OK, I'm getting very close to finishing my EGT and boost gauge installations. I've read some good stuff and received some advise as well (thanks Claudius, Smokingjoe, Incognito & the rest).

Anyway, there are more questions than ever swirling in my head
In addition to the controversy regarding where to take readings from (TIT, TOT, near the Cyl head, Just before the turbo, etc.). I've gotten conflicting info as to what settings to expect.

Some experts tell me that the way to establish a baseline temp is to take the (stock) car out to the highway, get to 4K or 5K rpm in 3rd or 4th gear and go WOT using the brakes to maintain the rpm very steady. I'm told this will give you the maximum EGT that you are likely to see and those are the max safe levels you should ever reach.

According to some experts, these are likely to be in the 900°C (1652°F) range. Now, my gauge only reads to 1600°F, obviously this will never do... Now, others say that the EGT should be much lower than that to be safe, something like under 1400°F (760°C) All these are TIT readings such as could be obtained from the probe located in the manifold near the cyl head.

Another possibility is to mount the probe somewhere near the turbo outlet in the DP. This location would produce temps about 300°F to 400°F lower than the alternative. I guess I could obtain a baseline EGT with a similar method as described above and just make a note of whatever that temperature is.

The Autometer instructions suggest a DP location for the probe in turbocharged vehicles. The Autometer tech service advisor says:

Thank you for your inquiry. The mounting location of probes for EGT readings is a much disputed subject. "Accurate" readings are a relative term. Our gauges will "accurately" show you the temperature of where ever they are mounted to within 2% of the true temperature of that location. Most of the controversy occurs over whether pre or post turbo installation of an exhaust gas temperature gauge is best. Both locations can be suitable for tuning but, as an individual you need to consider what you are using the gauge for. If you are just establishing a baseline temperature to tune against, either location is fine. However if you are going to be comparing your temperature readings to specs that someone has provided to you or that you've read on either a website or a magazine article, it is critical to know exactly where those temperatures were taken from in the exhaust and what engine modifications were made as these can have a dramatic effect on the overall temperature registered. For example,if you read in an article somewhere that you should see about 1500ºF at a given throttle position on your vehicle from 2-3" off of the cylinder head, if you have your probe mounted 2-3" after the turbo instead, your readings could be 300ºF cooler due to heat exchange and bleed off. Ideally you want to have your probe mounted in the exact same spot as the temperature location as the readings you are going to compare to. One final piece of advice on pre-turbo installation, be very meticulous during your installation, as sending even tiny metal shavings through your turbo can be a very costly proposition! If you have any further questions, please let us know.

Anyway, what I think would be useful is to have some data from all the folks who have EGT gauges installed. In other words, please tell us what type of EGT gauge you have, where is it mounted and what temps are you seeing under what conditions?

I'd love to see this data, and I'm sure many other would like to have it as well.....

Thanks,

Manuel

 

Ah, my first post

I'll admit, in this case I was too lazy to do a search to find out what your TIT, TOT, etc. (turbo in, turbo out?) are short for, but you want to mount the probe as close to the exhaust port of the leanest cylinder. Historically, on DSM 4G63s, this is the #1 or #2 cylinder. I doubt the Evo is much different.

Mounting the probe after the turbo (in the O2 housing or the top of the downpipe) will read 200-300°F less than what your EGTs are when measured in an exhaust manny runner, so beware.

I don't think there is any sort of "baseline" for EGTs and I wouldn't say whatever it shows stock means anything other than a "target" as you make changes. From the datalogs I've seen so far, even stock, the car is not getting maximum timing advance (14-16° at redline) so it seems to me that the stock EGTs are not particularly ideal. In all likeliness, the max timing on the ECU table is around 22-24° and that extra 8° or so of timing will make a monster difference in power. The trick is to get the timing and keeping it (no knock).

Probably a topic for an entirely different thread (tuning), but if you tune for max timing and no knock (need a datalogger and something to tune with , everything else will almost have to fall in line (EGTs). You would want to run just lean enough to accomplish this and I would only use the EGT to make sure things aren't getting out of hand. This has been my tuning philosophy for years and it works. If you see knock, your EGTs are too high, period. Of course, you can run higher EGTs on race gas or a cooler air charge without knock so what your EGTs could be will change depending on that...and that is probably the different temps you're seeing thrown around.

With race gas, it's definitely not unheard of see 1600-1650°F EGTs, but keep in mind that's at the end of a run after a full WOT blast through at least 3 or 4 gears, which give EGTs plenty o time to run up. The point is that these numbers are not sustained. I certainly wouldn't want to be driving around town with constant 1500+ EGTs

Personally, on the street with pump gas, I am comfortable with peaks around 1450°F and wouldn't be afraid to see 1550-1625°F with race gas (probe mounted in the exhaust runner). Again, these EGT levels are strictly based on how much timing I run and how rich I need to be to do it. I would probably have a heart attack if I ever saw over 1650°F on the track.

I haven't installed the EGT probe in my Evo yet, but the gauge is mounted, so as soon I get some time, I will do that (in the #1 exhaust runner) and will let you know what my actual Evo numbers are, but I will be curious to see EGTs on other Evos and if possible, your max timing at redline for that EGT (please specify pump/race gas, gear and any timing changes you made).

