hand throttle between the seats?

Still don't understand why they have them on CIS motors - never used mine.
Pat

They are installed on CIS engines because that's how you activate the cold idle enrichment function. The shops were, in the past, littered with 911s with exploded airboxes because owners didn't use the hand throttle. (That's what prompted my friend Jan Bieren to invent the cool little Backfire Pressure Relief Valve you see on so many CIS cars, mostly on replacement airboxes ...........). BTW, the hand throttle has to be calibrated in order to work properly. Seems to me it first appeared in 1969, with the introduction of MFI. Later CIS cars use a temp sensitive mechanism for cold idle enrichment, and it IS NOT the same as the cold start enrichment circuit, which is controlled solely by the thermotime switch and starter activation.

The hand throttle simply pushes a little block clamped to the throttle rod (911s don't have a throttle cable). The location of that block is adjustable. If they were to have mounted the hand throttle on the dash like a choke pull knob, there would be a lot of monkey motion levers, cables, and connection pieces added to the mechanism. Simple most often is best, and this elegant system was applicable to carbs, MFI, and CIS, over nearly a decade. Now you know.

The Cap'n

[Tom_T]

Thanx Cap'n....."Wery Interesting" - as Arte Johnson on Laugh-in used to say! (IMG:style_emoticons/default/biggrin.gif)

By the same token, moving the lever closer to the driver's seat could've caused all sorts of confusion with the heater lever, to disastrous results! (IMG:style_emoticons/default/blink.gif)

I always liked the trouble free (usually) automatic Cold Start Valve (CSV) on my 73 2L's D-jet.......no worries....most of the time.... (IMG:style_emoticons/default/smile.gif)

...until our Pacific onshore coastal salt air got in & corroded electrical connections on the EFI - esp. when I lived 3 blocks from the beach in Huntington Beach & even with a closed garage! (IMG:style_emoticons/default/dry.gif)

[Cap'n Krusty]

Thanx Cap'n....."Wery Interesting" - as Arte Johnson on Laugh-in used to say! (IMG:style_emoticons/default/biggrin.gif)

By the same token, moving the lever closer to the driver's seat could've caused all sorts of confusion with the heater lever, to disastrous results! (IMG:style_emoticons/default/blink.gif)

I always liked the trouble free (usually) automatic Cold Start Valve (CSV) on my 73 2L's D-jet.......no worries....most of the time.... (IMG:style_emoticons/default/smile.gif)

...until our Pacific onshore coastal salt air got in & corroded electrical connections on the EFI - esp. when I lived 3 blocks from the beach in Huntington Beach & even with a closed garage! (IMG:style_emoticons/default/dry.gif)

If you lived in Huntington beach, your CSV NEVER activated. It was never cold enough for it to come on. The Cap'n

[Pat Garvey]

I thought we were talking about 914/6 cars which are all carbs.

Rich

I thought I'd impart a little experience, since many sixers have MFI and CIS systems, aside from the carbs.

Sorry, I'll just shut up.
Pat

[Tom_T]

If you lived in Huntington beach, your CSV NEVER activated. It was never cold enough for it to come on. The Cap'n

(IMG:style_emoticons/default/agree.gif) Not in HB -

...but then I did go places like Big Bear, Arrowhead, Mammoth, Tahoe, Brianhead/Cedarbreaks, Park City, Ashland, etc. & assure you that the CSV did activate there! (IMG:style_emoticons/default/poke.gif)

...heck, I still even have ski racks & a set of chains for the 165HR15s for the Teener! (IMG:style_emoticons/default/biggrin.gif)

In fact, I'd even done the Body Surf 1/2 day at the Beach & Ski 1/2 day in the mountains - ALL in ONE day thing - on several occasions! (IMG:style_emoticons/default/shades.gif)

...also went up north during winter part of Rugby season to play games when it was actually cold enough to kick in the CSV! (IMG:style_emoticons/default/icon_bump.gif)

They did allow us to leave HB every once & awhile ~ (IMG:style_emoticons/default/driving.gif)
...don't they let you out of Santa Maria Krusty?? (IMG:style_emoticons/default/blink.gif)

FYI All Y'all - the above are mountain ski resorts/areas with winter weather.... (IMG:style_emoticons/default/popcorn[1].gif) (IMG:style_emoticons/default/dry.gif)

[Tom_T]

I thought we were talking about 914/6 cars which are all carbs.

