LS2/LS7 coils and DWELL Time

[Matt]

Next on my TODO list...

[skylinegtrhr]

Here is some good info about coils

http://efi101.com/forum/viewtopic.php?t ... c&start=20

When time comes I'll by Lances coils... A lot of satisfied customers

[Matt]

Ive updated nistune 1.2.1 to display dwell times. Tested in er34 and s14 prior to the accident

Adjust the dwell vs volt table to use larger coils

(ECUs have a pulse processor which reduces pulsewidth as rpm increases. The dwell vs rpm table is to compensate for this to maintain a fixed dwell time. Most Nissans about 2ms. Dont adjust the rpm table)

Increase dwell volt for larger coils and watch the dwell duty length gauge. Updates every 10 seconds

Currently support s13-s15, r32, s13 ca18. Can add others on request.

limits i mentioned before will not affect how we set that table either

[Nuyskov]

[quote="Matt"][/quote]

Hello, Matt!
Don't see such option on ER34 and WC34 - didn't make it?

[Matt]

It is on the big gauges on R34. Latest test version. Just put another updated version up yesterday

[supersayianjim]

so which table do i adjust now again?? the duty cycle or dwell time??

so if i put 3.0-4.0 across the table for the dwell time, would that do it??

[supersayianjim]

is this the right way to go about it??

[Matt]

Not sure what you are trying to achieve doing that.... you need to raise the dwell time if you want longer pulses

See what I did with my R34 to get about from 2.5-3ms to about 5-6ms (this is from memory so watch the gauge... don't use my example verbatim)

[supersayianjim]

but wait. aren't I supposed to be between 3-4 ms for optimal firing?? and in that chart above do I copy the red line or the purple line?

[Ben C]

The y axis scale is in percent,not milliseconds, so you are not setting a specific dwell time.

You increase the original values as per matts post. Otherwise if your method was correct the stock dwell time would be enormous.


The dwell time is increased as battery voltage drops to ensure the coils are charged fully.

[Matt]

You can see from what I did (in red) that I effectively doubled the dwell time (%) compared to factory (in purple)

[supersayianjim]

kick ass matt. with that dwell adjustment I made 350whp at 15psi and stupid rich at 9afr. will include the map I used later.

[Matt]

Good stuff. I have the feeling the coils are on the way out on my RB25 NEO so this may be an option now

[STATUS]

The Coils to get are:
C1512
D514A
OEM part 12573190

These are all part numbers for the same denso coil. Lots of testing has been done on all the variants and this one does not false fire (effectively uncontrolled added advance) at higher dwell levels like the others. There are plenty of documented engine losses due to this artificial advance (sometimes upto 20 degrees)

They retail at $280 for 8 so you will have 4 or 2 left over either way. We have made over 1000rwhp with them and they are ultra reliable.

We just finished a GTR with nistune and had no issues at around 500rwkw with these coils and modified nistune dwell settings.

http://www.ebay.com.au/itm/CHEV-LS2-LS3 ... add&_uhb=1

[Ben C]

The Coils to get are:
C1512
D514A
OEM part 12573190

These are all part numbers for the same denso coil. Lots of testing has been done on all the variants and this one does not false fire (effectively uncontrolled added advance) at higher dwell levels like the others. There are plenty of documented engine losses due to this artificial advance (sometimes upto 20 degrees)

They retail at $280 for 8 so you will have 4 or 2 left over either way. We have made over 1000rwhp with them and they are ultra reliable.

We just finished a GTR with nistune and had no issues at around 500rwkw with these coils and modified nistune dwell settings.

http://www.ebay.com.au/itm/CHEV-LS2-LS3 ... add&_uhb=1

Thanks for sharing that. They are the type I have which I believe are the coils on the current commodore.



If you could share the modified tables that would be great, as from my experience it seems both tables need adjusting to get an optimal result.

Thanks
Ben