Trunk Monkey
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Kinda confusing about your adjustment to the initial run.
DT Headers Dyno Result Thread (4 Viewers)
- Thread starter RobRed
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- Thread starter
- #42
Too early to tell but it looks promising based on instant readout from Scan Gauge.
Sometimes when you do a run you 'll get anomalous results if one of the variables change, like maybe the truck hiccups or the operator changes throttle input etc. The initial run (as often is the case) was reviewed for the best result we could get. Upon further review it was discovered that out of the 10 runs the high number was anomalous and didn't fit with the other 80% of the results. More over it was unlikely the LC would only have a 10% driveline loss, especially in light of it's 146k miles. To put it simply we threw out the high result because it was not in character with the real world or the other control land cruiser on hand.
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re_guderian
SILVER Star
I guess it'd be good to have it if you need it, but how often do y'all get up to 4000+ RPM in your daily driving? I've been doing a lot of data logging from my OBD II data (Torque app), and my typical driving style would see about half the max gains based on my typical RPM's. 'Course, if I had the extra oomph, I'd probably be mashing the skinny pedal more.
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Muchas Gracias Roberto Rojo.. 210 is a pretty good number, works for me. I'll concur there is a noticeable increase in all-around power, little better response, and a touch more "staying power" on grades. thanks again for the efforts here, really cool to have some numbers to back up the seat of the wallet/seat of the pants results. 
How did the one anomalous run throw the initial curve so high? If there were 10 runs wouldn't that be less impactive to the overall average? Or am I misunderstanding how the average is calculated?
Thanks for the time and effort Rob! Not trying to knock your efforts at all, just trying to better understand what's in the numbers.
Edit: I guess I'm also confused at how the dyno could be erroneously high in the first place. Dynos can only measure wheel torque, right? HP is just a product of torque at RPM - straight math. So for the HP number to be erroneous, either the torque number had to be off or the calculated RPM was off. Trying to figure out how either could be high? Could it be caused by an open center diff doing funky stuff on the dyno between the ends?
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- Thread starter
- #46
The torque value/curve has been essentially consistant in all runs which is what the red flag was to begin with. It's hard to say why it happened and I think in the scheme of things it's not important. Today was 3 runs all with the same results.
- Thread starter
- #47
I guess it'd be good to have it if you need it, but how often do y'all get up to 4000+ RPM in your daily driving? I've been doing a lot of data logging from my OBD II data (Torque app), and my typical driving style would see about half the max gains based on my typical RPM's. 'Course, if I had the extra oomph, I'd probably be mashing the skinny pedal more.
I think the value is the increase in performance/drivability is at every RPM level. There may be aside benefit of improved economy as well.
I guess it'd be good to have it if you need it, but how often do y'all get up to 4000+ RPM in your daily driving? I've been doing a lot of data logging from my OBD II data (Torque app), and my typical driving style would see about half the max gains based on my typical RPM's. 'Course, if I had the extra oomph, I'd probably be mashing the skinny pedal more.
If you look from left to right, you'll see there is an increase in both power and torque starting a lot lower than 4k. I wonder if there is an opportunity to reprogram the ECU to take better advantage of the headers?
interesting, at my typical cruising rpms, ~22-2400, there is very little difference in performance. i'll probably still get a set
Also keep in mind that you're looking only at a WOT curve. We rarely operate at the points on that curve. However, small improvements in flow multiplied by thousands of miles can result in noticeable improved economy. How much? Who knows.
Thank you! Looks like good gains.
excellent data Rob, thanks for doing this
Did the other truck get run on the dyno too?
- Thread starter
- #54
Not yet. The other truck was there to confirm initial curves which helped solve the first "shockingly good" run dilemma and provide a consistant baseline.
We will be returning to the dyno in 2 weeks with both trucks.
- Thread starter
- #55
Absolutely - the lower AFR curve is from the headers run. I would bet that some ECU tweaking could pull a lot more out of this thing. Thinking about testing a Cat Back system as well. This my friends is a slippery slope.
As the cliche goes: HP sells cars, torque wins races. And that's a pretty nice fat area between the torque curves across the meat of the power band.
Thanks for the data!
Thanks for the data!
if the numbers are OK that is a nice gain indeed
interesting that there is no real point in going above 4000 rpm with that engine. (not that I would go that high ever anyway...)
[now that the numbers look good, you should go hit the manufacturers for an advertisement fee... ]
interesting that there is no real point in going above 4000 rpm with that engine. (not that I would go that high ever anyway...)
[now that the numbers look good, you should go hit the manufacturers for an advertisement fee...
]
Really? Not saying that I spend much time in the nether regions of the tach, but with the autobox there's not much you can do. If you need more power for say merging uphill it's just gonna go there. And that's probably the biggest benefit to the headers - expansion of the WOT curve for events just like this. Not much will be gained on the trail...
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I just pulled a camper over a few passes. I manually dropped the transmission to 2nd, then had the engine anywhere between 3000 and 4500 rpm's for a pretty extended period of time (7 miles?) going between 35 and 50mph. Truck ran great, was really responsive, I was able to pass folks going uphill, only slowed down because of sharp corners, was exactly like you'd drive a stick at that point. And it felt to me like this practice was easier on the truck, than allowing it to lug down in 3rd then having to floor it to downshift. Engine felt happy camped out at 4000 for a few minutes.
I haven't been following the particulars, but this is for the DT Headers with the stock exhaust? Nice.
