Has anyone attemted to use this device on a rotary motor yet. It basically retards timing as your boost pressure increases. It also coms with a dash **** allowing you to retard from 1 to 3 degrees , per pound of boost pressure. A friend was telling me about it and i heard THE key word- Detonation resistence.
Any of the big boys have any experience???
JT

 

I too have seen this with much curiousity...I think it is generally for a nonEFI application such as a blow-through setup. I have seriously suggested this product....anything that allows for timing adjustment under boost is a nice tool. ........waiting for a chime....

 

Why couldnt you just tune your ecu to pull timing under boost?

 

Are you willing to buy three of them for all three channels of ignition?
And then adjust all 3 to the same setting?


-Ted

 

hhhmmm...Well, the unit I was looking at was a BTM that coexisted with the MSD 6a....so I assume you could use it on the leading or which ever side you had the MSD. Could the trailing be left alone and only use it on the leading???

Ya if we all had standalone EMS's then we wouldn't need these little gadgets

 

Im a standalone guy myself and dont have a need for it, i should have been more specific in my post. I was trying maybe to give some suggestions to the guys running carbed turbos.

 

Like ReTed Stated.

your gonna need three boxes...
and all three need to be set to the same amount of retard.

 

Actually you need to set the trailing to half the retard of the leading... Think about it for a minute.
...and of course if it's an FC you also need an adapter so the ECU won't cut off the trailing when it fails to see them fire.
You might be able to use a single BTM on the trailing by intercepting the trigger signal going into the trail coil pack, but I don't know if the trigger edge is correct for a BTM (and a bunch of other "minor details" too).

 

i have in in my FD. u wire it into your leading ignition. with stock computer it does not let u do this adjustment. so u can use the **** it brings to adjust how much to retard timing or u can put a specific resistor and just set it and forget it. thats how i use it and it works great.

 

Boy, either people get paranoid, or they have no idea what they are doing...


-Ted

 

How EXACTLY does this thing retard the timing...?

How would you use it on a blowthru using a distributor...???????

 

If I remember right, the BTM uses a pressure input and an adjustable **** retards timing anywhere from 0 to 3 degrees per 1psi of boost.

I've messed with a 6BTM before, and the **** was pretty sensitive on adjustment.

These are used as crude retard devices, and really shouldn't be used on a rotary which came stock with a turbo.



-Ted

 

Ok so the BTM gets it's reading from pressure/boost, but then what does it do to actually retard the timing...???

I don't think you can use this thing AT ALL on a blowthru set-up utilizing a S3 (for example) distributor. The stock S3 distributor has VACCUUM advance pots for both trailing and leading... but what other way is there to retard ur timing while driving if ur not running EFI....???? That is why I don't think this thing can work on a carbed set-up.

 

In new light I beleive a simple vac line from the advance to the manifold to make sure there is no advance during boost could be a simple answer, and some hi octance. This thing does seem scetchy..........

 

All in the electronics.
For a strict distributor/coil ignition, it's almost impossible to implement.


-Ted

 

Thats EXACTLY what I thought and I had NO CLUE... Which would render it useless to me right now.

 

the btm is most often used when a turbo is added to a na. i put one on an old turbo saab to replace the barbaric step function boost retard control.

it is normally used to interupt/delay the grounding wire to the coil, from the distributor or ign module. IIRC, they do make special versions for the miata and viper, that use direct coil ign's with no distributor.