Labonte Motorsports Alky

[Labonte]

Hmmm, interesting. I'll have to look into that the next time I get over to NC. I'll have to see where this particular Snow unit is tapped into, whether before or after the Translator.


After checking the Snow site, I'm sure this is the unit they call the GM low frequency MAF controller. It's for GM 86-9x MAF's

In 2004 we were selling the VC-MAF controller through snow. It was designed for 0-5V hot wire MAFs like used on the Fords and some imports. We later designed a small black converter box named GM MAFT. It reads the frequency based MAF and converted the output to 0-5. It had a few switchs on it to change the slope of the conversion. We made two versions of this box, one for the low freq maf and one for the high freq maf.

We later redisgned the VC-MAF controller to accept 0-5V and three other frequency based MAF signals. It has a white cap on the back near the connector which you use to access the switch inside the box to select the MAF type.

Let me know which unit(s) you have and would be glad to help you with it. Since snow does not sell them any more I would be suprised if anyone there would be able to answer your questions about it.

 

[TurboDave]

It'll be a couple weeks before I get back over there to help him out with tuning.
The issue we have in the Buick community, and what Turbobob was trying to help me explain is that contrary to what you've stated above, a MAF based controller is NOT the best way to go, at least not with the ECM/MAF limitations that the vast majority of our 86/87 systems have.
Here's the rub....

The ECM is limited to Hex FF, or decimal 255. So, the frequency being read and converted within the ECM is limited to 255 gps (grams per second). It has been learned over the years that this limit is QUICKLY reached when approaching 14-15 lbs of boost. In a bone stock GN, this is not a problem.

Problem is, hardly any are bone stock and alky generally isn't needed at stock boost levels.

It is when running 16-25# of boost that the alky is needed.

If max is reached at 255 gps maf flow and it's reached at 15#, that tells me the max flow is reached at 15#, (FAR TOO EARLY!!!!) and can't be increased beyond that point.

That's why the MAP based system is more desirable in this situation. We can turn the alky on at say 10# of boost and ramp it up to max at maybe 20#.

Hope I'm not confusing the issue.

IMHO we've just got to get away from these MAF based systems on high boost applications that are using a limited 8bit ECM.

 

[TurboBob]

Bob, thanks for the correction. I thought that might have been incorrect when I posted and should have checked my notes on Buicks before posting.
My appologies.

GM used the AC Rochester Hot Film MAF starting in 1984 on the 3.0L and 3.8L and then later in 1990 switched to the Hitachi Hot Film MAF on the 3.3L and 3.8L.

MAP based injection works well, but depends on the type of turbo and if it can hold boost to redline. As seen in the chart below, the turbo on this engine makes peak boost quickly and then drops off. In this case a MAF based system would be a better option. The MAP based controller would reach peak injection flow to soon and then meth would drop toward redline where it is needed more.

For the cars that peak the boost really high and then run in choke-flow all the time, a MAP only style control is too limiting.

GN's are not typically set up that way. We typically run constant boost or close, and run in 'cross-over' where the exhaust pressure is higher than manifold. In these cases the torque is falling as the RPM's rise, and so the HP is almost constant. So a nearly constant flow alcohol system can work pretty well, and a MAP only system works very well.

For Dave's situation, he needs to connect the Snow controller to the input side of the translator. It will work ok there as long as the intercooler is not too huge.

Bob

 

[SGRIM]

Just buy a new Isac and it will all be okay

 

[TurboDave]

For the cars that peak the boost really high and then run in choke-flow all the time, a MAP only style control is too limiting.

GN's are not typically set up that way. We typically run constant boost or close, and run in 'cross-over' where the exhaust pressure is higher than manifold. In these cases the torque is falling as the RPM's rise, and so the HP is almost constant. So a nearly constant flow alcohol system can work pretty well, and a MAP only system works very well.

For Dave's situation, he needs to connect the Snow controller to the input side of the translator. It will work ok there as long as the intercooler is not too huge.

