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Alcohol Injection

 

If one wants to run 20+ psi of boost on the street, then one will normally have to either run higher octane race gas in the tank, or use alky injection in conjunction with normal premium gasoline in the tank.  Let's face it.  Once we have turned the boost up to 25 psi, it is hard to drive around with 16 psi on tap.  Being that race gas is very expensive to run in a daily driver, alky injection becomes a very viable alternative.

If one sprays alky, it not only acts as a chemical intercooler, but, it becomes a fuel source adding a higher octane component to the fuel equation when running straight methanol on the alky side.  More than one have managed to run into the Nines with unleaded premium in the gas tank and a dual feed alky system under the hood.

This is a good place to insert a Warning.  Alcohol, of any type is inflammable!  When mixed with water, so that the percentage of alcohol exceeds approximately 50% of the total mix, it will burn!  Any leak, whether from faulty plumbing, or caused by a wreck, can be ignited if the alky injection fluid is above 50%.  This can cause the loss your car just like a broken fuel line can.  Many that run alky on Buicks spray 100% methanol and my comments below pertain to such a percentage.  Be forewarned and make your own decision as I am making no representation that such a percentage can be safe if it leaks in the engine compartment.  Examine the kit that you propose to buy and consider the suggestions made by the manufacturer.

After many years of using alky injection, I have come to the following opinions.

Alky injection is the greatest thing since sliced bread for street cars that see some strip duty if used wisely.  When properly dialed in on a properly running car, it should be easy to run 25 psi of boost on 93 octane as a routine matter.

It can be a more dangerous proposition on race cars that are routinely pushed to the edge than is race gas.

Single line/nozzle kits are adequate for most of us and are much easier to tune than dual line/nozzle kits.  Dual line/nozzle kits are for the guy that just has to run his race car on 93 octane and they are much harder to tune and far more dangerous in the hands of those that don't fully understand fueling.

Alky does not allow as much timing as race gas and this is particularly true on the street.

Alky will allow a bit more boost to be effectively run from a stock turbo and intercooler due to the chemical intercooling effect than may race gas.

In Buicks, straight methanol works better than combinations of methanol and water as a general rule.  Straight methanol is very hard on the pump and pumps should be rebuilt every couple of years to insure that the system continues to function as intended.

As the methanol acts as fuel supplement to some degree, one can go faster on a given fuel pump than one will be able to achieve on straight race gas.  Be sure to monitor your fuel pressure to insure you have not reached the point of no return on the pump.

A quick tap on the Test button helps to insure the pump is primed and going to work prior to a run and may save you a new engine.

 

The greatest problem with alky is with those people that keep adding alky trying to cure a detonation problem without realizing that they have a fueling problem when it comes to the gasoline side of the equation.  This may lead to "The Big Bang" as our intakes are dry intakes (not designed to flow both gas and air) and the resulting distribution to the cylinders is often erratic.  Also, methanol is susceptible to pre-ignition and this is more destructive than detonation.  Once the amount of gasoline being injected diminishes sufficiently, and the methanol becomes the significant source of fuel, then bad things can suddenly happen.  This is greatly aggravated when running lots of timing.  See my opinion above.

For the best distribution, nozzles that spray a very fine mist under high pressure are desirable.

Above all, pay attention to the set up recommendations of the kit manufacturer.  Assuming that you were wise enough to buy from someone that developed kits specifically for Turbo Buicks, his suggestions will be very close and should require very little tweaking.  If you find you need to vary from the start up recommendations very much, it is time to take the time to figure out why.  I don't like to suggest vendors but in this case, I would only buy a kit from Alkycontrol.com as he has had numerous years to tailor his kits specifically for our cars.

Another problem associated with too much methanol is the transition of its introduction to the air stream.  If we turn the spray on too early, then we can kill the turbo spool.  Alky burns cooler than gasoline and it is heat that makes the turbo spool.  If we delay the turn on point to above our normal stall point at launch, then try to ramp up the gain on the alky to get it spraying in quantity, we may see what we used to call transition knock with the older, non-progressive kits which looks like rich knock, or whatever we want to call it...appears as a sudden burst of timing retard that normally rapidly goes away as the combustion temps heat up.  The reduction in timing does nothing for our power output.

This problem is not nearly as significant with a single nozzle kit as it can be with a dual nozzle set up where it is much more difficult to taper the increase in flow with the boost coming on.  In a race car with a high stall converter, it tends to approach an all or nothing matter so it gets easier to handle.  On a street car, it is yet another reason to stick with one nozzle as one has to be prepared to deal with a variety of conditions when coming down on the gas.  Assuming that you were wise enough to buy from someone that developed kits specifically for Turbo Buicks, his suggestions will be very close and should require very little tweaking. 

We typically run a bit less timing than we do on race gas...particularly on the street, if for no other reason than a margin of safety.  One may be able to run 23 degs of timing in first and second, and 21 in third gear.  On the track, it is not uncommon to see more being used..perhaps 25-23 or so.  Remember...no magic numbers, what works in your car is the right number.  Stay out of detonation as reflected by timing retard on the scan tool.

Air/Fuel ratios will vary depending upon how hard the car is being pushed as well as the engine combo.  A car running in the Tens may use a third gear A/F around 10.8-1, while one up in the Elevens may run quicker at 11.2-1.  Don't count on those as being the right numbers for your car...find out what is safe for the car.  Don't aim for a specific number because Joe Blow runs it...Find the A/F that works for your car under your local conditions.  There is no specific cook book of recipes when you start to seriously push it. Start rich!  10.8-1 is richer than 11.0-1.  Don't mix your lean and rich up when tuning.

Using the stock oem O2, one may see something like 750-770 mv up in third.  As always, the key is NO Timing Retard !  When running with boosts up in the 20s, it takes very little detonation to push a head gasket, or worse.  Remember that at 28 psi of boost, our cars think they have something over 600 cubic inches while the crank and rods are built for a 231 cubic inch engine.  A little detonation at 28 psi is a heckuva lot more damaging that it is at 14 psi.  Don't think you are ok because you have not heard any detonation.  It will be covered up by the engine letting go!