Full Version: Temp Sensor Spacers
Sorry guys I just read a thread on these spacers where a guy has them for $24 ea. but I can't find thread and I'm a dumb shit with search features.
QUOTE(76-914 @ Feb 24 2010, 07:25 PM) 
Sorry guys I just read a thread on these spacers where a guy has them for $24 ea. but I can't find thread and I'm a dumb shit with search features.
Brad Mayuer 914Ltd.
QUOTE(detoxcowboy @ Feb 24 2010, 07:49 PM)
QUOTE(76-914 @ Feb 24 2010, 07:25 PM)
Sorry guys I just read a thread on these spacers where a guy has them for $24 ea. but I can't find thread and I'm a dumb shit with search features.
Brad Mayuer 914Ltd.
Yea, Thanks detox. I got that already from Blanders later post but when I do a search on it I'm not coming up with it. Brad actually responded to one of Blanders post with the info on how to order them but as I stated earlier; cranial rectosis here. Thanks anyway.
QUOTE(76-914 @ Feb 24 2010, 08:25 PM)
QUOTE(detoxcowboy @ Feb 24 2010, 07:49 PM)
QUOTE(76-914 @ Feb 24 2010, 07:25 PM)
Sorry guys I just read a thread on these spacers where a guy has them for $24 ea. but I can't find thread and I'm a dumb shit with search features.
Brad Mayuer 914Ltd.
Yea, Thanks detox. I got that already from Blanders later post but when I do a search on it I'm not coming up with it. Brad actually responded to one of Blanders post with the info on how to order them but as I stated earlier; cranial rectosis here. Thanks anyway.
I read that posting and he just said he had them for sale but did not give specific directions on how to obtain them.. I would think..pm email or call...
tell him a detox cowboy sent u. it will confuse him..
914 Ltd Inc. (309) 694-1797
Info and pics in this thread:
http://www.914world.com/bbs2/index.php?sho...=103298&hl=
Just PM Brad Mayeur and he'll set you up.
FWIW, installing this spacer is the best thing I've done in years to make my car run better. No more surging and crappy idle while warming up, and it doesn't screw up the mixture once the engine is warmed up (as does a ballast resistor).
The heads must heat up and cool off quite rapidly. What do people who have a VDO head temperature gauge see on their cars?
BTW, Brad Mayeur made a comment that I suspect explains how this problem came about. He said the 1.7's don't have this problem. Since they preceded the 2.0's, I suspect that the CHT's NTC resistor characteristics were chosen for that engine, and to cut costs, Bosch/Porsche eventually decided not to go with a different CHT for the 2.0L's, which seem to want a richer warm-up mixture (perhaps due to the increased cylinder and piston surface area?). They did use a different sensor on the first 2.0's ('73), but that was likely due to their use of the same ECU as the 1.7's, and it helped the engine run richer overall to help deal with the fact that the 1.7 ECU didn't have the right speed correction board in it. I suspect the ballast resistor they used was partially an attempt to improve the warm-up behavior. Once the 2.0L ECU's came out, they reverted to the 1.7's CHT and dropped the ballast resistor.
http://www.914world.com/bbs2/index.php?sho...=103298&hl=
Just PM Brad Mayeur and he'll set you up.
FWIW, installing this spacer is the best thing I've done in years to make my car run better. No more surging and crappy idle while warming up, and it doesn't screw up the mixture once the engine is warmed up (as does a ballast resistor).
The heads must heat up and cool off quite rapidly. What do people who have a VDO head temperature gauge see on their cars?
BTW, Brad Mayeur made a comment that I suspect explains how this problem came about. He said the 1.7's don't have this problem. Since they preceded the 2.0's, I suspect that the CHT's NTC resistor characteristics were chosen for that engine, and to cut costs, Bosch/Porsche eventually decided not to go with a different CHT for the 2.0L's, which seem to want a richer warm-up mixture (perhaps due to the increased cylinder and piston surface area?). They did use a different sensor on the first 2.0's ('73), but that was likely due to their use of the same ECU as the 1.7's, and it helped the engine run richer overall to help deal with the fact that the 1.7 ECU didn't have the right speed correction board in it. I suspect the ballast resistor they used was partially an attempt to improve the warm-up behavior. Once the 2.0L ECU's came out, they reverted to the 1.7's CHT and dropped the ballast resistor.
