Whats the importance of having an EGT? I have an hks egt in my fd but wanna put an aem wideband in its place and i dont see the point of having it. Any reasons?

 

The exhaust temp is a clear indicator on how well your mixture is burning. But the necessity of the gauges should be determined by the mods on your car. Single turbo, definitely get both. Stock twins with a tuned stand alone ecu, I'd just get a wideband.

 

EGT measurements are nice to know as far as reading through a data acquisition system goes. Gauges usually read too slow to know what's going on in a transient driving condition.

 

Agreed with arghx, plumbing dual EGTs into your ECU's inputs is a much better use than having it read on a physical gauge. Run them (1x EGT for each combustion chamber, installed pre-turbo) to the computer as useful inputs that you can use while mapping or to trigger safety features.

Installing an EGT sensor just so you can add another gauge on the dash is a waste of money imo.

 

I respectfully disagree. Not a waste of money when you have a plx display to show multiple items. Having a visual display helped me see that my center fuel injector wasn't spraying on the center rotor on my 20b. Having this kind of info right in your face is invaluable imo. Plus you can easily see the uneveness of each rotors compression based on the temp differential. A/F is nice but, it only gives you an accumulated reading from both chambers. One chamber could be lean with a slightly clogging injector while the other chamber is rich from you adding extra fuel to compensate. This will fool you into thinking you have an ideal A/F ratio when in fact, everything is out of wack. Then you blow the engine and are wondering WTF??? Having a background in aviation maintenance, I can't believe I waited this long to install egt's on my fd.

 

Yeah I'm single turbo with an apexi fc. Why do you say if you have twins then you don't need one but if your single you do? Just curious!

How the hell do you do that? Lol

So your saying you can look at the egt's of each rotor? On one gauge? Or do you have 2? I have an hks egt and it has a select button and when you push it this green light turns on on it and it changes its reading. What does that do?

 

You need to have 2 probes, one on each exhaust port exit. Depend on what gauge setup you have you might need 2 separate gauge, but if you have PLX gauge then you can daisy chain the module and have as many as 4 read out in one gauge, so you can have AF, both EGT and one extra read out on one screen.

EGT monitoring is good to have, single or not.

 

My point is that a visual EGT is far inferior to running EGT as an ECU input.

If you're driving aggressively then you're not likely to pay as much attention to your gauges (you're focused on where you're going). If you're driving aggressively and you visually miss the lean condition then your EGT gauge doesn't do diddly, since your engine is still gunna be toast.

If your EGT is feeding to your ECU than you don't *need* to see the temperature change, your ECU does and will adjust accordingly.

Get an ECU that's not based on 20 year old technology

Newer (quality) ECUs have the option of dedicated thermocouple inputs, or at the least you can get a set of EGT's with converters from temp to voltage.

 

With the PLX Dm200 you can display 4 items at once. I can see 3 egt's and oil temp all at once.

PLX DM-200 | OBD2 OBDII Scan Gauge

 

I'm NA so I have more leeway when it comes to blowing an engine. You make a valid point but the visual reference is still useful when you have a streamlined set-up like I have. I believe it also has the ability to send info to ecu as well (need to recheck the install instructions ). This is the best of both worlds and not a waste of money.

 

There seems to be a lot of misinformation here. Closed element K-type thermocouples (What the vast majority of EGT probes are) are actually slower to react than a properly functioning O2 sensor. HOWEVER, an EGT probe tells a more complete story of whats going on inside an engine and what its doing to the exhaust system ONCE you know how your engine/exhaust reacts to rich and or lean conditions over time.

What I mean by that is that you'll spike in temps when lean, as well as when rich, and it really all depends on how your manifolding is plumbed/egt placement.

In my opinion the proper way to monitor an engine is to have an EGT probe in each rotors exhaust path as well as an O2 sensor ~18-24" down the exhaust stream. You'll get a clearer correlation between mixture and EGT as well as have redundant sensors. Also, as I mentioned earlier, I'd tend to use the O2 sensor for any closed loop feedback rather than the EGT sensors, as they're significantly faster to react than an EGT probe

 

With gauges, not ECU data acquisition, the limiting factor is typically the gauge itself rather than the sensor. On a digital AFR display it might be a choppy refresh rate. On an EGT gauge, which are typically analog needles, the needle may be "lazy" when compared to data displayed by a data acquisition system (a datalog dumped to an Excel file).

If you want to have gauges and data acquisition, go for it. It costs money though, and takes up space.

 

I would agree to the advantages of having the EGT readings per rotor, (correct me if I'm wrong) but some guys are having problems with the probes they keep braking off from the heat... Any of you guys having some of these problems? Did you find any solutions? What kind of probes are you guys using? The ones supplied with the PLX series?

Cheers

Andrew

 

I'm just thinking out loud. Why not have wideband sensor on each exhaust port to see what's going on at individual rotor housing? I wonder if some ECU can adjust each injector pair according to each rotor housing's AFR reading rather than making global incremental changes.

 

I would bet that a wideband on each runner would have to be placed way too close to the engine. The heat would probably kill them faster than you would ever want to replace the sensors.

 

The temperature and pressure would distort the signal greatly.

 

Well typically when you change out the stock turbos for a single, lots of things get changed including the fuel system. New larger or bored out injectors greatly affects the AFR's all across the board. At idle, under boost, at cruise, all of those conditions have to be tuned and verified that it is at an optimal setting. If you still have the stock twins and are only upping the boost then the only thing to worry about is (regarding this conversation) is to make sure that you have enough fuel under the elevated boost scenario.

 

100% true. after 10+ years of road racing, i can say that you need to build the car so that it is reliable with no gauges, as the driver wont use em.

for diagnosis and tuning though, stick as many in there as you want

there are people that use AFR on each rotor. AFR and EGT are two different things. with EGT we are concerned with the peak number, too hot is bad. AFR is related, in that its one of the things that influence EGT, but its not the only thing

 

Does porting the exhaust ports and manifold lower egt's?