at what temp should you think oh fook its getting too high

 

Above 900°C on a Cossie is almost at the point of critical mass . Lower is better . Obviously this does not include ALS induced EGTs. Above 950°C and the turbo is likely to let go, or with a Mar-M 247 shaft, you get an additional 100°C safety margin... .

 

maybe i should use less AL

 

I don't know the temp of the exhaust but the turbo is made to withstand 850-900C being noramlly made of HIGH SILICONE CONTENT SG IRON, but some are made of a HIGH NICKEL CONTENT CAST IRON able to withstand over 1000C
tabetha

 

Ceramic internals can take this to over 1230C, spend some more money roosie!!
tabetha

 

Inconel is a very good material for turbo applications, and is often used (turbine wheel, turbine housings, wastegates).

There have been ceramics used in some production cars (can't remember which, think it was a Japanese make) and from what I can remember were relatively fragile? Ceramic ball bearings have been used in roller bearing turbos for a while.

 

Surely it depends entirely on where the sensor is.

 

...bill i beleive my skyline gtr32 has ceramic turbos.

 

my sensor sits about 50mm from turbo on the front pipe

 

Matters on the spec of the engine, fuel, fueling and spark.


i see 880-910oC in my cossie, but thats on a std ish c/r engine, running 450ish bhp on road fuel.



i would say a lower c/r cossie will be more like 800 - 860 oC.

 

As C - where are your sensors?!

 

He said his is 50mm from turbo.

Same as mine.

 

never let mine above 800 when i last set it up it would rise to 750 with a 6 second hold in 5th gear at 2 bar , sensor was in the same place as yours

my new ecu wll back the boost down and add more fuel if does go above 800

 

totally pointless unless your sensors in the headers.

 

tell audi that as im sure they will be pleased the new tt has a sensor in the back of the turbo

 

that wont be for what your using it for, test your temps in the headers and after the turbo see if you think the same then,the temp after the turbo trells you nothing about actual egt ie what matters, only the temps on exhaust transfered turbo heat .

 

until the tip breaks off the thermocouple...

Then you think...damn, why did I put that there !!!


You are all mentioning turbos, manifolds, ceramic this and that....


Dont forget your exhaust valves !!!! they aint gona like getting cooked either.

 

i know what your saying,
But its not pointless at all. As its a CLEAR indicator.

 

I always learned, that it is best, to place it in the hottest runner of the engine, because that is the actual temp, and not after the turbo!


Which one is the hottest exhaust runner at a Cosworth, if you are using std 4wd inlet manifold?


Regards

 

No-one is denying that it is best before the turbo, but as others have said, its a balance. It isn't totally useless after the turbo and at least there the risk of doing damage if the sensor breaks is not a worry.

 

ok so the temps in the headers read 400c and the after turbo reads 1200c how usfull is it then ? just telling you the turbo is cooking and theres nothin you can do,i dont mean leave them in the headers just use for setting up IMO
if you melt 1 off in the headers then i think thats the least of your worries

 

am with tim on this one if it melts off its to late a molten bit of piston will fuk the turbo anyway
bit like a oil presure switch if the light comes on it had a kind way of saying get ya wallet out

i got a boss in each runner and one in the collector currently running the collector one only

 

or use a different type thermocpuple,,, somethnig like a type R maybe

 

headers 800degress cooler than after the turbo ?

I would be worried !!!

Who said the tips melt ? I had a head gasket fail on an engine before. The water rushing past broke the EGT probe, it went through the brand new turbo, destroying the turbine blades.

Ive heard of other failures with temp probes. Sometimes it just happens.

 

its one of those perpetual motion machines

 

Whilst on this topic....

Whats the cheapest and easiest way to monitor EGT's, in 1 or preferably more cylinders ?

Normal EGT gauges are pretty expensive, and can only do 1 at a time.


And even better for the setup to give a 0-5v output for easy logging ?

 

have a look at avionics

 

sparco engine monitor does 4 egt sensors but supply just one probe
gaerth whats a typr r and dont say honda

 

most people use a type-k thermocouple as a the temp probe,,, there there are others you can buy,,, one being a type-R,, of cause the output scales are different so you would need a type r reader

i think the top end of type-k's are 1100 degrees,,, so i hope no-one is going over that

 

Which runner ( cylinder) is normally the hottest one, if you are using std inlet and exhaust manifolds?

So, which cylinder has the leanest AFR with WOT?



Regards.

 

number 3 normally

 

some good information on this thread

https://passionford.com/forum/viewtopic.php?t=266954

i have used http://www.conrad-direct.co.uk/goto.php?artikel=100567 that does datalogging and peak hold etc

 

Innovate stuff will monitor 4 channels at once, showing the highest, the average, or any one u may select. It also warns you, and of course has very powerful data logging.

Having a sensor after the turbo is fine, you just add on say 200 degrees for header temperature.

 

thats what ive been told by quality tuners also i will be using a audi tt sensor in the back the turbo exhaust housing wired to my new ecu then hopefully if it works itll back the boost and add fuel if it gets to hot

 

hmmm,


so if id seen 1100 degrees + in the down pipe off a skyline, that would be bad,
had it removed after the turbo change as the sensor had taken some abuse at some piont, look like it had been chopped my a stray turbo blade

 

total rubbish having got both you wouldnt believe some of the results until you test it
out of interest how many people with views have tested this?

 

depends what the header temp was and under what conditions, wot, overrun etc

 

i've never had one after the turbine, only 4 in the headers

 

Glad I saw this post
I have a tc-1 for the 4 header sensors

and i use the pectel monitor for the one after the turbo.
after reading this post i found out the tc-1 has a programmable alarm so I am now gonna wire that up and set it to 900degreesC for top speed runs

a question
why does a mar-m shaft allow higher temps to be run? surely if it was in danger of melting the blades would melt first?
I thought it was maybe because of the shocks involved in ALS?

 

Having been out in Roosie's car it was hitting 1400C within seconds of Anti Lag being switched on!!
tabetha