I decided to try some dyno tuning yesterday. The steady state ve and maf tuning didnt go well and I ended up going back to stock ve table and the street tuned maf. We did a couple pulls and I played with timing some. My stock pull I had 259hp and 356tq. My final pull was 316hp and 421tq so I think that is some pretty nice improvements for now.
very nice gains
the boat dealership I work for has an 8.1 suburban , 2 8.1 avalanches , and an 8.1 reg cab with 4.10's and an allison It has been tempting to spend the credits , especially on the avalance I have been using a lot lately
PB's 1/4 mi 12.21 117.75 trap ,1/8 mi. 7.779 93.99trap , 1.949 short time (FWD W body)
These 8.1s are night and day after tuning. After I flashed the factory tune back in to go down to the dyno it was amazing how much better it was to drive with a tune.
We went from a 99 with 454 and were amazed how good the 8.1 felt with stock calibrations. It seems like as I have tuned this it keeps getting a little better and a little better so you don't notice the improvements until going back to stock!
How were trying to do steady state on the dyno?
Which Dyno?
Any increase in MPG after the street tune?
It turns out that I did not ask the right questions at the local speed shop. When I asked them about tuning on the dyno I asked if it could do steady state and they said yes , it was a mustange dyno and it could simulate hills and everything. After getting strapped down to the dyno I got everything set up to do ve tuning afr% err and explained to the operator that I would like to get up to speed in 3rd and hold that while increasing load to fill my histogram. He was a little confused and had not seen tuning this way but could see what I was trying to do so he was trying to hold the dyno and kept talking about the dyno having like train brakes and getting hot. You could smell the brakes from the dyno and it kept getting a shudder either from the dyno or my rig not sure which? I gave up on ve and we tried maf but it was not going well either. Thats when I decided to go back to stock ve and street calibrated maf. I then talked to another local tuner and he said that shop didn't have a load bearing dyno and steady state was not possible on their dyno. I am not very happy but still felt good about the improvements over stock.
I have not really tried to improve on mpg yet, mostly been working on performance but we do get about 12 mpg mixed driving and about 14-15 on hwy. And when towing 8-10,000 lbs we get around 8-9 mpg.Originally Posted by jeff
A bit of a strange story regarding the dyno tuning, initially describe the Mustang dyno perfectly. Mustang's software to operate the dyno is much like HPT software, I find both complicated.
If it is a Mustang you can select a speed such as 50 mph. The dyno will hold that speed so you can easily tune the MAF table & hit & hold every cell. You can do the same with RPM, select a column from your VE table, hit & hold every cell. Or for the VE you can pick a speed that is the equivalent to the RPM column you want. Either way will allow to tune those tables very nicely.
The good part is the power gains you made, nice!
Too bad about the tuning side as it does work very well.
Would like to see the tune. A buddy has an 8.1 Crew cab
Any way you could post it..
Thanks...
those are huge gains
Here is the tune that I have been using and made 305hp 411tq with. The only difference between this and the one I made the most power with on the dyno was an additional 4* timing in the WOT area. I did have a little KR at the end of that pull though with the increased timing. I would only look at my tune as a idea of what to change on your buddys truck. Different rigs take different tunes. I was also about 3% richer than what I was commanding on the dyno pulls. I plan to get my fueling more inline and return to the dyno.
Here is a hpl of the 305hp pull.
I am wrong. It is a dynojet dyno. I am not sure what model and I have no idea why I thought it was a mustang dyno. I got confused somehow between talking to different shops I guess. Still not sure how that changes the steady state tune problems because they did say it could do steady state calibration.
if its a dynojet. with the eddy.. the load comes from a electomagnet.. it gets hot but takes a bit to do...
Being my first time on a dyno I didn't know anything about the dyno part. The dyno operator had also never seen tuning the steady state stuff like I was trying to get done. They normally have a local guy do the efi stuff.
So what did you do, just MAF tuning (street) and some timing advances? 87 octane? I have a Yukon 8.1 (all stock) and I'd like to work on tuning for mileage while towing. I guess the only way to do it is to hook up a heavy trailer and go do some tuning?I decided to try some dyno tuning yesterday. The steady state ve and maf tuning didnt go well and I ended up going back to stock ve table and the street tuned maf. We did a couple pulls and I played with timing some. My stock pull I had 259hp and 356tq. My final pull was 316hp and 421tq so I think that is some pretty nice improvements for now.
Empty I notice a lot of mid-throttle KR on light hills on the stock tune. My only change so far is stoich to 14.2 as we get mostly E-10ish crap fuel here.
I do also have a volant cai, flowmaster muffler and 180 stat. I think that most of my KR was reduced when I changed to the lower t-stat. I have also been running 92 octane while tuning lately but the tune I posted above was made on the street with 89 if I remember correctly. We also only have "up to10%" but I have found that it is actually more like about 7% ethanol.
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