How To Convert Throttle Linkage on 3.6 Transplants?
 

How do guys do the throttle set-up on earlier cars when a 3.6 is tranplanted??

I have a Hot-Rod 3.4 with the plastic 3.6 intake. My ('85 Targa) has hard linkage from the foot pedal all the way to the engine. I need to use either a cable set-up from the foot pedal back or some other known solution.

So I need the same deal as the 3.6 transplant guys. Advice please

Thanks

Throttle cable by Patrick Motorsports is what I have seen.

Asphalt,
I've got a great solution for you. Buy a generic hot rod throttle cable (36" is the right length, I think).

$40 for a nice braided stainless one from Summitracing:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=LOK%2DTC%2D1000HT 36&N=700+%2D104640+115&autoview=sku

You need to add 3/4" to one of the bellcrank lever arms on the 915 tranny. (That changes the leverage between the pedal and the throttle plate.)

And you need to buy a clevis pin (I bought one from ACE Hardware) and cut it off to fit into the clip on the factory throttle pull.

I'll post pictures shortly.

If you cannot weld and don't have a local resource, you could send the bellcrank to me and I'd modify it.

Doug

It is necessary to fab this bracket (black, seen best in the middle picture) which holds the end of the cable at the transmission, as well. You could easily use 1" x 1/8" steel bent to shape. Worst case, you could send it and a gusset and I'd weld in the gusset to strengthen it.

I used sheet metal and welded the gussets in place.

The throttle kit comes with the ball and socket you see attached to the modified bellcrank. Note, the lengthened bellcrank arm is the one attached to the throttle cable.

http://forums.pelicanparts.com/uploa...1160171085.jpg

http://forums.pelicanparts.com/uploa...1160171114.jpg

http://forums.pelicanparts.com/uploa...1160171137.jpg

Doug - So you keep the OE throttle rod /linkage from the pedal assy all the way back to the trans bell crank and run a cable from there?

I have extensive fabrication / welding experience

Yes, sir! I just adapted this solution from the bellcrank to the throttle body, nothing on the on the pedal side. You won't need to use much of your fab experience to do this one!

I did have to reset the throttle stop so I wouldn't bend anything when I hammer the gas pedal.

I'm hunting for a pic on the throttle body side. The throttle cable has a ball at the end that you pull against. I have a hole through the clevis pin (about 1/4" in diameter) which sits against the ball and rotates within the factory clip on the throttle body arm.

Does that make sense?

I will measure that the cable is 36", also. If you buy oversized, you can trim the cable and trim the housing, as necessary. Mine requried zero trimming. $40, some welding and a bit of fab and it looks factory.

BTW - the arms on the bell crank retain the same angular reference to one another. Only the length on the one was increased.

Doug

Found a beautiful picture of it:http://forums.pelicanparts.com/uploa...1160171802.jpg

AND one more:http://forums.pelicanparts.com/uploa...1160171877.jpg

lay a string from the bellcrank up to the zinc plated bracket that you see above and you will have the right length - leave it loose.

Finally, I zip tied the cable housing to the top of the tranny breather to make sure it didn't wrap around the axle.

Doug

Doug thanks for all the detailed info and pics. I just may do it this way. It looks like the simplest way to go.

Anyone else do something different?

Why so complicated. Use a stock 964/993 throttle cable, shorten the outer mantle, fabricate a shand-off at the tunnel exit and you are done. It woks much nicer than the old-fashioned linkage.

Hey, I have the Timmins setup on my conversion and although it works ok and is a simple solution I'm also concerned it might let me down one day. With this in mind I would be interested to hear more about the setup you sugest - can you point me into the direction of any more details?

Cheers

Bump

Jevvy-

I also have the Timmons setup. My mechanic has told me that it may indeed fail some day. He suggested the Patrick Motorsports throttle cable as suggested earlier.

OK, I'll try to give some more details of the throttle cable setup I use.

The 964 cable is a bare steel cable that has the ball-pan connecting it to the pedal pivot point in the tunnel close to the pedal. The other end connects to the throttle body on the engine. The outer mantle running from the tunnel exit to the engine is made from rigid steel wires wrapped in black plastic sheeting.

I used a 1/4 inch teflon tube in the tunnel to route the steel cable. It makes sure the cable does not interfer with the shift linkage. The outer mantle of the 964 cable runs from the tunnel to the metal flange on the engine. It is a bit longer due to the shorter tunnel in 964/993 cars. I shortened it by cutting the plastic part with a sharp knife and using a triangular metal file to cut the steel wires. Once you have the right length you need to fabricate a stand-off at the tunnel exit. You can use a large washer welded onto the exit or a piece of steel tube. Since I had no access to a welder at the time I used a PVC reduction piece from an irigation system jammed into the tunnel exit.

