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Discussion Starter · #1 ·
Been wanting to up the power to the 500hp range at 3000rpm. It will be for daily / weekend driving fun. I posted this on my build page as well. Please advise.

As far as my long-term goal for more horsepower goes I have several obstacles to overcome a little at a time.
1. Lift pump- I think the aftermarket fuel lift pump is not up to the challenge. I have read that there is a Cummins factory pump with a certain cast number that will do the trick. Planning on changing this soon. The trick falls on its face around 3000rpm. I plan on tapping into the pump supply with a gauge, so I will know for sure where the fuel pressure is and know if
2. Head gasket issues- I milled the head and ran a Felpro gasket that looked like a OE. Big mistake. With 19 degrees of timing when running it hard it lifts the head and a small amount of coolant leaks from the rear of the head even with ARP studs. I lubed and retorqued all the bolts one at a time with no luck. So, to correct this I ended up dropping the timing to 16 degrees. But to achieve the HP / RPM goal. I am thinking that the timing will need to be in the 19 to 25 degrees. So, a new Cummins OE head gasket is what I am thinking about trying to accomplish this. I see a few posts about the Victor / Mahle gaskets working ok but I am not sure if that is the case at this performance level. I lapped the valves when the head was off in the previously but still had a few minor pits I couldn’t remove. Maybe this go around I should fix this and polish the head a little better as well.
3. Transmission upgrades- Torque converter is a Transtar billet piston converter that is a little loose for my liking. Tranny is a stock 2003 4l80e I was told had low mileage. So, I been researching what is needed to make it hold more power. So, I am thinking that I can get a triple disk torque converter from Jake’s Transmission. Use their upgraded input shaft, dual feed the direct drive and ask for any other hydraulic improvements they recommend. The other option is to buy a complete stage 2 or 3 kit from Jakes.
4. Drive train – Run a set of custom Reaper traction bars to prevent axle wrap after getting the pinion angle where is needs to be. I still need to research this but I am thinking that a transfer case brace would be a good idea to. It’s a long setup with the 4l80e np205 and GV OD. I am also concerned the u-joints may not hold. Still running the stock u joint I think it’s a 1350 greaseable joint. I am wanting to do some searching for a stronger non-serviceable joint. When my rear drive shaft was built I requested for a HD tube. Not sure what they used but he was confident it would hold.
5. Fueling- Currently I am running the factory 180 delivery valves and 5x9 factory injectors. I am thinking about going with a 500 or 550 hp fuel set up from Power Driven Diesel. Kit includes injectors 5x12 and 025 or 7mm DVs. Then I would like to put it on a dyno and see what it does. If I am not happy with it a compound set up would be the way to go but I seen some dyno pulls done by PDD with a gated S362 with a tight turbine housing. Seemed like it is exactly what I need without the trouble of fitting a second turbo.
This is all a trial and error so please if you have any advise from similar set ups please share it.
 

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A few comments. I assume you're running the P7100 injection pump. No fuel plate might prove to be a mistake should that thing ever hang. For the fuel needed for that much power an aftermarket lift pump is what you need. Either the Fass or Air Dog units can feed enough fuel. The stock lift pump probably can't. Head gasket issue I could understand. Although some guys claim to be running far more timing, 16 deg is pretty much the limit on a stock head gasket. To get about that you need the head O ringed. No matter how much you update it, I don't see a 4L80e living with that engine. The torque will destroy it because you'll be in excess of 1000 lb ft. I also don't see much chance of reaching 500 HP on a single turbo. No single can handle the boost needed for that much power. You're may be talking in execss of 40 PSI. Member Dougal can compute how much fuel and boost will be necessary. 5 x .012 injector can possibly can do 500 HP. Those were used on the 370 HP marine engines. Not sure how much beyond that they are capable. Larger delivery valves may or may not come into play. Those often make an engine that isn't very street friendly.
 

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Discussion Starter · #3 ·
A few comments. I assume you're running the P7100 injection pump. No fuel plate might prove to be a mistake should that thing ever hang. For the fuel needed for that much power an aftermarket lift pump is what you need. Either the Fass or Air Dog units can feed enough fuel. The stock lift pump probably can't. Head gasket issue I could understand. Although some guys claim to be running far more timing, 16 deg is pretty much the limit on a stock head gasket. To get about that you need the head O ringed. No matter how much you update it, I don't see a 4L80e living with that engine. The torque will destroy it because you'll be in excess of 1000 lb ft. I also don't see much chance of reaching 500 HP on a single turbo. No single can handle the boost needed for that much power. You're may be talking in execss of 40 PSI. Member Dougal can compute how much fuel and boost will be necessary. 5 x .012 injector can possibly can do 500 HP. Those were used on the 370 HP marine engines. Not sure how much beyond that they are capable. Larger delivery valves may or may not come into play. Those often make an engine that isn't very street friendly.
Char1355 greatly appreciate for your thoughts. I am running the 180hp P-pump. I have heard from several people that it can hang up. I wonder how that happens. I am thinking maybe if the AFC foot is gound to much the foot can slip off and not let it return to neutral because its behind the AFC foot. I haven't ground the foot on my AFC yet put I swapped the factory spring since it would spring bound around 30psi prevented travel. I used a old gov spring that I cut a coil off of. Testing it with a regulator it seems to work pretty good and hits wide open at 40psi. With the stock fueling I am putting out around 42 psi of boost 1200egts and at WOT its looses power and usually just a light haze under acceleration. Drive line / exhaust pressure would be helpful to know. It has a sweet spot at about 1/2 throttle. Currently my gauges are mounted under the dash and hard to see. I need to mount them on the pillar, the dash or above the rearview. I just cant make up my mind. I would guess its putting out around 300hp. I know I am pretty fortunate With out dual feeding the direct clutchs and upgrading some hard parts I haven't broke anything in the 2 years I been running it.

