txhokie4life

My Motec48 system is using LS1 ignition coils for my 911 RSR.

Nice thing about them is they are easy to source.

Mike

Hilton

Other thread with good map info (thanks to Ken):

https://rennlist.com/forums/928-foru...k-xdf-tp5.html

(including xdf files to read stock maps in Tunerpro).

blau928

Do you know at what temperature this was done...???

blau928

Mike,

What are you using to ignite the coils? Bosch units on the 928, or another?

I will be using a CDI unit... Basically a Motec CDI-8 which has a CDI plus the IEX, so I can use inductive, or a CDI 2 wire coil.. (Mine is made by M&W... They make all the motec stuff..)

Thanks,

blau928

Hi Colin,

That's interesting...

I can set a fixed dwell time in the Motec M8.. Not sure if the M48 or other units most use here can do this..

Couple questions:::
How many wires on the Cayenne coils? Do they have an ignitor on them (a la smart coils)?

You mentioned that there are many dumb coils that you know of to choose from, which brands are those? Are they COP/Pencil coils, or are they Coil near plug with plug leads to the coil towers?

Thanks,

blau928

Hi Mike,

Thanks for the note.. I realize the LS coils are easy to source and can be used with the unit..

However, if I can, I would like to go to the newer pencil type coils so I can omit the plug wires, and just have the the CDI box with the IEX inside wired to the pencil coils..

I also don't have that much space in my engine bay, and 8 LS coils take up a lot of space...

With all that said, it is still a backup as they are plentiful and inexpensive, and work.....

Thanks,

blau928

Thanks Hilton,

blau928

Anyone ever used these, or know someone who has experience with these?

They are supposed to be decent, and better than many other coils on the ricer scene..

http://www.weaponxperformance.com/we...oils-c-13.html


Any of you using the Denso Pencil coils? I believe they are found on many Hondas and some Lexus cars. They are supposed to be the standard for OEM pencil coils..

Thanks,

Lizard928

Richard,
Those weapon X coils will work but are a dumb coil.

The cayenne units are "logic" coils with 4 wires. But if the switching signal doesn't have a minimum of 18mA they will not fire! This is during cranking as well. I've faught with each instal having to tweak things up and down. I wish they were an easy coil to fire, but alas they are not.

blau928

Thanks, I think I will stick with the plan to source some decent dumb pencil coils..

Besides, the box provides 115MJ of energy, and that should fire in a tornado.. I'll keep everyone updated as I progress..

Best,

BC

Technically, the testing sheet I posted shows they do not need 18.

Mike Simard

I have Bosch coils and separate Bosch igniters which are similar to the 928 but I have 8 of them.

IIRC there are a handful of possible CDI coils for you and they are specific aftermarket things but I don't know what's out there right now.

Have you called Motec? The ability to call them anytime is the reason their products are highly regarded!

blau928

Hi Mike,

Thanks for the note..

I was trying to see if anyone here has had good experience, so I can gauge their feedback.

I have a list of things I am making for my call to Motec. I have not contacted them as yet about my new list......

Thanks,

ptuomov

No, I don't know. However, I wouldn't be shocked if it would be the standard day in the UK.

Let me ask you a question, though. Why does it matter at what temperature the measurements were taken? I think that the sensor is supposed to give the same voltage for the same air mass flow rate, regardless of the density or temperature.

blau928

Hi Tuomo,

The MAF sensor will give the mass (weight) of the air as you described.

However, To calculate the mass of air in a MAP system, you need the temperature to convert it to Kpa (absolute pressure). Temperature is affected with density (pressure), and vice versa.. a la boyle's law..

If I know the temperature and the mass of air at the temperature it was measured by the MAF, then I can calculate what the absolute pressure is of the mass of that air at the given temperature. When I do that, I will be able to get the MAP values, and easily convert the MAF voltage in CFM/KG per min etc to Kpa, as the MAF voltage value will tell me what the mass of air is at the given temperature...

I already know the engine's swept volume per cylinder, total displacement etc.. So, if I can get this measurement, I can have a MAP - MAF converter scale and see where the engine actually is compared to the calculated values and VE etc...

I am trying to understand the factory calibration for < 100Kpa values, or the fatory calibration using MAF values, but converted to MAP with the help of mssrs Boyle-Mariotte...

Hope that helps with my reason for wanting the temperature..