RIAT Temp sensor for ST205 - O for Awsome !

[gt4dude]

Regarding your boost creep problem, have you got custom downpipe? You will need to either restrict the downpipe (severely), or invest in external wastegates (along with custom manifold or spacer), or put back stock exhaust.

Stock down pipe, stock exhaust except for an extra Coby between the Flexi and the OEM resonator.

The only thing different is that I have an "Upgraded CT26" from Alltech Turbo & Diesel which nobody can give me any information about.

My mate Tim from TTT tested out my wastegate with an air compressor and the actuator arm moved at 10psi so I know the wastegate isnt stuck.

A guy on the phone at Alltech said that generally when they rebuild 3S-GTE turbos that they don't get the parts to rebuild CT20b turbos so they build up CT26's up to a similar spec with steel wheel and shaft and a TD04e compressor. I asked if the standard internal gate was large enough to cope with this without needing it bored out he said he runs an identical turbo on his MR2 and can run 7psi at the low setting at 1.2 bar at the high setting. So he sent me in search of a man named Richard Doig whom I found but was unresponsive to email.

So I've just put up with the boost creep until the day I can afford a real turbo like a Garrett with manifold, external gate, down pipe and ECU.

[mr30%jr]

no whats happening is you have had an upgraded turbo but the stock waste gate does not flow enough to pull enough exhaust away from the turbo and its going to over boost.

[Heylin]

MR2 got boost creep after installing dual 3" highflow mufflers.

As for the intake temp sensor I thought any open air unit like the Bosch ones that Link sell for use with the Link G4 would provide fast enough response.

Although they are $80.

[gt4dude]

no whats happening is you have had an upgraded turbo but the stock waste gate does not flow enough to pull enough exhaust away from the turbo and its going to over boost.

This is what I suspect.


Anyways, have e-mailed the guy to purchase one of these. I'll post my findings when I get it.


Is this the plastic plug that goes into the air box? Why does the information about the RIAT talk about something tapped into the Intake manifold?

[Akane]

You guys running L-jetro who wants a piece of the pie, how are you gonna hook the new sensor up? your factory sensor is inside your vane meter.

[XS1V]

ST205 have two air intake sensors, one in the airbox and one in the inlet manifold. It is the one in the Inlet manifold that we swapped over in Franks car and is what the sensors here are. 185 guys, unless you have put one in, you dont have one

Easy enough job to do on the 205, with a soldering iron, 19mm spanner and a lighter..... Worth the investment, same type of sensor as TTE ran in the 185 and 205 in the WRC

Brad

[mr30%jr]

st165s are still plaugued with a slow air temp reactions it mostly came down do the smaller intercooler radiator and a few other things of heat soak.. if you keep the intake temp down they run $&#$% fantastic... cold dewy morning is st165 country

[sergei]

ST165 has a sensor on the manifold. Not sure if it affects much, never tested as when I used ST185 ECU it was omitted.

[Akane]

I'll put a hold on this one, money can be better spent elsewhere... like... a shiny new GT3071R

[Prymal]

Already got a haltech sensor before the TB on mine ( franks seen this ) but i wouldnt mind an uprated sensor on the other side of the equation to balance things out ..

Ginmme a message or pop in at work on saturday frank , and we'll have a look

GT$dude - i waved at you last night in mangere , saw your car on the way to the motorway ion massey road after dropping off my friend ..

Im sure you would have noticed me..

PS frank , is now certain that theres only 4 of us left ..

The white ones a cube .. She got crushed on the weekend ..

[gt4dude]

Already got a haltech sensor before the TB on mine ( franks seen this ) but i wouldnt mind an uprated sensor on the other side of the equation to balance things out ..

Ginmme a message or pop in at work on saturday frank , and we'll have a look

GT$dude - i waved at you last night in mangere , saw your car on the way to the motorway ion massey road after dropping off my friend ..

Im sure you would have noticed me..

PS frank , is now certain that theres only 4 of us left ..

