So now that I have the plx gauge installed , I am monitoring iat, timing, egt and lambda . So the other day I was playing around and I noticed that on an open road I floored it and hit max boost non sport mode, and I noticed that my egt/cat temp went from 1200 def f to almost 1500 deg f , although it dropped back fairly quicly, the question I have , what is the max temp for egt before stuff starts getting funky and I thought with lower back pressure exhaust I am supposed to reduce egt, can't imagine what the temps would look like after a tune. The afr tends to stay between .73 and .80. I have europipe stage 1 , and that's all the mod I have done so far

 

AWE provided some data during the development of their 750R package and the 997GT2. A stock GT2 will reach 1600F at WOT (as will a VTG modified 997TT with 200cell cats) at 6500 RPM.

 

The exhaust temperature is restricted to a maximum of 980°C or 1795°F by boost pressure adjustment or fuel enrichment.

 

Thanks bob and stef, so if I had the stock exhaust and did the same test as above, would my egt be higher then what stated with the am eexhaust because of restrictive stock exhaust? too bad I didn't have this gauge to monitor when my car was stock

 

With such a simple test you won't see any difference in temperature.
You'll measure the temperature at the exit of the turbochargers and not the temperature of the exhaust gas leaving the muffler. Besides high temperatures at the turbochargers are great as long as they are lower than the 1795° F. Air expands as the temperature rises so with very hot air the air speed will be very high too. The turbochargers will be more efficient with those high speed exhaust gasses.

That's also the reason why the 996TT and 997.1TT stock headers are partly double walled : keep the heat inside.
The new 997.2 stock headers are even fully double walled.

 

got it stef , thats interesting that the headers are double walled, that makes sense why the oem exhaust input flange (that connects to turbo) are double walled as well? is that why ep also has double wall around the cats, or is that for heat shield, so would it be beneficial to ceramic quote the headers? just curious, i think it wont hurt it!

 

Yes the cones near the inlet flanges are double walled as well.
The heat shields around our cats are there to prevent them from heat shocks. Nothing worse for catalytic convertors than heat shocks. They also keep the heat away from the engine. The gap between the cat heat shield and the engine is just 5mm ( less than 1/4 inch ).

Ceramic coating is beneficial in theory. I have never found real info on header temperatures with and without ceramic coating though.

 

so bob from what you are saying then 997 tt with stock exhaust will see higher then 1600 ? at wot the reason i am saying this is i am seeing 1500 with 100 cell ,with no tune or modded vtg

 

Your post got me curious so I did some datalogging. After about 15 min of street/freeway driving in 65 F weather, I WOT'd it. Here is what I got for EGTs (0 cell cat) under some good load and high boost.

 

Ron, I haven't datalogged a stock 997TT. Not sure how high it will go.

bob

 

thanks for taking the time, that is interesting results, as your egt never went over 1300 F, and i see you are running ~ 1.4 boost, that is funny i went for a spirited HS drive yesterday and i didnt data log but i was using my PLX GAUGE, and every thing was on the money except my egt went up too 1650 F, with 100 cell , (full boost, stock tune) so i am confused now, or am i missing some thing here, because what am I going to see if i do a tune with higher boost, theoraticaly it will be worse? unless some thing isnt right with my car?

 

Hi Ronnie, Try datalogging with Durametric and see what you get. Maybe the calibration is off between the two. Also, I don't know where the exhaust gas sensor is located, before or after the cat? Dave

 

TT are you using durametric for logging? If so how do you get boost to show like that?

 

EGT sensors are pre-cat

 

Yes, I'm using Durametric. It spits out boost in mPa. I enter an equation in excel (mPa-950)/1000 to covert it to bar. Likewise for EGT--reads out as Celcius but converted to F using C*1.8+32.