The benefits of the 964 setup are that it does not use any linkage parts in the tunnel. There is not binding or dead play at all and you have a perfect pedal feel with no parasitic forces.

I have seen the early Timmens setups and they reminded me of cheap bicylce break parts from the early 70's. The Patric cable is nothing else but a modified 964 cable. I just didn't feel like droping a lot of cash so I did it myself from a used cable. Once I get back from Asia (business travel) I'll snap some pictures. The engine is currently out for some R&R so it's a good time.

Cheers,
Ingo (in Tokyo)

Jay, thanks for mentioning your Mechanics comments - seems my concerns are shared by a few.

Hey Ingo, thanks for the explanation - I think it makes sense but of course pictures would help, I will try to find a 964 cable while I wait for your pics. Hope you are having fun in Tokyo, my mrs used to go there a lot and I seem to remember her mentioning having lots of fun in a club called "dump truck" and that Shibuya and Shinjuki are nice places to eat and shop.

Guys,
How close is my setup to Timmons? I'm very confident in this setup not breaking, but simple is usually better. I replaced the ball and sockets when I put this together, too. The mechanism is very tight and responsive.
Thanks,

Doug

Doug

Your setup uses the same principle as the Timmins one however you have used far superior materials, If I was going to just re-do mine I would do it like you have but I'm gona look at alternatives before I do.

FWIW my timmins stuff has done great for the 10k miles I have done since the conversion and cant really fault it however I'm sure there is a better longer lasting solution available its just im not bright enough to think of it myself!

Hey Ingo(and others)

I have tracked down a cheap throttle cable and wondered if any of you might be able to tell me if it will be of use on my LHD 3.2-3.6 conversion.

The part I have found is 993.423.024.03. For an early 993 RHD.

Since I dont know how the front end hooks up I dont know if the LHD/RHD difference is a problem or whether the 993 one is the same as the 964 mentioned above. FWIW my engine is a 993 non-vram.

Hope someone can help - pics of the connections used would also be awesome.

Doug,
this is a great solution... in the pic you posted your missing the washer at the bottom of the tranny mount, or at least I have one there.
http://forums.pelicanparts.com/uploa...1171979104.jpg

Also... what the heck is up with your car?? Did you get the motor taken care of and what was the problem? SmileWavy

That is what I am using and it works very well. Is not cheap but very well made.

The Timmins cables I have seen were crap. May have gotten better in the last few years but the last thing I want is to take a chance on the throttle cable sticking wide open and ruining an engine because of it.

Herman,
You are right!
I need to add the washers.

Thank you,

Doug

PS - on a side note, I'm close to a heat solution worked out with Ben M (M&K). He's doing a bit of Aluminum fab work for me and sending me some bulk flex hose. It will use only one Heat Exchanger, but that should be more than fine for me. This will be simple, clean and at least provide me defrost.

Throttle Linkage
 

All of that is well and good. My '75 race car has an even simpler solution. From the gas pedal all the way back to the swing plate on the engine block, it is all 911. So all I have to woory about is how to attach the rod to the throttle body.

What the car's builder did was weld a small ball to the 993 throttle body, shown in these pictures.


http://forums.pelicanparts.com/uploa...1171991351.jpg

http://forums.pelicanparts.com/uploa...1171991388.jpg

Works very well. Also works with the 80 mm Ford throttle body I installed last year.

Simple. Works.

I can take pictures of the entire setup if you need them. I think if you can weld, this is a $5 solution. Actually, you don't even need to weld it on, you can screw it on as well.

I just completed my throttle setup, based on Ingo's info. All I had to do is cut off about 12" of the outer mantle and it was the right length. I made the stand off with a brass plumbing reducer and a barbed fitting with an OD almost the same as the ID of the adjuster on the 964 cable.
I got the cable for the doner car and the other stuff was in my plumbing bin.

Only question I have is that the throttle spring seems like its going to be weak. Is there just 1 on a 964?

Bill, I only have one spring on my 964 that is integrated into the throttle mechanism. It is strong enough to pull the throttle shut all the way and engage the idle microswitch. Maybe you need to lube the mechanism a little bit.

MikeZ uses the Timmens setup. He had to put in an additional spring to make the throttle close all the way.....

It works fine, I just wonder what it will feel like under my foot!
I'm almost there my freind!

Hey Ingo, thanks for swinging by - any thoughts on the above?

I've been using the Timmins setup for 5 years without a glitch. Many track days.

Has anyone heard of his engines blowing up because of a stuck throttle? The way it's setup, I just can't see how that could happen.

I think RHD and LHD are the same - no reason for a difference since the cable goes through the center tunnel. As far as 964 and 993 they are the same for sure.

