[Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Posts about anything do to with modifying your car such as fitting aftermarket parts, bodykit, or tuning the engine for more performance.

Moderators: IMOC Moderators, IMOC Committee Members

Post Reply
Martin F
IMOC Moderator
Posts: 14822
Joined: Fri Aug 04, 2006 1:19 pm
Location: The Couch !

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by Martin F »

I received the Boss from Ashley, it was perfect, so Thankyou very much Ash :thumleft:

Just got it welded today, I welded it to a 90 degree bend that comes away from the throttle body, will fit it tomorrow and post results before booking some dyno time.
I am going to cut the end of the standard MAT sensor (is that a bad idea ?) and use it as a plug where the standard MAT sensor sits, that way if I run into problems on the dyno I can just swap it and the rait sensor round.... :eye:


here is a pic with a standard mat sensor in it

Image

Image
C35Rob
Posts: 2108
Joined: Wed Dec 04, 2013 1:14 am
Location: Gateshead

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by C35Rob »

looks good martin :thumleft:

no need to cut the plug off the stock sensor though, just screw it back in.. or you can buy a m16 blank for a couple of quid.. but I'd just put the old sensor back where it came from and leave it intact
EX MR2 owner, currently on a '00 Honda CBR600 Follow me on Instagram @c35rob
Martin F
IMOC Moderator
Posts: 14822
Joined: Fri Aug 04, 2006 1:19 pm
Location: The Couch !

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by Martin F »

Rob - East Coast Imports wrote:looks good martin :thumleft:

no need to cut the plug off the stock sensor though, just screw it back in.. or you can buy a m16 blank for a couple of quid.. but I'd just put the old sensor back where it came from and leave it intact


Probably way off the mark but in my head I have this sensor near the intake for cylinder number 3, which in standard engines has been known to let go at higher boost levels.
Was just thinking out loud by suggesting cutting it as it creates a small blockage, I know the air is under pressure but you never know :-k , or as said, I am away off the mark :-k

will post my findings tomorrow regarding temps, be interesting as I have had many issues with temps on the dyno over the years, could heatsoak have been contributing to my many failings with intake temps while getting past cars mapped :-k

do you have a link off the bolt I would need Rob ?

I went into a bolt shop and tried m16 x many pitches and none of them fitted #-o
C35Rob
Posts: 2108
Joined: Wed Dec 04, 2013 1:14 am
Location: Gateshead

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by C35Rob »

cyl 2&3 run leaner than 1&4 due to the design of the inlet manifold, they get the lions share of the charge air which why they're the most likely to suffer det etc at higher power, and also why most decent mappers will run them a little richer than 1&4

http://www.ebay.co.uk/itm/B2-00590-M16- ... SwpDdU5Wso

that is the same blank I drilled for my sensor, the same as the one I linked to earlier in this thread, so prob the same as the one peter used to make your adapter, so will 100% fit your stock manifold
EX MR2 owner, currently on a '00 Honda CBR600 Follow me on Instagram @c35rob
Martin F
IMOC Moderator
Posts: 14822
Joined: Fri Aug 04, 2006 1:19 pm
Location: The Couch !

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by Martin F »

Rob - East Coast Imports wrote:cyl 2&3 run leaner than 1&4 due to the design of the inlet manifold, they get the lions share of the charge air which why they're the most likely to suffer det etc at higher power, and also why most decent mappers will run them a little richer than 1&4

http://www.ebay.co.uk/itm/B2-00590-M16- ... SwpDdU5Wso

that is the same blank I drilled for my sensor, the same as the one I linked to earlier in this thread, so prob the same as the one peter used to make your adapter, so will 100% fit your stock manifold


I just stuck the standard sensor in, it's nowhere near cylinder 3 or any other cylinder :oops: Thanks for your help anyway Rob ;)

Fitted it today, unfortunately the wiring was about 1" too short so out came the soldering iron 8)

Took the car for a drive but it started raining so didn't get a chance to see temps under boost, around 0.6 bar before the rain came and the results were pretty surprising.
Image

outside temps were 11 degrees, after half a mile temps went down to 10 degrees before rising to 12-13 degrees, under small boost (0.6 bar) it didn't really move, up to 14 degrees :shock: max

parked the car, turned ignition off for 15 minutes, turned it back on and it was saying 23 degrees, started driving and it quickly dropped back down to a steady 14 degrees within 1 mile...

Maybe i'm best not using the car or accelerating hard until I get it to the dyno, just to play it safe :-k

so just cruising (doesn't matter what speed, be it 70 mph or 30 mph) I am seiing a max of 3 degrees above ambient.... :shock:

Resting place for the sensor is on the underside of the 90 degree bend nearest the throttle body....

