turbulence

ok, i tried searching and nothing came up for smt...so
what's the deal wit this? i remember when ha.com was running, people found out it would work, but you still couldn't adjust timing more than +/- 7 degrees because the ecu would think there's a misfire. has anyone figured that out?

a_gut

I'm not sure anyone has gotten timing to work at all with the SMT-6. The SMT-6 expects a certain timing signal and sends out a certain signal. The problem with our cars is the transistor that fires the high power signal to the coils is built into the ECU, where in a standard setup that transistor circuit is outside the ECU, and the SMT-6 normally modifies the signal going from the ECU to that circuit.

When I installed my SMT-6 this weekend I got a CEL, not sure what it was for (the understaffed autozone nearby didn't want to send a person out to read it for me), but when I changed the wiring so that the camshaft position sensor signals (theres 2) do not go through the SMT-6, the CEL didn't come back up.

I've been reading a lot about timing modification on cars with similar ECU's as ours, and it seems there is definately a way to do it. People successfully modify timing with a MSD unit, which is in between the ECU and the coils. Also, there's a setup that's been done with the eManage that modifies timing in a similar way. From what I've read, the eManage setup for our cars (or those with similar ECU-timing setup) requires an inverter->eManage->ignitor->coils. The inverter is required because the ignitor inverts the signal, so it is necessary to invert it again so the signal to the coils is correct (unless you can get a leading edge triggered ignitor which does not invert the signal).

What I haven't read about is how to properly scale down the power of the signal from the ECU. The signal from the ECU is around 12A I think, if you hook that up to your piggyback computer that much current will likely fry it. That power has to go somewhere, and from studying electronic circuits, I think you can just stick a low resistance, high wattage resistor in parallel between the ECU and the piggyback. This would bleed off most of the power of the singal and allow only a small current to flow into the piggyback. What I don't know is the input resistance of the piggyback and the required input current to the piggyback.

For the SMT-6, I'm not sure the inverter would be required, as there is an ignition output wire that is an inverse of the normal ignition signal wire, so you could just hookup whatever signal wire that will make it work. The added benefit of the above circuit would be you could send a higher power signal to the coils giving better spark with the ignitor.

If I had a scope, I could figure out some of this stuff a lot easier.

Also, from what I've read with the stock ECU, if you change timing more than 7 degrees it will throw a CEL no matter what your setup is, unless you reflash the ECU. Has anyone been able to change timing more than 7 degrees using the MSD? I may be wrong in this area.

silvertibbs

Here's a huge discussion we had on it not too long ago.

http://www.rdtiburon.com/forum/showthread....&highlight=SMT6

Unfortunately SMT is only 3 letters and you need at least 4 to run a search.

Try SMT6 or piggy-back/E-manage/SAFC

Agarwal

It's indeed possible to modify timing with the SMT6, even without igniters. It can be done with igniters too.

I'll point DenisST78 to this thread, since he knows his stuff about the SMT6 (being a reseller and using it in his car and playing with timing with it).

OdessitPashka

A_gut, I know there is two inputs for the crank shaft sensor, for A and B sensor or something. Which one did you disconnect? I'm a little lost of what you did.

Did you advance your timing at all?

a_gut

At first I had both signals going through the SMT-6 (cps -> smt6 -> ecu). After getting the CEL and reading about timing issues, I assumed this was what was causing the CEL. So, I changed the wiring so the cps signals go directly to the ECU, and SMT-6 is tee'd into this to read it only, no modifying it (cps -> smt6 & ecu). The CEL didn't come back, so I think it's safe to say the first setup caused the CEL. I didn't change timing at all, I had all maps zero'd out.

Did DenisST78 open up the ECU at all? If you can tap into the connection between the ECU signal and the transistor circuit that amplifies it inside the ECU, I can see how that would work.

OdessitPashka

so you are saying that you can't adjust timing with SMT6 and our ECUs?

a_gut

No, I'm saying the way I currently have it wired I cannot adjust timing with my SMT-6. I used the wiring diagram on Tim's website.

If DenisST78 can adjust timing and will share his setup that'd be great wink1.gif.

OdessitPashka

Which wiring diagram did you use? the one that Tim has on his website or something different?

Denisst99

you don't need to wire the SMT6 to the cam sensor,
you only wire it to the crank sensor

our cars use a balanced crank sensor signal wich is kinda "odd"
i'll get a look at Tim's website to see wich diagram you're speaking about

but anyway, lets go to the facts,
i'm indeed playing with the timing on my car (2.0 N/A)i'm adding 8° at idle to smooth out the idle because i've got cams in the car,I'm also adding timing else where in the timing map

i do "sometimes" get a CEL for a bad crank sensor wich is quite odd i can use the car 2 days in a row and the CEL won't come on and sometimes the CEL will come on after 15 minutes of use
i'll have to play a bit more with it to confirm it's related to the SMT6 or the car it self
when i'll have an empty spot i'll get the car in the shop and mess around with it a bit

The code that our ECU throws in is an informative code,car still runs nice and pulls hard so it's "just" annoying,not "bad"

i didn't open up the ECU but one buddy of mine tried it with an E-manage without any luck (taping in the transistors)

give me a few days and i'll try a few test/tricks on it


edit,
just got a look at the wiring diagram, it will work, just keep in mind that a and b signals are from the crank sensor not related to the cam sensor
this diagram wil llet you cheat the MAF a bit like the SAFC or can be used with extra injectors to clamp the MAF signal
keep in mind alos that by using beta 2 cams you're changing the "timing" point of the cam sensor, so it might affect on how much you can pull or add timing