Holley Systemax II Race Kit

[Rick 91GT]

Originally posted by 8950LX
I have installed a few Systemax kits with excellent results. Out of the box performance is very respectable. Just don't use the cam in the kit with EFI. Lunati which is a Holley division supplies the cams for the kits. Unfortunately Holley didn't take the advice of Lunati engineers when it came to the specs for the cam. The problem with the cam is the lobe separation angle is to narrow (107deg./102intake centerline). Vacuum and idle quality suffer drastically,the surging will drive you nuts. A Lunati rep. claims the engineers where never able to get the test car to idle reasonably enough to work with EFI. I was told by the same rep. that Holley offers another cam for customers unhappy with the kit cam. Also for reference,when Holley designed the Systemax kit it was tested on a GT with an AODw/3500 stall and 4.10 or 4.30 gears,30lbs. inj,75mm Pro-M. Holley makes no claims to have tested the Systemax kit on a 5spd setup. Use a cam grind from any of the popular cam companies and you can't go wrong with the Systemax kit.

Goodluck,
Bill

The cam Bill is referring too is the non-emissions cam, which is the cam I ran in the beginning. ALthough I never had surge issues it had one hell of a lopey idle and vaccum was very low (due to 64 degrees overlap). I swapped the cam out because it just wasn't enough cam to get me where I wanted to be. Holley does offer the kit with the emissions legal cam that has a more friendly 112 centerline, just ask for this when you order the kit or be prepeared to buy another cam to max out the combo, just remember th new kits come with 2.02 valve heads. I thing I strongly suggest is get 30# injectors, I had issues with the 24# going lean up top the swap to the 30# made the whole car smooth out and run so much better.

I think some of the surging issues are due to a 75mm Pro-M with 24# injectors. Pro-M could not get the fuel curve exactly right with a 75mm and 24# if you run 30# you are ok, for some reason they just could not get the 24# calibration right and it runs rich down low and lean up top. Many guys have had this problem, the swap to the 76mm was a good buy for me.

We installed the non-emissions cam (.509/.509 218/224 102/107) in my buddies stock motored car, and it idles great and really woke it up, the car runs nice and strong with the stock pieces. I think the Holley pieces make that the cam not run as nice since the flow so much more air. He has 4:10 gears, stock everything else but exhaust, and he has a BBK cold air kit and underdrives.