Egt too low/high

[n boost]

Hello people,

 

I was thinking about egt readings and did a search, but could not find an answer to my question.

So i thought some one in this dept should be able to answer it.

Okay so most of us know if our readings are too high, much above 850-900 degrees and chances of heat damage occurring is very likely if kept there for sustained periods.

My question is, can u r egt readings be too low and if so what is considered as the lowest reading u should see as i understand that egt can reflect on timing curve and advanced timing would cause low egt while retard would cause high egt.

 

So please if u know can u try and answer

Thanks.

[tDR]

I can't see it being too low being a problem. As usual with EGT's though an accurate reading depends entirely on good placement of the probe - as close to the cylinder head as possble in the exhaust manifold.

 

Cheers,

 

Brian.

[Mike B]

can u r egt readings be too low

 

 

To be honest I would say if your readings are too low it either means your probe is knackered or the sensor is halfway down the exhaust pipe.

 

what are your readings, and where is your sensor?

[n boost]

hello guys,

My sensor is brand new as just fitted gauge, and it is mounted in the 6th runner 2" from port.

My readings are 670-680 degrees c at wot and 1.35 bar boost.

I don't think my readings are way too low and my afr is around 11.6, so it isn't that rich.

1, I was curious that if my egt is this low does that give me room for more boost?

2, Also if u r egt temps are high are u closer detonation?

There seems so much conflicting info on the net and mixed views so it all can get a bit confusing.

[n boost]

Hello guys,

 

Checked my egt after a good pull through the top gears and it peaked at 705 degrees c.

[Soonto_HAS_soop]

If you are single, then maybe you could up the boost a little, without knowing your spec I can't say.

If you are still TT then I would lower your boost as you aren't getting anything else out of it.

Althouhg if you are TT and are hitting 705 on standard stuff at 1.35bar, then I would be seriously worried that something is very wrong somewhere.

[Nic]

Hello guys,

 

Checked my egt after a good pull through the top gears and it peaked at 705 degrees c.

 

Is your EGT sensor after the turbo? When they are located after the turbo they usually read around 200C lower.

[Soonto_HAS_soop]

Is your EGT sensor after the turbo? When they are located after the turbo they usually read around 200C lower.

 

"and it is mounted in the 6th runner 2" from port"

 

Apparently not...

[Mike B]

Hello guys,

 

Checked my egt after a good pull through the top gears and it peaked at 705 degrees c.

 

That is pretty low, can you tell us what your spec is? as I have no experience of egt on TT, only single.

 

I am presuming that you are single as to get an egt in runner 6 on TT is a mission I recon. My guess is that you are single with a big ar on your turbine housing.

[Soonto_HAS_soop]

That is pretty low, can you tell us what your spec is? as I have no experience of egt on TT, only single.

 

EGT's on a TT will be generally higher than that of a single. Mine used to run into the low 900's on the twins, now I have trouble getting anywhere near 825-850 on the single. Running 1.35 bar on the TT's should be returning a stupidly large EGT figure.

 

However I have mine in runner 5 as the exhaust port on that cylinder is smaller than on that on cyclinder 6.

[Mike B]

However I have mine in runner 5 as the exhaust port on that cylinder is smaller than on that on cyclinder 6.

 

really?? surely you mean that the length of the runner is shorter, not the diameter of the runner?

 

I thought in an ideal world the length and diameter of every runner should be the same?

 

I need to move my sensor to the manifold, but on a long sustained ull with all runners heat wrapped, the turbo blanketed and the dp wrapped as well I can't see how I am losing the quoted 200 degrees from maifold to DP. I'd say that although the reading is less immediate the temperature on a sustained pull is the same.

 

If I ever get round to switching the position we will find out.

[n boost]

hello guys,

 

Yes mate it is a single hks to4r 0.96 ar. I was concerned that if i am running too low egt then might not be producing enough heat to generate max hp/tq.

The readings i have got have been late at night, and generally air temps are cooler and on a hot day they might rise a bit.

so is around 700 degrees c too low for a single?

Should i wind in a bit more boost i.e 1.45 bar and check egts?

[Soonto_HAS_soop]

hello guys,

 

Yes mate it is a single hks to4r 0.96 ar. I was concerned that if i am running too low egt then might not be producing enough heat to generate max hp/tq.

The readings i have got have been late at night, and generally air temps are cooler and on a hot day they might rise a bit.

so is around 700 degrees c too low for a single?

Should i wind in a bit more boost i.e 1.45 bar and check egts?

 

 

Wind away, but I wouldn't, I'd want to make sure that the fueling is OK. Best get it done professionally.

[Mike B]

Yes mate it is a single hks to4r 0.96 ar. I was concerned that if i am running too low egt then might not be producing enough heat to generate max hp/tq.

The readings i have got have been late at night, and generally air temps are cooler and on a hot day they might rise a bit.

so is around 700 degrees c too low for a single?

Should i wind in a bit more boost i.e 1.45 bar and check egts?

 

 

I knew it would be a larger ar, mine had really low temeratures to with a .95. They went up with a smaller ar. 700 is the same as mine on a colder day.

I have to say the car is 100% better with a smaller ar.. and if you want a more drivable experience spend 100 quid and get a smaller ar housing. Mine was shockingly poor with the .95.

 

make sure your car is mapped for it before cranking the boost, and although I'm not certain I recon you can explode you engine without heat, so check with one of the mappers.