Good luck,
Ingo

Here is a picture of the 964 and the SC cables at the point where they enter the tub.
Sorry my picture is bad. Having problems with the focus on my camera.

The front ends of both have the same threaded connection onto the part that snaps on the ball on the lever.

The black part on the 964 cable can adjust about 1" and some moer ajustment is avalible (if needed) by bending the stop on the engine side.

Someone posted a picture of the throttle end before.

http://forums.pelicanparts.com/uploa...1172518425.jpg

I found a few more pictures
Here's the adapter by itself

http://forums.pelicanparts.com/uploa...1172519636.jpg

Nice work Bill. I simply punched a plastic reducer into the tunnel to work as stand-off on my setup . At the time I was kind of on the last legs of my project and really anxious to get it going. Today, if I had to do it again I would probably try to source a piece of the tube on from a 964 and weld it in properly. But oh well, you know how this goes - at some point you need to start to cut corners if you want to get the car on the road....

Cheers and keep us posted on progress,
Ingo

Thanks William and Ingo - I have ordered the cable and I will see where it gets me.

Here's another picture I found of the cable entering the tunnel flange.
http://forums.pelicanparts.com/uploa...1172591893.jpg

Can you post some pictures of the cable when you get it?
I wonder what comes with it.

To strip the outer layer I first used a utility knife on the black plastic, then used the dremel to cut the stranded wire at the new location, then unpeeled the inner metal jacket and cut it at the new location.
Pictures of this process would be good for the thread.
Hope the cable comes soon!

Ok guys I have the cable and it now makes more sense. I have fitted the cable to the throttle and fed things forward so I'm at the point that I need to decide how much to cut off.....!

I think it needs to be fairly accurate, cut too much off and you will have too much slack running forwards, too little and the cable wont reach the pedal.

How did you guys judge this - I have layed the cable out under the car to roughly where it needs to be and marked it but this seems a little hit or miss, would it be best to feed it all into the tunnel then measure from there?

Also did you guys build in some adjustment anywhere other then the very front mount where it connects to the pedal?

Thanks again in advance for your help - off to raid B & Q for brass fittings :-)

Throttle for 3.6 or 3.8 in earlier car
 

Looks like you are on your way with a cable solution, so my approach may not be relevant to you, but may help others searching and discovering this thread.

My approach uses stock linkage all the way to the plate that is mounted to the 3.6 case. The plate is from an earlier 911, and bolts right onto the case. Then I run a rod between that plate and the throttle body. So you have to add a ball to the throttle body as I mentioned earlier. PMO sells these for a few bucks. So really, all you need to do is add a <$5 ball and find a throttle linkage rod with the correct length, which you can probably find at a Porsche dismantler.

Some special things on my car not needed for most conversions...

I am running Haltech, and a 993 intake manifold. I want the intake window to work and so I use an RPM switch to control it. To mimic the logic of the factory CPU, I need a switch for ~67% throttle, so you can see I have mounted a magnetic switch to the plate for that. A car with the factory computer would not need that, as the stock throttle body will have all of the microswitches you need.

I also have a BBK 80 mm throttle body for more power, so that is a little different from what you'd need with a typcial 3.6 conversion. Since I have the big throttle body, and no idle stabilizer stuff, I strapped the intake manifold to the case so that it doesn't move as much and this improved my idle sufficient for a race car. You can see one of the straps in the pics below.

Also, the BBK has a rather weak spring, so I added one for better response. The stock 993 throttle has a nice strong spring.

http://forums.pelicanparts.com/uploa...1173820188.jpg http://forums.pelicanparts.com/uploa...1173820225.jpg

jevvy,
In my first picture above, I had the SC throttle rod and the 964 cable lined up side by side. The pedal ball ends clamped to a workbench so they were even. The other ends streached out. You can see where the SC rod enters the tunnel by the position of the rubber boot.
This is the approximate length considering what your using between the outter seith of the cable and the tunnel. Mine came from a doner car and it has this nice adjuster at that spot. The adjuster is black plastic and can take up to about 1" of slack.

I installed the engine about a week ago and it all works great.

Mike, I love your setup and wish I thought of it or saw it before I got as far as I did.

jevvy, you will find that running the limp 964 cable thru the tunnel is a pain. There are 2 or 3 plastic bushings that it needs to be threaded thru. Luckily I did this when the seats were already out. I removed the shifter housing and the e-brake. With these out of the way I could pretty much feed the cable with my hands.

Excellent, I never thought about working back from the front using the ild rod on a bench - sounds perfect.

I was thinking I might slide a length of tube forwards over the rod before a remove it then I can use that to feed the new throttle cable through upto the pedal - might even leave the tube in place to protect the cable as Ingo suggests above.

Thanks for the help