Dyno

[Shadrach]

So I wanted to run my "new" truck on the dyno just to find out how it would do. My 03 305 engine did 278 to the wheels ( 91 % ) so I was happy with that, and that was with just a cam change & and a fresh engine, I hadn't done the turbo, CAC, the exh manifold or Smarty at that point. My 08 has a Smarty set on 3 with timing and a full delete. We started out at 250 horse then increased the power up. 270 was no problem but getting warm. When we tried 280 the pyro climbed rapidly and we backed out at 1500* ( pre turbo ). Now granted on a truck dyno there is no air movement even tho the temp was just above freezing outside and the shop door was open. The truck was backed in and the winter front was off, the hood closed to allow it to suck air thru the coolers. When I was driving thru the mountains with my TT last summer ( total combined weight about 18k # ) I didn't have any issues with heat. When the temps got hot I just down shifted and the RPM came up and the EGT's went down. I admit I'm a little disappointed in not knowing the numbers it would have put down, but it would appear I can't use all the power I have. My coolant temps are not an issue.

To those of you who tow what are your thoughts? I could of course change the CAC which would help, or add water meth but then I have to mount a tank and keep it from freezing in winter. BTW the water/meth people say you can run -20 windshield washer fluid. I find that funny as up here we only have -40 fluid and the other day I saw fluid advertised as good to -45. I am not going to just throw $ at it to see what happens. I don't drive in real warm area but it can get to 40*C ( about 104*F ) going thru central BC.

David

 

[promisedland]

Thanks! Interesting...
i'll be reading along to see whats next! fun! [turbo?]

 

[NIsaacs]

I am interested too, however I know next to nothing about a Smarty. What do the numbers you posted mean? The 250/270 and 280.

Nick

 

[promisedland]

That would be rear wheel horse power on a wheel dyno....

 

[RustyJC]

I'm surprised the numbers are that low for a deleted 6.7 with a Smarty. My 2002 ETH/DEE 3500 dually pulled 347/762 uncorrected on a Dynojet with an Edge EZ, Diesel Dynamics stage 2 injectors, BHAF and Jardine 4" exhaust - pretty typical numbers for this configuration. The stock Holset HX35W-12 was slightly short of air as I could see 1450 degF pre-turbo if I stayed into it, but it was an excellent towing rig for our purposes if you kept an eye on the pyrometer.

Rusty

 

[Shadrach]

...I am interested too, however I know next to nothing about a Smarty. What do the numbers you posted mean? The 250/270 and 280...

Thats the horse power that we got at the rear wheels before we shut it down because of too much exhaust heat. Stage 3 on a Smarty adds 60 horse and changes the timing. So in my case instead on 350/650 ( horse power/torque ) it would more like 410/770. You always loose some power thru the driveline and it's different for a standard trans and an automatic. Quite often it can be between 10 & 20 %. My 03 putting 91% to the wheels was excellent. For those of you who don't know anything about dyno there are different types. A lot of you have seen the portable ones mounted on a trailer at the race tracks or at truck shows, like a Mustang Dyno:http://www.mustangdyne.com/update/w...loads/2011/03/Mustang_PortableSeries_2010.pdf. This wasn't one of those. It was the kind that a Semi dealership would use to test their trucks and is known as a water brake or hydraulic chassis dyno like a Taylor Dyno: http://www.taylordyno.com/products/chassis-dynamometers/ for an example.

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[NIsaacs]

Okay, I am still confused. Like Rusty, that seems way too low. If your '03 with 305 stock made 278 to the ground, including the drive train loss, how does your '08 350, plus the Smarty's 60 only make 270 or so? 350 plus 60 (smarty) equals 410, times 80%, is still 328 to the ground.

Nick

 

[NIsaacs]

Just to compare, my '01 stock is 245 hp/505 tq, with RV275 injectors, 30 hp/90 tq plus level 5 Juice adds 120 hp/350 tq. On the dyno it put down 397 hp/967 tq. Edge uses rear wheel power on their numbers.

My '91 stock is 160hp/400tq, with some mild mods it puts out 263hp/708tq. My Cummins Ford is about the same.

Nick

 

[promisedland]

On a comparisen of a 07 5.9L and a 08 6.7L the 5.9L spanked the 6.7L.
EPA......
Diesel power mag. They where testing how well the trucks test stock and also with adding intake/exh/tuning... the 5.9L spanked the 6.7L stock AND moded
[they did keep the DPF though]

 

[Shadrach]

It may "seem low" but don't forget that wasn't the final number. We had to stop because I didn't want to go any higher on the EGT. It didn't faulted at all when we got to 280, it just got hot. It would be interesting to try it on a Mustang outdoors. I was hoping to get some where close to 350 RWHP, but I wasn't about to do damage to my engine just to prove it.