Image

would be interested in hearing peoples thoughts on these results ???
jimGTS
Posts: 14024
Joined: Tue Dec 14, 2004 1:40 pm
Location: North Kent

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by jimGTS »

I don't think I've ever heard intake temps in the teens without water/meth in there.

Unless your talking 10-14c above ambient?
But guess you wasn't boosting much and low boost at that.

As mentioned you will always have cooler temps in a pipe location like that outside the manifold.
The mani temps will always be a truer reflection of what's entering the engine IMO.

I imagine some pulls and more boost would see those alot higher.

Guess end of the day it depends what the mapper wants to use to measure temps?
Will he use your readings, or stick a probe somewhere!
In which case wouldn't have mattered what location and what sensor you used, ha.

How are you reading the numbers? Power FC commander I guess?
Martin F
IMOC Moderator
Posts: 14822
Joined: Fri Aug 04, 2006 1:19 pm
Location: The Couch !

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by Martin F »

jimGTS wrote:I don't think I've ever heard intake temps in the teens without water/meth in there.

Unless your talking 10-14c above ambient?
But guess you wasn't boosting much and low boost at that.

As mentioned you will always have cooler temps in a pipe location like that outside the manifold.
The mani temps will always be a truer reflection of what's entering the engine IMO.

I imagine some pulls and more boost would see those alot higher.

Guess end of the day it depends what the mapper wants to use to measure temps?
Will he use your readings, or stick a probe somewhere!
In which case wouldn't have mattered what location and what sensor you used, ha.

How are you reading the numbers? Power FC commander I guess?


Only reading 2-3 degrees above ambient, just cruising about.

It is totally believable though, the core is 25 % larger than the one used in your old mr2, it is stone cold, as are the pipes.

It will benefit me while mapping as the sensor heatsoaks on the dyno which then stops mapping in it's tracks, maybe wouldn't have done with this chargecooler but smaller units and sidemounts fail at higher boost, not so much the cooling failings but with the ecu picking up the heatsoaked readings and retarding the ignition.

The stock sensor is designed for a standard car and not designed for the real world of bigger turbos and higher boost settings. Hence changing it and it's location.

Deposit is paid for a dyno session in two weeks, will update my findings then, good or bad :wink:

They also use their own probe so will be interested in hearing what the mappers opinion is.

Readings on a hand commander, might be a 10 degree difference between the two locations but there is virtually no heatsoak in the later, which can be 25 degrees above ambient and a bu88er to get down when in the standard location.
tiff_lee
Posts: 384
Joined: Thu Jun 04, 2015 2:18 pm

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by tiff_lee »

Martin F wrote:
Readings on a hand commander, might be a 10 degree difference between the two locations but there is virtually no heatsoak in the later, which can be 25 degrees above ambient and a bu88er to get down when in the standard location.

Have you tried the new sensor in the OE location? I doubt very much you would get anywhere near 10 degs difference in temperature if you did.

You could perhaps pick up one of those cheap thermocouples off ebay and slip it under the hose joiner just before/after the sensor for a confidence check in the readings being reported and then if possible (modify a blank or something?) find a way to fit it in the sensor OE location which would give a comparison and put an end to that debate as to whether or not it makes a real difference.
jimGTS
Posts: 14024
Joined: Tue Dec 14, 2004 1:40 pm
Location: North Kent

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by jimGTS »

Don't get me wrong I understand the issue is heatsoak. And the best place for it is likely outside the manifold.
Whether you put a high speed sensor or not pre TB.

I just wonder why it's placed where it's placed out the factory.
On cruise, when the throttle body is almost closed, I imagine things past it likely are quite hot, which a sensor pre TB won't show. I thought this was a concern, but probably likely not as the temps on boost, WOT, are likely more important at the end of the day.


Which begs a new question can you get a sensor in a st205 CC?


On a slight tangent, recently picked up an awesome little air temp sensor from auber with alarm led and buzzer!
But unsure of where to place it.
Not that my sensor in the Oem location is going to tell the ecu anything different, it was just for peace of mind.

I'm weighing up different locations. Or of course in the cc itself.

Image

Image

Image

Image
jimGTS
Posts: 14024
Joined: Tue Dec 14, 2004 1:40 pm
Location: North Kent

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by jimGTS »

perhaps welding a nut on the nipple here would work???

the probe is long enough to reach inside??

:-k :-k


certainly would save the hassle and worries of drilling and welding a bung somewhere else on it?

