Is there any advantage to this? I've always thought that you get higher torque at lower RPM with a diesel. Is there any advantage to making a TCM tune that will hold 4th or 5th gear when going 100% throttle at a low RPM (1500 or so)? I have a dyno event coming up in a week, and I'm thinking about giving it a try.
Start your pull at low RPM?
- Thread starter JoshH
- Start date
Dyno pull
Josh on my pull Maddog told me to start at 70 mph witch was i think 2000 or 2100 rpm. I would think that if the turbo spools faster or slower it mite make a difference on were to start at. I'm note sure though still trying to learn. Jeff
Josh on my pull Maddog told me to start at 70 mph witch was i think 2000 or 2100 rpm. I would think that if the turbo spools faster or slower it mite make a difference on were to start at. I'm note sure though still trying to learn. Jeff
Tony Burkhard
Allseason Diesel Per.
When i run the trucks at the danville performance dyno days i start them all at 35 MPH. The LBZ and LMM's i had to roll into the trottle to prevent them from shifting down.
With those twins, I'd think you would be better off to pull the highest gear you can run, 5th or maybe even 6th. Definitely, start your pull around 1800 rpm if you can. The last time I dynoed even a GT4088, the start time and load that the dyno operator put on the truck made a 100 hp difference (same tune).
I would guess making a tcm that would hold 5th or 6th in T/H mode would be the easiest if you don't have the computer plugged into the truck or don't have a Tech 2.
But make sure you get those twins loaded up to get your best output. I've also heard of riding the brake a bit while you bring the power in slowlly to help put a load on the engine. I don't know if I would do it or not but that is also an option.
I would guess making a tcm that would hold 5th or 6th in T/H mode would be the easiest if you don't have the computer plugged into the truck or don't have a Tech 2.
But make sure you get those twins loaded up to get your best output. I've also heard of riding the brake a bit while you bring the power in slowlly to help put a load on the engine. I don't know if I would do it or not but that is also an option.
I start my pulls at 2500 rpm since that is where the "racing range" starts, and I'm less likely to hurt a stock trans or stock engine. Torque kills.
for turbos that spool like stock or compable to them.
mine start pulling about 1600-1700rpm then the turbo is full boost by 2000 rpm..
higher spooling turbos
if i had a setup like pats 4202 were it doesnt start spooling to 2500 then i would raise the starting point as required.
just my .02 i tune for off line and mid range...
mine start pulling about 1600-1700rpm then the turbo is full boost by 2000 rpm..
higher spooling turbos
if i had a setup like pats 4202 were it doesnt start spooling to 2500 then i would raise the starting point as required.
just my .02 i tune for off line and mid range...
well i yet found one person to get mine to fully spool out the most anyone can get is 45 psi boost. was going to go to danville performance dyno i talked to him and he said well i dynoed nasty girl and it was a 1000 hp so a single charger truck is no problem. but there dyno day they could not get a single charger puller to go max boost. so i guess im give up on dyno and focus on drag times to get the hp numbers
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This is how I generally do them to get the most accurate numbers. Usually find the peak torque in the 1900 to 2500rpm range depending on the mods. Pat is right, torque kills, kinda... I only remember one DMax that failed shortly after making 715hp on the stock motor, oh wait make that two of them.
