Thread: Any projection experts out there???

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Got a couple of questions about the Holly projection setup.

Primarly I'm wondering who versital the programing is, and what is required to change it if necessary for different altitudes and and temperature ranges. i.e. would it require reprograming in a temperature range from 60 degrees to 120 degrees and altitude changes from 5000 feet to 1000 feet (it's for a stationary 454).

Does anybody know of a WEB site that can give the tech information on the system.

Thanks

Mod note: moved to engine tuning

We've got a 454 in a stationary applications to power various pieces of equiptment. The whole setup is occcasionally relocated to different locations where can be a pretty wide variance of elevation and temperature from one to another. One month it might operate at all day long at an elevation of 1500-2000 feet and the day time temp might not get above 60 degrees, and next month it could be at a location that's at 5000 feet and the temp will be 120 degrees by noon.

It currently has a carburator (which with those extremes should really be rejetted to run properly at the differnt extremes). There has recently been some discussion about switching to a sytem such as the projection in order to overcome this. The main thing I'm trying to figure out is wether there would still be tuneability issues. I.E. would the system have to be "re-programed" for the different extremes or is the programing versital enough to compensate.

If you havent found it yet, here is the manual for the unit.

http://www.holley.com/data/Products/...7-6%20scan.pdf

It's a pretty crude unit, the only sensor is a coolant temperature input (plus an optional oxygen sensor input). There is some limit to the horsepower rating, I think. The stock Chev TBI unit is more sophisticated but I dont know how well the Chev unit would do in a stationary application (usually stationary apps run constant rpm). There is also the Chev marine TBI that you see on egay sometimes. All would probably be better than a carb anyway.... is cost a factor?

A better solution is the Edelbrock TBI...there is one on egay (item 290135644662). These units have a MAP sensor and an air temp sensor so they would be much more flexible. The price is higher though. It uses a GM controller.

mike in tucson