L78 Total advance

[L78steve]

What are you L78 gurus running for total advance? I'm running 36 and think it could benefit with a bit more.
No spark knock at all with pump premium.

[WILMASBOYL78]

What is your initial set at?? What rpm does the total come in at?? Are you running vacuum advance??

Assume this is stock L78 specs...compression/cam??

Auto? stick? rear gear?

wilma

[Lynn]

1. Possible it would benefit with a couple more degrees.
2. Remember, just because you don't hear an audible ping, doesn't mean there is no detonation. The detonation you hear is just the extreme. It starts a bit before it is audible.

3. While I agree with Tom that all the numbers need factored in, I am going to ASSUME you are fine with the all around performance, and already have the curve and vac dialed in. You are just contemplating advancing a bit. Also ASSUMING you are running the vacuum to straight a manifold vac and not a "ported spark" source. That takes the vac advance out of the equation under load.

If all of that is correct, I would bump it up to 38 and give it a shot. Because you called it an L78, again, I am ASSUMING you mean close to stock compression, cam, etc. I will be the first to admit it has been many years since I helped tune an L78. So many years, we still had regular leaded gas available (without going to the airport). Seemed the ones I worked on liked right at 36 total (excluding vac of course).

Seat of the pants can be very deceiving. Many times we "feel" a difference just because we WANT a difference. If you have a Gtech or something similar, you could make back to back runs in an appropriate area to see if there is any measurable difference. If there is no performance benefit, I would put it back to 36 just in case there is an inaudible ping at 38.

Way more than you asked, but trying to cover all the bases in one post.

Good luck.

[L78steve]

Stock L78, Full Vac avail. to Dist.Not that it matters at WOT.Car runs good just wondering if anyone is running more total than 36. With 11:1 I'm wondering why no spark knock and run on after shut down with today's fuel unless I'm not running enough advance for max power, even if I need to add some racing fuel to the mix is OK if a timing bump will help.
Curve and Vac is dialed in, Static is where ever it needs to be for total setting. As long as the starter will crank it I don't worry about initial too much but I will guess its about 12.
Tom are you having any issues with ping on your cars?

[WILMASBOYL78]

My cars won't run on the 93 pump stuff without a serious dose of race fuel or av gas. I think we run 36* total..16-18* initial...all in by 3,000rpm. Vac adv is hooked up to manifold vacuum.

I'm amazed you can use the pump stuff and not have pinging...did you ever calculate the compression ratio when the motor was apart? Those rect port heads are notorious for having bigger chambers than advertised.

tom

[L78steve]

Tom, the only difference is i'm all in at 3700. I never calculated CR but engine is bone stock std. bore heads uncut. I'll give it a 2 degree bump and see. Stock Garner exhaust so if it pings I should hear it.

[JRSully]

Speak to Eric at Vintage, he did my orig L78 dizzy. Basically bone stock L78/4spd/3:73 except for headers. Timing is all in at 3k and engine responds very well to that. Also run a Crane breakerless ignition, dead reliable for a bunch of years now.

[WILMASBOYL78]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JRSully</div><div class="ubbcode-body">Speak to Eric at Vintage, he did my orig L78 dizzy. Basically bone stock L78/4spd/3:73 except for headers. Timing is all in at 3k and engine responds very well to that. Also run a Crane breakerless ignition, dead reliable for a bunch of years now. </div></div>

You still running that rod on diesel??

[JRSully]

steady trips to the local airport takes care of the fuel issues. And, as a matter of fact, I'm now waiting to see what VW is going to offer to buy back my Passat diesel, It's too bad cause I love the car. 600 miles out of a tank of gas, tons of torgue and it is fast. VW is either offering to neuter the car or buy it back

[L78steve]

I would not give up the Diesel VW. Your PCM has a custom performance tune that you cant get any longer.

[Pat_Dilling]

Related topic if I can piggy back on this thread. Looking for similar advice for an L72 in a 68 Biscayne, M20 4 speed, 3.73 gears. Motor is .030 over otherwise internally stock with an MSD HEI distributor.

