2018 whipple cal. pulley experimenting

[engineermike]

2018, whipple stage 2, a10, whipple cal only.

Has anyone played much with true pump gas and pullies? My results are as follows....this is on straight 93 with no octane booster, 4th gear pulls.

On the supplied 3.875 pulley and stock thermostat, my timing hits 17 deg at about 5300 rpm. It might bump 17.5 at 6000, and sometimes touch 18 at 6500. I guess heat takes over and it usually starts pulling timing from there. By 6700 it falls to 17-17.5. It might hold 17 to redline, or it might drop to 16.5.

On a 3.75 pulley and 160 thermostat, I see identical timing up to about 6000 rpm (17). From there up, it runs 1/2 to 1 deg less timing vs above, dropping to 16, maybe even 15.5 by redline. I do find it harder to get a clean log with this pulley, as it breaks the tires loose in 4th when it comes into the mid-range.

What are other folks finding? At what point does adding boost not add power due to loss of ignition advance? Is it worth trying the 3.625 on 93? Would it still be safe if I got a bad tank of gas or had to use 91 in a jam?

Thank,
Mike

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[Ruiner46]

I doubt you are making less power with the smaller pulley due to a degree or two less timing when you have more boost. Adding boost will eventually push the limits of pump gas and you will see knock retard. You should be looking at more than the raw timing number because there are several things that can adjust timing. It's very valuable to watch the knock retard pid with a datalog, Ngauge, OBD app, etc.

Most likely, the smaller pulley is pushing your load up, which pushes you further down the timing table to timing advance values that are lower. The tune uses timing tables that are based on load and rpm, and generally increasing either will reduce timing advance.

 

[SVT-DADDY]

Like @Ruiner46 said I'd want to know KR values before you do another pulley drop.

I'd also want to know what my A/F ratio is and boost. People are making sick power with these 2018's and 3.625 pulleys. You could be at the limit of your fuel system and 93 octane.

 

[engineermike]

Lambda is the same 0.74 all the way to redline.

Knock retard in all cases hits -4 at 5000 rpm, then ramps up. By 7200 it’s between -.7 and +1.1. Dustin has posted that the cal only allows up to -2 on the 18, so I’m assuming that’s only at high rpm.

I did plot the base timing curve (timing plus knock retard) and it was the same with both pullies and 2 different cal revisions.

 

[SVT-DADDY]

So if KR is +1.1 at 7200, what is at redline?

Honestly for me any positive KR value is too much. I'd sit on what you have, but I tend to be conservative.

 

[engineermike]

So if KR is +1.1 at 7200, what is at redline?.

1.1 is the most kr I’ve seen on any pull. On that one, it shifted at 7350 where it was still 1.1. On other pulls it was .9 or less at 7600-7800.

 

[engineermike]

I put 6 oz of boostane professional in a full tank of shell 93. The mixing chart says it should be almost 99 octane. The result seemed to be 1-2.5 deg less KR than without boostane. I saw a peak of 17.5 deg at 6300 rpm. It fell to 16.5 by the shift and held 15.5-16 through 5th gear.

This is with the 3.75 pulley, 160 tstat, 86 deg iat.

 

[Roh92cp]

Not an 18 but on why 15 I've done a lot of testing different pullies on 91-93 race gas and Boostane and meth injection. had a lot of conversations with Dustin on this and he's always told me you will make more power with max timing, taking advantage of fuel octane limits over boost. Just look at the power the E85 guys make. I have 2 friends who went E85 and both ran a 3.65" and 3.5" pulley on 15 Mustangs on 91 cali fuel and they had a hard time to see 18 max timing with this pulley and octane level. One ran a 3.5" pulley on 91 octane for along time and it was always had some positive knock, and he made mid 670's wheel like this. When they swapped to E85 and Lund tune commanding 22* at full song they both made 790 wheel on a 3.5" pulley and no more positive knock. Like Dustin said timing is King. 4 or 5 degrees of spark advance is a lot of power as you can see. Always so tempting to pulley down but if your loosing peak timing than you will loose peak HP like this most likely. Pulleying down may feel stronger on the hit because peak torque should increase until spark knock starts trimming power.

 

[Tommy V]

You said .74 measured a/f that is pretty damm rich!!!,do all the whipple cals command that much fuel at wot??

