nutrulz

iTrader: (14)

So what are safe EGTs and AFR for water injection? I've gone into 1560s deg. F and no knock, but honestly I am somewhat worried. My AFR is about 10.6 is this Ok at high RPMs? Can I push it more?

Correct me if I'm wrong, but WI seems to not effect EGTs, but it definitely effects knock thresholds.

ITEM9

iTrader: (3)

1560 deg F might be pushing it for the turbo. The turbine can't too hot or it may suffer some damage. For quick bursts it may be okay, but I would'nt do it for too long or too frequently. About 1300-1350 deg F is the most you want to sustain for any period of time. This is standard for most turbos, unless you have one with a turbine made of more exotic materials, then it could be more.

SlowCar

iTrader: (4)

1560F = 848C

You are fine. What kind of timing/boost r u running and what octane gas?

TTP Engineering

iTrader: (465)

What kind of nonsense is this.

900*C is conservative.

950*C is on the more aggressive side.

1015*C I have run while drag racing.

On injection, you should be in the 12's AFR, not 10.4. Don't ask me why your car is so slow.

nutrulz

iTrader: (14)

12 AFR on 91 oct. and no methanol? I am using water only.

TTP Engineering

iTrader: (465)

91 octane I would run a little richer, but methanol does not have as much of an impact on your target AFR.

The best way to tune it would be while reviewing knock counts via Evoscan.

I would likely target 11.5-11.8 if water volume was sufficient.

C6C6CH3vo

iTrader: (9)

What psi is this at anyways?

Was 10.6 sensed at the tailpipe?

If not detonating at your highest boost then give it a little timing and and pull some fuel. EGT, whats that? What temp sensor you use to get the reading and where? Just curious

nutrulz

iTrader: (14)

This is coming from a zeitronix EGT and O2 sensor. The EGT is in the second runner, and the O2 is in the DP just before the Test pipe. This is at 20 psi tapering to 18, controlled by an AEM with a GM boost control solenoid. I know this is conservative, but with 91 oct. how far would you push it if it were your car?

C6C6CH3vo

iTrader: (9)

If it was my car, depending on the timing, I would say 22-23psi with the 100% H2O injection and maybe lean it about 0.2-3 (still conservative). I wouldn't woory about the EGT reading for they are likely precise but not an accurate indication of whats left.

Now if you decide to add some methanol, even 50%, then totally different story.

It's good your tuning gradually.

gunzo

iTrader: (2)

I would look more at adjusting the timing than the fuelling if you're running pure H20 only ..

As long as you can run the timing without knock then you're okay ..



I run on average around 880-920C with spikes to 940-950 on occasions ..

the only issue is what is consider sufficient water
The guide of 10-15% water to fuel volume doesn't really hold true for me (either that or I'm running way too aggressive timing !! )

ItalianEvo

Hi TTP,

you are talking about temps picked up by an EGT sensor, max 2" from the head, correct ?

I'm asking because I read 90/100* C more from the turbine inlet EGT sensor...

Thank you.

TTP Engineering

iTrader: (465)

I don't think the gasses would be hotter, further from the head.

Secondly tapping an EGT at the turbing housing is probably not a very good idea.

ItalianEvo

It's been already discussed in another thread...
at high rpm, where the 4 collector merge into one just before the turbine inlet, the temps are much higher than in a single collector near the head.

And this is even confirmed by Eng. Bell in his " Maximum Boost " book.



Sorry, it's not tapped ON the housing !
But in the exhaust manifold, in front of the turbine inlet.

TTP Engineering

iTrader: (465)

There is more reasoning that goes into tapping cyl 2. I is typically the lean cylinder in the 4g63 motor. If you tap the collector you are merging the temperatures and not getting a solid reading on this lean cylinder.

ItalianEvo

TTP,

I have 2 EGT sensors !

And one is in the 3rd collector, 2" from the head.

That's why I asked you what kind of readings were yours.

Bye.