Thanks

Pat

[SuperNovaSS]

Can't you just unneuter the VW when you get it back? I thought it was software only.


Jason

[JRSully]

That is the quandary a lot of us VW diesel owners will be in; 1. do I keep the car and hope I can get the PCM reconfigured back to performance/mileage tune that it has now and basically run it into the ground cause the resale will suck.? 2, OR will the buyback offer be to good to refuse, as I have to figure VW will add some &quot;sauce&quot; to the offer to alleviate/lessen class action suits.
It's a wait and see for now

[mockingbird812]

Hmmmmm. I'm a TDI owner affected by the ScAnDaL. I see only goodness coming from this. All affected diesel owners should have received their $1,000 &quot;rebate&quot; by now - $500 on a Visa (to be used however you want), $500 on a VW card (to be used at the dealership). If/when a fix is announced there is little doubt that the cars will accelerate worse and fuel mileage will suffer. I do not believe VW or the U.S. gov't can compel us to have the &quot;fix&quot; done to our diesels. Why would you volunteer? I submit that the desireability of the car will increase on the market for those tdi's not &quot;fixed&quot; as they will perform better (accel and mpg). Also, it is not just about the extra emissions that these tdi's put out, but when the recall fixes these tdi's they will not go as far on a gallon of fuel and therefore a negative impact on the environment (i.e. less efficient).

EPA will require a severe knee-jerk response from VW in order to allay the concerns of the tree-huggers. EPA, IMO, is anti diesels for the U.S. car industry. The standards for diesel emissions is stricter than gasoline, when there is generally more energy in a gallon of diesel (i.e. the car will go further on a gallon of diesel) than there is in a gallon of gas AND it takes significantly less energy to process diesel than gasoline. Washington wants all cars to be looking to electric car technology (where does all that electricity come from???? <<GRAEMLIN_URL>>/hmmm.gif it's FREE - right?! with absolutely no impact on the environment!!!). Where do all those nasty chemicals go to when the batteries wear out? The GM at my VW dealership recommended that I do not act on the recall as the value of the car will go down!

For the record - my 2014 tdi Sportwagen (w/ 45K miles) averages 42 mpg (calculated vs on board computer) AROUND TOWN! .......... 48mpg on the hi-way!

[Pat_Dilling]

&quot;I do not believe VW or the U.S. gov't can compel us to have the &quot;fix&quot; done to our diesels.&quot;

In states like California that have regular emission inspections before the registration can be renewed, the State can do exactly that. At that point it becomes fix it or park it.

[mockingbird812]

Of course CA and Phoenix and other places with annual emmissions will compel it - but I don't think the other non-emissions testing areas have any recourse.

[L78steve]

Here in NC there is no diesel emissions test. So residents in this state and others like it should leave well enough alone.

[JRSully]

I know NY will hammer the car on annual inspection just being a TDI, they will demand certain readings I'm sure. That is a shame because a normal &quot;new car&quot; inspection is cheap and quick here. I have my $1k gratis $$ from VW and was going to save it for tires, cause I have the skinny rubberband Conny's and they are pricey and don't last. It will all depend on the offer from VW and if it can be &quot;parlay'd&quot; into a better deal for a newbie VW maybe. I have a '14 Passat with every option and I will need something comparable to hang with the Wolfsburg gang

[mockingbird812]

yr mpg Sully?

[JRSully]

Hey Sam, mpg, easily 50 or better on the hwy. 18 gallon tank and I consistently get 550, sometimes 600 miles out of a tank if I run it down to empty. As the car sits right now, there are so many advantages to it; 1. Diesel fuel is the same price as regular around here currently, 2. the TORQUE is incredible, when you punch it, and the turbo comes up, it really flies. This is a fairly big car considering and only 140hp. People that sit in it don't even know its a diesel, because it is very quiet on the inside, no smell, factory 10k oil change intervals.
It is my .02 here, but I will miss this car if I cannot get everything back that made the car such a value in the first place. You may be right Sam, that these cars could become cult collectibles if they can be retro'd after the fact, we'll see...