This.. http://www.msdignition.com/Products/Ignitions/6530_-_MSD_Digital_Programmable_6AL-2.aspx.. is the one I mentioned earlier for use with our engines. All you need is a serial port/pda adapter and a laptop to tune the entire ignition curve once the total timing is locked out into the distributor. This is because the system only pulls timing from that locked baseline number and can never add to it. IMO, the real beauty of this system for a street car is the availability for MAP based tuning. This allows major timing advance at idle when mixture density and its overall speed is lowest and extra spark lead time is required to make maximum cylinder pressure.. but allows you to take timing away as load(vacuum drops) and rpm's increase. It even has time based settings for nitrous and allows different timing plots/curves for gear changes too. That's not possible with a conventional disty aside from the vac advance pot "pulling timing back out" under load as vacuum drops away at WOT. So far, I've only tuned 2 engines with this system, mine included, and engine vacuum is the highest I've ever achieved with moderately sized cams. Using a MAP based system like this with larger cams would likely be even better. One engine is my 11.5:1 385 Chevy with an extreme energy hydro roller(XR282HR-10) of 230/236* @.050 which now makes a tad over 15" @850 rpm idle speed.. and just above 16" @1,700rpm with 54 degrees of total advance locked into the distributor. That's a full 3 inches higher than the best curve ever achieved with my regular 6AL box.. and 6 inches higher than the cams advertised rating of 9" @800 rpm and 5" higher @1,000 rpm. The other engine is a 10:1 327 Chevy running a solid flat tappet with 242* @.050 and that motor also makes 3+ inches more vacuum(near 15") than we could ever squeeze out of the regular 6AL box combo no matter how we curved the disty. Throttle response and average mileage is also up substantially on both combo's(mine's up around 20%/3mpg) and considered to be outstanding given the 500 and 400 horsepower output of these engines. If I stay out of the gas.. which is extremely difficult for me to do over an extended period of time because I absolutely hate getting gridlocked behind big-rigs for miles at a time.. my S10 Blazer gets over 20MPG and averages about 17-18 with minimal amounts of excessive passing speeds. As you can tell.. I'm more than overly impressed by the results and could easily go on and on about the merits of these types of ignition controllers.. but I'll leave it at that for now. You would surely not be disappointed should you ever decide to upgrade to this type of ignition controller. :Handshake