 

I think your car would be far quicker in the real world with a smaller ar. Maybe not on the dragstrip but I couldn't live with .95, although I do run a different turbo than you.

[n boost]

Hello guys,

 

I love the hks to4r with the .96 ar and find it suits my driving style. Also there seems to be very little lag on this turbo and get full boost at around 4200 rpm.

Mike, ur temps of 700 degrees c are on cold days, so how much difference is there on hot days as my temps were taken when cold at night?

Also i have heard of engines blowing due to high egt, but has anybody blown an engine due to low egt i.e 700 degrees c?

I also have 650 cc injectors so can up the boost and have fuelling to match.

What is the max boost recommended for stock bottom end on shell v power?

[Mike B]

I love the hks to4r with the .96 ar and find it suits my driving style. Also there seems to be very little lag on this turbo and get full boost at around 4200 rpm.

same as mine; although spool was not so bad but the throttle response was really bad. It's because I had a responsive single before the .95 that I realized something was missing.. if you can drive a small ar jump at the chance I think you will find it a lot better.

 

Mike, ur temps of 700 degrees c are on cold days, so how much difference is there on hot days as my temps were taken when cold at night?

I saw no higher than 780, it was very low!

 

Also i have heard of engines blowing due to high egt, but has anybody blown an engine due to low egt i.e 700 degrees c?

not possible surely! if you do blow it up it's not due to the engine being cold. Colder egt the better afaik. You can't melt pistons without any heat!

 

I also have 650 cc injectors so can up the boost and have fuelling to match.

What is the max boost recommended for stock bottom end on shell v power?

Same size injectors as me. Depends on your fuel pressure and airflow, but I see 1.5 and steady fuelling, just make sure you map has been done to this level, otherwise you really will see you egt's rise, and your overdraft shortly afterwards.

 

TBH on stock I would probably keep it at 1.3, that way you get no nasty surprises!

[dandan]

......on a long sustained ull with all runners heat wrapped, the turbo blanketed and the dp wrapped as well I can't see how I am losing the quoted 200 degrees from maifold to DP. I'd say that although the reading is less immediate the temperature on a sustained pull is the same.

 

Mike - I'm afraid you are well off with that statement. This is the very essence of how a turbo works.

 

The turbine extracts energy from the exhaust gases in the form of heat. If you get no temp drop across the turbine then something is VERY wrong.

[Mike B]

Mike - I'm afraid you are well off with that statement. This is the very essence of how a turbo works.

 

The turbine extracts energy from the exhaust gases in the form of heat. If you get no temp drop across the turbine then something is VERY wrong.

 

I'm sure you are probably right, my egt's must be quite high then, yet I have no impirical data, but will if I swap the sensor posn over, which tbh I should do.

 

I thought the energy transfer was mostly pressure? how does heat turn the wheel of the turbine? as the pressure drops downstream of the turbine the gas will cool though for sure, just like it does out of a gas canister, so I guess you are right there.

 

But if on a sustained pull I see 800 degrees behind the turbine wheel in the DP that means I am looking at 1000degrees in the manifold, I don't like the thought of that much.. that's with WI. The ecu and knock amp still detect no det.

[n boost]

hello guys,

 

Mike...is ur sensor in ur downpipe?

I read somewhere once that the turbo requires heat to create the energy to spin the turbo. I think that is one of the reasons why heatwrap can reduce spool times because the heat which does not escape helps spool the turbo.

So Mike, if ur seeing 700 degrees from sensor in downpipe then my egt seems very low.

Some folk say it can be because of too much timing advance, but if thats the case then should i not be getting any det?

Another reason can be if ur fuelling is very rich, but my afr is between 11.6-11.7, so surely this can not be the cause.

So is it safe for me to run at 700 degrees as i have been driving her for the last month mainly at wot and not experienced any problems?

[Mike B]

Mike...is ur sensor in ur downpipe?

I read somewhere once that the turbo requires heat to create the energy to spin the turbo. I think that is one of the reasons why heatwrap can reduce spool times because the heat which does not escape helps spool the turbo.

So Mike, if ur seeing 700 degrees from sensor in downpipe then my egt seems very low.

 

yes, it's 2 inches behind the turbine wheel.

 

your temp is low but don't knock it; I would much rather have 700 than 1000.

 

afaik det is caused my many factors, but heat is one of the main contributors. Honestly if you are worried get it on a RR with an experienced mapper, or buy yourself a det monitoring system. A sound investment for a tuned engine. Your AFR is leaner than mine; I run 11.2.

 

Someone is going to have to explain to me how putting my turbo in an 800 degree oven is going to make it produce 1.4 bar lol..

 

I can see how wrapping the dp may prevent as much of a gas temperature drop, ie hotter gas = more gas, thus less volumetric flow, but I have a 4" downpipe and so I really think it's irrelvant for me.

[n boost]

Hello guys,

 

Mike...There is a full explantion of how heat creates energy on a thread. I think it might have been one of the turbo manufacturer website... Garrett?

Mike the car is not detting and i did map it on a dynapack but at the time did not have my egt connected as it did not arrive in time.

After i had it connected and went out to finish off on a road tune realised that egt temps were around the 700c mark, so tried leaning out my afr to 11.6.

I am just trying to find if 700c is a safe temp (in cold at night).

I read on a thread yesterday that it was fine at around 7-750 degrees c.