rage2

[quote]Originally posted by Russ Murphy:
<strong>Oh rage.... I sure would like to see the new and improved fuel map.</strong><hr></blockquote>

Some notes with this map. I haven't tweaked the fuel at 20psi and higher (really rich), and my settings here are a bit lean at 10-13psi (A/F ratio at 13.0:1). The ignition timing is good, I ran 25psi today without detonation on 91 octane, but it was really rich, so dialing it back to 12:1 A/F might start knocking. I may be able to go a little more agressive on the timing in the future, but I'll leave it for now, things are working great.

<a href="http://www.virgeweb.com/rage2/944t/2002-07%20sdsmap2.XLS" target="_blank">SDS Map HR Stg 3 Turbo 72# Injectors Excel</a>

[quote]Originally posted by Russ Murphy:
<strong>By the way, the new bearings and new turbo were awesome this weekend at the DE. The ambient temps on the track were over 100 degrees with high humidity and the water temp never budged above the normal position right above the first white line. There definitely is more lag than with the K26/6 but I've got 13 psi by 3200 rpm. I ran 16-17 psi all weekend.</strong><hr></blockquote>

Sounds great. I don't have any temperature problems on my car either, I ran 'er really hard on some back mountain roads for a full 40 minutes non stop. Pretty much non stop accelerating (to around 230km/h), hard on the brakes for 100-130km/h corners, and repeating... 7/10ths all the way home. 13psi by 3200rpm eh? My turbo's definately bigger, I don't see 13psi until at least 4100rpm.

[quote]Originally posted by toddk911:
<strong>Rage, what hp/tq wre you making before you got timing, a/f set and running 12psi?</strong><hr></blockquote>

12psi, around 310rwhp, way too agressive timing, way too rich, and still wanted to detonate when it gets hot, or when I turn up the boost ever so slightly... it sucked.

[quote]Originally posted by toddk911:
<strong>I see you are at 360RWHP now with new adjustments. Just curous to know how much difference.

Also, anyone done dyno runs to see pros and cons of more boost with more retard timing? i.e. when does timing retard start to affect hp/tq gains regardless of increased boost (assuming a/f is set right) <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> </strong><hr></blockquote>

The difference was unbelievable. I should've done this long ago... dial back the timing completely, crank up the boost to a safe 12.5:1 A/F, then advance timing until it knocks lightly, then dial it back 1 or 2 degrees.

Russ Murphy

[quote] Also, anyone done dyno runs to see pros and cons of more boost with more retard timing? i.e. when does timing retard start to affect hp/tq gains regardless of increased boost (assuming a/f is set right) <hr></blockquote>
todd, check this out.<a href="http://www.sdsefi.com/meltdown.htm" target="_blank">Pushing It Too Far</a>

rage,
thanks so much. I'll check it out.

rage2

[quote]Originally posted by Danno:
<strong>In contrast the stock chips have:

17 degrees advance @2000rpm
15 degrees advance @3000rpm
19 degrees advance @4000rpm
19 degrees advance @5000rpm
20 degrees advance @6000rpm</strong><hr></blockquote>

At 18psi, I'm currently running :

14 degrees advance @4000rpm
14 degrees advance @5000rpm
13 degrees advance @6000rpm

At 26psi, I'm currently running :

13 degrees advance @4000rpm
13 degrees advance @5000rpm
12 degrees advance @6000rpm

I'm not getting *any* detonation at 26psi on 91 octane fuel (it feels wicked at 26psi by the way).

The article that Russ posted states you should not run lower than 20 degrees total advance, or the EGT's will spike and autoignition/damage can occur. Is this a good rule of thumb? Or do our engines have a different advance limit I should be aiming for? Going to do another round of tuning this evening... Danno?? =)

Russ Murphy

Keep in mind that the advance for the stock chips is for the stock boost level of, what, 10 to 12 psi?

rage2

[quote]Originally posted by Russ Murphy:
<strong>Keep in mind that the advance for the stock chips is for the stock boost level of, what, 10 to 12 psi?</strong><hr></blockquote>

True, but what's got me worried is the following quote off the SDS site :

[quote]Most engines are not very happy with less than 20 degrees of total timing at high rpm under boost. If you have to pull back timing this far, you should either reduce boost, the compression ratio or get some higher octane fuel.<hr></blockquote>

That's why I'm curious if I should run lower boost on 91 octane because my timing is dialed so far back to run 26psi on 91 octane. The power's there, just not sure of the side effects.

superjet.1

rage it looks quite scary to me id say that your timing is a bit to agressive.especially on the high end and on 91 octane?do you have a knock sensor ?is it accurate?if not give DANNO a call and have him send you the knock link its adjustable and has a led display.just my 2 cents keep up the good work.

