Ok, we will be installing an egt in our turbo nx.
If a remeber a post a while ago, the sensor should be installed in the exh manifold BEFORE the turbo correct?
If that is the case well and good.
the real question is what temps are good and what are bad?
any info will be appreciated (oh yea, as soon as the GTi-R install starts, I'll post some pics.)

Second, since we have the liberty of having no bumper(the front end is all tube framed) would there be any advantage to installing a ultra thin fan on the GTi-R INTERCOOLER? This would certainly help the lack of frontal area on our cars i would think.

Usually around 900-1000 celcius you want to pay attention. About 1200f-1600f for long periods may cause some melting action.



Larry

i personnally wouldnt go over 900 deg celcius !
after that you could start burning valves

yeah, 1600F is bad bad bad.... stuff starts melting at that point.

yah i prefer to stay under 900-1000 celcius. Actually our cars can handle higher but it all depends.The sr20 can actually handle 1200F for short periods maybe higher. I was told once by 2 VERY recognized members that going up to 1200F is no problem , as long as its in moderate time periods. of course you vehicle has to be properly tuned. They even went to say that 1600F(not celcius)
in burst was fine , also i was amazed but still prefer to stay 900-1000 celcius.
My car has been run this way for over 2 1/2 years with no problems.


Larry

You guys have a very interesting interpretation of temperature units:

Tf = 1.8*Tc + 32

Tc = (Tf-32)/1.8

1200 F = 648 Celsius = not very freaking hot. A N/A car will run that hot at WOT.

1650 F = 899 Celsius = about as hot as you want to safely go. You can run higher, but you are taking risks.

1000 Celsius = 1832 F = you better know what you're doing or your motor's close to blowing up.

Exhaust valves are made of iron alloys (steel or stainless steel alloys). They are not going to melt anywhere near 1600, 1800, or even 2000 degrees F.

With conservative tuning, little reversion, and a free-flowing exhaust, you shouldn't see EGT's much over 1450 F. These are just a guide, as you can have nice low EGT's and still detonate and fry your motor, especially if you have too much timing advance.

High EGT's are usually a sign of either running lean, or high degrees of exhaust flow reversion (back flow of exhaust gas into the cylinder). These are warning signs of impending detonation, and it is the detonation that is often accompanied with high EGT's that destroys stuff in your engine, not the high EGT's themselves.

Well tuned race motors running on race gas built with good internals can live with high EGT's. Most race motors will run hotter than a street motor will.

EGT's over 1400 F can be bad news for your turbo, though. Many (most) shitty aftermarket turbos are made with GMR 235 turbine wheel alloy and ductile cast iron turbine housings. These materials cannot withstand temperatures over 1400 F for prolonged periods of time. Cracking of the housing and wheel failures will result.

Better turbos have Inconel 713C turbine wheels and turbine housings with silicon and molybdenum alloys which push up temperature acceptance quite a bit.

oh Rob you just confirmed what Mike told me along time ago. In any case i run 900-1000 celcisus egt's peak . Like i siad seems to be working fine for me, plugs look good after a rolling shutoff, got the 4bar iam happy for now. I should be installing my 3037within a week , i hear this turbo might max my injectors out on the dyno.
True?

Thanks
Larry

Originally posted by ClassicSE-R

With conservative tuning, little reversion, and a free-flowing exhaust, you shouldn't see EGT's much over 1450 F.

...

EGT's over 1400 F can be bad news for your turbo, though. Many (most) shitty aftermarket turbos are made with GMR 235 turbine wheel alloy and ductile cast iron turbine housings. These materials cannot withstand temperatures over 1400 F for prolonged periods of time. Cracking of the housing and wheel failures will result.

Better turbos have Inconel 713C turbine wheels and turbine housings with silicon and molybdenum alloys which push up temperature acceptance quite a bit.

Yikes, this seems kind of scary. "Conservative" tuning will get you 1450*F EGTs, but your turbo may start to fail? Aren't the S13, S14 and Bluebird T25s equipped with GMR turbine wheels? Or are they slightly different so they can handle the heat better?

Please enlighten. Thanks.