Bob

Bob, do you mean it's as simple as taking the present snow signal wire where it's tapped and t-tap it to the LS1's signal wire that feeds the Translator?

 

[TurboDave]

Just buy a new Isac and it will all be okay

That would be nice, but it's definately NOT in the budget.

 

[TurboBob]

Bob, do you mean it's as simple as taking the present snow signal wire where it's tapped and t-tap it to the LS1's signal wire that feeds the Translator?

assuming that model of Snow controller can be set for a high frequency signal.

Bob

 

[TurboDave]

assuming that model of Snow controller can be set for a high frequency signal.

Bob

We'll have to try and figure that out. It's a unit designed to run on GM stuff. Like the original GN MAF's

 

[Razor]

That would be nice, but it's definately NOT in the budget.

I have some chinese tools to change headgaskets. I need to make this chinese socket and TQ wrench hold 90 ft lbs of tq. Getting the correct socket or tq wrench is NOT in the budget

Wrong parts are wrong parts. You think some things are not in the budget.. blow a hole in the motor and we'll see about your budget. Sorry.. I tried staying out. But rubbing nickels together to achieve a poor result is just that.

TurboDave, I hope he doesnt blame you for the meltdown when it happens.

:redface:

 

[SGRIM]

That is why our system is Plug and Play with about any system on the market already:biggrin:

No need to buy new wrenches:wink:

 

[TurboDave]

I have some chinese tools to change headgaskets. I need to make this chinese socket and TQ wrench hold 90 ft lbs of tq. Getting the correct socket or tq wrench is NOT in the budget

Wrong parts are wrong parts. You think some things are not in the budget.. blow a hole in the motor and we'll see about your budget. Sorry.. I tried staying out. But rubbing nickels together to achieve a poor result is just that.

TurboDave, I hope he doesnt blame you for the meltdown when it happens.

:redface:

Thanks for the constructive criticism, just exactly the kind of help we're looking for. :frown: "The system you have is junk, buy something else"
The Snow system in the car now is what came with it, so it's what we have to work with. It's working (we'd just like to make sure it's working properly). That's why we've got the boost pulled back to about 20 and have the timing pulled out of the TT chip for now.
Do you actually think we're stupid enough to run big boost numbers until we've got it figured out??

It's certainly not our fault we don't have a crap load of money laying around to throw at a brand new alky system of the two mentioned in this thread. Some of us aren't quite as well off as others.

Ya'll have a fine day!

 

[Razor]

Thanks for the constructive criticism, just exactly the kind of help we're looking for. :frown: "The system you have is junk, buy something else"
The Snow system in the car now is what came with it, so it's what we have to work with. It's working (we'd just like to make sure it's working properly). That's why we've got the boost pulled back to about 20 and have the timing pulled out of the TT chip for now.
Do you actually think we're stupid enough to run big boost numbers until we've got it figured out??

It's certainly not our fault we don't have a crap load of money laying around to throw at a brand new alky system of the two mentioned in this thread. Some of us aren't quite as well off as others.

Ya'll have a fine day!

No you dont get it. If you have something that doesnt work correctly for the application you dont use it. If you dont have the budget to buy the correct piece, then you simply dont continue to use what doesnt work correctly and possibly hurt some part of the engine doing so. Putting you in a real bind.

If you cannot afford to race a car, dont. Running higher than stock boost levels is asking for an issue, that you cannot afford to have. Best advice, drive and enjoy the car. Not race it knowing you have an issue.

Personally I understand what it is not being able due to circumstances afford to buy "X". But when i've had those issues, the last thing I did was go and try and create more issues that could cost "X+Y".

As long as your alive.. your doing fine. Car stuff is just that. Dave, please dont take what i'm saying offensively. I've seen too much engine carnage over too many years from things done in an improper fashion. Its hard enough to keep things together when your doing them correctly. :redface:

 

[TurboDave]

Oh, I "get it".

I think you assume too much so let make a few points clearer.

