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Discussion Starter · #1 ·
should i install an exhaust temp, oil pressure or oil temp gauge?! which is next most important for our turbo car?! most recommend me to install exhaust temp but may need to drill a hole to accomodate the sensor on the pipe?! in this case, which location is best on the pipe ie. exhaust manifold or downpipe?! any welding required after fitting the union?!
 
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Discussion Starter · #2 ·
Go for the oil temp gauge as that is pretty important if you cane your car regularly....especially on circuits!
Re the exhaust gauge...IMO this is only important if you have modified fuel map and/or a ignition timing controller such as the A'pexi ITC. You may run the danger of running your car too lean...and unusually high exhaust temperature is one of the main signs. The sensor will require the drilling of the down pipe, and the welding of a thredded mounting thingie on top of the hole.

As for make....have a look at defli...they have a pretty good looking line-up.
 
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Discussion Starter · #3 ·
The second gauge I put in was an EGT. It is a good idea even if you are just raising your boost levels. I bought a GReddy gauge which I am very pleased with. It has peak hold ability with memory and has a warning light when the temp. passes any value that you set. It also outputs a signal when you pass the set point which can be used to sound a buzzer, turn on another larger warning light, or to switch off the boost controller, which is what I have used it for. Most other EGTs have these features though.

Don't tap the fitting in the down pipe, the exhaust looses a lot of heat passing through the turbo (100 - 200 degrees C) and you will get lower exhaust temperature readings. When you think you are running safe, you may well be in the danger zone. Put it in the manifold, either at the collector (if you want an average reading of all four cylinders) or in the number 1 or 2 (depending on who you talk to) manifold runner to read from the leanest cylinder.
 
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Discussion Starter · #4 ·
The only problem with putting the thermocouple probe in the manifold is if the probe breaks off, which has happened before, you will wreck the turbo.
 
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Discussion Starter · #5 ·
Wreckleford.........it is recognised by most experts that the difference in temperature across the turbo between manifold and downpipe is between 100 and 150 degrees C. The physical distance is quite short on the EVO too, after all the manufacturer (along with most others) choose to locate the Lambda probe after the turbo which is broadly used for the same job but under different operating temperatures as an EGT.

sk_evo........there isn't a great deal of point (apart from to be amazed at how hot the exhaust gets) in installing an EGT unless you are going to modify your car with a programable ECU in which case it becomes a useful tool for the tuner. If you just want more gauges on your dash, thats a different matter.

I would suggest a knock gauge is very useful to make sure your car isn't detting which could be caused by something as simple as a bad tank of fuel. Detting can seriously damage your engine, and it is obviously of some benefit to know if this is happening.

So far as oil temperature gauges are concerned even those who have modified cars and track them are only seeing temperatures peak and stabilise at around 110-120 degrees C on the VI, and I think most good engine oils easily are designed to cope with these kind of temperatures. The question begs therefore what the point would be in having one, other than for general interest.

Now a G meter would be a good idea.

Steve
 
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Discussion Starter · #6 ·
I think the knock sensor is a good idea, I installed a Knock Link in my VI and it's proved to be very good during tuning etc.. Just put some 95 ron in the tank and watch the det ( thats with raised boost levels )

Good for detecting bad fuel ( not that we ever get that of course :D )

Rgds Kevin A
 
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Discussion Starter · #7 ·
Placing the exhaust temp sensor in the manifold is utter madness on a road car!! As mentioned it can brake off and enter the turbo causing pretty serious damage! Sure racing cars place them in the mani as the engine is pretty much revised and checked after every race....but in a road car it is different....wouldn't you say???? All such installations performed at respectable garages ALWAYS place the sensor after the turbo, in the down pipe. Sice it was said that temps before and after the turbo vary by around 100-150 deg whats the point of risking a potential disaaster??
Only my 2p worth.
 
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Discussion Starter · #8 ·
yupp, that's a good point okitenik!! so placing the sensor after the turbo seems safer but should it be located on the top, side or bottom of the downpipe then?! on the downpipe bend or flat surface?!
 
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Discussion Starter · #9 ·
My EGT probe was installed expertly by Dragon Autosport, and is located as close as possible to the downpipe flange before it takes the turn under the engine and in the left hand side as you stand infront of the engine. I would point out this is on an EVO VI with the HKS turbo elbow and HKS downpipe. The probe therefore has line of sight from the turbo impellas and is about 10 cm or so from the Lambda sensor.

Like I said before, I wouldn't bother with it unless you are going to seriously tune your car.

Steve
 
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Discussion Starter · #10 ·
T27.....
When you installed the Knock Link did you use the factory knock sensor or fit an extra one.
If u used the factory one did you unplug it from the ECU or just tap off the wires
 
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Discussion Starter · #11 ·
The Link Electronics Knock Link Module which I think Kevin refers to is totally independant of the ECU. The sensor is simply attached as close as possible to the cylinder head on the outside of the block to listen for Det. The module in the cabin displays this with a row of lights which flick up from green to red subject to the level of knock. No doubt he will confirm.

