gauges/reading etc

[raj]

when using the oe gauge would you say its a better idea to plumb it into the aei line as this would show what boost the engine is seeing rather than carb top.

later on im thinking of fitting 2 boost gauges. 1 from as mentioned above and the other directly from the turbo.

just thought it would be good to see what losses of boost pressure occurs from the boost source to the engine.


also has anyone got an egt gauge fitted? if yes where is it plumbed? drilled into exhaust manifold or the downpipe.

[Andrew Cooke]

I dunno if the standard gauge would like vacuum.

EGT goes in the manifold.

[Trevhib]

EGT sensor to be plumbed in before the turbo?

[car.crash]

EGT sensor to be plumbed in before the turbo?

yes.

[Trevhib]

Great, we're all learning together :rolleyes:

I'm not stupid enough to question Andy's input, I'm looking for expansion.

Please.

[car.crash]

i was told that if your using just 1 egt sensor on a turbo engine then the probe needs to go in the manifold where all the pipes join from each cylinder but as close to the head as possible for the most accurate reading. the turbo can absort a fair bit of heat so readings after the turbo will be significantly lower and less accurate. if your using a egt sensor on each cylinder then they want to be 1 in each branch of the manifold as close to the head as possible to moniter each cylinder individually.

[Trevhib]

Thanks Marc. :agree:

I think my original thought was that you'd have to measure after the turbine housing believing that the turbo would add heat and in that case, understanding what the temps coming out the back were, was going to be what you needed to know.

Thinking about it a bit more, I guess it becomes fairly obvious that it's the temp that's coming out of the back of the head that's of utmost importance and therefore to get an accurate reading you'd have to measure before the turbo of course.

I'm surprised the turbine would reduce EGT though. I thought it was hotter there than anywhere?

[Andrew Cooke]

Think about it Trev, where does the heat in the turbo come from?:coffee:

[Andrew Cooke]

btw, I run EGT and TIP in the collector.

EGT is like, hmmm, that's a bit cold I need to look at my tune, and Oh **** I'm going to melt something, I need to look at my tune. No real clue as to what to look at.

TIP is handy for looking at turbo efficiency and cam choice.

[Trevhib]

I think I thought that: N/A cars have lower EGTs, thus the addition of the turbo increases them. Maybe I thought subconciously that it was the speed of the internal parts of the turbo that caused the extra heat.

Now I know different. I could now have a good guess where the extra EGT heat comes from over N/A but it would be quicker and easier if one of you guys spelt it out for me :homer:

btw, while I'm in dunce mode (and without using google for now), what's TIP?

[car.crash]

trevor the sensors are put in place to help with fueling setup.
if the sensors become cold then your probably running rich, if it becomes hot you are probably running lean, but there are many other factors that can cause the variation in the temps.
i bought mine so i could pair it up with my afr to give me a better idea of what im doing with my fueling, although i have not yet fitted it as well as the other pile of parts and ideas i have sitting around :laugh:

[raj]

thanks for the info andy, as mentioned im personally wanting one to keep a closer eye on temps.
whats the max temps we should be getting before failure? ie cracking liner/ melting a piston.

infact is there a law of what max temp the engine should make? yes this will vary from car to car with different componants, boost pressures etc.

[Trevhib]

Marc, no probs, I've always understood the link between a lean AFR and high EGTs.

Still not sure what the TIP acronym is though.

[Andrew Cooke]

Turbine Inlet Pressure

I'm not sure that turbo engines will be hotter then NA engines, a quick look at an F1 engine on a dyno will show that.

I don't know what an engine will take before it breaks as I haven't broken one. I've not seen over 920C, and would get stressed at 950C - but that's only for quick bursts.