VEMS Community Forum

Technical => Triggering => Topic started by: rossi46numberone on December 13, 2011, 09:18:28 PM

Title: Why sequential????What improvement????.............
Post by: rossi46numberone on December 13, 2011, 09:18:28 PM
Hi,
What would be the improvement by going from wasted sprak to sequential ignoring the fact that the coil's will work a half time with less heat for the same Dwell time?

Michele.
Title: Re: Why sequential????What improvement????.............
Post by: MWfire on December 14, 2011, 11:43:42 PM
Gains are if you have long duration cams.
Title: Re: Why sequential????What improvement????.............
Post by: uzelac on December 15, 2011, 08:01:35 AM
Can you explain this ?
Title: Re: Why sequential????What improvement????.............
Post by: MWfire on December 15, 2011, 08:56:42 AM
If you don't have problems with wasted spark( ignition in intake mainfold), you will gain nothing with more coils.
Title: Re: Why sequential????What improvement????.............
Post by: rossi46numberone on December 15, 2011, 11:46:59 AM
ok....
And what about the injector angle curve table?
It seems that we need to run sequential to be able to work with that table.
Can you explain what is the utility of that table,what improvement?....
Thanks ,

Michele.
Title: Re: Why sequential????What improvement????.............
Post by: uzelac on December 15, 2011, 12:50:43 PM
Now that you mentioned it, i do have problems with ignition in intake manifold.
I noticed it only at idle.
Is this problem common, is it only on idle/low speed or i probably have same problem on higher speeds.

Btw. i plan higher duration cams, i suppose that will only cause more problems.
Title: Re: Why sequential????What improvement????.............
Post by: MWfire on December 16, 2011, 09:19:54 PM
With high duranation cam wasted spark can ignition mixture in intake. Also if you have nitro it's better to use cop coils(in sequential mode).
For injection, with sequential mode you have only advantages. More torque, less consumption, more power if you have big injectors(400+cc for 150HP on 4cylinder), better idle ...
Title: Re: Why sequential????What improvement????.............
Post by: andreNL on December 16, 2011, 09:29:39 PM
You can use the distributor, you have sequential spark then  ::)
Title: Re: Why sequential????What improvement????.............
Post by: uzelac on December 16, 2011, 09:30:20 PM
Ouch, damn .
I haven't got rid of old problems, now you gave me new one, and it is serious one.
I still use stock 240' cams and plan to put 300' instead.
If i have problem now, what will happen with the new ones :/.
Secondary trigger, there is no other way.

Thanks nevertheless :)
Title: Re: Why sequential????What improvement????.............
Post by: MWfire on December 16, 2011, 09:32:41 PM
on WOT and high rpms you will not have problems with wasted spark.
Most problems will be at idle and low load and low rpms.
Title: Re: Why sequential????What improvement????.............
Post by: uzelac on December 16, 2011, 11:04:46 PM
Good to hear, thanks :)
Title: Re: Why sequential????What improvement????.............
Post by: fphil on December 19, 2011, 10:33:15 PM
I am considering doing wasted spark on the odd fire V6 engine of the Maserati biturbo
The issue is that the best match couple gives 30deg at intake for one cylinder when the other is on the firing TDC. Indeed this may lead to problems at idle ... I need to test.