 

Oops, I should've read AM's response I see they mentioned the temp difference between before and after the turbo. At least they threw you some useful info there, but said the only thing they could say: it reads temp where ever it's at and can't say what the temp should be.

No can really say what the temps should be, I just tossed mine up from my Talon as examples of what max I am comfortable with for each scenario...

 

Thanks a lot, this is exactly what I hoped to get, real life experiences with the EGT, gauges, etc. What has me concerned is the 1600°F max range of the Autometer, but it looks like it might be perfectly fine for my use in a street car. Apparently the 1600°F is actually quite high and not a desireable number to see under normal circumstances (outside of a dyno tuning session for instance).

Thanks again and keep up the good input. I should have known that the DSM guys are light years ahead of the EVO owners in tuning knowledge. maybe I should look in the DSM forums?


Manuel

 

I had a Defi EGT gauge in my WRX. Nice quick-reacting stainless probe, and the gauge was in imperial units to a max reading of 2000 F.

I think the melting point of aluminum is in the 1800 F range, and you risk engine damage from the high 1600 range on up anyway, so having the ability to see above that point may be .....pointless?

My EGT probe in the WRX was installed before the turbo in the up-pipe which replaced the cat. Not as good a location as right in the exhaust manifold, but much better than after the turbo, and the bung was already there so it was a simple install.

I ran a VF23 turbo w/upgraded top-mount IC, and a full 3" turbo-back w/race cat. I ran an MBC set at 14.5psi. Stock fuel maps/ECU. With the EGT probe in the up-pipe I would typically see EGT's in the 1200-1300 range, and when pushing it hard would see EGT's climb as high as 1350 F. I figured in a 200 degree differential between the manifold and up-pipe, which was actually very close to the manifold pipes. Corrected, this would have put me in the 1400-1500 F range with my max of around 1550 F.

WRX guys running the stock turbo, I/C, a little more boost (15-16 psi)and leaner uni-chip maps were seeing much hotter temps. I seem to recall a few with temps in the mid -upper 1600F range which for me would be concerning.

Using similar logic I would assume that if you install the probe in the manifold at the hottest cylinder on an EVO, you will probably see EGT's in the 1400-1500 F range, and some higher EGT's closer to the 1600 F mark with harder pulls and hotter climate/oil temps.

I guess since we are running 19 psi the temps might be slightly higher , but the EVO also has the big stock FMIC keeping the charge air cooler, and the injectors have also been sized/engineered for that kind of boost as well.

Just my .02 based on my WRX experience.

 

More interesting info..... Thanks, it's useful data for sure. I do think though, that the 200° differential you are assuming might be a bit high. The reason I think so is that the turbine rather than the length of the up-pipe would be the place where most of the heat would be lost.... Maybe I'm wrong, but it seems that the temp differential between the header location and the up-pipe would be less than that, but I could be wrong......

OTOH, the other WRX guys were getting higher temps?? Where were they measuring the EGT? Was it in the same place as yours or closer to the cyl head?

Thanks

 

Stay below 1600 degrees Fahrenheit if you want to keep your pistons alive. This is assuming you mounted it in Cylinder #2 like we did on the DSM's.

 

I haven't installed it yet because of the 1600°F range of the gauge.... However, I'm thinking more and more that I really don't need to let my EGT get even to 1600°F... In this case, the gauge might be just fine. I have not decided where it should be mounted yet. I'm thinking that maybe it should go near the turbo...

Anyway, I can't wait to do it since my SAFC II and MBC are already here I just went out and put in the K&N filter... Do I need to reset the ECU?... If so, whats the best way to do it?

Thanks

 

Its so easy to mount the egt probe in the evo header - if fact easier than doing it elsewhere so - youy should really do the manifold

As far as temps go - the evo likes to run much cooler then the wrx

While the wrx could easily do 875 C with a good tune to make power - - - the evo typically is at 825 C - - I have never gone over 875 with the evo it seems hard to get there at least with the factory ecu

 

Excellent, thanks Al, this is more information that I can use.... It's looking like at least 3 or so folks are seeing temps within the range of the Autometer
Did you gets those temps after leaning out the engine with the SAFC II or some similar device?

Thanks,

Manuel

 

Manny, you already know this..but for everyone else, I mounted the EGT on the raised heat shield mounting spot - on the number 1 cylinder.



Very easy to tap into and the heat shield mount offered enough height so that the EGT probe wouldnt bottom out before the cap nut touched the NPT fitting.

My temps are 800 at ilde and slightly over 1000 while cruising.

 

Hey Joe, have you tried to hold boost at 4K rpm at WOT?... I know a guy at work who's a racer (rally, Improved Touring, etc.) He's the one who suggested finding a stretch of road and holding around 4K rpm in 3rd gear with the brakes while applying WOT. He said that was how they established the max EGT that their rally car would produce he said 900°C was tops (and the highest safe temps they would run) but he also said that was a race car running 110+ octane fuel (not gasoline).... I presume a street car running on 93 octane gasoline should be treated much more carefully..... That's why I'm thinking that the 1600°F gauge might just be enough even when reading off the hottest cylinder.... Please correct me if I'm wrong.. Please do, I mean it

 

Not yet.. when it stops raining, I'll give it a shot and note the temps.

 

well

ive seen my turbo red hot

should i worry about that

 

No. Just ensure you let the turbo cooldown before you shut off the engine. I have seen lots of photo's of red DSM turbo's.

Speedlimit..