Last_Mohican

I have heard that MSD's BTM does not work very well with the 450 /AFC hack.(due to more low end timing advance) If this is true how bad is it and is a BTM good enough for a FMU/fuel Pump setup. Any help would be greatly appretiated!!!!! I really wanted to go SFC or SMC+ but since i cant chip my ECU for timing retard i need to know that a BTM will work or else i must go the crappy FMU route.

Last_Mohican

bump please help

Dr.Boost

I don't see why it wouldn't work. What are you worried about timing in the low end for? The btm will retard the timing enough by the time you hit the top end. You shouldn't need to retard the timing on the low end. So, do you have a AFC or any kind of fuel management yet? I would avoid the whole Vortech fmu deal. That is just ghetto IMO. Why not run the fpr vac line through the cab and squeeze it when you hit boost? That would save you $75 for the FMU
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Last_Mohican

well i plan on buying a smc+ and 450dsms or a AFC and 450 dsm's as soon as i can confirm that if i buy a BTM i will be able to get the timing issue straight. I really want to buy the stuff now but i dont want to buy it a then have to go a whole different route because my timing is messed up. Only reason i was worried was because i was about to give the smc+ and 450's a go when i heard that with the hack timing needs to be controlled by more than a BTM. I think it was the moderator Joseph that said this but i am not sure.

-Ty

Dr.Boost

The BTM is adjustable. You can make it retard your timing to the point of stalling if you want it to. Just turn it up a bit more than most people if you are worried about it. I don't use a BTM. I just retarded the timing a little. No worries.

BTW I would get the S-AFC over the SMC. Thats just my opinion though.......
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fork

I'm pretty much in the same position as you. I know the BTM only retards timing when it sees boost and you can adjust the ratio like 1 degree retard per pound of boost, 2 degrees per pound, so before you make boost, like at idle, it will not change the timing. The problem with the afc hack is that when you cut the voltage from the map sensor ( thats what leaning out the afc does) the ecu also advaces the timing. The only fix I've heard for this is to get the ecu chipped with a retarded ignition map. Thats where I'm at now trying to find out how to do this, I can install a chip but I'm not really sure how to burn one. So

Last_Mohican

SEE THAT IS WHAT I REMEBERED. i mena i know all about the BTM i understand how it works. The problem is that aparently like he says te hack actually advances timing before the car even sees boost rendering the BTM useless. Man this blows casue i have an OBD2 accord not easily chipped . I guess i have to change to OBD1? will i lose anything going to OBD1?

Last_Mohican

Well unless i can use the knock sensor and fool it so it retards timing before boost. that might be a good plan actually but how would i go about this. It is perfectly logical but not sure how i could do it.

Tom-Guy

BTM retards based on pressure above atmospheric... so you get a couple degrees knocked off your total timing at, say, 4 psi... when you are running the AFC hack at 4 psi you are 10 degrees advanced of FMU w/ check valves at 4 psi is the whole problem. You knock 2-3 degrees off with the BTM, but you are still ~7 degrees advanced.

Dropshop got the setup - AFC and BTM - to work GREAT. He had mutant torque coming in very low in the rpm range, on a high mileage engine, with complete reliability. He also did a lot of tuning by wideband, had an EGT, and had a pretty good grasp on tuning theory.

AFC and BTM works - but if you aren't wholly confident that you are "the man" and want to lay your engine on the line to prove it, then it's not for you. Besides, a chip burner is much cheaper than a BTM, and people start looking cross eyed at you because you can chip ECUs.

Last_Mohican

would i be able to chip my OBD2 with a burner. Did you read what fork said about the andanced timing before boost? I mean i have pepole keep explaining to me how a BTM works and i have known how it works before i started this thread. If you say somone has gotten it to work i might try it anyways if i can chip my ecu. If i could chip my obd2 where would i get the Burner? thanks for all the help guys!