Rich

I thought I'd impart a little experience, since many sixers have MFI and CIS systems, aside from the carbs.

Sorry, I'll just shut up.
Pat

Hey Pat, I'm sure others enjoyed the input, given the wide range of replies on both the 914-6 & 911 sides! (IMG:style_emoticons/default/biggrin.gif)

...I am!!!! (IMG:style_emoticons/default/popcorn[1].gif)

[Pat Garvey]

Its a mechanical extra set of linkage that goes to the carbs.
It pulls on the carb linkage and its purpose is to allow the owner to hold idle at say 1500 while they wait for the car to warm up.
Once driving, you need to push it back down.

Rich

Yeah Rich, it does that on carb's cars, as well as MFI and CIS cars. Helps a lot when it's working properly.

Back in the late 70's, I had a sporto 911E, and was living in Kentucky - working in Cincinnati. Came accross the bridge into KY at about 110 - KY trooper waiting! Stopped me about a mile up the hill. Told him I lived 5 miles away & the throttle was stuck. Just needed to nurse it home to fix it.

Looked at me dubiously & asked that I fire it up. Reached between the seats & pulled the lever up, started it, and the engine fired up to high rpm's. Shut it down quickly & told the officer "stuck linkage - I can fix it at home, but not here".

After a couple of minutes, he offered a tow. Told him it would wreck the front pan.

So, he told me to go home, but keep my foot on the brakes to keep the speed down, and turn the motor off & on when I got onto side roads. He followed me until I left the freeway, while tapping the brakes regularly to ease him.

Once I left the freeway, and he was gone, I drove the rest of the way at 30 mph.

True story!

I'll bet it would still work today. Who would know an old Porsche has a hand throttle between the seats?

Still don't understand why they have them on CIS motors - never used mine.
Pat

They are installed on CIS engines because that's how you activate the cold idle enrichment function. The shops were, in the past, littered with 911s with exploded airboxes because owners didn't use the hand throttle. (That's what prompted my friend Jan Bieren to invent the cool little Backfire Pressure Relief Valve you see on so many CIS cars, mostly on replacement airboxes ...........). BTW, the hand throttle has to be calibrated in order to work properly. Seems to me it first appeared in 1969, with the introduction of MFI. Later CIS cars use a temp sensitive mechanism for cold idle enrichment, and it IS NOT the same as the cold start enrichment circuit, which is controlled solely by the thermotime switch and starter activation.

The hand throttle simply pushes a little block clamped to the throttle rod (911s don't have a throttle cable). The location of that block is adjustable. If they were to have mounted the hand throttle on the dash like a choke pull knob, there would be a lot of monkey motion levers, cables, and connection pieces added to the mechanism. Simple most often is best, and this elegant system was applicable to carbs, MFI, and CIS, over nearly a decade. Now you know.

The Cap'n

Kruster,

Look, I know this could be construed to be, well hell it is, non-original text. But since we have it started....

Many teeners have CIS motors in their 914s. How is this hand throttle calibrated ?
Pat

[Michael N]

Every once in a while I forget to push the lever down all the way after warming my 2.4S MFI up. When shifting in the 1800 - 2200+ rpm range the car feels very zippy. It makes the car really want to go since the S cams and MFI doen't really bring the engine to life until 3000+ RPM's. I sometimes pull back on the lever when driving backroads to keep the RPM's up.

[Eric_Shea]

Sorry guys... the hand throttle is simply a rod that actually goes "forward" to the pedal assembly.

The bell crank on a 914-6 pedal assembly has a wing off the side that this rod pushes against, effectively pushing your pedal down for you. When you lift the hand throttle you can actually see the pedal go down.

No extra linkage to the carbs and no blocks.