Reducing EGT's

Ok so I'm hopefully, depending on when it arrives (Gaz!), going to fit an EGT sensor soon. My question is, if for something goes wrong and the EGT start to rise, I can add fuel to bring them down again, however, too much and I'll start to get bore wash.

I don't intend to use this as a day to day "performance increaser" or anything like that, I just want to use it as an added safety feature, and as such I don't really want to try the "suck and see" method of getting high EGT's intentionally, and then just adding small amounts of fuel to bring them back down bit by bit.

If the EGT's rise above a certain failsafe threshold I'm also going to fire up some alarms, and possibly add a bunch of ignition retard.

Can anyone basically suggest values for the following:-

 

EGT normal operating temps.

EGT max accepatable temp. (after which car will go into failsafe)

Amount of extra fuel/duty to add.

Amount of ignition to retard.

 

You all know my set-up and I know that recommending an exact value for anything will be impossible but something close would be good (eg do I want to add 1% duty for every 20degs over failsafe, or more like 10%)

 

Cheers

 

Tony

No cats, exhaust, running 1.2-1.3 bar

 

MAX: 950 degC would be max temp

NORMAL: 600-850 degC it could be lower than 600 it's been a while since I watched while driving around town...

SUMMER HOT DAYS: At WOT upto ~900-910 degC

 

Just got in with 16 degC external air temps:

NORMAL:450-850 degC (450C off throttle rolling to 810 at WOT)

4th Gear 40mph 1400rpm 520 degC

4th Gear 80mph 2400rpn 610-620 degC or was it 710-720 too many numbers to remember

Idle for cool down 380 degC

 

 

HTH

Originally posted by TLicense

Ok so I'm hopefully, depending on when it arrives (Gaz!), going to fit an EGT sensor soon. My question is, if for something goes wrong and the EGT start to rise, I can add fuel to bring them down again, however, too much and I'll start to get bore wash.

I don't intend to use this as a day to day "performance increaser" or anything like that, I just want to use it as an added safety feature, and as such I don't really want to try the "suck and see" method of getting high EGT's intentionally, and then just adding small amounts of fuel to bring them back down bit by bit.

If the EGT's rise above a certain failsafe threshold I'm also going to fire up some alarms, and possibly add a bunch of ignition retard.

Can anyone basically suggest values for the following:-

 

EGT normal operating temps.

EGT max accepatable temp. (after which car will go into failsafe)

Amount of extra fuel/duty to add.

Amount of ignition to retard.

 

You all know my set-up and I know that recommending an exact value for anything will be impossible but something close would be good (eg do I want to add 1% duty for every 20degs over failsafe, or more like 10%)

 

Cheers

 

Tony

 

IIRC you control the boost pressure from the ECU as well? Can you get it to drop to wastegate control, i.e. lower the boost to the minimum possible as soon as you get EGTs too high?

 

-Ian

yep, what ian says. ignition retard will probably increase EGT and will definately if u r adding more fuel at the same time. just reduce boost. retarding ignition will reduce det and power.

My post updated.

mine seem to have gone down since having walbro fitted. most i have seen was just below 900 and that was racing at santapod at 1.1bar

 

seems nothing temp wise just driving about.

Mines got an EGT gauge and that bleeps at me all the time under WOT. The boost gauge also indicates I am hitting 1.5 bar at times. I am so not happy with this. Is there somewhere in my local area of Bournemouth/Southampton that I can have the car looked at and the SAFC2 tuned and the turbo-timer setup properly etc so I am not risking melting my engine every time I drive the car?

Originally posted by dangerous brain

Mines got an EGT gauge and that bleeps at me all the time under WOT. The boost gauge also indicates I am hitting 1.5 bar at times. I am so not happy with this. Is there somewhere in my local area of Bournemouth/Southampton that I can have the car looked at and the SAFC2 tuned and the turbo-timer setup properly etc so I am not risking melting my engine every time I drive the car?

get a restrictor ring in to be safer. mine used to hit 1.5bar and real high egt`s 1050 degrees with stock fuel pump.

 

now only seem to hit 1.1 bar and under 900 degrees

 

when it blows turbos you will wish you sorted it for sake of a restrictor ring

 

you can make your own with a bit of alloy plate

There seem to be some big variation in high end EGT around.

 

Since fitting my new fuel pump and Greddy SMIC, I am seeing 650 at legal crusiing speeds and 780 on 1.15 bar bursts. The highest EGT I have seen since the refit is 820 on the peak hold but can't remeber what I was doing to hit it. I have a restrictor ring too that got me down to 1.2 from 1.45

Hmm I have a walbro pump. I have decided to bite the bullet and take it up to the thor guys. I don't know anywhere near enough to start messing about with this. i wouldn't mind a power reading anyway and I want the SS dial faces that they do so it all makes sense. I need the SAFC2 setting up anyway.