Adding EMP Gauge, Any Reason For EGT Anymore?

[A5INKY]

So my McNalley boost/EGT gauge dropped and LED segment again. It is too small of boost range anyway at 0-30 PSI, initial spike is pegging it every time. I am thinking of new gauges and am leaning heavily toward ISSPRO. Going to add a EMP gauge while I am at it.

First question is if an EGT gauge will still be necessary when I am monitoring EMP? The EGT gauge was handy going over mountain passes when the car still had the stock turbo and nozzles, taught me to drop to 4th even when it still pulled 5th well as EGTs were getting to the danger zone. But I expect the longer injection duration combined with a tiny turbine was the reason. Thinking EMP was getting pretty high under those conditions though it might have provided the same basic warning. However, now with a GTB2056VK and shorter duration with the bigger injectors it shouldn't be the same issue. Thoughts?

Second question I am hoping to hear from some of the experienced tuners using the GTB turbo's from both sides of the pond. What range of EMP gauge should be most appropriate for my 2056 turbo. I am pushing 28 PSI through a mildly ported head with a Colt Stage II cam, Drivers Fire tube manifold and out through a 3 in. straight exhaust. I am thinking a 0-40 PSI boost gauge. Should I go 0-60 on the EMP gauge or go for the 0-100 PSI?

 

[O.C.TDI]

I have not been very impressed with my McNally gauges. They are nice but tend to be finicky and temperamental .

I have been looking at the Performax line from Isspro. I actually won a set from them at a dyno day last year but have yet to redeem them.
http://www.isspro.com/performax.php
The benefit here is the ability to data log a bunch of different parameters.
I would run 3 gauges. Boost 50psi, EGT, and a gauge of choice, temp, emp, etc.
Read up on them... oldpoopie is running the along with a few others around here.

If you don't go that route...
40-50psi boost, 50-60psi emp. If you peg either of those gauges something is not right.

I would not get rid of egt. It is a great early detection device. I can easily max out my egt's if I am pushing it really hard. A 1/4mi pass has me at 1650*f.

I see high of 35-38psi on my emp normally even during the tip in spike. Occasionally I will get a 45psi spike, usually in a strange load situation.

O.C.

 

[jackbombay]

FYI the convex glass that comes on some of the isspro gauges looks cool in advertising pictures, but in real life it has significantly worse glare/reflection issues than gauges with flat glass, I'd never pay for a convex isspro gauge again.

 

[A5INKY]

@O.C.: Thanks for the info. I too am looking at the Performax gauges.

Considering how low your EMP is staying that 0-60 PSI EMP gauge looks just right. Only question I still have is if the 2056 might be prone to a little higher EMP than your 2260 with it's freer flowing turbine. I have seen the housings side by side and the difference is substantial. Anyone with specific EMP ranges with the 2056?

Wonder if anyone has figured out how to best match VW lighting on these? Oldpoopie?

ISSPRO makes a 0-2000F EGT gauge, I'd go with that one. As for safe limits on EGT, seems I read somewhere the GTBs can take 1920F sustained. Mine has gotten as high as low 1700s at high speed/WOT and I don't think it has been an issue. Considering how low your EMP is staying and still getting EGT that high I am inclined to agree with keeping that gauge.

 

[Keebler145]

a5inky -

1. Yes you should still have an EGT Gauge, cheap insurance.
2. EMP gauge from talking to Kooyajerms and having my 2256, a 0-60 psi gauge would probably be best. They read most accurate in the middle of the gauge as we all know. You really shouldn't spike more than 40-45 emp and if you are you need to adjust some things mechanically.

Side note: Why no love for Mcnally? I actually like my gauges a lot I had the faceplate adjusted to read higher than 30psi. The LED has gone out on it before but they fix it for cheap or free if it's in warranty.

The only gripe I ever had with them was the oil pressure/temp sensor aluminum housing ALWAYS leaks and eventually fatigued and broke on me. But, he sent me a new one no charge and it was beefier than the original (they must have revised it) and it seems pretty solid after about 5k miles.

