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Re: Megajolt installation Firenza 2000SL

PostPosted: Fri Apr 06, 2018 9:29 pm
by fistfullofV5's
1972nail wrote:Hi Dave, Do you have an update for this thread? I'm interested to hear how you've got on.

Hi again David and apologies as I've only just found your post. The car has not been on a rolling road as yet and has only had some off road runs but is working very well on the Megajolt. I'm running a slightly modified 2.0 XE map with 35 deg maximum advance at the moment and the engine is tolerating it very well and revving very cleanly with a few pops and crackles on the overrun. I've set the cranking advance to 9deg as it seems to make life a bit easier for the starter motor. Aftermarket ecu use isn't for the purist admittedly but you do get precise control,but I've still got lots to learn.
Regards, Dave.

Re: Megajolt installation Firenza 2000SL

PostPosted: Sat Apr 07, 2018 8:54 am
by 1972nail
Thanks for the update. It sounds like you've got too much part throttle or closed throttle advance dialled in. The 8.5 CR Slant 4 can't take much more than 6 deg whereas a modern twin cam engine can take much more without problems.

35 degrees sounds OK, the 1800 engine had 32 degrees and 2300 engines had 36 degrees as their maximums. However a tuned 2300 with raised compression (HPF) used a 32 degree distributor. Low compression Bedford CF engines had about 42 degrees. All car engines were fitted with 6 degrees vacuum advance and maximum mechanical advance took place around 3250 to 3750 rpm, depending on the application.

Re: Megajolt installation Firenza 2000SL

PostPosted: Sat Apr 07, 2018 4:43 pm
by fistfullofV5's
1972nail wrote:Thanks for the update. It sounds like you've got too much part throttle or closed throttle advance dialled in. The 8.5 CR Slant 4 can't take much more than 6 deg whereas a modern twin cam engine can take much more without problems.

35 degrees sounds OK, the 1800 engine had 32 degrees and 2300 engines had 36 degrees as their maximums. However a tuned 2300 with raised compression (HPF) used a 32 degree distributor. Low compression Bedford CF engines had about 42 degrees. All car engines were fitted with 6 degrees vacuum advance and maximum mechanical advance took place around 3250 to 3750 rpm, depending on the application.

Thanks for your input David, I'll get the laptop connected when I'm off work and see if I can dial in the vac advance /load a bit better. I'll have to check the map to see what advance it's using on the vac , as I think it's likely more than 6 deg.
Regards, Dave.

Re: Megajolt installation Firenza 2000SL

PostPosted: Thu Apr 26, 2018 7:59 pm
by 1972nail
Was just researching my project and came across this which may be of interest.



When reading these you must remember that the distributor rotates at half crank speed and therefore crank speed and BTDC ignition advance at the crank are double what is shown here. Even though vacuum advance is not related to engine speed you still need to double the figures to get actual crank advance as it is distributor advance that is given here.

Re: Megajolt installation Firenza 2000SL

PostPosted: Fri Apr 27, 2018 8:33 am
by 1972nail
Almost forgot, you still need to add the normal static ignition timing.

Re: Megajolt installation Firenza 2000SL

PostPosted: Fri Apr 27, 2018 5:13 pm
by fistfullofV5's
1972nail wrote:Almost forgot, you still need to add the normal static ignition timing.

Thanks David, no information is ever wasted :thanx:
Regards,Dave.