Image
ashley
Posts: 7628
Joined: Tue May 13, 2008 8:08 pm

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by ashley »

A random comment, but I thought of this thread when I read it- just setting up my ECU and read this:

MoTeC wrote:Air Temp Sensor
The Air Temperature sensor is mainly used to correct for air density change
due to air temperature variation.
The sensor contains a temperature dependant resistor and is designed for
high speed response in an air flow.
The Air Temp sensor must be placed to measure the air temperature before
the butterfly (and after the inter cooler on turbo charged engines).
Avoid placing the sensor too close to the stand-off vapour in a multi-runner
manifold as this will cool the sensor and give a false reading.
Nails
Posts: 1398
Joined: Thu Aug 07, 2008 10:06 am
Location: durham-ish

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by Nails »

jimGTS wrote:
I just wonder why it's placed where it's placed out the factory.
On cruise, when the throttle body is almost closed, I imagine things past it likely are quite hot, which a sensor pre TB won't show. I thought this was a concern, but probably likely not as the temps on boost, WOT, are likely more important at the end of the day.




easy answer. Either cheaper.to make or easier.to build. Which also means cheaper. I saw many new models and subsequent model changes at Nissan. All of them meant cheaper or easier to build. While I'll agree I'm not talking about mid ship runabouts but thats the end game. Either make it cheaper to build. Or do something that you can charge more for. Mr T aint in it for the game. Same as the rest.
if the I ket and head are getting heatsoaked it will make a difference to the charge temps but not as much difference as a heatsoaked probe.
bobhatton
Posts: 3351
Joined: Fri Aug 25, 2006 9:34 pm
Location: Bodmin Cornwall

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by bobhatton »

Martin F wrote:

will post my findings tomorrow regarding temps, be interesting as I have had many issues with temps on the dyno over the years, could heatsoak have been contributing to my many failings with intake temps while getting past cars mapped :-k


You can only get heat soak on engine parts, inlet etc. once the engine has been run and hot. Once turned off all the parts of the engine in contact with each other will transfer heat till they are all equal.

Once the engine is started again the colder air from the outside through the filter will start to drop the temperatures of all the pipe work, intercooler and inlet manifold. The time taken will be down to the amount of cooling air coming in and the delta T.
Any so called “tuner” should never make a power run until the heat soaked parts are back to their correct temperatures.

If you want an engine correctly mapped, book a week on an engine dyno.

How many 4 hour mapping sessions on a rolling road do you think Toyota spent setting up their stock ECUs?
Designer for turbo set ups on F1 cars, and Nitrous Oxide Systems of the USA in the 80s
Martin F
IMOC Moderator
Posts: 14822
Joined: Fri Aug 04, 2006 1:19 pm
Location: The Couch !

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by Martin F »

bobhatton wrote:
Martin F wrote:

will post my findings tomorrow regarding temps, be interesting as I have had many issues with temps on the dyno over the years, could heatsoak have been contributing to my many failings with intake temps while getting past cars mapped :-k


You can only get heat soak on engine parts, inlet etc. once the engine has been run and hot. Once turned off all the parts of the engine in contact with each other will transfer heat till they are all equal.

Once the engine is started again the colder air from the outside through the filter will start to drop the temperatures of all the pipe work, intercooler and inlet manifold. The time taken will be down to the amount of cooling air coming in and the delta T.
Any so called “tuner” should never make a power run until the heat soaked parts are back to their correct temperatures.

If you want an engine correctly mapped, book a week on an engine dyno.

How many 4 hour mapping sessions on a rolling road do you think Toyota spent setting up their stock ECUs?



It takes the best part of an hour to get the temps back down with the engine off, that's roughly £100 dyno time, so not a practical solution :(

I went out for a drive this afternoon, temps were higher, ie. 8 degrees above ambient.
Popped in to see my sister for 40 minutes, came out and temps were 35 degrees, this went back down to 20 odd degrees within a minute or so, with the sensor in the original location it would have been 50+ and taken 20 minutes to get back down to 24 degrees, so the biggest difference I am seeing is eliminating the heat soak element plus roughly 4-6 degrees lower running temps...

I will make sure all these facts are passed on before any dyno work and can swap the sensor positions if required, so no harm done....

I have decided not to boost the car until the next dyno session , or even drive it, will update with results in a couple of weeks and see if the sensor is suited to this location, or not... :-k
C35Rob
Posts: 2108
Joined: Wed Dec 04, 2013 1:14 am
Location: Gateshead

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by C35Rob »

Martin F wrote:
It takes the best part of an hour to get the temps back down with the engine off, that's roughly £100 dyno time, so not a practical solution :(

I went out for a drive this afternoon, temps were higher, ie. 8 degrees above ambient.
Popped in to see my sister for 40 minutes, came out and temps were 35 degrees, this went back down to 20 odd degrees within a minute or so, with the sensor in the original location it would have been 50+ and taken 20 minutes to get back down to 24 degrees, so the biggest difference I am seeing is eliminating the heat soak element plus roughly 4-6 degrees lower running temps...

I will make sure all these facts are passed on before any dyno work and can swap the sensor positions if required, so no harm done....