 

[engineermike]

It starts at 0.81 then drops to 0.74 when it switches to cat protect mode.

 

[engineermike]

It starts at 0.81 then drops to 0.74 when it switches to cat protect mode.

 

[Burkey]

Not an 18 but on why 15 I've done a lot of testing different pullies on 91-93 race gas and Boostane and meth injection. had a lot of conversations with Dustin on this and he's always told me you will make more power with max timing, taking advantage of fuel octane limits over boost. Just look at the power the E85 guys make. I have 2 friends who went E85 and both ran a 3.65" and 3.5" pulley on 15 Mustangs on 91 cali fuel and they had a hard time to see 18 max timing with this pulley and octane level. One ran a 3.5" pulley on 91 octane for along time and it was always had some positive knock, and he made mid 670's wheel like this. When they swapped to E85 and Lund tune commanding 22* at full song they both made 790 wheel on a 3.5" pulley and no more positive knock. Like Dustin said timing is King. 4 or 5 degrees of spark advance is a lot of power as you can see. Always so tempting to pulley down but if your loosing peak timing than you will loose peak HP like this most likely. Pulleying down may feel stronger on the hit because peak torque should increase until spark knock starts trimming power.

Um...Can we rewind a bit?
On the one hand we’re saying that peak timing is king and yet a blown car on e85 is seeing something in the order of 10 degrees less spark at peak than an NA car...
Surely the science is more tricky than “timing is king”
If that was completely true, we wouldn’t bother throwing ANY boost at them cos you’ll almost always be at a timing deficit (for a given fuel type).
I don’t have the answers, but this just sounds wrong

 

[Roh92cp]

Um...Can we rewind a bit?
On the one hand we’re saying that peak timing is king and yet a blown car on e85 is seeing something in the order of 10 degrees less spark at peak than an NA car...
Surely the science is more tricky than “timing is king”
If that was completely true, we wouldn’t bother throwing ANY boost at them cos you’ll almost always be at a timing deficit (for a given fuel type).
I don’t have the answers, but this just sounds wrong

Right and I was speaking to only boosted applications here, not comparing to NA. Sorry if I made it confusing.

 

[engineermike]

Just for kicks....

A whipple Stage 2 on a stock 18 gains around 320 rwhp (290-350 seems to the the range) at 11 psi. That’s about 30 rwhp per psi boost. They also run about 10 deg less timing than stock. Due to diminishing returns (losing 1 deg at 16 hurts more than losing 1 degree at 28), I would venture to guess that the first psi adds closer to 40 rwhp while the 11th psi adds closer to 20. We’ve seen several cars and my old coyote truck gain about 20 rwhp per psi of boost beyond 10. We’ve also seen e85 gain up to 40 rwhp per psi added, as you said, likely due to the timing remaining in.

That said, I do believe that 1 psi can add up to 40 rwhp as long as you don’t have to retard the timing any. If you pull 1 deg, that 40 is probably closer to 20 rwhp. If you pull 2+ deg per added 1 psi, you’re probably making less power now than before you raised the boost.

Make any sense or no?

 

[Roh92cp]

Just for kicks....

A whipple Stage 2 on a stock 18 gains around 320 rwhp (290-350 seems to the the range) at 11 psi. That’s about 30 rwhp per psi boost. They also run about 10 deg less timing than stock. Due to diminishing returns (losing 1 deg at 16 hurts more than losing 1 degree at 28), I would venture to guess that the first psi adds closer to 40 rwhp while the 11th psi adds closer to 20. We’ve seen several cars and my old coyote truck gain about 20 rwhp per psi of boost beyond 10. We’ve also seen e85 gain up to 40 rwhp per psi added, as you said, likely due to the timing remaining in.

That said, I do believe that 1 psi can add up to 40 rwhp as long as you don’t have to retard the timing any. If you pull 1 deg, that 40 is probably closer to 20 rwhp. If you pull 2+ deg per added 1 psi, you’re probably making less power now than before you raised the boost.

Make any sense or no?

Yes this is basically what I was saying. Adding boost with fuel octane limits maxed usually results in no additional peak power or maybe even reduction depending on knock activity and timing pulled. Whipple SC aka Dustin Whipple has told me many times I would make more peak power on 93 octane fuel with a 3.65" pulley over a 3.5" pulley.

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