What effect does lower CR have on Turbo??

[Billman]

What effect will lower compression pistons have on the output of my Turbo?

I have read here about Higher Exhaust Output with 18's but I'm not getting it. I understand the theory behind being able to run more boost with less CR, but how will this effect Spooling up? Quicker or slower? My guess would be slower.

Turbos operate on Exhaust Heat & Energy. Won't this be reduced with less Compression?

What can I expect it to do to my GM-8?

What would it do to a Non-Wastegated Turbo?

[rjschoolcraft]

There is a little less response with lower compression ratio, my experience. I also am experiencing more smoke...less complete combustion. More air is in the works...

[gmctd]

The Bosch IP application for the 5.9 Cummins employs a fuel regulator controlled by Boost - no Boost, min fuel, no smoke.

As Boost increases, so does fuel quantity per inj stroke.

Max Boost, max fuel, min smoke.

So, how does this help the 6.5, using an (proposed) HX-35 turbo from a 5.9?

Sorry, folks - there is no help for a 6.5! tongue.gif

;)

[rjschoolcraft]

We'll see...

[Billman]

"Sorry, folks - there is no help for a 6.5!"

You sure changed your tune in a hurry...

Hope all is well, jd.


RJ stated what I thought was obvious. Wanted to be sure. Thanks.

[arveetek]

Lowering the CR on my 6.2L resulted in an increase in boost from a max. of 14 psi to 17 psi. Boost builds quicker than before as well. Of course, the old engine had one broken ring, tapered cylinders, worn timing chain, old IP and injectors, etc. So I'm sure the new turbo injectors, IP, timing gears, bored cylinders, new pistons, etc, might also have a part to play in the boost! ;)

Casey

[gmctd]

My apologies, Billy - jest couldn't resist a little dark humor on a Tuesday the 13th.

But, you're almost right - I let the clutch in on that NV4500 one time, and I was hooked fer life.

Second, third, then fourth, without using the go pedal, that big six sorta growling at me at each upshift.

Accelerate up to 45, then into 5th, nail it, climb to 65 with a snarl, ease off for a contented purr at just under 2k rpm, and the turbo spools down to a soft whistle.

Check the mileage on the first tank for 25 miles per gallon, and all that on a 3500 dooley, a\c burnin' the entire time.
(No mileage test-runs with a\c off here in Texas, this time of year).

So, the tune hasn't changed - it's just in the key of C(ummins), now. :cool:

That's my story, and I'm stickin' to it........ smile.gif

[C.K. Piquup]

I`m running w/o wastegate and motor is crude,yet snappy.Crude:the boost pushes the truck at low rpm/clutch out.