Tuning my 347 with rear mount turbo

[Dono]

I had it under the truck. It was a super straight shot for the air flow, other than the sensitive sensor being under there, I thought it was an awesome spot. It was actually really well protected.
Don Lasota didn't like the distance and asked me to move it, so I did.
I can't move the maf anywhere else due to pipe size restrictions thru the wheel well. Real-estate is super hard to come by.

I think I'll have to install the solenoid (I already have it, so its not a super big deal) and pull the intake elbow off to drill and tap for a nozzle.
The solenoid I have is an older version of this: Snow Performance Electronic Solenoids 40060

 

[boominXplorer]

Your going to get a ton of turbulence from the throttle plate and get inaccurate readings from your maf setup how it is. If you can get about 3" more away from throttle body I'd think you'd be ok.

 

[Dono]

The maf actually reads pretty good. It's just placement of the water/Meth nozzle that was creating an issue for me.
I currently have the nozzle in the elbow (Right by the pressure sensor), and the maf is not happy with it at all. I need to move the nozzle.

 

[Dono]

Meth nozzle moved, I just need to wire in solenoid power to the pump power, and ground.
I hid the solenoid behind the cruise control on the fender. Fit pretty good there.

 

[vroomzoomboom]

i was just about to say why not put my old elbow on, and put the nozzle in there, but.....

 

[4pointslow]

It needs a nitrous nozzle right next to it. LOL

 

[Dono]

i was just about to say why not put my old elbow on, and put the nozzle in there, but.....

I'm still stuck on the fact that I only have 2.5" piping from the back of the truck. I just don't think there would be a gain in going bigger on that elbow.

The good news is that this motor is behaving better timing wise. It's not detonating as soon as it's breathed on.
This is awesome for many reasons, including header temperatures. Super low timing had been causing me all kinds of heat issues.

 

[vroomzoomboom]

I'm still stuck on the fact that I only have 2.5" piping from the back of the truck. I just don't think there would be a gain in going bigger on that elbow.

The good news is that this motor is behaving better timing wise. It's not detonating as soon as it's breathed on.
This is awesome for many reasons, including header temperatures. Super low timing had been causing me all kinds of heat issues.

i totally agree with you on that. the reason why i had said to use it was it might have been easier to drill into it. and if it got destroyed no big loss. good on the heat thing as well. remember went i mented not one, but 2 heater boxes because of that lol

 

[Dono]

Your right Tim, there's always some stress tapping a hole you just made. I'm no pro at this stuff.
The thread pitch is 1/8-27 which is the same as pipe thread, so as long as I threaded the hole ok, I can easily plug it if I need to. I know that since I used a 1/8 pipe plug to seal the hole in my intake pipe.

The good news is that I didn't end up cursing myself with a fresh hole in the elbow that I needed to somehow plug.

 

[4pointslow]

Have you been able to retest and did the maf/hesitation clear up?

 

[Dono]

No re-testing yet. Probably Monday.
Wot logged rich with no meth spraying, then I 'misplaced' my dongle between work and home.
My plan is to set wot a/f at 12:1, then add the water/meth.
At least if something happens to the spray, I'll still be in a safe range.

 

[Dono]

I know it was the w/m as I moved the adjustment so it wouldn't start spraying till 8psi+ and the hesitation was gone.
I did have a closer look at my wot log, and my shifts were at about 5100rpm, and shift point was set to 5800. The relative throttle position to closed was only just over 700 at WOT. I just finished adding a couple of zip ties to the end of the throttle cable, and I am betting that my shift points will go up to where they should be.

 

[gmanpaint]

Yes! $0.50 zip tie mod ftw!!

Funny how something so simple, can make such an impact.

Time to unleash the Krakken

 

[Dono]

The zip ties did help. WOT throttle is now at 760. Although, I did end up with some binding somewhere (Even though the throttle cable was still loose) and had a high idle. I removed one of the zip ties, and all is well. I just need to remember that wot is a throttle position of 760 when tuning.

Also, moving the water/meth nozzle fixed the bogging (sort of).
I can see in the log's now that the maf isn't getting odd ball readings like it was, and the bogging is gone when the meth starts.
I have a different bog now, its right at about 5800 rpm, even though the rev limiter is set at 6500. I'm not sure what that's about yet. I lowered the 1-2 and 2-3 shifts slightly.

I was getting a little bit of chatter from the knock sensor at the upper rpm's, and now that's gone with the w/m added. So, I added (removed?, lol) a degree of timing up top.

Also, I wen't from an a/f ratio of 12:1 to 10.6:1 with the w/m added. Is that too much w/m? I re-tuned for 11.6:1.

 

[gmanpaint]

Did you lose boost when it bogged?

 

[Dono]

good question...I was busy hanging on to my shorts.

I'm sure It did, but I'll have to do another pull to see.
The weather is not great, so its been difficult to do a good pull. I really need an evening that I can find a stretch of highway that isn't very busy (and dry roads).

 

[vroomzoomboom]

I really need an evening that I can find a stretch of highway that isn't very busy (and dry roads).

Let me know if you find a road, what time and day. I’ll come along and bring evil

 

[4pointslow]

Take a video camera too!

 

[Dono]

I still managed to end up with a bog/rpm limiter, or whatever is happening on the way home last night. Its kinda funny how people get all riled up and want to get in front of you when you do a quick wot pull. lol
I'll have to try to remember/find what happens when the rev limiter is hit. I'm guessing the injectors shut off.
I can add injector duty cycle to my log and see if that's the case.

I also moved to a smaller water/meth jet to make sure that too much liquid spraying isn't the problem. I wen't from a #5 (5.94gph) jet to a #3 (2.77gph) jet. There's a substantial difference in gpm rating. Since I'm using low boost anyway, If a #3 jet fixes the issue I won't argue with success as I know that cylinder cooling is still happening and my installation efforts are not wasted.

 

[Dono]

ok, motor is running strong.
I was still fighting a seemingly random p0300 random misfire code.
I tried everything mechanical.... A few times I thought I had it fixed.

What I was starting to notice is that the code would only get thrown if I started driving without thoroughly warming the truck up.

I started with start-up fueling and carefully adjusted the fueling in open loop at initial start. Big table based on time since start, and coolant temperature. Took some time, and I did make start-ups way better. No joy on the p0300 codes though.

So, I started looking at spark at start-up. Look at the table I found. "Maximum Allowed Spark Table Cold Start"

Spark limited to 15, even after 90 seconds of warm up time. That's crazy low max allowed timing. So, I'd really need at least 5 minutes warm-up time before driving to see reasonable cruising timing numbers.

So, as yet another experiment (And I knew I did not want the timing retarded like that), I followed the recommendation and set the whole table to 50 so there would be no timing retard based on start-up.

BOOM! Fixed. No more P0300's. This time I'm 90% sure. It's been a week without any codes.
I guess this motor is running that much closer to the edge and is more temperamental. I never had this issue before this motor, and I know this table was never touched in the past.

This was a pretty exciting find for me. I think I can check one more gremlin off the list.

Another thing to make note of is shift points. I was making my shift point at wot based on the thinking wot was the top of the table giving the value of throttle position (TP) at 1020. In actual fact, I only see 773 throttle position as wot when logging (Yes, the throttle body butterfly valve is opening all the way). I guess that explains why I seem to short shift at wot.

This is fixed now.
I added a TP field of 800, and set my desired shift rpm. I set it a bit below what I actually want, as the shift takes a bit of time. I'll creep up more as I get more comfortable.