Steve Lavigne

[quote]Originally posted by rage2:
<strong>That's why I'm curious if I should run lower boost on 91 octane because my timing is dialed so far back to run 26psi on 91 octane. The power's there, just not sure of the side effects.</strong><hr></blockquote>

The following is theorizing based on my limited knowledge:

Under high boost and mild timing, the combustion may still be happening well after the piston has reached its halfway point in the bore, and possibly even as the piston is travelling back up. In other words, the BMEP may be increasing, or at least not falling off fast enough as the piston starts accelerating back up in the bore. Once the exhaust valve opens this would be eliminated. In any event, it is easy to understand why this could be pretty bad.

Ok, now I'll just wait till Danno comes and kicks the crap out of my pseudo tech gibberish!

toddk911

Cool info on that site Russ. It says what I was asking about. It is more effiencent ot run less boost and more advance unless I am reading I wrong.

Also, they don't define effeciency. Best fuel effeciency? most power per stroke??

I guess only a dyno will tell.

toddk911

QUOTE FROM SDS:

As the timing is retarded, PCP is developed later in the cycle. This allows more energy to be lost through conduction into the water jackets because the piston is further down the bore and the rod has a less advantageous angle on the crank pin to deliver force to the crankshaft. Retarded timing also raises the exhaust gas temperature considerably. This raises the thermal stress on the pistons, spark plugs, valves, exhaust system and turbocharger. In severe cases of retarded timing, the mixture is still burning when the exhaust valve opens. Because turbochargers are driven by the energy in the exhaust stream, high EGTs caused by retarded timing produce so much energy at the turbine that even a fully open wastegate cannot control the boost pressure. All in all, retarded timing is counterproductive to producing an efficient, powerful engine.

DANNO??

rage2

Got a warning on my Wideband O2 sensor... "temperature too high". So retarded timing and high boost is NOT the way to go, even though it makes big power. Lowered boost down to 15psi on 91 octane, with total timing hovering around the 16 degree mark at 15psi (17 degree retard). Drove really hard for a while, no temperature warnings. Danno??? =)

tecart

Just curious, Rage or Russ if you were adjusting your dme fuel quality/timing 7 position switch, which setting would be closest to your timing settings overall, -3 degrees timing, -6 degrees, or advancing it +3, or +6 degrees. I believe this dme switch covers the total rpm range + or - so im curious what is closest to your adjustable timing SDS timing values to match someone who is using only that switch? Assuming no change in the fuel quality just timing?

Danno

You can only retard timing with the DME switch, not advance it.

rage2

[quote]Originally posted by Danno:
<strong>You can only retard timing with the DME switch, not advance it.</strong><hr></blockquote>

Danno!!! Any ideas what the safe total advance is for our engine?

Alan C.

Rage,
I can run 18 psi on 93 octane pump gas at 19 degrees advance with the Tec3. No problems with A/F set at 12.2
Alan

rage2

[quote]Originally posted by Alan C.:
<strong>I can run 18 psi on 93 octane pump gas at 19 degrees advance with the Tec3. No problems with A/F set at 12.2</strong><hr></blockquote>

I'm at 15psi, 91 octane, 16 degrees advance, A/F at 12.0. Going to try to turn timing up slightly and see if the knock sensor picks anything up. I'm going to aim for 18 degrees advance.

Russ, my latest SDS map is now available <a href="http://www.virgeweb.com/rage2/944t/2002-07%20sdsmap3.xls" target="_blank">here</a>. I got idle and light load completely done (runs awesome with closed loop off), as well as a nice boost curve for my rpmfuel curve. 12.0 A/F ratio. The wideband O2 is really sensitive, and jumps around the 11.7 to 12.3 mark, but it averages out over 12.0. Just gotta work on my timing and 20+psi boostfuel curve. I scaled the 20+psi boostfuel curve already, but didn't get a chance to test it due to rain.

Here's a 3rd gear run. Boost is the blue AUX line:


Here's a 2nd, 3rd, 4th gear run. Note the richness from the acceleration pump:


Here's the 3rd gear 20psi run. Note how rich it gets when it jumps onto the 20psi map: