Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - problems with running my supercharged 351w
View Single Post
  #54 (permalink)  
Old 10-21-2012, 08:13 PM
F-BIRD'88's Avatar
F-BIRD'88 F-BIRD'88 is offline
Yada Yada Yada
Last photo:
Join Date: Oct 2005
Location: Ontario, Canada
Posts: 9,284
Wiki Edits: 0

Thanks: 5
Thanked 399 Times in 393 Posts
If you cannot under stand locked fixed timing that does not move 36deg BTDC for start up. How the fug do you think you will understand and program the computer timing tables???

The timing required will stay near 0 change right up untill boost is add at which point the motor needs LESS timing

same at idle as at WOT but must retard as blower boost comes in to avoid detonation on pump gas.
What is frigginhard to understand.???? the computer has to have a reference point.
It has to be somewhere inorder to move from that somewhere.
That somewhere is 36deg BTDC. Since you do not have a pressure sensor to sence blowermanifold boost to retard the timing in reference too, the computer is as dumb as you are.
So then RESET the ignition timing (fixed) at 26deg BTDC to start testing under boost @WOT on the dyno and creep up on the tune up.. 26 to 32deg BTDC

You have something that you don;t need and have no concept on how it needs to be programed.
The only processor you need is a spark retard box. Go buy the jets nd the power valve plugs I listed before testing. Get someone wit a clue to set them ignition timng. set all tables to 0.
No change. Run the engine at 36deg BTDC. Then move the crank mag pickup so the timing is 26deg BTDC. (using a timing light) Now you are reay to start WOT testing. The computer tables do no tneed to be set up because YOu don;t have a clue what the tables should be anyways.
A roots blower motor is not like other motors.
You wil make tmore power and it will run better with blower carbs and a simple ignition system with boost retard.
FOR A fraction of the money. and a fraction of the bother. YOU DON:T HAVE MONTHS of engine dyno time and chassis dyno time AND $10000000 's to spend on dyno ,drive mode testing to create a fuel map or a timing map etc etc etc.
You are wasting your timing and money for nothing and are hell bound to end up witha damged burned up motor. Find someone who has a clue as to how these roots blown motors actually run.

I don't have the time or patience or the 10pages of text to explain how the world works, how engines run, how roots blower motors run and why they need 36deg timing at idle. ( Stick you head near the carbs and wack the throttles open when the blower is cold with the timing set as you think it should be and you will get lesson #1 on blower motors.
You will have all that time till your hair and skin grows back to think about what just happended. (if you don;t damage the blower rotors from blower back fire. You will then run out of money and buying pistons trying to figure out why I say to start timing at 26deg BTDC under boost on pump gas. @ some 14lbs boost. ( a really dumb boost level to start tuning at.
GET SOME RACE GAS. Consider yourself for---warned ...

36deg BTDC for start up/warm up 26 to 32 dg BTDC for testing under BOOST.

Get a distributor ....lock out its mechanical advance curve and stick it in the motor.
A computer is just a dumb machine unless you have a clue how and why to program its.

Last edited by F-BIRD'88; 10-21-2012 at 08:28 PM.
Reply With Quote