HKS Twin Power vs MSD 6A etc
 

http://www.hksusa.com/images_products/L_2617.jpg

http://www.hksusa.com/products/?id=842

The HKS Twin Power (rotary engine model) is an ignition amplifier specifically designed for our cars that amplifies both leading and trailing coils. It is very popular on the 3rd gen cars, especially because there is a plug and play harness, but it's not that common on FC's. I recently switched from one MSD 6AL only on the leading coil (same as MSD 6A and similar to Crane HI-6 and Jacobs FC1000 basically) to the HKS unit. I'd like to argue here that at least for some applications, it's worth the cost due to the ease of installation, the physical size of the unit, and its lower power consumption.

Quick background: I am running a big street ported 88 Turbo II with a 60-1 T04S setup at around 18psi (race gas, low 11's AFR) and a Power FC for engine management. I was getting spark blowout with the 6AL on the leading despite running B10EIX plugs (gappable low cost race plug actually designed for bikes). I tried adjusting the gap, the dwell in the Power FC, nothing seemed to work. Given the FC's reputation for a relatively strong ignition system (FC coils are upgrades for FD's) I figured amplifying just the leading with an MSD box would be enough, but for whatever reason (maybe my coil is weaker than some people's? Maybe I'm just making too much power/boost? not sure) it wasn't doing the job.

http://www.sdsefi.com/msd1.jpg

At this point I had to make a decision. Do I install two more MSD boxes? Where would I even put them? The HKS twin power box is about 40% of the size of one MSD box, and it can amplify all the coils, whereas it would be a bit of a pain to wire in two more bulky boxes and keep the installation clean. I don't have a pic right now, but my box is located in the stock battery location. Clean soldering and careful use of loom etc will make the wires very hard to notice, which is true for both HKS and MSD, but it's easier for the HKS box.

Now, for the HKS unit, there are 5 total wires to amplify the whole ignition system:

3 go to the ground wires on the coils (1 leading, 2 trailing), spliced in
1 goes to ignition power
1 goes to chassis ground

Just one MSD 6A box needs I believe 6 wires (you have the cut the power and ground wires on the coils rather than just splice in a wire to the ground like Twin Power requires). So with 3 MSD boxes, that's 18 wires including three wires to the battery--except my battery has been relocated, so that's one more hassle of either tapping in to the main battery cable or running wires through the car. The HKS box is going to draw a lot less power too as all it needs is that one ignition switched power source rather than pulling a bunch of current from the battery like an MSD unit. Clearly the HKS is superior for clean installation just on the basis of wiring alone.

What about cost (Ted has raised this point in older threads, it is a very valid point)? Well three MSD boxes, purchased used for say $150 shipped each (I'm sure you can find them cheaper occasionally), is about $450. The Twin Power used to be really expensive ($600ish), but these days it's come down in price. HKS lists $430 on their website, but I got mine for $370 brand new at a local shop (almost $400 with tax). FD guys on the forum sell used ones for under $400. So the cost of amplifying all 3 coils is equal between the two options, or possibly even cheaper for the HKS.

In conclusion, if you need/want to amplify your whole ignition system, or if space and cleanliness of installation is a major issue for you, take another look at the HKS twin power. So far I'm happy with it, and so are a ton of guys who have FD's. For mildly modded vehicles with no ignition blowout problems (including just about any nonturbo application) it's not necessary to amplify all the coils (or any of them if you have no misfire), but once again the clean installation is nice. If you are going standalone you can also redo the entire ignition system with new coils etc which may make the HKS box unnecessary.

Worthy of archives

Now, I have no data to back this up, but when I was doing my research on ignition systems, I remember a comment that concerned me. Someone said that they plugged the hks into an oscilloscope and found that it indeed did not "amplify" the signal, but only messed with the dwell time. Is there any way you could confirm or deny this myth for the sake of proper information?

Thanks
~Tweak

All I know is that I don't get any blowout and I don't have 18 extra wires and two square feet worth of MSD boxes in my engine bay.

