Better throttle response for free!
05-30-2012, 08:03 PM
#32
Nordschleife Master
Thread Starter
Thanks for the pic Reb 
that pretty much confirms that later cars had a different set up (and it's not that the cup car had a special change compared to normal 964s).
that pretty much confirms that later cars had a different set up (and it's not that the cup car had a special change compared to normal 964s).
05-31-2012, 02:04 PM
#33
I suspect the change came when Porsche introduced plastic inlet manifolds. Adrian's book (p139) says there were 2 different versions of the idle speed control valve - the later version incorporated a small noise muffler (why does the noise need to be muffled?!)
05-31-2012, 02:14 PM
#34
Post trackday thoughts:
Last Thursday, Oldtimer and myself travelled down to Castle Combe for the annual 928 trackday. On the way down the springless throttle was a pleasure to use. Light on the foot and it seemed very responsive. Very useful in those convoy situations where you get separated by a numpty that wants to get in the middle and then have to accelerate quickly to catch up the gap.
Last Thursday, Oldtimer and myself travelled down to Castle Combe for the annual 928 trackday. On the way down the springless throttle was a pleasure to use. Light on the foot and it seemed very responsive. Very useful in those convoy situations where you get separated by a numpty that wants to get in the middle and then have to accelerate quickly to catch up the gap.
06-05-2012, 08:33 AM
#35
Three Wheelin'
Just taken mine off
Throttle now feels much lighter and it makes it easier to keep the revs up when heel & Toeing (or appears to at least)
Good find Steve
Its not going back on
Throttle now feels much lighter and it makes it easier to keep the revs up when heel & Toeing (or appears to at least)
Good find Steve
Its not going back on
06-09-2012, 12:27 PM
#36
Nordschleife Master
Thread Starter
UPDATE
I'm currently trying out a lighter throttle return spring (TRS). It's a little longer in its resting state than the original (top of pic) - 60mm vs 55mm:
Here it is attached to the throttle mechanism in the rest position (idle microswitch making contact):
As I open the throttle the new TRS stays at the same tension which means the light pedal feel that we've been seeing without a TRS is retained. Here it is again with the throttle just opening (no longer in contact with the idle microswitch):
As I get close to WOT the new TRS starts to tense up and this continues right up to WOT:
The result of all this is that when driving the throttle pedal is very light and responsive when I first press my foot on it and firms up as I get close to WOT (but not as firm as it is with the original TRS). This seems to give the best of both worlds...a light and responsive throttle with the security that there is a spring there to prevent being stuck at WOT when I have to lift off.
It's early days but I'm pretty pleased with this set up at the moment.
Oh! and the lighter springs cost me 3 quid for three of them! They're supposed to be meant as spares for an MG.
I'm currently trying out a lighter throttle return spring (TRS). It's a little longer in its resting state than the original (top of pic) - 60mm vs 55mm:
Here it is attached to the throttle mechanism in the rest position (idle microswitch making contact):
As I open the throttle the new TRS stays at the same tension which means the light pedal feel that we've been seeing without a TRS is retained. Here it is again with the throttle just opening (no longer in contact with the idle microswitch):
As I get close to WOT the new TRS starts to tense up and this continues right up to WOT:
The result of all this is that when driving the throttle pedal is very light and responsive when I first press my foot on it and firms up as I get close to WOT (but not as firm as it is with the original TRS). This seems to give the best of both worlds...a light and responsive throttle with the security that there is a spring there to prevent being stuck at WOT when I have to lift off.
It's early days but I'm pretty pleased with this set up at the moment.
Oh! and the lighter springs cost me 3 quid for three of them! They're supposed to be meant as spares for an MG.
06-09-2012, 12:41 PM
#37
Three Wheelin'
06-09-2012, 02:07 PM
#38
Nordschleife Master
Thread Starter
PM me your address Gary and I'll pop one in the post to - I don't need more than one as a spare!
For others interested:
http://www.ebay.co.uk/itm/2307892786...84.m1423.l2649
For others interested:
http://www.ebay.co.uk/itm/2307892786...84.m1423.l2649
04-15-2014, 12:25 AM
#42
my 1990 has the spring, but i did noticed that cars without the spring also don't have the idle microswitch, i put mine back cause i was having terrible hunting idle problems and i never realized that this was the root caused.