The white ones a cube .. She got crushed on the weekend ..

Hmm... I'm pretty sure my car wasn't in Mangere last night, Atleast I sure hope it wasn't lol.

Gutted about the WRC :'(

I didn't have the money or the space to take it but I would have definitely transfered everything from my car over to it if I did...

This breaks my heart.

[Jon Fennell]

Hi All,

I've joined your forum so that I can answer the questions raised.

Firstly, someone’s questioned if the sensor is actually an improvement over the standard sensor. I can only speak for the 1 Celica St205 that I have looked at in the UK. The owner had spotted my product for the RX7 and had bought it to try on his car. He had an Apexi with commander so was able to 'see' in real time the effect (if any). I made the trip to visit him and I could see that the standard sensor was, like the RX7, a thermister buried in a plastic shield. This gives the sensor a large 'time constant', the time it takes to read the environment. With the new sensor the ECU was reading the environment without this lag, and was better able to fuel the car appropriately. I'm not a calibration engineer, I'm mechanical, but I understand that for a car with a MAP (manifold air pressure) sensor type fuel injection management system the ECU uses three main inputs. RPM, Inlet air temperature (IAT) and inlet air pressure (MAP). Its not difficult to imagine that if you improve one of those inputs, the outputs (timing and fueling) will be better. With that in mind, I suggest the sensor is a step forward, this is backed up by my basic calculation that 40degrees is worth half an air ratio. If your sensor has heatsoaked to 80deg and your actually pulling in 20deg air your fueling (and timing - the ECU would retard the timing at those temperatures quite significantly) would be significantly incorrect. And this is only going to get worse if you have water injection.

Boost creep - nothing to do with the sensor, but I had this problem and cured it by removing the turbo and porting the wastegate passages with a die grinder. I increased the aperture size to 1mm undersized to the flap of the wastegate.

This product is specific to the ST205 as this uses a MAP system, not a MAF system (Mass air flow - I belive its a hot wire) so cannot be used on an ST185. Unless the car has been converted to Apexi which is a MAP system and requires the sensor.

Bosch sensor - my sensor is similar in principal to the bosch sensor, its an 'open element' type. My sensor does come with a harness and its more cost effective. Tried and tested in the UK as well and I have one happy customer in NZ now as well.

Airbox sensor vs manifold sensor - on the ST205 model there are two sensors. The airbox sensor is measuring ambient air temperature. I do not know why. I would leave this sensor standard as ambient air remains steady in the context of the issue concerned. (its not the sensor that measures outside air temp for your dash is it?)

As a final note, the standard location of the sensor in the plenum on the ST205 is less than ideal as the sensor sits in a cast recess, I would move the sensor to sit opposite the throttle plate.

Best regards, Jonathan

[mr30%jr]

just a point jon

earlier 3sgtes use an "AFM" which is just flap measuring the air with a variable resistor.

they still use an intake air temp sensor and still does very much so affect the performance

so yes you could probally benefit the same

alot of people just do the "constant temp mod"

heres a link of that they do

http://www.alltrac.net/mods/AirTempMod.html

it helps but think its not the best as if the air is actually hot it should know so to stop detonation.

installing one of these sensors may be a bit tricky as you would need to seal it against boost like the old sensor is screwed in...

i have heard of people taking the platic off them or even just cutting the end and soldering a new naked thermistor on.

http://www.ls2gto.com/forums/attachment ... 1160686512

i could get the multi meter out and log some temps. on thee ol st165

[fivebob]

This product is specific to the ST205 as this uses a MAP system, not a MAF system (Mass air flow - I belive its a hot wire) so cannot be used on an ST185. Unless the car has been converted to Apexi which is a MAP system and requires the sensor.

Not quite correct, it's suitable for any GenIII and above 3S-GTE not just just ST205 but also late model SW20s (chassis # > 87385) and also ST215 and ST246s, or even some non turbo engines that utilise a 2.5kOhm manifold temp sensor.

[fivebob]

List of engines that use the same sensor.

