High Speed Inlet Temperature Sensor
11-11-2008, 01:43 PM
#1
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Join Date: Sep 2006
Posts: 5
Dear forum members,
A couple of years ago I found that the inlet temperatures I was seeing (Apexi ECU with commander) did not tie in with what I knew was happening. I expected the temperature to fluctuate as I accelerated through the gears as the turbo's passed through their range of efficiency. I was running stock twins, at 1.1 BAR, so they were running above their normal operating range.
On inspection I found the standard air temperature sensor to be heavily shielded with a large time constant. This means that any change in temperature will not register quickly with the ECU. If you have wondered why your water injection, or a sudden increase in speed (and intercooler efficiency), does not translate into variations in inlet temperature, then the standard inlet temperature sensor can be blamed. We may never know why the standard sensor is so shielded from actual intake conditions. I suspect it is to avoid surging during acceleration from heat soak.
I have developed a new sensor using current low thermal mass sensor technology. This unit has the same calibration as the standard sensor, fastens with the same thread, and comes with a harness to connect to the standard loom. The sensor has been trialled in twenty RX7 FD’s with success. UK tuner, Dragon Performance, has tested the unit and recommends it, commenting that “the difference is like night and day. The logs show it better than I can explain, the speed and accuracy is in another league, highly recommended.”
Because the sensor responds so much faster, the car can be mapped leaner. Why? Because your ECU will now see the surge of cold air as the water injection kicks in or the air starts to flow externally through your intercooler, it is no longer necessary to add a blanket, rich map, to protect the car from heatsoak events. The new sensor just does not heatsoak. At all. Why is heatsoak dangerous? When the standard sensor heatsoaks, the ECU thinks the air is 70 degrees C. It thinks the air is hot and thin, with not much oxygen. As you accelerate away from heatsoak, joining a freeway perhaps, you trigger the water injection and the intercooler starts working well. Inlet charge temperature drops to 5 degrees C. The ECU doesn’t know this yet as the sensor is still reading 69, 68, 67 slowly catching up with reality. Now the engine is breathing cold, dense, oxygen rich air. This causes a lean condition taking you closer to the detonation limit and potentially overheating your turbine blades in your turbo. Of cause this doesn’t really happen, your experienced tuner will have mapped your car rich because back in the day, he had engines blow when he mapped them lean. So your engines safe, but drinks fuel and your mates tell you she blows black smoke on hard accels.
If you are interested in this sensor, please feel free to contact me at this address for an information pack:
Jonathan.f@hotmail.co.uk.
If you wish to purchase a sensor, please send £69.99 (UK Sterling) to this Paypal address:
Jonathan.f@hotmail.co.uk.
At present, postage will be included in the price. Free postage, better economy, more power, and a nice present for yourself for Christmas!
Best regards,
Jonathan Fennell
A couple of years ago I found that the inlet temperatures I was seeing (Apexi ECU with commander) did not tie in with what I knew was happening. I expected the temperature to fluctuate as I accelerated through the gears as the turbo's passed through their range of efficiency. I was running stock twins, at 1.1 BAR, so they were running above their normal operating range.
On inspection I found the standard air temperature sensor to be heavily shielded with a large time constant. This means that any change in temperature will not register quickly with the ECU. If you have wondered why your water injection, or a sudden increase in speed (and intercooler efficiency), does not translate into variations in inlet temperature, then the standard inlet temperature sensor can be blamed. We may never know why the standard sensor is so shielded from actual intake conditions. I suspect it is to avoid surging during acceleration from heat soak.
I have developed a new sensor using current low thermal mass sensor technology. This unit has the same calibration as the standard sensor, fastens with the same thread, and comes with a harness to connect to the standard loom. The sensor has been trialled in twenty RX7 FD’s with success. UK tuner, Dragon Performance, has tested the unit and recommends it, commenting that “the difference is like night and day. The logs show it better than I can explain, the speed and accuracy is in another league, highly recommended.”
Because the sensor responds so much faster, the car can be mapped leaner. Why? Because your ECU will now see the surge of cold air as the water injection kicks in or the air starts to flow externally through your intercooler, it is no longer necessary to add a blanket, rich map, to protect the car from heatsoak events. The new sensor just does not heatsoak. At all. Why is heatsoak dangerous? When the standard sensor heatsoaks, the ECU thinks the air is 70 degrees C. It thinks the air is hot and thin, with not much oxygen. As you accelerate away from heatsoak, joining a freeway perhaps, you trigger the water injection and the intercooler starts working well. Inlet charge temperature drops to 5 degrees C. The ECU doesn’t know this yet as the sensor is still reading 69, 68, 67 slowly catching up with reality. Now the engine is breathing cold, dense, oxygen rich air. This causes a lean condition taking you closer to the detonation limit and potentially overheating your turbine blades in your turbo. Of cause this doesn’t really happen, your experienced tuner will have mapped your car rich because back in the day, he had engines blow when he mapped them lean. So your engines safe, but drinks fuel and your mates tell you she blows black smoke on hard accels.
If you are interested in this sensor, please feel free to contact me at this address for an information pack:
Jonathan.f@hotmail.co.uk.
If you wish to purchase a sensor, please send £69.99 (UK Sterling) to this Paypal address:
Jonathan.f@hotmail.co.uk.
At present, postage will be included in the price. Free postage, better economy, more power, and a nice present for yourself for Christmas!
Best regards,
Jonathan Fennell
04-09-2009, 02:19 PM
#2
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Thread Starter
Join Date: Sep 2006
Posts: 5
Hi Guys,
These sensors are available on UK ebay for $100 or so. I searched for RIAT Sensor. Shipping is free. I've got them on a number of cars and have had nothing but good reports. There is alot of information on the advert. Long read but well worth it.
Jonathan
These sensors are available on UK ebay for $100 or so. I searched for RIAT Sensor. Shipping is free. I've got them on a number of cars and have had nothing but good reports. There is alot of information on the advert. Long read but well worth it.
Jonathan
08-02-2009, 03:03 PM
#4
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Join Date: Sep 2006
Posts: 5
Originally Posted by mazdaspeed7' post='920144' date='Apr 9 2009, 07:25 PM
I call BS.
No sure where that came from. I've never had any negative feedback.
Just to bring you guys up-to-date. I've bought a thousand of these sensors, harnesses, connectors etc so the price has come right down to £30, and they are receiving a good review on MazdaRotaryClub. If you think they are BS, fair enough, but the inlet air temperature is absolutley fundamental to how an engine is fuelled. Its common knowledge the standard sensor heat soaks. The Ebay advert explains it all.
http://www.mazdarotaryclub.com/forums/show...6579&page=5
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...:EOISSA:GB:1123
08-04-2009, 01:04 PM
#6
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Join Date: Sep 2006
Posts: 5
Originally Posted by Rob x-7' post='925145' date='Aug 4 2009, 01:26 AM
you bought 1000 sensors?
Hi, yes. I view this sensor as a 'must have' that every RX7 should be fitted with. For that to happen, the cost needed to come down. I have about 900 left and they are selling about 10/day. Some through ebay, some through emails and some direct to the big tuners (it makes mapping easier and safter for them). At this rate they will all be gone in three months- so the gamble is paying off so far. Helps everyone avoid blown engines too which is great for the reputation of the RX7.
08-10-2009, 03:29 PM
#8
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