I have decided not to boost the car until the next dyno session , or even drive it, will update with results in a couple of weeks and see if the sensor is suited to this location, or not... :-k


from your results/findings so far it would seem that you've achieved exactly what you set out to in the first place :thumleft: I will certainly be moving my sensor before I get round to doing my mapping. and obviously you don't need days and days on the rollers to tweak an already known good map.
EX MR2 owner, currently on a '00 Honda CBR600 Follow me on Instagram @c35rob
bobhatton
Posts: 3351
Joined: Fri Aug 25, 2006 9:34 pm
Location: Bodmin Cornwall

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by bobhatton »

Martin F wrote:
Popped in to see my sister for 40 minutes, came out and temps were 35 degrees, this went back down to 20 odd degrees within a minute or so, with the sensor in the original location it would have been 50+ and taken 20 minutes to get back down to 24 degrees, so the biggest difference I am seeing is eliminating the heat soak element plus roughly 4-6 degrees lower running temps


What the ecu needs to know is the temp of the air going into the engine.
With the sensor before the TB it will read the temp of the air after the intercooler but may not be temp going into the engine as it is now missing the heat input from a hot manifold.

With the sensor in the manifold after a run and the engine off if will read high because of the heat from the hot head transfering into the manifold.
Once the engine is started again, with the colder air coming into the manifold the sensor reading will drop but not as fast as it would be if it was fitted before the TB as the air in the manifold will still be heated from the hot manifold. This is the true temp of the air entering the engine.
Designer for turbo set ups on F1 cars, and Nitrous Oxide Systems of the USA in the 80s
Martin F
IMOC Moderator
Posts: 14822
Joined: Fri Aug 04, 2006 1:19 pm
Location: The Couch !

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by Martin F »

bobhatton wrote:
Martin F wrote:
Popped in to see my sister for 40 minutes, came out and temps were 35 degrees, this went back down to 20 odd degrees within a minute or so, with the sensor in the original location it would have been 50+ and taken 20 minutes to get back down to 24 degrees, so the biggest difference I am seeing is eliminating the heat soak element plus roughly 4-6 degrees lower running temps


What the ecu needs to know is the temp of the air going into the engine.
With the sensor before the TB it will read the temp of the air after the intercooler but may not be temp going into the engine as it is now missing the heat input from a hot manifold.

With the sensor in the manifold after a run and the engine off if will read high because of the heat from the hot head transfering into the manifold.
Once the engine is started again, with the colder air coming into the manifold the sensor reading will drop but not as fast as it would be if it was fitted before the TB as the air in the manifold will still be heated from the hot manifold. This is the true temp of the air entering the engine.



That's the thing though Bob, Because of the heatsoak the ecu isn't getting the correct air temps going into the engine, In fact it is hugely off in some instances.
ie. reading 50 degrees in the standard position and taking the best part of 20 minutes of driving at 60 mph to get anywhere near what it was showing before the engine was cut off.
On the dyno the car is sitting at idle for ages before getting a power run, which again is giving highly inaccurate readings.

All I have done is move the position 12 inches away from all the heatsoak and the standard position, on testing it may be reading 4-6 degrees lower than it would be with the car cruising about therefore eliminating all the heatsoak and giving a much more accurate reading as well as going down in degrees a twentieth off the time (at least).

How important is this sensor anyway ??? considering the standard one is so slow to respond and the way it holds the heatsoak etc. ?

Just a thought :-k
ashley
Posts: 7628
Joined: Tue May 13, 2008 8:08 pm

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by ashley »

I really wouldn't get too hung up on it, you are using a programmable ECU- a decent mapper will map the inlet temperature compensation table based on what they see when mapping. So as long as you have the same sensor, in the same position as when the car was mapped, you shouldn't have any issues.

IMO anyhow :eye:
C35Rob
Posts: 2108
Joined: Wed Dec 04, 2013 1:14 am
Location: Gateshead

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by C35Rob »

Martin F wrote:

How important is this sensor anyway ??? considering the standard one is so slow to respond and the way it holds the heatsoak etc. ?

Just a thought :-k


not very tbh, the power FC doesn't do a great deal with the air temp readings. the most important table is the ign vs air temp, which pulls ignition based on inlet temps. the base map has it set to start pulling ign at 60 deg c in a linear fashion up to -5 deg @ 80 deg
EX MR2 owner, currently on a '00 Honda CBR600 Follow me on Instagram @c35rob
jimGTS
Posts: 14024
Joined: Tue Dec 14, 2004 1:40 pm
Location: North Kent

Re: [Mk2] [Turbo] Better air intake temp sensor and positioning.Results page 6.

Post by jimGTS »

dyno? :mrgreen:
Post Reply

Return to “Modifications”