Code: Select all

    Model              Date     Chassis Code
_____________________________________________________
ARISTO              9110-9708 JZS147..V
CALDINA             -9708     ST215..GTT
CELICA              9402-9908 ST205
CHASER              9108-9210 JZX81..GT
CHASER              9210-9609 JZX90..TOUV
CRESTA              9108-9210 JZX81..GT
CRESTA              9210-9609 JZX90..TOUV
CROWN               9110-9112 GS13#
CROWN               9112-9904 GS13#,YS130..HTWC,LPEFI
CROWN/CROWN MAJESTA -9308     GS141
HILUX               9408-9708 YN107,8#
LITE/TOWNACE V,WG   9201-9610 YR21,30
LVN/CRE/TRN/MRN     9106-9505 AE101..GTZ
MARK 2              9108-9210 JZX81..GT
MARK 2              9210-9609 JZX90..TOUV
MR2                 9311-9908 SW20..GT
SOARER              9105-9608 JZZ30
STARLET             9601-9907 EP91..GLZV
STARLET             9106-9601 EP82..GT
SUPRA               9305-9709 JZA80..TWT
SUPRA               9108-9305 JZA70, GA70..LB..GT



[ST205 GT4 NZ New Group A]

Does any one tune cars out there and have an opinion on if re tuning will be of any benefit with these new sensors ?

Interesting to see that these sensors can be used in MR2, supra, Caldina hm...

[sergei]

My only question: how fast ECU samples that sensor?
It will not be good of fast sensor if ECU samples slow and filters heavily the input.

[Jon Fennell]

My only question: how fast ECU samples that sensor?
It will not be good of fast sensor if ECU samples slow and filters heavily the input.

Good point, I have the raw data from an Apexi Ecu Rx7, Dragon Performance's RX7, the fastest Rx7 in europe at the time, the data is in 90ms (millisecond) increments and you can see it updating cell by cell as the boost kicks in and the turbo starts making heat compressing the air.

The standard ECU may have smoothing algorithms built it, we wouldn't be able to tell unless we logged the outputs (to determine the inputs) or if someone has hacked the ecu?

I assume all Apexi's use the same base processor. We need an expert.[/img]

[Jon Fennell]

There is alot of knowledge on this forum. This is the best informed community I've come across.

The 'constant temp mod' shows a lack of understanding of how an ECU works. Fooling the ecu that its cold will give you a rich advanced condition leading to bore wash and possibly detonation. I suspect you can get away with it as your eating into the safety built into the ecu by the manufacturer. Here at Triumph we run the engines to determine the knock and pressure limits and then back away by a certain number of degrees to take into account natural variation bike by bike. Having said all that, when I was younger and running naturally aspirated cars, this is just the sort of mod I would have gone for!

Mr30%, how about I send you a sensor out gratis? I have been looking for someone to work with to prove the sensor in other vehicles, fitting is surprisingly easy, if you have a drill and can borrow an M10 x 1.25 tap you can fit it in the inlet piping anywhere upstream or downstream of the throttle. If the inlet pipes are plastic simply drill a 9.0dia hole and the sensor will 'make' its own thread. It seals well against boost with some thread sealant. This is a common mod on RX7's to move the standard sensor from the aluminium plenum to the plastic elbow. If you can take some pictures of your installation to help my understanding that would be a help. Question: how would you connect my sensor into your loom, as I imagine it there is a 4pin connector into the AFM?

Fivebob, a big thankyou for taking the time to post that info, I think that will be a big help in growing my business. Let me know if you need a sensor.

Regards, Jonathan
Jonathan@fennelldevelopments.co.uk

[mr30%jr]

Hi

jon would love to test one for you, any reason to get about and about and get back into fixing up the st165.

im not too sure id be keen to start drilling and taping my intake manifold as there would be metal shavings going into my intake manifold and taking the manifold off on one of these is just not an option....

the stock sensor is located in the manifold already.... here are some pics as you can see its been a topic of focus before with the heat shrink....