How much ignition advance is normal?

"Jake - Has Bad Luck So You Don't Have To" (murdersofa)
09/15/2014 at 22:47 • Filed to: None

Just drove around a bit with Torque running with my new OBD2 dongle and it was saying I was getting 35 to 40 degrees of timing advance when cruising at 65mph.

This seems like a lot, should I be worried? I'm not really well enough versed on this sort of stuff to know how to interpret it.

Engine is a 3.8l Buick V6, ZZP PCM1.0 tune, 9.4:1 compression (factory numbers), 91 octane fuel

DISCUSSION (20)

claramag, Mustaco Master > Jake - Has Bad Luck So You Don't Have To
09/15/2014 at 22:50

My 3.8 mustang (based off the GM 3800) does the same at light load. It's normal. Freaked me out first time I saw it on Torque though

Jake - Has Bad Luck So You Don't Have To > claramag, Mustaco Master
09/15/2014 at 22:51

A mustang with an engine based off the Buick 3.8?

Whaaaat?

claramag, Mustaco Master > Jake - Has Bad Luck So You Don't Have To
09/15/2014 at 23:01

Mhmm. Back in the late 70's or so Ford needed a 'fuel friendly' engine so they reverse engineered the 3800. Same bore, stroke, OHV, almost the same engine, but almost no interchangeable parts with the buick. I think the later engines had slightly higher compression ratios....

Ford's 3.8 never got the same love as Buick's with the public or internally, mostly because Ford spent all their attention on the 5.0 and 4.6. The 3.8 was just tossed in the mustang and vans and such. Ford used to just toss whatever into the base mustang (like that 4.0 truck engine. God, what a horrible match)

(Side note, do you know roughly the max power capabilities of the Buick's internals are? IIRC Ford's last 3.8's could handle up to the mid 300's, cuirous if the Buick's are similar)

Jake - Has Bad Luck So You Don't Have To > claramag, Mustaco Master
09/15/2014 at 23:23

A friend of mine took a supercharged 3800 Series III up to 600hp, and has plans to hit 1000. I've seen them in Fieros making absurd amounts of horsepower because people have a death wish.

claramag, Mustaco Master > Jake - Has Bad Luck So You Don't Have To
09/15/2014 at 23:39

That's...not factory internals right? Forgot to add that bit, what can factory internals take

The most powerful 3.8 I've ever read about was making 650hp or so and was supposedly ludicrously expensive to hit. Though with gearing and slicks it was hitting 10's it's still disappointing to know how limited the engine is

Found the link, 601rwhp 825lb/ft, 9.83@136. Literally the only 3.8 mustang with that sort of power. So um, Buick 3.8 wins that one

Jake - Has Bad Luck So You Don't Have To > claramag, Mustaco Master
09/15/2014 at 23:55

He has stock pistons, cranks, etc. only thing different about the engine is forced induction, nitrous, water/meth injection, and LOTS of intercooling.

We don't expect it to last longer than a month or so.

Sweet Trav > Jake - Has Bad Luck So You Don't Have To
09/16/2014 at 00:14

Yes, if you look at the logger function you'll see under load the ECU won't give as much timing when you step on it from a dig. More advanced timing under light load typically means better gas mileage.

They used to increase timing with vacuum, under light load the engine creates solid vaccum and would advance the distributor, Through a vacuum advance module, literally a rubber diaphragm attached to a stick with a spring. This would increase your timing from an intial timing of 6-8 degrees usually, though mechanical centripical advance was there when you stepped on the load pedal and the engine made little vacuum.

33-40 degrees advanced max under load at 3000 rpm used to the be number for SBC's without vacuum advancd

Jake - Has Bad Luck So You Don't Have To > Sweet Trav
09/16/2014 at 08:37

So I should be getting better fuel economy because it's advanced more than it was on regular fuel?

For some reason Torque can't read my knock retard so I have no idea if premium has solved my Heisenberg issue.

Sweet Trav > Jake - Has Bad Luck So You Don't Have To
09/16/2014 at 09:07

Give me the full rundown and ill see if i can be of assistance.

Jake - Has Bad Luck So You Don't Have To > Sweet Trav
09/16/2014 at 09:12

A week ago I was running my car on regular gasoline and I drove around with my friend and his Snap-On OBD2 reader tablet thing. What we found was the engine running super SUPER rich (forget the number) with about 7 degrees of knock retard.

I now switched to premium to get the knock to go away, and Torque isn't able to read the knock sensor or knock retard for some reason so I have no idea if I've fixed the problem by switching fuels or not. I'm hoping that the car will adjust to the premium by running leaner than it used to now that it can do so without knocking, and I'll get slightly better fuel economy. Unfortunately so far I have been seeing *worse* fuel economy.

I'm puzzled and doubting everything I know about engines (which is not much)

Sweet Trav > Jake - Has Bad Luck So You Don't Have To
09/16/2014 at 09:15

My guess is your tune calls for premium fuel. Your engine noticed a knock on regular and shut your timing advance down.

Jake - Has Bad Luck So You Don't Have To > Sweet Trav
09/16/2014 at 09:17

Yeah, we looked at the tables with HPTuners and it appears to have two tables; one for "low octane" and one for "high octane", so it should run well with either (though better all-around performance on high octane).

Of course, I wasn't expecting much out of a naturally aspirated tune, I mostly wanted the increased transmission line pressure, shift poinds, and decreased kick-down delay

Sweet Trav > Jake - Has Bad Luck So You Don't Have To
09/16/2014 at 09:19

Try the low octane tune. Pre-detonation will rock a motor to pieces and HPtuners no doubt has the knock sensor on high alert to prevent engine damage.

Jake - Has Bad Luck So You Don't Have To > Sweet Trav
09/16/2014 at 09:21

It automatically switches between the two when knock is detected. Even that wasn't enough though and it was still knocking like crazy. I feel like it's just a result of the engine getting old and now I'm doing damage control. I'm not sure how wear could cause knock, but 223,000 miles is quite a bit of wear.

Sweet Trav > Jake - Has Bad Luck So You Don't Have To
09/16/2014 at 09:26

Probably hot spots from carbon deposits or to much timing advance for the fuel. Not to tell you what to do, but I'm going to tell you what to do. If you're at 223,000 miles the last thing you need to be doing is running this engine hard, or tuning it, especially if its your primary vehicle.

Jake - Has Bad Luck So You Don't Have To > Sweet Trav
09/16/2014 at 09:27

Seafoam, then run the engine into the ground and buy a 1998 Buick Riviera.

Or buy a new engine for $450 (yes, they're quite often that cheap on Craigslist)

Sweet Trav > Jake - Has Bad Luck So You Don't Have To
09/16/2014 at 09:29

I'd do a series III swap. but that's just me.

briannutter1 > Jake - Has Bad Luck So You Don't Have To
09/16/2014 at 09:45

That's normal at low load part throttle...often even up to 55 degrees in larger bore more inefficient combustion engines. Go WOT and you'll see it drop down into the 28 degree range

Jake - Has Bad Luck So You Don't Have To > Sweet Trav
09/16/2014 at 10:21

$500 will get me a Series 2 Supercharged, but right now my larger concern is wheels/tires so I'll probably be buying 17" Mustang GT wheels/tires before I consider an engine.

DocWalt > Jake - Has Bad Luck So You Don't Have To
09/16/2014 at 16:34

Sounds normal. My GTI is at 45 degrees advance at light load. That said, I just blew it up, so who knows :P