Microtech Area is for discussing Microtech systems

Microtech Coil Question

Old 03-02-11, 05:19 AM
  #1  
Full Member
10 Year Member
Thread Starter
 
extreme_rotary's Avatar
 
Join Date: Nov 2003
Location: Chester Springs, PA
Posts: 239
Likes: 0
Received 0 Likes on 0 Posts
PA Coil Question

Hey i was wondering if there are any suitable replacements for the bosch coils that come with the microtech system. I blew one out, and would like to try a different kind.
extreme_rotary is offline  
Old 03-02-11, 11:15 PM
  #2  
Rotary Enthusiast
iTrader: (26)
 
Join Date: Mar 2009
Location: Clayton NC
Posts: 1,066
Received 0 Likes on 0 Posts
you can probably just use MSD coils. maybe something like this http://www.amazon.com/MSD-Ignition-8.../dp/B000COUP18

or http://www.atlanticspeed.com/product...idcategory=119

Those will probably work fine. Lots of people use the Blaster SS coils and they are cheap
Sandrock is offline  
Old 03-03-11, 09:36 AM
  #3  
Two doritos, on a stick..
5 Year Member
iTrader: (2)
 
Join Date: Oct 2008
Location: calgary alberta canada
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
I'm using two FC3S trailing coils with the ignitors removed to allow them to function with the microtech and x4 box. Its a simple modification, widely done and pretty reliable from what I've seen!
abtosway is offline  
Old 03-03-11, 11:19 AM
  #4  
501 WHP Club
iTrader: (18)
 
Sammy Built's Avatar
 
Join Date: Feb 2008
Location: England, UK
Posts: 481
Received 4 Likes on 4 Posts
same here t2 coils
Sammy Built is online now  
Old 03-03-11, 03:34 PM
  #5  
Senior Member
5 Year Member
iTrader: (11)
 
drifting in drifting's Avatar
 
Join Date: Feb 2008
Location: drifting .pa
Posts: 368
Likes: 0
Received 0 Likes on 0 Posts
The stock coils are said to be better than the bosch
drifting in drifting is offline  
Old 03-04-11, 12:49 AM
  #6  
Corn Fed FD
5 Year Member
iTrader: (1)
 
tony94s4's Avatar
 
Join Date: Mar 2008
Location: fort worth
Posts: 407
Likes: 0
Received 1 Like on 1 Post
I am using IGN-1a race coils with my lt10s, I deleted the x4 box

not sure if I can post link from another forum, if a problem mods can delete the post

http://www.efi101.com/forum/viewtopic.php?t=6269
tony94s4 is offline  
Old 03-13-11, 11:09 AM
  #7  
Full Member
10 Year Member
Thread Starter
 
extreme_rotary's Avatar
 
Join Date: Nov 2003
Location: Chester Springs, PA
Posts: 239
Likes: 0
Received 0 Likes on 0 Posts
So to simplify the situation, I can purchase Blaster SS coils, and hook them up to my mircotech box, and eveything will be okay? I see people talking about boxes and everything, and i just want to have a reliable spark. I'm only runing 15psi, and it breaks up randomly around .7 bar.

What kind of dwell time should i be using on these new coils?
extreme_rotary is offline  
Old 03-13-11, 11:11 AM
  #8  
Full Member
10 Year Member
Thread Starter
 
extreme_rotary's Avatar
 
Join Date: Nov 2003
Location: Chester Springs, PA
Posts: 239
Likes: 0
Received 0 Likes on 0 Posts
Oh, and if i use the stock FC3S trailing coils, what "modification" needs to be done? Cuase i'm 95% sure i have a few coils laying around!
extreme_rotary is offline  
Old 03-13-11, 01:50 PM
  #9  
87 SE WITH S5 T2 SWAP
iTrader: (11)
 
joeylyrech's Avatar
 
Join Date: May 2004
Location: allentown pa
Posts: 2,070
Likes: 0
Received 0 Likes on 0 Posts
Sorry to highjack your thread but what about running aftermarket coils with a LT8S that is setup to run stock coils? I guess that you have to keep the stock ignitors to fire the aftermarket coils if you dont have a x4 box.Is that possible?
joeylyrech is offline  
Old 03-13-11, 09:01 PM
  #10  
Two doritos, on a stick..
5 Year Member
iTrader: (2)
 
Join Date: Oct 2008
Location: calgary alberta canada
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Extreme rotary, as long as they are direct fire coils with no built in ignitors the x4 box will work with them just fine. And really thats the answer to your second question too! If your using FC3S coils they have to be trailing coils (four of them all told, naturally). The reason is because the ignitors (the large metal part) can be removed from the coil (plastic part labeled T1 or T2). Then you simply disconnect the wires between the two you have a fantastic coil to use with an x4 box!

