Whipple 700sci Mods
04-14-2010, 01:41 PM
#81
Registered
Join Date: Oct 2000
Location: Fresno, CA, 93722, USA
Posts: 1,436
Likes: 0
Received 4 Likes
on
4 Posts
On the early 600-700 they were mapped for 91 or higher but if you put 87-89 in them the knock sensor would pull the timming back so you could run them without damage, now the new ones you can run them on 89 and still make "their" max power. With the Whipple stuff I know he wants 91 or higher but if you have to buy lower oct. will it still back the timming off enough to run them ?
04-14-2010, 03:49 PM
#82
Registered
Join Date: Jan 2003
Location: Stafford Va.
Posts: 2,806
Likes: 0
Received 0 Likes
on
0 Posts
You still have knock protection, but in reality, it will only help, not save your motor. Knock sensors sense detonation, which is the event, the reaction is the system reducing timing and richening the cylinders. This works, but the system is constantly trying to put the timing back, so if it just keeps detonating, then your sooner or later gonna have trouble. Mercury reduced timing 2 deg's to make them 89 (600 87oct) safe but in reality, thats how much of safety margin was left in them. With more boost, its harder to run low octane. If you stay low on the boost, you would be fine, or you can just change the pulley and bring power down. But you can't make 960 on 89 on this application. So yes it can be done, but not at the same power level and you should still be conservative with the throttle.
04-14-2010, 04:18 PM
#83
Registered
Join Date: Oct 2000
Location: Fresno, CA, 93722, USA
Posts: 1,436
Likes: 0
Received 4 Likes
on
4 Posts
You can also use Torco octane booster. I don't like most other versions, but the Torco stuff is top notch and really boost the octane, 5 to 7 full points. On the cars, we bump boost up 2-3psi and 2-4deg of timing with 1 can per 20 gallon.