Originally posted by AntonioG


Yikes, this seems kind of scary. "Conservative" tuning will get you 1450*F EGTs, but your turbo may start to fail? Aren't the S13, S14 and Bluebird T25s equipped with GMR turbine wheels? Or are they slightly different so they can handle the heat better?

Please enlighten. Thanks.

Yes, those wheels are GMR. They run high sil + moly housings on those turbos, though.

Cast iron goes through a phase transformation around 1400F, and therefore can't be run that hot without taking serious risks.

GMR doesn't go through a phase transformation at 1400 F, it just doesn't have the strength at temperature that Inco does. This isn't a big deal if you aren't putting much stress on the turbine. The 6 psi stock turbo is barely even spinning, so the stresses in the wheel are very low. A little loss in material strength won't hurt anything.

Go run a ton of boost on that turbo, and you start to take chances.

I have the apex egtemp it installed after the turbo before the flex pipe. I believe you want to measure air coming out of the turbo not stright out the motor.... but i could be wrong(please ocrrect me if i am)
Also I dont let it go past 900c. when it hits 800c i let off the throttle
regular high way temps 600c and street driving like 400-500c

Originally posted by sr20lbmonster
I have the apex egtemp it installed after the turbo before the flex pipe. I believe you want to measure air coming out of the turbo not stright out the motor.... but i could be wrong(please ocrrect me if i am)
Also I dont let it go past 900c. when it hits 800c i let off the throttle
regular high way temps 600c and street driving like 400-500c

You have your EGT probe in the wrong spot. It should be before the turbo, in the manifold somewhere. After the turbo, the turbine wheel has already "used" the hot exhaust gases to spin the compressor wheel, so the temperature of the gases after the turbine wheel is a lot less than before the turbine wheel.

Rob, thanks for clearing my question up for me.

wow!!! I had it all wrong i thought that when the exh gas goes throught the turbo causing it to spin at a very high rpm creates friction which entails heat so your saying that once it goes through thte turbo its less hot than what it was when it first came out ...logic would say it'll be hotter once it goes throught the blades spining at 110,000rpm or am i worng once again? please correct me if i am

Yup, you have it backwards. In a compressor, that is the case, but not with a turbine. Turbines use the energy of hot, active gases to create work. Compressors use work to uhhh, compress gas...and compression of gases increases the temperature of them, that's why you need a good, well-placed IC.

Pick up a thermo book, you will learn to love it, I guarantee. ;)

thanks for the clarification.......... where do i get it??

I run at about 950 degrees F. at 65-70mph and about 1250 degrees F. under full boost during a hard pull. I have my probe after the turbo... is this acceptable? I've heard that I should add about 200 degrees to those number since it's after the turbo. Am I correct? How do you guys drill and tap the cast nissan manifold? I have the GTI-R with a T3 flange. Thanks
Travis

I remembered finding this when looking for information on Westach gauges:EGT probe stuff. (http://www.se-r-list.org/archives/2000/2000-05/msg02370.html)As a matter of fact, Westach was the search term I used to find it. ;) I think that finding the leanest cylinder may be practical with an I/R pyrometer, but that's just a wild guess.

I'd take that 200F rule not very seriously, about as seriously as I'd take the 15% drivetrain loss rule. There's only one real way to find out and that's to stick another EGT probe in the manifold. Of course, there's even debate as to which runner to stick it on buy whatever :)

As for the Thermo book, I dunno about loving it but it is highly useful.

Khiem

Originally posted by unlucky
I run at about 950 degrees F. at 65-70mph and about 1250 degrees F. under full boost during a hard pull. I have my probe after the turbo... is this acceptable? I've heard that I should add about 200 degrees to those number since it's after the turbo. Am I correct? How do you guys drill and tap the cast nissan manifold? I have the GTI-R with a T3 flange. Thanks
Travis

You cannot put your EGT gauge after the turbo. It tells you nothing there.

Adding 200 isn't going to get you there, either. The temperature drop through the turbo is a function of the amount of gas going through the turbine and of the amount of work being done by the compressor. In short, it varies a lot depending on a bunch of stuff. Put your EGT probe upstream of the turbine. That's the only place it means anything.

Is it also true that it should be placed into the port of the weakest cylinder, if so what is the benefit of that? TIA

Travis,
Why do you always fail to ask me? I have the drill and tap in the cupholder of my truck. I tell ya.
John