Maybe I should shoot for 450hp with my current turbo. But after watching a youtube video on the BG S362SXE and some other videos by Power Driven Diesel it had me thinking I need a better turbo and waste gate.
I search all time for guys that are running the 4l80e with similar set ups pushing the limits for details. I have found a couple so far one on here Bonesfab broke a input shaft on this compound 12 valve. He swapped his 4l80e with a Alison but still really liked the 4l80e and kept it for another build. Another that comes to mind is a guy who had a compound 600hp set up with all mods and billet parts that drag raced it but every time the trans brake was used something broke and he went with a different trans after that.
I will call Jakes Transmission soon to see what his experience and recommendations are for my application. Just wanting it to be really fun to drive and dependable. I am thinking that I should be shooting for 400 to 450hp is probably a better bang for the buck.
 

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Discussion Starter · #4 ·
Ordered a new OEM Cummins lift pump

I ordered a Cummins Lift pump Part# 4988747 with casting number ABFJV. I found a post on another thread that said this pump has a larger plunger a few millimeter larger plunger than the Carter made pumps and chain store pumps. It would supporting high rpm fuel needs better and provide better cooling to the injection pump. To test this I ordered a 14mm banjo with a 1/8" port so I can get a fuel pressure reading before and after. Which will give me a idea if this is helping or not.
 

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You're talking in the neighborhood of 70-80 HP per cylinder. I just don't see any single turbo delivering enough air to do that. Stress on a turbo shaft has to be getting critical when you go into the 40 PSI range. The P7100 can be tuned to get to that level without a problem. Your new lift pump with the 30mm plunger may get there. Need to keep a eye on the fuel pressure which you have in the plans. There is a modified model of the pump you have ordered which is designed to high HP engines. Need to maintain around 25 PSI fuel pressure as a minimum. More wouldn't hurt. Probably need to plan on a new overflow valve if you haven't already replaced it. Dual fuel feed lines would also be in order. As for the transmission, only time will tell. Even the Allison 1000 needs upgrades when dealing with high HP engines. You mention power dropping in the higher RPM. If you look at the power curve of a Cummins B series, the torque starts falling like a rock a little past 2000 RPM. You might be in the market for a better camshaft in the engine to shift the torque curve. The Colt stage 3 might be the ticket. The stage 4 might be possible for a street driven vehicle but its manners may not be so tame.
 

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Discussion Starter · #6 ·
My stock 4l80e tranny gave up on me after 2 yrs. I just changed the lift pump last and it felt a little more peppy.

It gave no indication but just wouldn't go in gear after moving it around the yard.

Checked the line pressure and only a pound or 2 in gear. Fliud level was good filter still in place. Found a little metal on top of the filter and towards rear of the trans.

I am thinking I am gonna have to pull it, see if it is fixable, then do with a triple disk torque converter, dual feed direct drive, and a 300m input shaft.

I knew it was coming but with stock injectors I was hoping it would hold out.


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Discussion Starter · #15 ·
Was that transmission running behind the stock 6bt? Just imagine the stress on that thing with very high power. That 4L80e just wasn't meant for a Cummins 6bt.
It did run behind the 6bt for the past 2 yrs. It did okay but I most likely put it to an early grave by being hard on it.

Will be tearing into it soon to see what the problem is and do some upgrades.
Planning on a new low stall converter maybe a 1500 rpm stall tripple disk Precision Industries, Hughes or maybe a Circle D converter. If you have any suggestions please let me know.

Also, want to dual feed the direct drive clutches, upgrade the input shaft and install several other Sonnex parts.

I think for the time being I am gonna keep the 60mm s300 turbo and hope to hit the 400 hp mark with it if get a chance to dyno it.

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Not sure what others think, but 1500 RPM might be a tad high on the stall speed. Not horrible, but might be about 100 RPM too high. A lot probably depends on the turbo. With twins you'd probably have decent boost just above 1000-1200 RPM where with a large single that will be delayed.
 

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Discussion Starter · #17 ·
Not sure what others think, but 1500 RPM might be a tad high on the stall speed. Not horrible, but might be about 100 RPM too high. A lot probably depends on the turbo. With twins you'd probably have decent boost just above 1000-1200 RPM where with a large single that will be delayed.
Thanks char1355. I believe that the factory is about 1800 stall. It's definitely not low enough. I'll try 1400. It usually builds 5 psi or so of boost there with a little load.

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Discussion Starter · #18 ·
Been a while since I posted here. My tranny quite making pump pressure and won't go in gear. Planning on building it using a Jakes Performance stage 4 or 5 rebuild kit and a Precision Industries tripple disk converter tuned for the 12 valve powerband. The main difference in the stage 4 and 5 kit is the super drum 36 element sprag. It's a $600 dollar part. Just on the fence if I need it.


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I ran no plate on my 6BT scout and never had a problem except for two destroyed clutch hubs. I ground the plate flat and put it back in because it was too much power for my scout with no plate. Problem with a flat plate is it puffs smoke into the little cars parked next to me in the parking lot when I start the truck. I think that's why the plates have a nose on them.
 
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