 

[A5INKY]

1. Yes you should still have an EGT Gauge, cheap insurance.
2. EMP gauge from talking to Kooyajerms and having my 2256, a 0-60 psi gauge would probably be best. They read most accurate in the middle of the gauge as we all know. You really shouldn't spike more than 40-45 emp and if you are you need to adjust some things mechanically...

Another vote for keeping an EGT gauge, thanks. Kooyajerms is running the same turbo as me, so thanks for sharing that. I could have sworn he was getting 2X boost pressure EMP spikes, but then again he fought mechanical VNT adjustments forever. I think my VNT is pretty well set.

...Side note: Why no love for Mcnally? I actually like my gauges a lot I had the faceplate adjusted to read higher than 30psi. The LED has gone out on it before but they fix it for cheap or free if it's in warranty...

Good guys at Mcnalley, agreed. Just that I have already had to send the gauge back for a burned out LED less than a year ago for what I thought was an upgraded LED. Now that one is burned out too. Gauges shouldn't take that much service.

 

[shadowmaker]

Nope. You don't need EGT reading for anything. Just keep EMP within reasonable limits and check your rear view mirror that there's no excess black smoke at the higher rev area. Some light smoke is OK, but when you start to make shadows in bright daylight, you are in the danger zone.

 

[kooyajerms]

I'm working on my Isspro Performax thread if you need some more ideas. I'll put it in the upgrade section. Max reading recall and the warning lamp are just really great. And you can datalog? You can't beat that. White face gauges look great too. Another member bradamoniom has the EV2's and says the color match is a bit off on the mkiv. My color match is great since the Ford's had the same ecto green color.

If I had room for 4 on my a pillar it would look like this:
40psi boost
2000 egt
100psi oil
60psi emp should be sufficient (I'm still using my temp gauge, but I'm so used to it now, it's an old friend)

We still have to look at it as PD vs VE. No one else has coughed up numbers on the VE. I may be running 2:1 on some spikes (partial throttle likes to give worse numbers on some random stabs like O.C. says, probably just because of n75 control) but it settles just fine. If I'm WOT its 1.5:1. It's a bit high, but that's where we think it should be. Hell, think of the folks with 17/22's I think they are running 3:1 on EMP.

 

[Keebler145]

My numbers were almost identical to yours jeremy although mine at cruise was much closer to 1:1 than yours before all the adjustments you had.

I have videos and what not in my thread somewhere.....

 

[kooyajerms]

cruise is 1:1 or so.

I'll take a closer look at the convex glass issues. The visibility of these during the day has been great, considering my placement on the a pillar (white face is great) and night obviously is perfect.

 

[O.C.TDI]

Not all Isspro gauges are convex glass. The Performax are flat. Non issue.

I will talk with the developers at Isspro to see if we can get a color match for the indigo.
The main engineer is a club member and is just up the road from me.

Normal cruising EMP is 7psi over boost pressure. At 3500 rpm it swings and EMP is 7psi less than boost pressure. The 35 psi is the tip in spike and once over 4000 rpm.

 

[A5INKY]

IDK, Shadowmaker has me wondering about the EGT gauge. Even before I got the turbo and tune just right, never saw EGT more than low 1700s no matter how much smoke it was blowing (which was considerable at first) or for how long. I don't think the car as it is set up can exceed the turbo's heat rating. Will have to think on that one. I am going with a 3 gauge pod and could use the other space for oil pressure gauge...

Thanks for chiming in Kooya, 0-60 PSI EMP it will be.

Good to know on the non-convex lens for the performax, O.C. Would be really cool if you could get ISSPRO to offer the indigo lighting. I am kind of anal about details like that.

 

[Chris Tobin]

A5INKY, where are you mounting the gauges in your MK5? I have had a hard time thinking about where to put traditional gauges and am looking at installing a Banks IQ or some kind of digital display like that to monitor vitals. I don't really like the look of the on dash vent replacement pod... And with the airbags in the pillars, we can't put gauges there...

