NHC 250 Turbo Conversion in M923

[Vintage iron]

I believe it is because a increase in flow may have dropped the pressure? The truck does run stronger though.

 

[350TacoZilla]

I havent heard of that problem but it makes sense. Seems shimming gives more pressure on spring, more fuel pressure and more rpm so by almost doubling flow you would lose some pressure and possibly some rpm.

 

[Vintage iron]

I will need to learn more about this shiming procedure.

 

[Cumminstx]

what turbo did you end up using? i have several Borgwarner S475s laying around the shop, so i was thinking about using one of them.

 

[crewcab454]

it is an ht3b turbo

 

[plumbingbuddy]

m923

How is working with the turbo? I have been thinking about adding one to mine.

 

[R Racing]

subscribe

 

[162tcat]

I've got about 5,000 miles on my turbo setup and love it! Initially I just added the turbo with no fuel mods. That gave a slight increase but cleared up the smoke. After about 1,000 miles I swapped the 27 button out for a 20 and added 1 shim to gain some RPM. That made all the different in the world. I hauled a load of 9 ecology blocks on my equipment trailer and the truck did great. I hit the scales at 64,180 lbs. It pulled almost as good loaded as it did when stock and empty. Where you really notice the difference is on hills, I can keep a decent speed now.

 

[srodocker]

Defiantly need to do something like this when my truck is done. Being a m928 quad cab with dual fuel tanks and all the extra gear. When its done of course. Shes already really heavy stock ha!

 

[162tcat]

Srodocker,

I see your not too far from me. I've pulled the Nisqually hill on I5 up toward hawks prairie with my equipment trailer and excavator in tow (about 22k plus truck weight) and was still going 40 mph by the time I hit the Hawks Prairie exit. Before the turbo, it would barely do that empty. I'm also running 53's which doesn't help but with the turbo and #20 button, it keeps up now.

 

[srodocker]

Dang! I would be pulling that hill a bunch. Where are you located? Yea I have 53s as well. Im defiantly now wanting to do this mod!

Im basically setting this truck to do the dune trip to oregon and to do expo shows and such.

 

[162tcat]

I'm in Olympia. The main reason I did the turbo mod was to clear up the obnoxious smoke, the extra power was an added benefit. I bought a complete 335 and took all of the parts needed from that. The turbo is sized right for the power level I was after. I'll probably add an air to air intercooler some day but for now, it works great.

 

[plumbingbuddy]

I did a #5 cam button and a 2500 rpm spring and made a big difference. I am going to add the turbo next.

Someone did a dual fuel line? Will this help?

 

[jdknech]

I did a #5 cam button and a 2500 rpm spring and made a big difference. I am going to add the turbo next.

Someone did a dual fuel line? Will this help?

are you meaning a fuel button?? and is this on the 855 cummins, or the 8.3L?? because that is a MASSIVE amount of fuel.. i hope you have a pyro.. I put a #15 in mine and it get a tad warm sometimes..

 

[162tcat]

I did the dual fuel mod at the same time as the turbo install. I can't comment on if it made a difference or not since lots of other changes were made at the same time.

I wouldn't run a #5 and spin 2500 RPM, that's living on the edge. It must make massive smoke too.

 

[plumbingbuddy]

It is the 855 cummins, I did install a pyrometer. Working great with no heating problems. A friend of mine did the same #5 cam button on his with a turbo about a year ago, the only time he has any issues is on a long hill, he has to back off the throttle a little.

 

[plumbingbuddy]

Very little smoke. I have it dialed back to 2300 rpms.

 

[tim410]

any pics of duel fuel mod and pyro install?

 

[162tcat]

I'll take a few pics of mine this afternoon and post them.

 

[elkhtr]

Subscribed!
Really interested in all the little performance mods short of the turbo install.