250/200's and Colorado emissions testing

[CurtisF]

Well, went today and had my truck emissions tested with these injectors. It PASSED!!!!

Last year I spent time tweaking my tunes on stock injectors, and the previous years were on stock tuning.

With stock tuning and stock injectors, my truck would see these opacity results:

60 mph: 8%-12%
50 mph: 6%-10%
40 mph: 10%-12%
Zero Shift: 0%

Those are the highs and lows from previous years.

Last year was my own race tune on stock injectors:

60 mph: 5%
50 mph: 3%
40 mph: 14%
Zero Shift: 1%

And finally my results this year with the 250/200's:

60 mph: 13%
50 mph: 10%
40 mph: 14%
Zero Shift: 0%


So the results are pretty close to stock injectors on stock tuning. Maybe I can continue to dial everything in and next year see if I can get closer to my race tune results on stock sticks. After all, Blowby set the bar for large nozzles passing emissions testing.

Anywho... thought I'd share with those who might be interested.

 

[Smokin6-0]

Really cool Curtis. I like seeing tuning continue to improve on this platform and much that improvement is not just for peak HP.

 

[CamTom12]

Good work!

 

[Dieselboy.]

Nicely done.
Excuse my ignorance Curtis, but is it just pulling fuel out in the right places ?

Couldnt you essentially pull a bit more out ?

Sort of like the defuel tunes for a stock trans ?

 

[TARM]

Very good job!!!!

For a emissions tune I can see trying to see how low you can go. I do not know if I would want to try and get it super clean like that for a DD or race tune though. I think not adjusting things to try and get all that fuel burnt and having some extra fuel left unburnt or not that sharp and crisp keeps things sort of padded. Easier on the engine from a cylinder pressure combustion curve spikes etc stand point.

I have yet to start tuning my own stuff so this is theory and based on research.


Congrats again on getting that tune dialed in

 

[CurtisF]

Nicely done.
Excuse my ignorance Curtis, but is it just pulling fuel out in the right places ?

Couldnt you essentially pull a bit more out ?

Sort of like the defuel tunes for a stock trans ?

Really it's been a long road, and I had a ton of help along the way.

But yes it's about getting PW, ICP, and timing right at certain points. Problems I have encountered included too much ICP and too little fuel, causing a truck that ran rough, ran choppy at certain RPM's, and just didn't have good street manners. Then there's the other side where I had issues over fueling, and blowing out too much smoke.

It's a balancing act.

Very good job!!!!

For a emissions tune I can see trying to see how low you can go. I do not know if I would want to try and get it super clean like that for a DD or race tune though. I think not adjusting things to try and get all that fuel burnt and having some extra fuel left unburnt or not that sharp and crisp keeps things sort of padded. Easier on the engine from a cylinder pressure combustion curve spikes etc stand point.

I have yet to start tuning my own stuff so this is theory and based on research.


Congrats again on getting that tune dialed in

Actually, what's funny is the tune that I did the emissions test on runs and drives almost exactly like a stock tune. I pulled fuel out from my normal daily driver, and did a few extremely minor tweaks, and the result was a very mild mannered, easy stock-like tune. It wasn't too sharp or crisp, and was actually very quiet with a good linear response on the pedal.

 

[Lowdown89]

That's awesome man!

 

[Dieselboy.]

Ic. Makes sense.

Did you ever get the idle smoother. I watch a few vids in your idle thread and mine idles exactly the same as yours warm. A slight chop to it. Curious to see what causes that. I prefer a truck that functions as close to stock as possible from idle to 1/2 throttle and then opens up past that to WOT.

 

[CurtisF]

Ic. Makes sense.

Did you ever get the idle smoother. I watch a few vids in your idle thread and mine idles exactly the same as yours warm. A slight chop to it. Curious to see what causes that. I prefer a truck that functions as close to stock as possible from idle to 1/2 throttle and then opens up past that to WOT.

It idles good compared to what it used to, but you can still hear that chop. The thing is, you can always hear a difference at idle between singles and splits. Now from off idle beyond, it drives like stock. Even in my high HP tune, first half of the pedal feels like stock.

 

[Sprunx]

How do they test for opacity in Colorado?

 

[CurtisF]

How do they test for opacity in Colorado?

Just some kind of light meter hooked up to the end of the tailpipe. The more the light gets blocked out by smoke, the higher the opacity reading.

 

[CurtisF]

Well I'm just going to keep chipping away at the myth that it's a bad idea to run larger injectors on PMR's as a daily driver.

I never really intended to use that tune I ran for emissions testing as a daily driver, but curiosity got the best of me, and I've been driving around town just in that tune. Peak boost at WOT will juuuuuuuust barely crest at 20psi, so it's pretty damn close to stock levels. Feels quite a bit like a bone stock truck too.

So for gits and shiggles I took a rolling WOT run straight up a long hill near my home. Granted I live at about 6,000 ft., so this was at a decent altitude. The run went from about 10 mph up to about 75 before I let off the pedal. All of it going uphill.

My pyro gauge reads in increments of 50 degrees. Peak EGT's during that run had the needle stopped dead between the 900 and the 950 degree marks. Seriously, a WOT run at high altitude, and all I could hit for EGT's was 925 degrees! Stock injectors on stock tuning can't even get nearly that low on the same run, and I tried that same hill MANY times with various mods and tunes over the years.

I was already impressed with the low EGT's on higher HP tunes, but I was shocked at the ridiculously low EGT's at stock-like power levels.

 

[Aaron S]

I believe your running a 38r, right?

Have you set up a tune that will top out at 1200 to 1250 egts on a long up hill grade at full throttle, and then dynod that tune?

I know it cost time and money to do, but I was just wondering if its something youve all ready done, but not posted or I missed.

Aaron

 

[Big Bore]

I believe your running a 38r, right?

Have you set up a tune that will top out at 1200 to 1250 egts on a long up hill grade at full throttle, and then dynod that tune?

I know it cost time and money to do, but I was just wondering if its something youve all ready done, but not posted or I missed.

Aaron

He did. I can't remember the specifics but he dyno tuned for 400HP and pulling his 8K trailer up Climax, which starts at 10K elevation and goes over 11K, I believe his temps never went over 1250 maintaining 65mph speed on that grade. Doing that at those elevations is nothing less than incredible. Most people have no clue what towing at those elevations is like.

 

[Aaron S]

If thats the case, it definitly helps prove the case that larger nozzles equals out to lower egts.

Thanks
Aaron

 

[CurtisF]

Yep, what Frank said.