We just installed a Snow Performance water/methanol system and put the controller/display on top of the dash between the A-pillar and the instrument cluster. It can display boost and EGT and I figured I'd install the Banks IQ screen right above it for all the gauge displays in one place.

 

[jackbombay]

I'll take a closer look at the convex glass issues. The visibility of these during the day has been great, considering my placement on the a pillar (white face is great) and night obviously is perfect.

The white gauge face could make the convex glass a non issue, I had convex glass with a black face in my TDI Vanagon, here is a pic, maybe being closest to the window was part of the issue, you can even see the glare in the picture :-/

 

[A5INKY]

A5INKY, where are you mounting the gauges in your MK5?...

Right now I have the single column pod for the McNalley. I am going to go to the New South triple dash mount now though:
http://www.namotorsports.net/detail.cfm/part_cd/NPPOD.013

 

[ryanp]

I've never monitored EGT, it would be useful in certain tuning respects but i keep smoke minimal and if something breaks/melts it needs upgrading!

 

[devonutopia]

I often use EGT as a guide as to whether the car is straining in its current gear. Eg up an incline on a motorway @ 75, in 6th gear (2000 rpm) I might see the EGTs around 400 to 440 whereas in 5th gear (say 2300 rpm) EGTs might come down even though revs are higher the engine is working less hard. That's just economy monitoring though. Don't often get the chance to push it to 800 degC+ like I have in the past.

 

[TDIMeister]

More useful (not to mention reducing gauge clutter) is a single gauge that can measure absolute pressure (IMP) with one needle and _differential_ pressure (IMP minus EMP) with the second needle. When the difference is positive at a glance, you know that life is good.

 

[TDIMeister]

But yes, you should still monitor EGT at a proper point upstream of the turbine inlet.

 

[A5INKY]

More useful (not to mention reducing gauge clutter) is a single gauge that can measure absolute pressure (IMP) with one needle and _differential_ pressure (IMP minus EMP) with the second needle. When the difference is positive at a glance, you know that life is good.

If I had ever seen or heard of such a gauge in the automotive world I would have remembered. Are you saying such an animal exists? Or just that it would be more refined information for what is needing to be monitored? That would be great. Although, might have to come up with a better name than IMP-EMP gauge. How about turbo happiness difference, THD for short. BTW, anyone thinking of producing THD gauges can PM me for my contact info for where to send the royalty checks.
What about O.C. TDI having a negative THD under certain conditions?

...Normal cruising EMP is 7psi over boost pressure. At 3500 rpm it swings and EMP is 7psi less than boost pressure. The 35 psi is the tip in spike and once over 4000 rpm.

But yes, you should still monitor EGT at a proper point upstream of the turbine inlet.

Smack in the center of the merge collector close to the turbine inlet. Perfect, right?

 

[mk1-83]

I got boost,oilpress/temp and a EGT gauge. I whant to now what's hapenings when I floor it. And it's a early waring when things go wrong.

 

[Drivbiwire]

If I had ever seen or heard of such a gauge in the automotive world I would have remembered. Are you saying such an animal exists? Or just that it would be more refined information for what is needing to be monitored? That would be great. Although, might have to come up with a better name than IMP-EMP gauge. How about turbo happiness difference, THD for short. BTW, anyone thinking of producing THD gauges can PM me for my contact info for where to send the royalty checks.
What about O.C. TDI having a negative THD under certain conditions?

It's used on some aircraft with Pratt, and Rolls-Royce engines, it's called an EPR or Engine Pressure Ratio. It is used to monitor the thrust output of the engine by measuring the incoming air pressure and comparing it to an exhaust pressure probe to derive an actual pressure output of the motor e.g. thrust.

As Dave described, comparing Absolute pressure or in this case local pressure, and having a ratio of EMP built in you will have a reference to actual turbo output and load...sort of.

But yes, you should still monitor EGT at a proper point upstream of the turbine inlet.

EPR (Engine Pressure Ratio) and TIT should never be used to over-ride the other and indicate completely different things.

