1995 Bluebird 5.9 24v front engine.

Vincef

Member
Joined
Mar 6, 2024
Posts
19
Hi just bought my first skoolie and driving it home noticed it seems to be governed at 65 mph. no ECU from what I can tell on mine so not sure if there is anything I can do. would like to be able to do 75 in it to have some passing power
I keep finding things for the 12v performance but nothing for the 24v. Are there some sort of changes I can make to get a bit more top-end out of it?

model B5.9-175
CPL 1550
Family SCE359D6DAAW
Engine no. 45191448

I'm located in NW Georgia
 
The b5.9-175 would be a 12v engine. No ecu would also mean 12v engine. Pretty easy to search online about how to mod them for more power.

There's only 2 ways for you to be speed limited with a mechanical engine. By being gear bound and a box mounted inline of the throttle cable.

The box is an easy fix, most can be popped open and disabled.

Gear bound is another story. There are a handful of ways to accomplish solving that. But I'd first recommend you figure out what you presently have for tire size, rear axle ratio, and transmission. That way we can verify you're actually gear bound, vs having other mechanical issues.
 
24 valve came out in 1998.5.

You'll immediately want to do this: https://www.cumminsforum.com/threads/best-killer-dowel-pin-kit.2576451/

Then retorque head bolts.

Install a boost/pyrometer: https://a.co/d/dVAglbT

Advance p-pump timing to 16•

Pinch off boost reference line with: https://www.harborfreight.com/4-pie...17789297798&product=65116&store=&gad_source=1

Remove fuel plate: https://www.dieselbombers.com/5-9l-12v-performance/7135-fuel-plate-no-fuel-plate-3.html Keep your EGTs under 1250 with throttle pedal.

Install 3KGSK: https://powerdrivendiesel.com/product/3k-4k-governor-spring-bundle/


That's where I am with my 12 valve and its spiciness has doubled over stock. Running a swapped A-2000 trans and she keeps up with traffic up to 85 mph

Shop is putting a K-27 turbo on now, hoping to drop the egts a bit. If not, getting an AFC live tuner.

Next steps for you are taller tires, that's a few mph.

Then decide on a transmission swap or rear re-gear.
 
24 valve came out in 1998.5.

You'll immediately want to do this: https://www.cumminsforum.com/threads/best-killer-dowel-pin-kit.2576451/

Then retorque head bolts.

Install a boost/pyrometer: https://a.co/d/dVAglbT

Advance p-pump timing to 16•

Pinch off boost reference line with: https://www.harborfreight.com/4-pie...17789297798&product=65116&store=&gad_source=1

Remove fuel plate: https://www.dieselbombers.com/5-9l-12v-performance/7135-fuel-plate-no-fuel-plate-3.html Keep your EGTs under 1250 with throttle pedal.

Install 3KGSK: https://powerdrivendiesel.com/product/3k-4k-governor-spring-bundle/


That's where I am with my 12 valve and its spiciness has doubled over stock. Running a swapped A-2000 trans and she keeps up with traffic up to 85 mph

Shop is putting a K-27 turbo on now, hoping to drop the egts a bit. If not, getting an AFC live tuner.

Next steps for you are taller tires, that's a few mph.

Then decide on a transmission swap or rear re-gear.

ok Sorry for the delay had to do some homework

Rear end is a rockwell international 4.88
Transmission is the 545
Tires are the 11r22.5
doing some more reading i learned the trans is good till about 230 HP
since im at 175 ish i feel like the mods listed above should keep me safe.
Would it be worth adding a trans cooler to keep the trans alive longer?
what tires size recomendation. they look fairly close now
 
Ok so you're maxed-out on tires and gear-bound. https://spicerparts.com/calculators/transmission-ratio-rpm-calculator

A rear re-gear will get you to the 70's, but you'll need some extra hp. Re-gear not necessary with the 5/6 speed Allison.

Definitely want an aux cooler on that 545 for the extra stress. I had taller rear gears and with the 545 slip and stock hp I never saw more than 65. A-2000 swap is IMO the way to get road speed, and again you'll need hp upgrades.
 

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a 545 at 230 HP with the torque of a diesel is somewhat laughable.. id say 230 on a gas motor that has much lower torque.. I wouldnt run it over 200, maybe 210 on a smaller engine like the 5.9


a transmission cooler will definitely help things out .. the fact that the bus is geared low is a help too..



4.88 gears and a maxx of what 2500 RPM on a 5.9? you wont be doing more than 60 or so with it pegged.. definitely not ideal for fuel economy.. but does help the transmission not get lugged..



11R122.5 is the biggest you'll get on a school bus..



time to BUIILD UP!!!

la Ca has it.. pump up the engine, re gear and retrans..
 
After pyro gauges you can find the boost reference line for your turbo, it'll be a rubber hose across the top of the engine going somewhere on the injection system. Put a fluid clamp on it to max out your boost, helps a lot.
 
so been using this as a to-do list.
i finished the KDP it had not been done.
had to redo all my coolent lines and heater hose lines
did the 3k gov springs
added a guage for EGT,boost,fuel pressure,trans temp


the TO-DO list below.
have not looked into any of this yet.

Then retorque head bolts.
Advance p-pump timing to 16•

Pinch off boost reference line with: https://www.harborfreight.com/4-pie...17789297798&product=65116&store=&gad_source=1

Remove fuel plate: https://www.dieselbombers.com/5-9l-12v-performance/7135-fuel-plate-no-fuel-plate-3.html Keep your EGTs under 1250 with throttle pedal.

24 valve came out in 1998.5.

You'll immediately want to do this: https://www.cumminsforum.com/threads/best-killer-dowel-pin-kit.2576451/

Then retorque head bolts.

Install a boost/pyrometer: https://a.co/d/dVAglbT

Advance p-pump timing to 16•

Pinch off boost reference line with: https://www.harborfreight.com/4-pie...17789297798&product=65116&store=&gad_source=1

Remove fuel plate: https://www.dieselbombers.com/5-9l-12v-performance/7135-fuel-plate-no-fuel-plate-3.html Keep your EGTs under 1250 with throttle pedal.

Install 3KGSK: https://powerdrivendiesel.com/product/3k-4k-governor-spring-bundle/


That's where I am with my 12 valve and its spiciness has doubled over stock. Running a swapped A-2000 trans and she keeps up with traffic up to 85 mph

Shop is putting a K-27 turbo on now, hoping to drop the egts a bit. If not, getting an AFC live tuner.

Next steps for you are taller tires, that's a few mph.

Then decide on a transmission swap or rear re-gear.
 
After pyro gauges you can find the boost reference line for your turbo, it'll be a rubber hose across the top of the engine going somewhere on the injection system. Put a fluid clamp on it to max out your boost, helps a lot.

ok so KDP done
3k gov springs done. (this also helped me idle better)
all new heater hoses and rad hoses
added a EGT, a trans temp, a fuel pressure, and boost gauges.

having trouble finding this boost ref line i have a few hoses like this.

BzjugJv
8Rz3Nx7
 
Last edited:

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