sunshineacid

ive got a friend with a 1st gen putting down about 200 horsies down w/ an n/a s5 and dual webbers (+ a few misc mods) who runs MSD. i personaly love msd on cammed v8's (my old setup on my prev car) however, hes got to run dual MSD packs (not coils, complete systems) in order to supply his 7 with enough spark over 6500 rpm. i cant remember, but i think hes got one system for leading and one system for trailing (although it makes more sense to me to have one for each rotor)
does anyone have experience w/ MSD?

im looking at the BTM personaly. its rated at high rpms (plus the timing features under boost are nice)

RETed

If you want to waste your money on an unnecessary boost retard section, go ahead be my guest.

The ECU already does this, so more ignition timing retard on top of the stock retard just kills power.

The search function allows used of the keyword "msd" - what is your excuse for not using it?


-Ted

walken

iTrader: (6)

why would you have the computer controlling ignition if you had an msd box?

sunshineacid

i dont need an excuse, if you paid attention to my post, you would see that it wasnt asking about boost retarding, i was asking if people had any experience w/ the newer msds, designed for compact cars, as my friend had to use two msd 6's in order to power his 7.
thank you.

bingoboy

compact cars? are you refering to that silver msd box that's called the sport compact something or other? if so, its the exact same thing as an msd 6a except that it's in a different box. i had an msd tech tell me this when i called them to ask about it.

as for what ted said...i'm not sure what he was thinking about, brain fart maybe :P

if you want to have the regular msd box powering all of your plugs, you will in fact need 3 boxes. one for leading and one for EACH trailing. however most people will see little to no different running the trailing boxes and stick with only a leading one.

turboii87rx7

on my n/a, i only have one msd 6a box... and everything seems to be fine.... is this possible? lol

ajsuper7

i put a 6al on my n/a, worked great. it pulled a little bit nicer on the top of the rev range and had better mpg, unfortunally i had it located on top of the radiator shroud and my stock radiator burst one day and fried the box. but i am looking into getting either another msd or maybe the jacobs rotary ignition pack(rx7.com) once i finish rebuilding my car.

scathcart

You only need one box for the leading coil. You don't need boxes on the trailings, it doesn't really accomplish anything extra over a single box on just the leadings.

scathcart

I read your post, and I read Ted's. Ted is right.
The MSD BTM unit retards timing with reference to boost. As the stock ECU and any aftermarket unit already does this, why bother using the boost timing unit? its a waste of money.
The BTM was designed to be used on distributor cars that didn't have a factory form of forced induction.
The BTM isn't rated for any higher rpm use than any of the other 6-series boxes. The BTM has no place on a TII.

No where in your post did you ask about newer MSD boxes, you told us you wanted to run the BTM.

Do a search for "MSD" and you will egt all the information you need.

RETed

WTF???

Did I read it wrong, or did you say...

"BTM" in reference to MSD is either their stand-alone boost retard box or the "6BTM".  Unless I'm missing something, please tell me WTF did I miss.

Either or of these units retards igntion timing versus boost reference and are basically useless on your FC.

You even mention "plus the timing features under boost are nice", which means you already have a Turbo II or are thinking about turbo'ing (SC?) your NA.  If you want to retard ALL the ignition channels, you'd need *THREE* of them to handle all three channels of ignition.  If we're talking about the 6BTM, that's like *$1,000* worth of electronics!  Now either you are super rich, really ignorant, or the rest of us have no clue what you're trying to do.


-Ted

sunshineacid

sorry if my question was unclear. (genuine, not sarcasm) im not clear on the BTM, except that ive been told/read/something that it is designed for higher revving smaller displacement engines, in fact, i think thats almost exactly how it was explained to me. sorry if i struck a nerve or something, i was just wondering if anyone had experiece w/ the MSD series. the 7 uses lots of gas for its displacement, (thus explaining one a the reasons the ports were relocated in the renesis) and a bit of unburnt fuel does leave the combustion chambers w/o ever getting detonated. with the long shaped chambers in the rotary, and the multiple spark output capable of burning more gas in the chamber, it seemed to be a way to free up hidden hp.
i just wanted to know if someone had experience w/ MSD, and it appears both turboii87rx7 and ajsuper7 do.
so thanks for the info guys.
again, sorry if i struck a nerve. wasnt my intention

scathcart

The BTM is just one version of any of the MSD 6 series ignitions. It is not any more powerful than the much cheaper MSD 6AL. The 6BTM is just a 6AL with a timing retard function that retards timing with reference to boost. Since the stock ECU already does this, this feature is completely useless. Thus, there is no sense in spending the extra money on the 6BTM when the 6AL when accomplish identical Multiple spark discharge/capacitive discharge.
It is the Multiple spark discharge (what MSD stands for) that nets the results in idle stability and fuel economy (which is active below 3000 rpm) while the single, powerful capacitive discharge spark is what gains the upper rpm smoothness by giving a more powerful spark which can decrease the chance of the spark blowing out.

I have also installed several MSD units, as well as Crane. They do exactly what their tasks intend, but the extra bells and whistles such as timing retard and rev limiter are completely useless*.

*retard becomes handy in Nitrous installations, and the rev limiters can be used if three boxes are installed, on both leadings and trailings.

Zach McAfee

The stock ignition system is already stout, but you can gain a little with a MSD6a box and a couple blaster coils. I gained about 3hp, so whether it is worth it or not is up to you.

sunshineacid

ahh, cool beans. thanks for the clarification =)