Dyno results

[sle2115]

The Moose matched or beat my peak torque from 1770rpms to about 2800 rpm's. Definitely more useable power there than the extra 11hp I managed to lay down. I am happy with my numbers but just kind of got the bug of 'Lets see what we can do next' and hit the rollers again.

And I know what you mean! I don't look at my truck as a performance item, never have...would I like a little more power, of course, but my heyday on the dyno's was years ago, when we drag raced...had a "427" in a 71 Chevelle SS, a flow bench, access to a wheel dyno, etc. If I only had a $1.00 for every hour I spent "trying and testing" I'd be retired! lol

 

[sle2115]

One thing I plan to do at some point is hook to the trailer at the county fair (actually two of them). I have a limited slip rear and locker in the front and of everything I've done to my truck, the gear change (to 3.73's) and the lockers have made it a much different animal, it went from getting stuck in wet grass to now amazing me and other at deer camp, etc. It has stock size tires, although rough tread, that are not super expensive BFG's, Goodyear's, etc. yet it's the go to vehicle when something needs pulled a new road is created! It pulls like a tank now, and I just want to improve on that without losing the ability to haul a tandem axle trailer at highway speeds, which everything I'm doing should be a win in all directions.

And yes, maybe someday the mule will make it to a rally! lol

 

[88 Ford]

Here's a caution about wiring wastegates closed. Drive pressure goes thru the roof when you do that, as well as EGT. High drive pressure is something that contributes to blown head gaskets. Big time.

Before I'd wire the gate closed, I would hook up a drive pressure gauge... a pressure gauge pre-turbo on the exhaust side. Put at least 18 inches of copper line before the boost hose to avoid melting the hose or the gauge). Compare boost pressure to drive pressure. Ideally, it's 1:1 (15 drive/15 boost) but 1.5:1 (22.5 drive/15 boost) is acceptable, but best to be as close to 1:1 as possible for max efficiency and low EGTs. I recently played with this on an engine in a dyno lab. We wired down the wastegate on an HX35. It picked up some power and went from 25-35 psi boost (Cummins 24V) but drive pressure was near 2:1 and EGTs were 400-500 degrees higher.

Time for a turbo upgrade at that point...

 

[88 Ford]

Something else I just thought about is how can we get a better load on the truck on the dyno? Cory's truck had quite a bit more power left in it but couldn't reach its max potential cus it wasn't fully loaded.

 

[92F350CC]

That's a proper thought. I'm willing to bet that Heath's truck is probably nearer to 500 tq than 440.

 

[justinray]

If the injection pump is the obvious weak point here, why hasn't anyone gotten a P-Type 8 Cylinder Pump, and put the DB2 gear on it, make a plate to bolt it to the Intake Manifold, or Gear Cover? Timing would be a hassle until someone got the fuel lines and injectors figured out, but that seems to be the key to the >500ft/lb lock.

 

[88 Ford]

There is actually a high output Db4 and a high output Db2 being tested right now. It will be interesting to see how they work out. One Db4 has already produced 292/614 on one engine, so the 500 lb-ft barrier has already been broken with an Idi, but the problems that have been inherent in that Db4 have now been corrected and fuel has also been increased on that IP. It will also be interesting to see how much power the Db2 produces and how well it holds up during testing. As for the 8 cylinder P-pump, it would be interesting to see. A P-pump definitely has a ton of power potential too.

 

[92F350CC]

IIRC, 500 lb/ft was achieved on a db2 by wmoguy.

 

[FordGuy100]

Fuel isn't a problem its turbo's. We see with these dyno's just how far these "stock" turbo can be pushed. I think it is safe to assume they can only really push enough air for 200-225hp with proper fuel mods.

 

[92F350CC]

Yeah, the turbo is definitely a weak point.

They really are increasing HP though, just not at peak. When you start making gobs of torque at 1600, your hp at that level becomes higher too...that's why the trucks feel faster even though the peak HP hasn't increased. You now have more of it at usable levels though.

 

[justinray]

There are calculators that will tell you how much an engine can push online, both NA and at a certain boost, an NA 7.3 can safely make 500 ft lbs, it just needs an easy way to get cold air in and an easy way to get hot air out. The fuel isn't there. The DB2's drop off starting at 1400 rpm. If you look at the dyno above, the turbo being wastegated or the wastegate being wired shut had no effect on the power because the fuel isn't there.

 

[88 Ford]

Well the weak link on the Db4 has been found and corrected, so fuel won't be a problem anymore if you ask me. The weak link of the Db4 was a cam pin and Racin and NMB2 have found one that is about twice the size if the stock one that came in it. Plus they cryo treated the internals and did other mods to it. All this will solve all the fuel problems they have had with it and I am damn near positive there won't be anymore Db4 failures...

 

[88 Ford]

Fuel isn't a problem its turbo's. We see with these dyno's just how far these "stock" turbo can be pushed. I think it is safe to assume they can only really push enough air for 200-225hp with proper fuel mods.

The turbo is definitely an issue. I agree with you there...

 

[92F350CC]

Did they solve the output issue though? Remember that NMB2 was swindled by Ken, and the pump only delivered 120cc's instead of 150.

 

[Ididriver]

Yeah they solved that and there new pump is suppose to flow 160ccs