Im not up on the Lt8s joey, but if im not mistaken it has no ignition booster ( thats why it can be used with stock coils). I can't really say if the ignitors can be used with aftermarket coils, most people seem to prefer an Accel or Msd box for that purpose dont they?? intriguing!
abtosway is offline  
Old 03-13-11, 10:04 PM
  #11  
Full Member
10 Year Member
Thread Starter
 
extreme_rotary's Avatar
 
Join Date: Nov 2003
Location: Chester Springs, PA
Posts: 239
Likes: 0
Received 0 Likes on 0 Posts
So if i mod my trailing coils as you describe, i can wire them directly up to my microtech ignition box? Is that what i am understanding?
extreme_rotary is offline  
Old 03-13-11, 10:28 PM
  #12  
Senior Member
5 Year Member
iTrader: (11)
 
drifting in drifting's Avatar
 
Join Date: Feb 2008
Location: drifting .pa
Posts: 368
Likes: 0
Received 0 Likes on 0 Posts
Yes the coils are marked + - .Take 2 sets of trailing coils pull the covers off and wire them up.
drifting in drifting is offline  
Old 03-13-11, 11:01 PM
  #13  
talking head
5 Year Member
 
bumpstart's Avatar
 
Join Date: Apr 2008
Location: Perth, WA, OZ
Posts: 2,775
Likes: 0
Received 2 Likes on 2 Posts
t2 trailing coil,, each 0.7 -0.8 ohms

HEC 715 =0.41 -0.45 ohms

that should be raising alarm bells to all those that "think" or "wish" the t2 coils produce a stronger spark
,, well,, this primary resistance is the corner stone in a triangle of factors used to determine the output
others include the secondary resistance and the number of winds

however,, primary resistance is pretty much the best indicator ,, and those t2 coils are not much better than generic bosch gt40 coils,, and not a patch on a HEC715 or HEC716


i know full well that leading coil SLIDFIS falls well short of the power of a trailing coil DLIDFIS,, which falls short of a bosch HEC715 DLIDFIS
( i run LPG fuel, under boost , and that soon finds which spark is weakest )


i also fit various combos to various cars according to the owners desires and get to tune them

and i know the hard way
that similar micro equipt cars with t2 trailing coil packages , stock coil packages,, and HEC coil packages all hit a different level of boost /flow before having spark issues


PS

if you blew out a HEC715,, there is a few more options--

1: try the modern versions of HEC716,, they are slightly lower again in primary resistance,, but require new leads as they have a male anode end on coil
new versions do not have the "pistol" look of old and have a revised layout to prevent arcing across the rear poles

2: if sequential ignition ECU and set up the right dwell ( more than 5.5 ms at 13v ) then MEC 723 coil or MEC 720 coil ( ca20 coil ) can get 120 mJ of spark
( while the HEC 715 is around 90 mJ at 13v and 3.5 ms )

Last edited by bumpstart; 03-13-11 at 11:19 PM. Reason: PS
bumpstart is offline  
Old 03-14-11, 07:30 AM
  #14  
Corn Fed FD
5 Year Member
iTrader: (1)
 
tony94s4's Avatar
 
Join Date: Mar 2008
Location: fort worth
Posts: 407
Likes: 0
Received 1 Like on 1 Post
Originally Posted by extreme_rotary View Post
So if i mod my trailing coils as you describe, i can wire them directly up to my microtech ignition box? Is that what i am understanding?
u will still need to use the x4 if u mod the t2 coil to dumb coil,
if u whant to delete the x4 u need to use the coils that I use or any lsx style coils that take + falling edge to fire
tony94s4 is offline  
Old 03-14-11, 07:38 AM
  #15  
Corn Fed FD
5 Year Member
iTrader: (1)
 
tony94s4's Avatar
 
Join Date: Mar 2008
Location: fort worth
Posts: 407
Likes: 0
Received 1 Like on 1 Post
Originally Posted by bumpstart View Post
t2 trailing coil,, each 0.7 -0.8 ohms