No you dont get it. If you have something that doesnt work correctly for the application you dont use it.

No implied that it's working incorrectly. I'm just trying to get a few pointers on making it better.

If you dont have the budget to buy the correct piece, then you simply dont continue to use what doesnt work correctly and possibly hurt some part of the engine doing so. Putting you in a real bind.

We're not pushing it hard enough to hurt anything yet. It's running the same boost and timing I run on straight 93 octane on my car.

If you cannot afford to race a car, dont.

I don't believe I remember mentioning that this car is raced. It's not. It's just a daily driven hybrid with an 87 powertrain.

Running higher than stock boost levels is asking for an issue,

I totally disagree on that point. Plenty of people are able to run higher than 12# of boost on pump gas these days (no, 15# of boost was not the stock level)

that you cannot afford to have. Best advice, drive and enjoy the car. Not race it knowing you have an issue.

Again, not a race car.

Personally I understand what it is not being able due to circumstances afford to buy "X". But when i've had those issues, the last thing I did was go and try and create more issues that could cost "X+Y".

As long as your alive.. your doing fine. Car stuff is just that. Dave, please dont take what i'm saying offensively. I've seen too much engine carnage over too many years from things done in an improper fashion. Its hard enough to keep things together when your doing them correctly. :redface:

Sorry but I did take offense. Condescending remarks will always do that to anyone. I have had at least a few years tuning these cars, and haven't pulled too many bone headed things. Early mistakes yes. But lessons learned have carried through.
I'm not mad, just a little disapointed, and thin skinned lately I guess.

Apologies for any inappropriate remarks.

 

[Razor]

Sorry I ever tried.

Good luck with your decisions.

 

[Mr.Spool]

the cost of doing one of these motor's should easily outweigh the need for speed of low budget but it rarely does.having experienced breakage myself i now think twice before i tinker.

 

[TurboDave]

assuming that model of Snow controller can be set for a high frequency signal.

Bob

Bob, Labonte, or anyone

Here's what I found out on my visit this past weekend.
It's a VC-MAF brand which means it has selectable frequency ranges as setup by rear panel dip switches.

(1) One switch will run it in "93 and older GM" configuration, and according to the front panel markings, this means (low frequency) a frequency range of 40 Hz to 220 Hz.

(2) A different switch can run it in "94 and newer GM" configuration, and according to the front panel markings, this means (high freq.) a frequency range of 2 Khz to 14 Khz.

In it's present cofiguration (car has a regular translator and LS1MAF), the VC-MAF is tapped into the ECM's MAF signal wire (gry/red). and dip switch set for operation (1).

Now, he was to set it up for (2) operation, and move the VC-MAF tap to the MAF signal wire somewhere between the MAF and Translator, can we gain better control or would it be a wash (just different freq range).

TIA!!!!

 

[TurboBob]

you should gain some additional range.

Bob

 

[TurboDave]

Thanks Bob, I was thinking along those lines, but didn't want to assume too much. But can't remember the varous freq ranges of the stock mafs or LS1 mafs, etc.

 

[Ttype6]

well winter is here so everyone that wants to reinvent the wheel has 3 more months to do it:biggrin: . Then show the RESULTS on the track

Another arogant bitch comment that makes no effort to answer the question by a guy proud to have you call him grumpy. How Cool! If you run a turbo charged motor and don't spray water into the compressor you're definately not trying to re-invent the wheel. Your throwing it away. Wow,the guy throwing away the wheel is name calling the guy trying to re-invent it. Brilliant!

 

[Grumpy]

Another arogant bitch comment that makes no effort to answer the question by a guy proud to have you call him grumpy. How Cool! If you run a turbo charged motor and don't spray water into the compressor you're definately not trying to re-invent the wheel. Your throwing it away. Wow,the guy throwing away the wheel is name calling the guy trying to re-invent it. Brilliant!

bla bla bla bla bla,, so you are goin to spray WATER great ..show us how its DONE @ the track.. Butt dyno's don't count