Hi, I have a s5 6 port with a t04e turbo. I am having problems keeping my egts down. Currently the exhaust mani, turbine housing, and even the vband clamp are glowing red when I shut it down after "spirited" driving. I have been running water above 5psi but it doesnt seem to help much. I have tried methol/water and it added quite a bit of power but I never checked the mani. Does anyone have any input on how to lower the egts even further? any coments would be greatly appreciated!

 

What is your ignition timing and AF ratios?

Sounds like it's running lean or maybe got a high ignition timing in the ECU. Now after spirited driving exhaust do get hot, but should not glow for very long. Remember even at cruising it will generate 800-900 celcius and that will make it glow. But if it lasts for a long time then something is wrong.

 

I'm with Jantore on this. Either you are running too lean or your timing is off. Retarded timing can really bring up EGTs. I use 24 degrees as my max advance for a 13B and I pull out 14 degrees of timing by peak boost (18 lbs) for 10 degrees advance total at peak boost. This is somewhat conservative given I'm running a blend of C16 and premium, but my motor is still pulling strong.

-Trent

 

The afr are in the 11 to 12 range from idle to 8k rpm. Ignition advance is at 25* last I checked I am not tuning it so I couldnt really tell you for sure but its on a conservative timing map. What I will try next is an ice box for my liquid to air and a fuel cooler. If that doesnt work I may get a gt300 hood just to lower under hood temps. My car has the stock undertray and the intake is routed outside the engine bay but idk how much these really help, I also have a godspeed 2 row rad. on the way!

 

Also I have 9.7:1 comp. and running 12lbs of boost. The car pulled noticable harder with the little meth that I did run. Im thinking about doing a 30:70 mix when I know I will be racing and just distilled water for the street.

 

11-12 is leaner than a stock S5 na!

 

Thats where the engine feels happy. 10 afr it floods and 13 afr it starts running rough. I will be going on a cruise the 13 in Omaha and will be running a methanol mix, so we will see how that goes.

I am also think about doing some dead end fuel rails (no fuel rerun). Maybe when if go E85? Any inputs on this? I know I have read something on here about that but I cant seem to find it.

 

Id say its your compression, 9.7 is higher than most people use for turbo builds. Adding timming and fuel isn't really going to help. Meth / water / alchy / whatever injection is really your only outlet, or a higher octane fuel.

As for glowing, my cars manifold, turbine housing and the first 8+ inches of my down pipe use to glow after a fun drive, and that was with, at least what i feel are acceptable egt's. You really should have a decent egt gauge to see what the temps really are, as Glowing isn't necessarily bad.

-Jacob

 

agreed, every turbo car has a glowing manifold/turbo after a hard run.

higher compression = higher EGT's. you actually should get an EGT gauge on it, best power should be about 950C about 3" from the engine. 1100C is the limit for stock seals. the turbine wheel might melt around there too, depending on which one?

 

Are you sure about that? All literature I have, from Mazda, NSU etc... indicates that higher compression also means higher expansion ratio. Peak combustion temps and pressure will be higher, but since they are expanding at higher ratio, final temperature on end of cycle is lower.

Tuning to rich best torque and minimum best timing, all other variables held equal, should give lower EGTs on higher CR engine. Excees retard of course could cause higher numbers, but not by utilizing higher CR....

 

Im only going off what ive seen, my 9.1 turbo build had higher egt's than the 8.7 build all lover. however what you say does make more sense.

-Jacob

 

no, but there is a fellow on another forum who was running 8.5's NA, and only seeing 1300f EGT's at the 200rwhp level thats really cold.

 

1300? where is the probe?

 

Thank you for all the input guys. I am aware that I need and egt gauge. During the winter I will pull the mani and get a bung on each runner too read each rotor seperately and run a dual gauge

 

bdw if you start running wather/meth you will need to retune your engine. And also when u run pure water you will need a difrent map. With a pure water map and adding meth and the engine will run rich as hell. Once it's tuned for water/meth and you switch to pure water it will run lean.

Now get dual EGT's and check what your EGT's are at idle, cruising and wot. And how long it takes for it to go back to idle temps.

JT

 

Ok thanks for the tip. But with the little meth I did run it made a noticable differance in power(faster). Im only injecting 360cc of whatever I choose to run that week. Is that really enough to make a conciderable difference? The way I understood it is that water didnt really change afrs, it just mainly cooled the egts and prevented detonation. If this is wrong please enlighten me. I would really appreciate it, this is the first car I have ran any sort of aux inj.