Recipe for High RPM

[bullfrogjohnson]

Want to talk about what everyone thinks it will take to spin 5k+ in and auto dmax?

I understand all the hard parts in the motor and valve train but what will it take tuning wise? I really want to run a S483 or GT47 as a single and be able to carry it down the track. I will be running low gears to help but what else will it take?

 

[Jared Duramax]

An a$$ load of fuel plus some:rofl:

 

[05smoker]

Can it be done safely with an LB7 and that damn FICM?

 

[JOHNBOY]

Can it be done safely with an LB7 and that damn FICM?

IMHO no

An LBZ is the best bet for 5000+ sustained.

 

[LBZ]

Ya Pat ran into problems doing just that with his lly in casper and I believe this may be a factor in his switching to an LBZ.

 

[SmokeShow]

I think a good bit of the RPM curve skew comes from the charger itself and when and how it comes to its milk.


Tuning wise, I like how things go when big injectors are used and the durations are able to be lowered. Especially in regards to when it's spinning fast.


I don't know any specific tuning changes to make though. That's above me so I'll be subscribing to this little jewel.

 

[redws6rocket]

i thought gainer had to switch to lbz software also to run that rpm.

 

[ecc_33]

3.5" gt 4788 aw that would be sweet. Nice choice

 

[duramaximizer]

You will need huge injectors and a short pulse width. I think you will need to look at table B0951 to be able to run that rpm or even close to it. I might also try talking with EFI live guys and see if they can lessen that more to help save the FICM. Then I think table A9001 would have to be more specific to your particular RPM as timing and fueling would be come less important down at 2000 rpms and more important up a 4000+.

This is all I know about the LB7 stuff and rpms. I still think LBZ would be better in the long run, but huge injectors and short pulse width should help.

 

[McRat]

Spinning past 5k is not the problem. Making peak power up there is.

The LLY will run solid up to 5250, so I imagine the LB7 can do it too.

 

[duratothemax]

AKAIK the LLY ECM has a slightly more powerful processor, but the FICM is still a bottleneck when you exceed the rated duty cycle of the FETs/injector drivers.

 

[05smoker]

Spinning past 5k is not the problem. Making peak power up there is.

Gonna need the right cam for it. I would also think girdle if I was running that high on a regular basis.

Ed

 

[Bako_Dmax]

What rpm do the valves float on the Dmaxs?

 

[McRat]

Something to think about.

IIRC:

The Audi Lemans car is 5.5L V12? and makes peak power at 5000, spins to 6000, running special fuel.

I've yet to see a dyno graph that indicates we can make more HP at 5500 than 4500 with any diesel, just a bunch of marketing posts. Maybe we can. Dunno.

Turbos act like cams. A GT45 is going to make peak at about 4500, so you'd something bigger than that.

 

[ecc_33]

I know kyle at CUD has ran some BIG singles on Climax. He had a really big stall something like 3100rpms and some low gears. I know he ended up changing over to lbz stuff to run the big R's just don't know how many.

 

[dmaxalliTech]

Tim Jackson has been in that area of the map I've heard

Camshaft/turbo/injector will be the biggest issue. V8's like to rev