"The heads must heat up and cool off quite rapidly. What do people who have a VDO head temperature guage see on their cars?"
Yes they (cylinder heads) heat up first and cool first both much faster when looking at the gauges oil temp. vs. cylinder head temp. especially heating up on a cold start.
Yes they (cylinder heads) heat up first and cool first both much faster when looking at the gauges oil temp. vs. cylinder head temp. especially heating up on a cold start.
QUOTE(detoxcowboy @ Feb 25 2010, 08:57 AM)
"The heads must heat up and cool off quite rapidly. What do people who have a VDO head temperature guage see on their cars?"
Yes they (cylinder heads) heat up first and cool first both much faster when looking at the gauges oil temp. vs. cylinder head temp. especially heating up on a cold start.
That's what I thought, because I was concerned that since the spacer doesn't have any initial effect (at start, same temp as the cold head), I thought the car would still act lean during the first couple of minutes (i.e. off-throttle surging). However, that's not what I see, it acts great through the whole warm-up transition. I figured that was because the heads must be heating up quickly, and by the spacer delaying that heat transfer to the sensor right from the start, the mixture is kept where it should be.
The quick cooling leads to the warm staring problem we discussed in another thread. This issue is avoided in water-cooled D-Jet implementations, as the engine temperature is sensed from the block. Hmm. You have to wonder if an oil temperature sensor instead of a head temperature sensor would have been a better choice for air-cooled implementations of D-Jet...
The rapid change in head temperatures also points out why avoiding ballast resistance is a good thing, too. If head temps are swinging over a significant range where the CHT resistance is going between 50 to 200 ohms, corresponding roughly to head temps of 300 to 200 degrees, then as little as 200 ohms of ballast would result in the ECU richening the mixture, introducting mixture instability, wasting fuel, and increasing emissions. The spacer helps smooth out those operating-induced swings (that don't actually reflect the cylinder/piston temperature conditions, which dominate the mixture requirements), an eliminate those effects.
QUOTE(pbanders @ Feb 25 2010, 08:32 AM)
QUOTE(detoxcowboy @ Feb 25 2010, 08:57 AM)
"The heads must heat up and cool off quite rapidly. What do people who have a VDO head temperature guage see on their cars?"
Yes they (cylinder heads) heat up first and cool first both much faster when looking at the gauges oil temp. vs. cylinder head temp. especially heating up on a cold start.
That's what I thought, because I was concerned that since the spacer doesn't have any initial effect (at start, same temp as the cold head), I thought the car would still act lean during the first couple of minutes (i.e. off-throttle surging). However, that's not what I see, it acts great through the whole warm-up transition. I figured that was because the heads must be heating up quickly, and by the spacer delaying that heat transfer to the sensor right from the start, the mixture is kept where it should be.
The quick cooling leads to the warm staring problem we discussed in another thread. This issue is avoided in water-cooled D-Jet implementations, as the engine temperature is sensed from the block. Hmm. You have to wonder if an oil temperature sensor instead of a head temperature sensor would have been a better choice for air-cooled implementations of D-Jet...
The rapid change in head temperatures also points out why avoiding ballast resistance is a good thing, too. If head temps are swinging over a significant range where the CHT resistance is going between 50 to 200 ohms, corresponding roughly to head temps of 300 to 200 degrees, then as little as 200 ohms of ballast would result in the ECU richening the mixture, introducting mixture instability, wasting fuel, and increasing emissions. The spacer helps smooth out those operating-induced swings (that don't actually reflect the cylinder/piston temperature conditions, which dominate the mixture requirements), an eliminate those effects.
Brad, thanks for taking the time to find that thread for me. I ordered one tonight. Might be a month before I get it installed. Also, thanks so much for all your work and personal time that you have invested so that hundreds of us DUMMIES can enjoy these sweet little cars. A million thank you's and counting. 
QUOTE(type47 @ Feb 26 2010, 10:59 AM)
That's it. Atwell's site is where I first heard about them.
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