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, use alky injection in conjunction with normal premium gasoline in the tank, or convert to E-85. 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 you have E-85 readily available in your area, and you are primarily a week end driver or don't put many miles on the car, then E-85 is an excellent, but expensive, alternative for some. I am going to stick to alky injection here.
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 a few have managed to run into the Nines with unleaded premium in the gas tank and a dual feed alky system under the hood. A few are on the verge of the the EIGHTS! This is quick no matter what the fuel especially when using a stock block 109 engine.
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.
.Single line/nozzle kits are adequate for most of us and are much easier to tune than dual line/nozzle kits. As one gets further closer to the low tens (quarter-mile of course) a dual feed alky system is probably required for safe operation.
In Buicks, straight methanol works better than combinations of methanol and water. 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.
I don't like to recommend particular vendors or manufacturers, but, when it comes to alcohol injection set ups, only one stands above the others, and that is the system produced by Alkycontrol.com. It has been constantly improved over the years and is head and shoulders above any other options.
As the methanol acts as fuel supplement to some considerable 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, in any case. I have seen a few cars go really fast on bad fuel pumps because the owner was not monitoring fuel pressure. The alky being sprayed saved them but it is not a desirable situation and luck was smiling on the car owner. Many of us that run alky have had fuel pumps die on us and we made it home by pushing the test button on the alky controller and driving on alky alone.
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. Purchasing the alky pump pressure tester from Alkycontrol.com costs more but it will insure safer operation over a longer time by alerting you when the pump is beginning to lose pressure.
Cars can be a bit more tricky to tune when spraying Alky. This is due to the need to start the alky flowing at lower boost to insure it is spraying enough as the boost goes up. One may find that he has to pull some fuel out of low gear to get the car to spool as it should. Turbotweak.com offers an "Alky" chip that removes fuel on the gasoline side of the equation which makes it easier to dial in alky. .I strongly suggest you start with the suggested defaults suggested by both AlkyControl and TurboTweak. Don't start making changes until you are comfortable with your understanding of both.
I suspect the guys trying to push into the 8 second range in the quarter are pulling a lot gasoline out of the fueling in low and second gear, cranking the timing up quite a bit, and making the car spool like crazy. Those guys are using after-market fuel management systems which give them a tremendous latitude in combining the two fuels. Again, I strongly suggest that guys running chips should follow very closely to the defaults suggested by AlkyControl and Turbotweak. If you are reading this, you are probably not trying to hit the 8's yet. :D
As I mentioned above the greatest problem with alky may be 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. I strongly suggest that a Powerplate from RJC Racing be used with any street driven car using alky, or not. From data presented by Russ and Melissa Merritt during dyno runs, the Powerplate goes a long way into equalizing A/F's and EGT's between cylinders. Many will wail and wring their hands saying it cannot possiblly work because it is restrictive, but that is not what the dyno says. People should learn to believe measured data and performance rather than what they think their eyes are seeing. Dave Bamford proved the Powerplate worked on the dyno and track years ago and people refused to believe it. I am sure that the same people are still saying it, but, some just don't learn. Melissa was running 9.0's on 93 and alky with the plate in place. She and Russ race almost every week end of the season and they are not blowing up stuff like some of the naysayers.
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!
Fortunately, on a car spraying alky, detonation is not a major problem if the car is mechanically and electrically solid. Just watch the alky performance to make sure it is doing what it should be doing-just like you do a car running on gasoline alone.
No matter what you are running, take it easy cranking up performance. Don't go from 15 psi of boost to 33 psi of boost in one step!!! Put the Eagles on the radio and Take It Easy. Baby steps!