EGT after market

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v5 tt

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I dont know if this has been done ? but i have a k04 022 if i change to a k04 023 would it be
possible to use an after-market EGT sensor in the turbo ?

thanks =0)
 
As in a none ecu EGT sensor?

Yes it is, there are some good sensors and gauges out there, although from experienc they don tend to be a direct fit. Having said that it's easy to drill andretap the existing EGT boss in the 023 to fit your new sensor.
 
TBH you are better off blanking the port in the turbo and welding the boss into the DP...

<tuffty/>
 
<tuffty/> said:
TBH you are better off blanking the port in the turbo and welding the boss into the DP...

<tuffty/>
Click to expand...

Would that give an as accurate EGT? The EGT in the turbine housing gives probably the highest temps you'll get, in the DP , it's after the turbine which will reduce the temp plus the larger dp volume will cause temps to drop further. so you'd want it in the heart of the action... I don't doubt your expertise tuffty, just curious
 
Why wouldn't it give an accurate EGT? its all relative... all the BT conversion we have done where an OEM EGT probe was present has been relocated to the DP... its just not practical to fti an EGT probe into the hotside in such cases so maps are adjusted as required (as I haev done on mine) so 'factory' protection strategies can be used if need be and you typically lose up to 100 deg across the turbine in tests... when I first did my BT conversion I put the EGT probe in the collector... wasn't the best plan... if you look at S4's for example the EGT probes are just before the turbo in the manifold flange and TABGBTS is suitably adjusted...

Doesn't matter as long as you are aware of the relevance of the temp you are seeing relative to its position further up... for me if I see temps getting over 850 deg I would be concerned... thats why TABGBTS is set to just below that on my map..

<tuffty/>
 
I understand all that, but we are talking aftermarket here, so we have no intervening control as its simply a monitor gauge and not ecu based where fuelling can be dumped in if the limit is met. Fitting an aftermarket sensor in the DP will only tell you what the temp is in th DP and thus it could be 100/150/200 c hotter and potentially damaging in the important housing. I see your logic when using stock ecu etc, especially if you have a bench mark to work off. But if with out that and you then see 850 degs can you be sure it's not 950/1000 etc where it counts... The only true and accurate ( this what i meant accurate for an after market ) place would be in the turbine housing. Admittedly fitting to the dp is far more logical and probably easier on many counts and the fact it's only a stock k04 I'm sure the EGTs aren't a major issue compared to a BT turbo.
 
Why does it matter that its after market? Bill typically fits VEMs gaugues that are AFR and EGT combined... I don't know why you are suggesting its inaccurate as the temp is relative to position... if its 850degs in teh DP its nearly 950degs in the turbo... its a matter of perspective...

I have seen race cars with EGT probs in the exhuast runners more or less at the head... teh EGTs are likely to be a different reading there too... but... its all relative... 900 degs just past the turbine in a DP is just as telling as 1000 deg at the collector...

Granted if the K04 the OP is using was a 023 then yeah, it would save welding a boss in but why change a known good turbo to an unknown turbo (assuming he isn't buying new) when all you need to do is weld a boss into the DP and just accept when the EGT is nearly 850 degs then its time to back out... its no different...

If you want to measure EGT temp where it counts then you do it at the exhaust ports...

<tuffty/>
 
Should be mentioned that APY runs a vastly differnt fuelling strategy to AMK/BAM... fuel is pretty much in the 10's on load... whereas EGT probe equipped ECU's run lambda 1 until knock/IAT/EGT intervention enrichens...

<tuffty/>
 
tuffty sorry to go off topic, do you know where i can buy a egt sensor but not main dealers?
thanks in advance
 
sambryant said:
tuffty sorry to go off topic, do you know where i can buy a egt sensor but not main dealers?
thanks in advance
Click to expand...

You can't that I know of... main dealer only and are 160 odd quid... there is very little discount as I have tried through trade and haggling..