HEC 715 =0.41 -0.45 ohms

that should be raising alarm bells to all those that "think" or "wish" the t2 coils produce a stronger spark
,, well,, this primary resistance is the corner stone in a triangle of factors used to determine the output
others include the secondary resistance and the number of winds

however,, primary resistance is pretty much the best indicator ,, and those t2 coils are not much better than generic bosch gt40 coils,, and not a patch on a HEC715 or HEC716


i know full well that leading coil SLIDFIS falls well short of the power of a trailing coil DLIDFIS,, which falls short of a bosch HEC715 DLIDFIS
( i run LPG fuel, under boost , and that soon finds which spark is weakest )


i also fit various combos to various cars according to the owners desires and get to tune them

and i know the hard way
that similar micro equipt cars with t2 trailing coil packages , stock coil packages,, and HEC coil packages all hit a different level of boost /flow before having spark issues


PS

if you blew out a HEC715,, there is a few more options--

1: try the modern versions of HEC716,, they are slightly lower again in primary resistance,, but require new leads as they have a male anode end on coil
new versions do not have the "pistol" look of old and have a revised layout to prevent arcing across the rear poles

2: if sequential ignition ECU and set up the right dwell ( more than 5.5 ms at 13v ) then MEC 723 coil or MEC 720 coil ( ca20 coil ) can get 120 mJ of spark
( while the HEC 715 is around 90 mJ at 13v and 3.5 ms )

great info Bumpstart,
si if runing MEC 723 coil or MEC 720 coil in sequential with the x4 whats the highest safe dwel to run with x4?

also have a friend with ltx8 with built in ignitors that has spark issues
wahts the most dwel you would recomend with the above coils?
tony94s4 is offline  
Old 03-14-11, 09:24 AM
  #16  
talking head
5 Year Member
 
bumpstart's Avatar
 
Join Date: Apr 2008
Location: Perth, WA, OZ
Posts: 2,775
Likes: 0
Received 2 Likes on 2 Posts
great info Bumpstart,
si if runing MEC 723 coil or MEC 720 coil in sequential with the x4 whats the highest safe dwel to run with x4?

also have a friend with ltx8 with built in ignitors that has spark issues
wahts the most dwel you would recomend with the above coils?
the best info is in the megasquirt and Dtec articles where some of these coils are directly compared

in the Dtec ignition coil PDF
at 13.4 V, 7A current is achieved with 3.5 ms if HEC715 ,, and this is 91 mJ on the ignition coil dwell calibration paper

at 13.4 V , 7A of current is achieved with 5.4 ms if MEC 720 ,, and this is 114mJ

at 13.4 V, 7A of current is achieved with 7.3 ms if MEC 723 and this is 120 mJ

as you can see , 7a has made a different energy intensity in each example ,, and taken a different rise time

indeed ,, if you subject a HEC 715 to 5.4 ms of rise time you will have more than 9A of current,, and possibly a driver or coil failure
( but a big spark for a short period )

also to consider
,, is that a sequential ignition rotary ( CNP ) has 13.34 ms of rise and fire period between events at 9000 rpms
,, while a wasted saprk one has 6.667 ms
and total saturation periods that are longer than that are not desirable in a wasted spark application

this is why the HEC 715 was initially best choice when ECU's had inbuilt igniters and wasted spark ( digi 2 pro )
but also why there is other coil options for sequential spark high revs if you wish to play the dwell settings

its also why if you have an ECU with only duty dwell ,, it will burn some coils and not others
( cause if set for 70/30 dwell time and use as CNP or sequential igntion at low revs you can force some coils past 10A )
bumpstart is offline  
Old 03-14-11, 05:40 PM
  #17  
Full Member
10 Year Member
Thread Starter
 
extreme_rotary's Avatar
 
Join Date: Nov 2003
Location: Chester Springs, PA
Posts: 239
Likes: 0
Received 0 Likes on 0 Posts
Wow. All this talk is WAY above me. I found my coils, they are out of a '91 N/A. Will they still work, or no? And what is an "x4" box? My microtech box is LT10S. So i'm just a bit confused about all this different talk with the coils. I did get that if you tell me these N/A trailing coils will not work, that i can use the updated bosch coils (HEC716). Now Bumpstart said that i need to rewire them because they are different. Are we talking ignition wires, or a simple mod to my wiring harness in order to literally hook up the coil?

