THREAD SIZE/PITCH ON EGT SENSOR FITTING

[M K]

hello people,

ive bought a vems wideband gauge and im sorting the fitting for the egt to my turbo housing but i cant find a correct thread adapter
this is a pic of where its gonna go in the turbo exhuast housing, the bung comes in the turbo from new which is handy   (its the one on the far left im gonna put it in)   this thread size is M18x1.5


Can someone please tell me the thread size of the fitting that comes standard with the egt sensor from vems, you can see it in the bag here the one im on about, its tapered one end of the double male fitting and normal the other,   can you tell me all the thread sizes on the male/male and the female one


basically i need an adapter to fit the vems supplied thread in the M18x1.5 hole but cant find 1 anywhere, other option is the tap the original bung?


also i need to lengthen my lead to the Bosch AFR sensor and have been told to cut the wires and lengthen them then solder up etc, do i need any special wire or just normal stuff i can get from maplins

thanks
marc

[dnb]

It's 1/8" BSP as far as I remember. 

The only thing I can think of that would work is an oilway bung from a Subaru engine, where the pressure switch is.   These have both the correct threads.

[M K]

It's 1/8" BSP as far as I remember. 

The only thing I can think of that would work is an oilway bung from a Subaru engine, where the pressure switch is.   These have both the correct threads.

so you think 1/8 bsp is the size of the tapered end?

[rob@vems.co.uk]

The EGT bung is 1/8bsp-t (tapered) so that the thread seals against a standard 1/8bsp hole.  I think there was someone selling a tap set for one of those on here a while back.

Cheers

Rob

[M K]

thats all i needed confirming

cheers chaps

[cliffb75]

also i need to lengthen my lead to the Bosch AFR sensor and have been told to cut the wires and lengthen them then solder up etc, do i need any special wire or just normal stuff i can get from maplins

thanks
marc

I hope Rob will confirm, but If you are going to lengthen the wires, this must be done on the gauge side of the connector. The connector on the sensor side has a calibration resisitor fitted (unique for each ensor). If you change the wire length etc then this will obviously be off, and require re-calibration.

[rob@vems.co.uk]

Yes, only lengthen on the gauge side of the plug.

[M K]

it was the gauge side of the plug i done, lucky as i hadn't read that reply then lol,
but my reason was if i did the sensor side i would have to do it again if i ever needed to replace the sensor so a good enough reason not to anyway

[cliffb75]

Another thing I've realised here is that you are fitting it after the turbine. This is good from a reliability point of view (if the tip falls off it won't go through the turbo), but bad from a measurement one.

Its normally pre-turbine gas temp that you want to measure, as you lose a lot of temperature across the turbo (typically around 100C, but could be more).

Since you already have the parts on the bench it wouldn't be that much work to have a boss welded into the collector or turbine entry now, and then you'll be measuring the right bit, and should be able to have more confidence when mapping. 

[M K]

edited as double post

[M K]

Another thing I've realised here is that you are fitting it after the turbine. This is good from a reliability point of view (if the tip falls off it won't go through the turbo), but bad from a measurement one.

Its normally pre-turbine gas temp that you want to measure, as you lose a lot of temperature across the turbo (typically around 100C, but could be more).

Since you already have the parts on the bench it wouldn't be that much work to have a boss welded into the collector or turbine entry now, and then you'll be measuring the right bit, and should be able to have more confidence when mapping. 

i wont be mapping it mate,   FIELD MOTORSPORT map/tune the car for me as it was built by them

im no what you mean about it not being accurate after the turbo but it just cost me approx £2000 to buy and fit that turbo lol so i dont wanna risk anything going through it if the tip failed/broke off especially when seeing excessive temps & pressures when using the ALS.

also the manifold has been profesionally coated with a triple coat zirconia to keep the heat in at a cost of £375 so any welding would ruin it now

i bought the vems purly for the WIDEBAND AFR gauge but as it also comes with the EGT display i thought i would install it as a rough guide even tho it wont be 100% accurate i no if im seeing normal temps of 700 for example then something isn't right if i start seeing 800 (just example figures as ive yet to find out my safe normal running temps from the tuners)

so it will just be there as a guide really as its the afr/lambda fuction i really wanted

[cliffb75]

Those are perfectly valid reasons to fit it where you explained.

I installed my thermocouple on my Subaru in the downpipe post turbo, as i could remove that easily whereas removing the manifold or turbo was a pain. Mine is still running completely standard - I was just interested to see what was going on.

As long as you understand the differences (both poitive and negative) you can make an informed choice  . It will certainly be more than a rough guide 

That sounds like one hell of a turbo kit. If thats an example of the whole build I can't wait to see the car in its entirity

[M K]

cheers mate,

here is the car in its entirity

its a 1600cvh 8 valve turbo mk2 fiesta xr2
bench dyno'd at 300.3bhp & 356lb/ft with a t34 but now running a hybrid gt30 as in the other pic for better response,
just swapping over the a new style of air injector this week as i wont hold the boost on the amal valve now and on its last rolling road day only made 222bhp due to boost and bad fueling,

hoping air injectors and aeromtive fuel reg will cure this along with a 12 position boost pot for obvious reasons road/track/santapod etc

a few random pics of the car inside and out, hope you like it

[Agriv8]

  .

Very imresive, good power and tidy install. I can imagine that upsets a few cars on track days !!!!!

Regards

Agriv8