Steve
 
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Discussion Starter · #14 ·
Yep Steve is correct, it's a completely independant piece of kit. I set mine up using a proper det listening headset and the results are pretty good.
Mine was purchased from Scoobymania ( Mike Tuckwood ) from memory it was about 100 quid , but well worth it.

Rgds Kevin
 
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Discussion Starter · #16 ·
Claudius...Techtom(I think they are called), does just that! It's like having all the guges you ever needed plus some handy little gadgets such as the det sensor and so on
 
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Discussion Starter · #17 ·
Guys,
Firstly if you re-read my post I stated that the exhaust loses about 100 to 200 degrees passing through the turbo. This was off the top of my head, if it is actually exactly 100 to 150 degrees I appologise, but anyway it probably varies from car to car and you will probably find examples that lose more than 200 degress through the turbo if you look hard enough.

Anyway, you guys are crazy if you think that a difference of 100 to 150 degrees in exhaust temperature is insignificant. If your engine is running peak EGTs of 800 degrees you are running pretty safely, you can actually afford to lean it out some more or advance timing a bit, however if you are running EGTs of 900 to 950 degrees you have problems. 100 to 150 degrees makes a VERY big difference.

Steve P. said:

........there isn't a great deal of point (apart from to be amazed at how hot the exhaust gets) in installing an EGT unless you are going to modify your car with a programable ECU in which case it becomes a useful tool for the tuner. If you just want more gauges on your dash, thats a different matter.

You don't seem to realise that the exhaust temperature directly relates to the running condition of the engine. It is detonation that drives up exhaust temperatures if you didn't know. The knock sensor senses detonation and retards the timing, leading to increased exhaust temperatures (combustion event happens closer to when the exhaust valve opens). When tuning my car I use the EGT to determine how much boost I can run and how much fuel to add or remove (using a super AFC).

Don't think that i am arguing against the knocklink. A knocklink can certainly be used for the same purpose, but I personally prefer the EGT. I like the fact that instead of dealing with blinky lights you are dealing with numbers, but I espescially like the peak hold feature and the safegaurd that the warning output signal allows is invaluable. I would much prefer to use the EGT gauge to automatically cut boost and therefore cut detonation rather than having to back off the gas when the red light flashes to achieve the same. Detonation is likely to raise its head exactly when you don't have time to be looking for blinking lights, like when your foot is to the floor in third gear and a left hander is quickly approaching.

By the way, I don't know which brand of EGT probes you guys are used to using, but I very highly doubt that the one on my car is going to fall off anytime soon. It not like there is a nut in there that can back-off and suddenly drop the probe into the turbine blades.The only thing that could happen is that the tip breaks off. How is that going to happen? What is going to break it off, the air pressure? Do you guys even know what the probe looks like and how it is attached? Maybe you guys should just stop buying British products. The fact is, Eclipse guys and others in the States have been putting EGT probes in the manifold before most of you guys knew what an Evo was, and I have never heard of one case where an EGT probe decided to jump into the turbine blades.

Anyway, that is my view. Feel free to disagree or correct any errors, spelling or otherwise.
 
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Discussion Starter · #18 ·
next question:

assuming i've got both boost and EGT gauges with 2 x 60mm A-pillar mount, which one preferably to be mounted on the top socket?! was thinking of mounting the mechanical boost gauge on the lower socket thus shorter vacuum hose required and less interruption. what are the norms or sort-of standard when it comes to fitting these gauges?!
 
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Discussion Starter · #19 ·
sk_evo4....I think that is pretty much up to you.

Wreckleford...I agree with what you said about EGT being more accurate in giving you numbers rather than blinking light. Both are good methods of quantifing detonation.
 
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Discussion Starter · #20 ·
Wreckleford.... I apologise that I didn't see your 100-200 degree comment first time round.

okitenik...an EGT is not an accurate way of measuring Knock.

I will simply say this, if you are using EGT to determine how much boost you should run on the hoof around corners etc, then you are likely to do one if not both of the following. Blow your engine, or put your car through the hedge. May I suggest you try and do your tuning on the straights before attempting any corners. Most cars these days have a throttle pedal which can be used to reduce boost by modulating the pedal.

Please talk some sense.

It ought to be pointed out that you can not use an EGT solely as a knock sensor, and anyone who buys one with this in mind will verify this as being correct after they have bought it. Boost, fuelling and timing on a turbo engine is a very complex three dimensional model, and you surely should not assume that rise in EGT temperature is solely caused by pre detonation. A rise in temperature might just as easily be caused by anyone of boost, fuelling or timing or all three. If you want to determine whether you engine is knocking, buy and knock link or similar. A red flashing light on a knocklink is knock, a rise in temperature could be anyone of three things.

For example: I ran my VI at the Nurburgring at Easter (ambient temperature 0-2 degrees C) holding almost 1.5 bar boost for 20 laps (260 miles). My EGT temperature was always hovering around 900 C and I never once saw any det. (Tuned by BRDevelopments using the EvoLink programable ECU). My EGT probe is after the turbo.

To go back to the which gauge next thing , you don't need an EGT unless you have an in-depth knowledge of the workings of a turbo engine and can make use of the information provide by this gauge.

Steve
 
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