David

 

[AH64ID]

The airflow won't lower your temps that much, and a dyno doesn't fully load the motor so often you get lower power/EGTs on the dyno than on the street. My current tune pulled at about 100° lower than it does on the street.

I would guess that the engine wasn't loaded enough to make its power. How much were you using the brake to load the motor before the pull?

 

[NIsaacs]

That big truck dyno must take a long time to build up steam and read your numbers. I have had all my rigs on dyno's and it only takes about 10-15 seconds, not enough time to get hot. I am sure your truck setup will produce 350+ hp. Did you get any torque readings at all?

Nick

 

[cerberusiam]

Unless you lock it into a high gear, 5th or 6th, and lock the TC you won't get a very accurate reading. This is using a accelerometer type dyno which is what I think it was?

Using 6th gear would be the best as it will load the engine the heaviest to get the closest reading. TC would need locked to transfer the load or numbers will be low due to the fluid coupling. You also would need to get boost above the defueling cut off at the lowest rpm possible to start the run.

Not sure what happened there but on a comparable 5.9 run those temps are comparable to 500 HP run.

A bit more description on the run was done would help determine what is happening also.

 

[Shadrach]

I have purposely left out a detail because of controversy. In the world I work in we ALWAYS dyno in direct , which means 4th in my case. This means you put it in 4th gear apply the power and load up the rollers. When in direct you are not only comparing apples to apples when doing different trucks with different over drive ratios but you are going straight thru the trans and not thru extra gears. When an engine is on an engine dyno you are taking power straight off the flywheel. On a chassis dyno you have to go thru a trans and a diff. A one to one ratio ( direct) is the same thing. I know some will disagree wit me but thats the way it's done in the big truck shops. That's my story and I'm sticking to it

Granted we normally do Semis but have done lots of Dodge Cummins as well. We did my 03 this way and didn't have any problems with it. We did try to dyno a Viper once but couldn't keep the wheels from spinning and therefore couldn't get a reading.

David

 

[NIsaacs]

I always dyno in direct. Did you try it without the smarty? It still should pull 300HP. What are your boost numbers/rpm under full power?

Nick

 

[RustyJC]

Dyno in any gear you want, but it will change the results on an inertial dyno. At one of the LSTDR dyno days, we used my 2002 ETH/DEE truck to prove this - the truck was mildly "bombed" as described earlier in this thread. We made 3 runs in 5th (direct) and 3 runs in 6th (OD) on a Dynojet. The 5th gear runs averaged around 315-320 RWHP (don't remember the torque). In 6th gear, the truck made 347/762. The inertial dyno couldn't load the truck enough in 5th to get the boost and fueling up to normal levels.

The dyno operator may be able to change the load applied by an eddy current or water brake dyno, but he can't change the inertia of the drum on an inertial dyno.

Rusty

 

[AH64ID]

I did my last dyno in direct because I only had 75mph tires on and I didn't want to spin them up to 100+.

What I found was the peak hp was identical to 6th; however, the torque was down because the motor isn't loaded enough at lower rpms. I did a short run in 6th from 1600-2200 rpms and my torque was back to 850 lb/ft from the 800 lb/ft it had been making in 5th.

It's just too hard to get the motor to build full power in direct for a full reading.

 

[cerberusiam]

Mustang makes both types of dynos, load and inertial, so it was bit confusing exactly what you were using. The readings you got were pretty normal for a load type dyno, unless you want to push to where the turbine housing is glowing red. If you want to see what the engine is capable of you will need to start the run at red line and pull the engine all the way down to just short of stalling it completely, regardless of EGT's. Even then, the calculations usually come of short of the inertial dyno because of the built adjustments.

Also, comparing to the 03 which IIIRC was a manual it won't be close. If you did not defeat the trans control and lock the TC it is apples to oranges comparisons. Without air flow on the front it will get hot faster than at speed so you have to kinda ignore EGT's.

What it is telling you that at that rpm and load and gear the max HP is all it will run continuous within EGT restrictions. You rarely see that on the road and if so a downshift and rpms solves the problem. If you want to see the close to the HP the engine is capable it takes an inertial dyno and locking it into the highest gear available to load the engine. Most of the inertial dynos will not load a diesel engine sufficiently to max the fueling anyway.

In reality a single number is not important, it is the changes to the numbers when compared to the changes to the truck that are important.