Last edited by extreme_rotary; 03-14-11 at 05:47 PM. Reason: addition
extreme_rotary is offline  
Old 03-14-11, 06:48 PM
  #18  
Full Member
10 Year Member
Thread Starter
 
extreme_rotary's Avatar
 
Join Date: Nov 2003
Location: Chester Springs, PA
Posts: 239
Likes: 0
Received 0 Likes on 0 Posts
Gotcha; ignition wires need to be different. Okay. Now, i can't seem to find anywhere online to buy any of these coils except for the HEC715. I'll have to make some calls tomorrow. I'll let you know. I think i'll try for the MEC720's if I can find them around here. If not, i'll have to Ebay myself a pair of HEC715's.
extreme_rotary is offline  
Old 03-14-11, 07:20 PM
  #19  
87 SE WITH S5 T2 SWAP
iTrader: (11)
 
joeylyrech's Avatar
 
Join Date: May 2004
Location: allentown pa
Posts: 2,070
Likes: 0
Received 0 Likes on 0 Posts
The x4 box is the igniter box that MICROTECH uses to fire aftermarket coils if you ecu is programmed to do so,if not you have to run factory coils and your na coils will work fine.
joeylyrech is offline  
Old 04-07-11, 01:45 PM
  #20  
Full Member
10 Year Member
Thread Starter
 
extreme_rotary's Avatar
 
Join Date: Nov 2003
Location: Chester Springs, PA
Posts: 239
Likes: 0
Received 0 Likes on 0 Posts
I just bought blaster SS coils since they are readily available here. Any idea what dwell time i should be setting?
extreme_rotary is offline  
Old 04-11-11, 01:04 AM
  #21  
Corn Fed FD
5 Year Member
iTrader: (1)
 
tony94s4's Avatar
 
Join Date: Mar 2008
Location: fort worth
Posts: 407
Likes: 0
Received 1 Like on 1 Post
Bumpstart,

finaly got the car running with the ign1a race coils with built in ignitors,
I ditched the x4 running them straight from lt10s,

so far I am very pleased with them, the car's response and drivebility is great
only at 2.75ms dwel for now, I havent boosted yet,

how ever I am having problem when I turn the ignition they fire and some time I get
small back fire,
the last back fire I had was little stronger and it bent my TB,

I thought my iac valve got stuck open but was surprised to see the tb buterfly bent at a minor pop,

is there a fix for this problem?
Attached Thumbnails Coil Question-coils.jpg   Coil Question-bnt-tb-2.jpg   Coil Question-bnt-tb.jpg  
tony94s4 is offline  
Old 04-11-11, 01:14 AM
  #22  
Corn Fed FD
5 Year Member
iTrader: (1)
 
tony94s4's Avatar
 
Join Date: Mar 2008
Location: fort worth
Posts: 407
Likes: 0
Received 1 Like on 1 Post
Originally Posted by extreme_rotary View Post
I just bought blaster SS coils since they are readily available here. Any idea what dwell time i should be setting?
not sure on the dwell for msd, but make sure your x4 is still in good shape,
when i blew my coil last time the x4 went toast also
tony94s4 is offline  
Old 07-16-15, 07:22 PM
  #23  
Junior Member
 
Join Date: Jun 2012
Location: Beaverton, OR
Posts: 35
Likes: 0
Received 0 Likes on 0 Posts
OR Help

So I know this is a very old thread, but can someone please answers this for me?: I currently have a microtech LTX-8, and old microtech/bosch hec-715 coils, as far as I know I do NOT have an X-4 box. I would like to switch to stock coils, do I have to order an x-4 box, or can I run stock coils straight off of the microtech LTX-8 like I am with the bosch coils??[/B]
revunlimited114@hotmail.com is offline  
Old 07-20-15, 11:29 AM
  #24  
Rotary Enthusiast
iTrader: (1)
 
13btnos's Avatar
 
Join Date: Oct 2004
Location: VISTA
Posts: 790
Likes: 0
Received 3 Likes on 3 Posts
Should be able to wire them straight because the LTX series are the older units with built in igniters before they switched to the X4/X6 external boxes.
13btnos is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
rgordon1979
3rd Generation Specific (1993-2002)
39
12-27-17 10:09 AM
sctRota
Old School and Other Rotary
7
11-10-15 12:57 PM


Thread Tools
Search this Thread
Quick Reply: Microtech Coil Question


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: