wow....SCs are faster than i thought!
 

I just wanted to reference this thread...

Why is my SC more fun....etc...

the mention of worn or ill-adjusted throttle linkage came up and prompted me to get mine checked. i had a suspicion that i wasn't getting full throttle from the rather sloppy feel of the accelerator. i was in the neighborhood and had Tyson at TRE check it out and sure enough, i was only achieving around 2/3 of my throttle with the pedal to the floor! fast forward a bit and after he fixed the linkage i took it for a test drive and GOOD GOD!!! it felt as though Tyson had mounted a turbo back there.....seriously it was a rather astonishing change in acceleration and also the feel and touch of the accelerator.

I thought i would mention this since it made such a huge difference in my cars performance right away!.....i mean 1/3 of 180 is around 60hp that i was missing from the top......i didn't know it but i was actually driving a 911T this whole time! This tells me that many SCs (or carreras) of similar age could have this issue.....

now i can really agree with the original review of the SC in car and driver when they say, "Riding shotgun in the raging, spitting, hair-trigger 911SC is just about the most awful and impossible way there is to remain passive." :D

I took my car to Tyson at TRE and he found the same with my SC. What a difference! It felt like a completely different car.

David

A T? You were driving a 912 :D

Yea, it's hard to believe how common this is.

My sc had the same problem, was not getting full throttle. Much, much, much better after adjustment.

Every sc owner should spend an afternoon looking at this.

Did I mention it was much better ?

Would this be applicable for my '79 930 as well? Same era, so I'd guess same linkage???

How does one check? Is there a specific area/part that's more prone to being out of whack?

Thanks,
Skip

http://www.pelicanparts.com/catalog/images/fuel_injection/new_images/fi_fielsystem_1-7-2e65.jpg

there are the bushings i suspect he speaks of. mine were found to be bad on a PPI and it was the 1st thing i did to the car. its a ***** to get to though. especially if you have not backdated your heat. the blower and all the lft side ducting must come off. even the the heater fan mounting brackets puts a nice crease/dent/slice in the back of your hand.

Is this the full throttle switch (aka WOT switch) that is being referred to? I think I remember reading a post by Steve Wong that mentioned that the full throttle switch is not working properly on most Carreras, unbeknownst to their owners, and it sounds like lots of SC's suffer from the same thing.

I just dropped my car off at the shop for a new clutch, and I asked the tech to check the operation of the full throttle switch. Maybe when I get it back I'll have a faster car!

In the SC it is not a switch but a series of rods, links and bell cranks that need to be adjusted to get full throttle.

This throttle linkage adjustment issue pertains to all engines in all machines, not just 911SCs. I once had a Toro lawnmower that was not getting full throttle for years. Who knew? :D

All Porsches and all cars and lawnmowers need to be checked for this, it's simple: Have a helper push pedal to the floor and hold it there. You walk around to the rear, (if it's a 911), and see whether the throttle, (butterfly valve), is open all the way, or can you grab it and move it further to the stop. In some cases all it needs is a simple adjustment, on my SC before the rebuild it was the shot linkage/bushings and it could not be adjusted properly until they were replaced. :cool:

I was there and can attest to the astonishment one jfw's face when he got back from the test drive. Had mine done about 1.5 years ago...a definite "must check" thing for all.

What was I doing at TRE? Nothing...just move along...nothing to see. Yet.

Is this something you can check yourself? Anyone have a photo?

I don't recall this in the 101 book.

What do I look for?

Still repairing that concrete damage are we :)

You mean that:

While the car is in neutral, you couldn't press the accelerator pedal and get your car to the RED line?

This is one of the oldest basic mistake and first thing to check. With engine off do you have full movement by pedal in the car of the Carb, MFI,CIS etc. it does not matter what your fuel deliver systom is. Sometimes it is something really stupid like the carpeting bunched up under the throttel pedal. In Alaska I had a customer ice fall off there boots and build up behind the pedals of there 73 bug till the clutch would slip becouse the pedal could not return. but most of the time the linkage wore a little bit in in enough palces that it did not move the full amount and just needed to be adjusted back to full movement.

On an sc, with the engine OFF, have someone press the gas pedal to the floor a few times while you look at the engine. It will become apparent what part is moving back and forth on the throttle body.

Then, ask them to press the pedal to the floor and hold it. Now if you can manually move the throttle even further then there is travel that is not being used and you may not be getting full throttle.

Now I have heard a rumor that if the linkage is adjusted to get full throttle and its done improperly there is a chance it can get stuck at WOT which on a 911 could be inconvenient so, proceed with caution.

I fiddled with mine for a while and couldn't get the adjustment I wanted so I cheated and had the accelerator rod that attaches to the back of the accelerator pedal lengthened by half an inch at a machene shop, but thats the neanderthals way out, I know your better then that.

Re: wow....SCs are faster than i thought!
 

Hey Jeff,
You only thought you weren't getting full throttle cuz the other day you were trying to catch up to my 3.2! LOL!
Just kidding of course. Glad you got it figured out. It must really zoom now.

haha....steve, yes i was actually having trouble keeping up with ANYONE on sunday....but that i think was mainly due to my rear tires which are LONG overdue for replacements...

yes the main problem in mine was the bushings i think...but i also saw tyson fooling with the spring and cursing loudly at it.....(i think that might have been from his fingers being burnt on my intake manifold though) http://www.pelicanparts.com/support/smileys/128.gif
here is a pic of the parts:
http://forums.pelicanparts.com/uploa...1110442287.jpg

My cousin has a 82 SC and his linkage wasn't fully opening until I adjusted it and now he really knows how a SC really pulls.