From the HKS website:


Now, clearly it works in a different way than the MSD boxes. On an MSD, you cut the power and ground wires to the leading coil (from the ignitor) for example. One end of each wire goes into the MSD box, and then the MSD's output wires go to the coil. The Twin power just has you splice into the ground wires of the coils (leading and trailing). I'm not sure if this is better or not from an engineering standpoint. I'm not sure if 3 MSD boxes will do a better, worse, or equal job compared to a twin power. I just know, as I mentioned, that the twin power fixed my problem with a cleaner installation than 3 CDI boxes and at a price that was competitive. If the Twin Power was still $600 I probably wouldn't have gotten one. I also could have used 1 MSD DIS-4 box (it's the top-of-the-line one they sell I believe), which should be able to amplify all 3 coils and have a 2-step feature, but those are what, $700+ ?

Yeup that is awesome, glad it did. I was just wondering on that statement, I was in no way meaning to "put down" the twin power box. :) Did you just end up buying a new one? I have been having the toughest time finding a used one, people just don't seem to get rid of them. :\

If anybody does have a twin power, and access to an oscilloscope, it would be awesome if they could post up some data. :)

Thanks.

the twin power was an awesome compact unit. had it on my old FC. when it had 1000cc secondaries with fmic, hybrid and all other power mods it misfired at high rpm. after installing the twin power with no other mods it cured all the misfiring issues. i didnt feel like my ignition system had issues prior to installing the 1000cc secondaries but my tuner highly recommended the twin power to me and it solved the issues without any issues before i installed my Power FC.

FWIW i dont even think i had to cut a single wire. if i remember correctly they came with ring terminals and i just bolted then to the corresponding locations. i may be wrong and i may have put them on myself it was years ago

arghx ive been looking around a bit at theses twin power ampliphers and have found most come with a 3rd gen harnesses or solumly sold for FD use how did you hook it up did you use the 3rd gen harness or did you make your own?
james

No, you cannot do this.
The DIS-4 was designed to trigger evenly spaced ignition events.
Trying to fire the assymmetrical ignition system with the trailings will cause it to misfire...all the time.
Someone mentioned the new DIS-4 can do this, but all rev functions are useless - I won't waste $500+ to find this out since MSD tech support are a bunch of idiots.

The HKS Twin Power is a "twin strike" ignition system.
It senses an ignition event, and it fires it's own ignition trigger shortly after.
This is why there is only one splice into each coil - one leading and two trailings.
The other two wires are just power and ground for the unit.
Yes, this is how HKS claims you will never experience ignition failure if the Twin Power dies - the system just reverts to how your stock ignition used to work.
Versus almost any other CDI box installed, if the CDI box fails, the whole circuit is interrupted, and you'll KNOW something is wrong.

FD guys claim the Twin Power is the shit.
I personally have a problem with such a small unit providing enough ignition power to handle such responsibilities.
If this unit is so great, why does some of the best CDI ignition systems (i.e. MoTeC / Autronic) still install in series?
Also, MoTeC and Autronic CDI boxex are HUGE compared to the HKS Twin Power.
I really don't have the time nor the money to experiment with the Twin Power, but anyone with an oscope can get all the data.

Yes, the Twin Power is very compact and easy to install - this is one of the reasons why the FD guys love it so much.

You should be able to buy a "flying lead" generic harness for the Twin Power to install into your FC.

Side note, MSD does make a box called a "Stacker 4" which basically does the same thing the HKS Twin Power does - installs the same: twin strike design.
I'm just tired of trying to get MSD tech support to offer any data on their crap, so I stop wasting money trying to find out for myself.


-Ted

^^ The box itself has a really short harness with one end of a plug. When you buy them brand new, it comes with a flying lead harness that plugs into the box's plug and has unterminated wires. If you buy them off the forum, I'm sure you could just cut the plug off the FD-specific harness and wire it in that way.

so it goes Box --> box's plug --> <-- flying lead harness or vehicle specific harness

^ Thanks for chiming in. I know you aren't a big fan of the Twin Power, and your reasons are understandable. I have been reading lately about some of the Twin Power's failing on some FD's. I don't know if it's the heat from the engine bay or the vibration or what. I have mine mounted next to the leading coil where the stock battery goes, so that should be decent protection from heat. I am going to maybe re-do my mount in a way that can reduce vibration (some kind of rubber damper or something).