Being a "GE" kind of guy, I would much rather see a shaft speed sensor in % of rated rpm... I can't stand EPR gauges! sorry but you'd probably have to be a pilot to understand this last statement.

Good advice Dave!

EPR + TIT tells you pretty much everything about where the engine/turbine are operating.

 

[NHgranite]

Being a "GE" kind of guy, I would much rather see a shaft speed sensor in % of rated rpm... I can't stand EPR gauges! sorry but you'd probably have to be a pilot to understand this last statement.

Or even better yet, FADEC !

 

[Drivbiwire]

Or even better yet, FADEC !

You already have FADEC, All TDI's are true FADEC systems thru and thru. Just look at the go pedal...no linkage!

The only thing a TDI is missing is a Dual ECU configuration with a limited mechanical system to keep things turning in the event of a dual ECU failure. However I can't think of the last time in cars or planes that ANY ECU has ever failed on the run.

 

[NHgranite]

I was referring to turbojets and thrust levers !! ;-)

You already have FADEC, All TDI's are true FADEC systems thru and thru. Just look at the go pedal...no linkage!

The only thing a TDI is missing is a Dual ECU configuration with a limited mechanical system to keep things turning in the event of a dual ECU failure. However I can't think of the last time in cars or planes that ANY ECU has ever failed on the run.

 

[devonutopia]

I wouldn't be without EGT thats for sure. My gauges are a little in your face but they sit perfectly to glance at without taking eyes off the road. I have EMP too, on temporary install basis, just for tuning purposes.

boost, EGT, joint oil & water temps (amazing how water varies with needle sat on 90...)

oil pressure

 

[A5INKY]

What about AFR?

Thanks to everyone for the feedback so far. Still don't know exactly what I will go with. At least I am gaining a better understanding.

I have since had an additional thought for a gauge possibility, air to fuel ratio. I am like most everyone else here and have been using my rear view mirror to gauge AFR. Seems like an actual wide band AFR gauge, especially with data logging could be a great tuning tool.

Anyone know why AFR measure is not more common in diesel tuning?

 

[JFettig]

They're expensive, not necessary, can soot up easily and get dirty. I still want one.

There are diesel specific sensors, but likely no gauges for them.

I plan to do both EGT and EMP when I get my setup rolling. Maybe at some point I will find that one of the two isn't necessary.

Jon

 

[Drivbiwire]

Thanks to everyone for the feedback so far. Still don't know exactly what I will go with. At least I am gaining a better understanding.
I have since had an additional thought for a gauge possibility, air to fuel ratio. I am like most everyone else here and have been using my rear view mirror to gauge AFR. Seems like an actual wide band AFR gauge, especially with data logging could be a great tuning tool.
Anyone know why AFR measure is not more common in diesel tuning?

AF is a measure of the load on the motor (richer = Higher load, leaner = lower load). However TIT (Turbine Inlet Temperature) provides a direct read of load on a motor as a function of the exhaust energy being directed at the turbine inlet.

I am having a hard time justifying an AF indicator, when TIT, EMP/EPR are so easy to read (reliably) and give you data that can also protect the motor (TIT) from thermal damage.

Another indicator that I think would be good is a compressor (turbine) rpm indicator (in %). This would tell you where the turbo is running in respect to TIT and rpm. A VNT-17 if I recall peaks at 162,000 rpm this would equal 100% You can plot the flow graph and know exactly what rpm ranges surge will occur.

But realistically, how much of this do you really need. Even on the whale I seldom if ever look at any of the engine gauges in any phase of flight, that's what the FADEC is for

 

[A5INKY]

You have a good point DBW. AFR would have been handier as I was going back and forth with my tuner after the build. Now that the tune is really powerful and clean it probably won't do any good except to drive my tuner nuts with my OCD driven requests for AFR perfection. Probably best to leave well enough alone.

I think I am going to settle in to going 0-40 PSI boost, 0-60 PSI EMP and 0-2000F TIT (like that better than EGT for some reason) and call it a day. I have reported coolant temp and IAT on my scan gauge II. Maybe I'll add an oil pressure gauge someday. I hate relying on idiot lights.