Bengt Sweden

I have just started to map my new 3.0, 8v and wonder what EGT and timing do you with tuned engines run?

I got an EGT of 1015C just off the ports with a timing value in the DME of 48. I ran 1.1 bar flat with AFR at 12.5.
I know that the ceramic ports maintains heat in the exhaust gas, but I think that 1015C is a bit too much. On the other hand I don't want to run too much ignition either.

I have a Knocksense knock indicator that comes on at about 6000rpm with least sensitive setting. I am not sure what to make of this. Is it just the magnitude of noise or what? Anyone with experience with Knock sense that has an idea?

TIA
Bengt

special tool

PM sent.

hosrom_951

EGT's don't only tell you about timming IIRC

1015 celsius is equal to 1,859.00 fahrenheit, that is far too much. A good tuned system should read 1500F +/- 50F (815.56 celsius +/- 10.00 celsius)

TurboTommy

What do you mean by, "value in the DME of 48"?
How much total timing is that?

Duke

That is completely wrong.

awilson40

18.5 degrees...I think

hosrom_951

Duke: How about backpressure, too much and EGT's rise

Bengt Sweden

yes I believe 1015 is too much, but it is difficult to generalise between different engines since engines with long runners and no insulation loose a lot of heat to the head and thereby show lower numbers in the exhaust pipe without actually having lower EGT at the valve.
1015C is too much for most turbines but then there is half a meter of pipe in between so the EGT at the turbo should be ok. I think I want to be below 950C to be safe.

I have seen different interpretations of the DME values. One says that 48 is about 18 degrees, which sounds about right.
48 is same as stock 951 from 4000rpm and then 50 at higher revs. I ran up to value 54 with my 2.5L at 1.3 bar.

Bengt

Bengt Sweden

Duke probably didn't see the "only"

Bengt Sweden

I can of course waste a bit more fuel and drop to AFR 12.0, but I really would like to know if I may run higher timing without risk of knocking.
Bengt

hosrom_951

For the record, a stock 951 (a good running one) gets 600C or so, at least the manual claims that to be the "normal" temperature.

hosrom_951

That would help out, but then you would have to face two "issues"

1) Loss of horse power, torque likes to be at rich AFR's, not power.

2) A richer mixture can only do so much, depending on the car's set-up.

Where did you mount/install the EGT probe anyways?

Duke

Sorry Hosrom, Bengt is right i didn´t see the "only". Had a rough night out yesterday

fast951

Bengt, glad to see that you got your 3L up and running. Where are you measuring the EGTs? How far from the head? The values of ~1850F are way too high.. Are you seeing those numbers under load/boost or cruising?
When you start dealing with the 3L timing becomes very cruicial for a long happy engine life. If you are using the 2.5L chips, I would be concerned about the PT timing values, as with the 3L there is a good chance you are accessing values that you never access with the 2.5L.

hosrom_951

Don't be, it happens to me as well