So I went to the dyno a few weeks ago and put down 230whp 229wtq.... not too bad but not great.

I am using a TS ecu for a 96 on my 97 + cattman headers + z32tt cat + 2.5'' catback. When it was on the dyno it was really lean down below 4k @ wot.... i think it hit 15.5-16.1 or something rediculous, but no pinging, and the dyno guy said his wideband was kinda old and dirty so it may not be reading super accurately.

So I ask my mechanic (a very knowledgeable guy) about the piggy back that I've been waiting forever to install (smt6).

He told me that even with it installed and a new tune, it wont help much because its using the 3.0 ecu. Basically he's saying I'm going to run lean regardless and power gains arent going to be huge.

This doesn't make sense to me because I always thought that piggybacks could make drastic changes in fuel tuning.

I know the 3.5 ecu is better for 3.5 motors duh, but is the 3.0 ecu really gonna hold me back???

Forget about the vtcs I've already learned to deal with that but cmon! The piggy should help me get at least another 20hp right?

 

I dont know much about the smt6, but no matter what you use to tune the car, getting that car to richen down to around 13.5 will net you a good amount of power on top of what you have now. And that goes for whatever piggyback you use. Get on the dyno and try to get that line as flat on 13.5 as you can.

 

what he said^. yea, its a different motor but still using the same fuel maps that came with the car/3.0 motor. Only thing you have different is a bored out motor and a little different air/exhaust flow.


so in short, you CAN get the a/f change. even with a AFC.

The only problem though, which i think he was referring too was the fact that the car runs in closed loop under either 2500rpm or 3000rpm. Even at WOT. So no matter what you adjust it too, the ECU is going to eventually correct it back to the stock fuel map.



Anyone step in and correct me if im wrong. Im just going off what i though/believe

 

Ill tell you that once I finished tuning fuel with my EU, I felt quite a change. I am also running a 3.5 with 3.0 timing/ecu/etc. I find it odd that you would be running that lean when you have the bigger injectors with the 3.5l. My car ran way rich after the swap. I have had to pull a lot of fuel just to get it to a steady 13.0 A/F. Install the smt6, and you will be greatful you did. Also, do you yourself have a wideband installed in your car?

 

what fuel psi are you running and what rpms is it running lean at
you may need to turn up the psi alittle with a afpr to richen up the a/f down low and pulling fuel up top with the smt6

 

Your setup should not be running that lean, even with a VQ35 swap. Id see if you have some fuel problem before messing with the SMT6.

And yes you can tune the SMT6 to add or remove fuel as needed. But it only makes changes past 3500 RPM, below that the ECU ignores the changes and runs in a closed loop mode.

I still use the SMT6 on my car and it still works great. I don't need any A/F fuel correction at all. As the car runs a near 13.0 flat from 3500 to redline. However I do enjoy the extra 8 WTQ and 13 WHP from the timing advance.

 

You have smt6?!?!?! Ok please help me.... I've tried to run this thing wired up according to the ecu pin out for EU. It wont work though... Something with the crank sensor. I DO have the black box with the filter on there so there shouldn't be any problems, but I think the 3.5 sensor reads inn opposite polarity from the 3.0 .

And is it true at WOT the ecu will overcome my smt? That would be extra homo.

 

You arent using the 3.0 Crank REF and Crank POS sensors?

 

I'll start working on that little project for you this week, should be in touch with you well before the end of the week. I'm disgusted though, power gains from eliminating the 3.0 throttle body will pwn running 5.5 ecu and probably even vtc!

However I agree with others, there is something else wrong here. tilley put a 3.0 fpr on your car, which is all well and good, except with that set-up you would still be running just a hair on the rich side, just a hair. If anything it's probably the dyno's wideband.

 

Had to bump this thread cuz its been years and still no progress on my part...

 

A lot of people should relate to that thread with the amount of 4.5gens.

I'll get the thread started and linked on npclub.com to get people to know it exists.

 

Why not sell that other thing and get an EU? There is a lot more support here and countless people have run it on the 3.5. In closed loop the ecu uses the feedback of the o2s to try to maintain a 14.7 afr. In open loop the car runs richer and mainly uses airflow feedback. With the EU you should be able to tune and get your afrs where they need to be and you should gain power. Also the TS ecu has an aggressive timing curve so hopefully you can get it on a scanner and see what it's really doing.

 

interesting, i have an untuned 4.5 , fp at about 37 psi, pahy tb, stock maf, and i, taking fuel out until 4500 then adding , more as i get closer to redline to be safe since i dont know how rich im running , i have seen ajcools dyno, and he seemed to be running rich up until around 4500, then leaner, i have looked at 95blkmax posts and he seemed to be taking fuel out all the time?? would be nice to get a no adjustment 4.5 dyno and wideband graph uphere from someone

 

Just get a wideband, don't be lazy now.

 

We have a wideband now but havent hooked it up to the laptop yet to log data yet. We did do a few quick run just watching the gauge and we were in the high 11's low 12's most of the time. Also we still have small issues to fix before we do any serious tuning anyway.

Also Im not sure if we're friends on FB but my brother did tell me about your request and thats fine with me. Maybe this wednesday or friday. The car is running pretty strong right now so it should be interesting.

 

im going to add you, next time you dyno would be cool to be there. i really need a wideband and stop being lazy for sure