I got mine from eBay.de in the end for 50 quid... best bet if yours has gone is to look for someone breaking an AMK/BAM S3, TT, LCR and also check out eBay.de as they seem to have loads of S3 bits on there..

<tuffty/>
 
ok thanks m8. yeah im sure mine has died, had a code come up that would suggest egts have reached 1100c or as bill said the sensor had died (most likely). car is dumping at 5k so poor fuel economy and wet performance.
 
Ok, I'm going to bow out graciously here :) you know it's 100 degrees less dp compared to turbine housing, I know it'll be cooler, but not having the experience of fitting there as you have I couldn't give a figure and I would assume the OP wouldnt know either and thus unless you knew the relative temps compared to location then JUST fitting it in the dp will give you a non perspective temp reading, basically a pretty looking gauge.

I totally get what your saying tuffty and whole heartedly agree with you....
 
beachbuggy said:
I understand all that, but we are talking aftermarket here, so we have no intervening control as its simply a monitor gauge and not ecu based where fuelling can be dumped in if the limit is met. Fitting an aftermarket sensor in the DP will only tell you what the temp is in th DP and thus it could be 100/150/200 c hotter and potentially damaging in the important housing. I see your logic when using stock ecu etc, especially if you have a bench mark to work off. But if with out that and you then see 850 degs can you be sure it's not 950/1000 etc where it counts... The only true and accurate ( this what i meant accurate for an after market ) place would be in the turbine housing. Admittedly fitting to the dp is far more logical and probably easier on many counts and the fact it's only a stock k04 I'm sure the EGTs aren't a major issue compared to a BT turbo.
Click to expand...

EGT is EGT..
so long as you allow for the 80-100'c temp gradient across the pre-turbine to post turbine 50mm downstream in DP, you have EGT measurement. The temp being measured is the important thing and as tufftys says relative.

EGT in collector is different to EGT in turbo hotside... See S4 vs K04 tabgbts figures respectively as the "relative" difference.

One main reason on after market egt probes, I my choice to locate the EGT sensor probe downstream of the turbine is concern of the egt sensor itself eroding/breaking and then damaging the turbine wheel on its way out.

Std K04-23 thread fixing is bespoke to Audi... M12x1 from memory, but into a counter bore hole thru the 5mm thru hole which relies on bottoming out on the shoulder on OE egt probe. most aftermarket are 1/8"NPT type fixings. You could I guess make a hybrid type probe which could screw into the M12x1 tapped hole.

see how the factory move their temp thresholds between assorted 1.8t cars, and it does seem to follow a pattern of how far away from the turbine they are determining the temps, and set the levels appropriate for that location..
 
audi upgrades
beachbuggy said:
Ok, I'm going to bow out graciously here :) you know it's 100 degrees less dp compared to turbine housing, I know it'll be cooler, but not having the experience of fitting there as you have I couldn't give a figure and I would assume the OP wouldnt know either and thus unless you knew the relative temps compared to location then JUST fitting it in the dp will give you a non perspective temp reading, basically a pretty looking gauge.

I totally get what your saying tuffty and whole heartedly agree with you....
Click to expand...

No worries dude... I learnt the hard way with mine... measured EGTs in the collector were higher than the factory set TABGBTS value and this lead to the ECU fuel dumping pretty much all the time and I believe lead to the accelerated wear of the piston rings in my engine...

Just for informational purposes my current EGTs under load are just over 700 deg at 1.2bar... under 500deg on cruise and mid 500's on the motorway on cruise...

When I had the probe in the collector I was hitting between 950 and 1000 deg... this of course was more than the 920deg TABGBTS value and went into instant fuel like a mofo mode...

Before...
20090914_CRW_3644.jpg


...and now... this was my previous DP but its more or less the same position in my recent DP and in fact actually closer to the turbine due to the design of the T3 hotside I am now using...
20100716_CRW_4149.jpg


<tuffty/>
 
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