I figured the DIS-4 could do it because it was mult-channel or something. I dunno how it works and my knowledge of the trailing ignition system is limited as well. A friend of mine had a DIS-4 (piston engine) and it failed on him very quickly. We pulled it apart and it was some kind of shoddy reman unit (even though he bought it new) with hot glue everywhere. So that kinda put me off from MSD shit even though I successfully ran a 6A on my nonturbo (which probably didn't need it anyway despite its relatively high output of 172rwhp).

I've only put 50 miles on the box so far but I'm still happy with it unless it somehow craps out on me prematurely. Since I am using more of the stock stuff (stock coils) it made sense for my application.

agrh ill be purchasing a twin power unit for my tii with in the next couple of week can u be kind enough to provide me a wiring diagram or maybe a picture of how and where you mounted and wired everything
thanx a ton
James

Does the 93+ wiring harness plug and play with our second gens also? or did you not use a harness at all?

NO.


YES, you need a harness.
HKS sells a generic flying lead harness.


-Ted

wheres the best place to purchase one of theses units and generic flying lead harness? directly from hks or is there somewhere else?

These days if you buy it brand new, the flying lead harness comes with it, it does not need to be purchased separately. The instructions it comes with are surprisingly good... it has a black and white photo and a diagram and everything. I mounted mine near where the stock battery goes (had already relocated it) near the leading coilpack. I glued some rubber thingies on the bottom from the hardware store in hopes that it would reduce vibration. It is annoying that there is only one hole for mounting the thing. I just used a self-tapping black screw. You are just tapping into four wires. i wouldn't use the crappy connectors that it comes with, strip the wires back (don't cut them, just strip them still attached) and solder.

I went to a local performance parts place and ordered part #43001-AK003 listed in the link at the top. It came with the aforementioned instructions and flying lead harness.

ditto. the wires from the harness were precut and the insulation just needed to be pulled off. i forget if it came with ring terminals but in any case that's what i used and placed them under the existing ring terminals on the coils

arghx i have a couple of questions for you. i an purchasing a unit w/ the third gen harness that i know i will have to cut up and rewire. i went through the instuction manual to try to figure ot everything before hand and reallized the instrutions dont accomidate for the extra ignitor on the trailing coils for the pfc. how did you hook it up did you spilt the two yellow wires to make 4 2 to each ignitor? thanx alot
james

I talked to Banzai Racing about that too. It makes no difference in the installation actually... the wires you tap into have not been modified by the trailing coil installation. When you pull off the trailing coil you'll see what I mean. Hook it up exactly as the instructions say.

ok i got u. does it matter which way i connect the yellow wire? and should should i just dis regard and cut the wires from the cars harness or do i just splice them in

for cheap there is a summit digital CDI that is comparable to the 6A, but probably better specs wise, its only 120 dollars, has more power output, and has dip switches for the cyl select instead of cutting a wire loop:
http://www.summitracing.com/streetan...C257A79A2E2%7D

i don't have the instructions anymore, but I know for sure that you DO NOT CUT the original harness wires. You strip them back and splice. I think there are two yellow wires, one that goes to each ignitor for the trailing.

does yours have two yellow wires or a yellow and a green wire for the trailing

arghx is there anyway you can take a look at the colors coming out of you box bc the rotary twin power instruction PDF shows there to be 2 yellow and a white and red but on the one im recieving there is red and white and yellow and green so I'm a not completely postive on how to hook if you could help me out I'd be greatly appreciative. Thanx
James

2 yellow, white, and red are are the colors on the flying lead harness which mine came with. I will have to go look at it if I get a chance tonight or tomorrow to see if I can come up with something.

I dynod my FD before and then after the HKS twin power was installed. I had the M2 ecu at the time so I couldn't tune the A/F. Since Brian had the ecu rich, with the extra ignition power, the car's hp/tg graphs shifted upwards for almost the entire dyno runs. I'll try to find the old post or graph that I had someone else post on the forum. If not, I'll try to find my graph again. It was also before I had an extra O2 bung welded into my DP, so I don't know my A/F ratio's for the before and after runs.

Did AEM EVER fix their ignition system they sold for the rotary?

Tim