4BTA final adjustment

[driverswanted]

The 85' Ram and 4BTA is on the road. I made my AFC start wheel and f"FULL LOAD" diaphram and tapered pin adjustment to within 10-15 degrees of max fuel. The star wheel is all the way down and I'm getting good boost with fuel. The About 5-6 psi with 3/4 throttle from a standing start. Hard acceleration will get to 12. 6 psi going through to 60 mph.

I have the Bosch 190's and the timing is where Pastor Bob said to put it.

I'm ready to set it up for towing a 5,000 # load now. I can tell it needs more fuel and boost before it will do a 5 to 10 % grade with my boat behind it.

Will this be the FULL POWER screw adjustment? Anyone have a good setup procedure with a load behind the truck? I have digital readings on EGT, RPM's and boost pressure to work with.

 

[bgilbert]

I don't understand what you are asking . More fuel will make the turbo boost more. Also raise egt's. Do you know that you have NO boost leaks? Any problem with shortening the 6bt intake plate- the gasket have surface on each side? Awesome setup though, looks great. You gonna make it to Tim at IRP in Indianapolis this summer?

 

[JLEONARD]

Bill makes a good point... . probably time to make up a rig and check for boost leaks.

I'd put the pin right at max. Did you grind the plastic collar?

You might as well play around with the fuel screw now and get it over with... . you'll be doing it eventually :-laf If you keep track of the changes you make you can always go back. 1/2 turn at a time is easy to keep track of and document the gage readings.

 

[driverswanted]

Your right. I have not checked for leaks yet. Could be wasting good boost. Is the concensus that I should be making more boost with my current settings?

The 6BT intake plate was not hard to rework. This one had the heater grid housing molded into the plate. I was able to saw across the plate just outside of one of the reinforcement ribs running across the plate. From that point I added JB weld across that rib and milled the face and sides of that rib to match the other end of the intake plate. You can see I like using 6BT parts on the 4BT. I think there larger sizes are perfect for a modified 4BT. If I could only find an e-Bay sticker to go beside my Summit Racing sticker on the back window now.

I'd like to go to that Indianapolis show. Have to check into that more.

I did grind the plastic collar down about . 050". The old score marks on the pin looked like I could actually remove that collar and still not come up to the top of the eccentric pin/cone. As I understood it you could have the side pin follow all the way up to the top of that cone.

I finally got my Hall effect sensor and magnets mounted near the vibration dampener. my ratios seem to be off from the calculations. At 65 mph I'm at 1725 rpm. This is ideal for fuel efficiency but it's tough running at 60 mph in 5th. The engine lugs below 1700 rpm in 5th gear. 4th gear is at 2100 rpm at 55 mph. I've been staying away from using 4th at 60 because it's been slightly loud. I had not covered up my shifter and transfer case openings yet. Just had a rag around the openings.

finished putting some of the foil covered heavy ashpaltic sheets all around the openings and over the entire transmission tunnel last night. Made one run last night down some local roads but need to see how quite it becomes in 4th when I go into work today.

Later,

Barry

 

[driverswanted]

Where's the details on the Indianapolis event

I cannot find anything on the IRP in Indianapolis. Can you point me toward the information?

 

[bgilbert]

Its on the DHRA's website under Indiana events or something like that. http://www.dhraonline.com/?GROUP=series&PAGE=natdtirp.

 

[driverswanted]

Looks like it's June 25th and 26th. Is there a gathering area for 4BT's?

 

[Forrest Nearing]

boost seems low with 190's, cranked pump, and HY35!

 

[driverswanted]

When I get a chance I'm checking for air leaks. Anything else?

 

[driverswanted]

Did my air leak checks and found a minor leak at the cap screw on the turbo. Fixed that.

Had to take the pretty 32" Wrangler tires off and go to 29 inches to get the road speeds and rpm driveability right. RPM's were too high in 4th at 50-60 and could not run 5th there due to lugging. 5th was not running nicely until 62 mph and 1725 rpm on level roads. The 29" tires look ugly with the lift springs but I have no choice at this time. I have to pull my boat for next week's fishing trip two states away.

Turned up the full load screw 3/4 turn yesterday after changing the tires to 29". What a difference! Acceleration improved substantially from 50 to 70. Idle RPM's went up to 970 after that; have smoke at low to mid range acceleration right now. Still have to turn the smoke screw back out.

I re-zeroed the max readings in the Data Center and did a test run with hard acceleration on level road. Recorded EGT's went up to 1017 F; Max boost is still 10. 7 psi.

I keep thinking I have too much restriction with the Volvo 600 intercooler. The inlet and outlets are 2. 5" but the core is about half the thickness of a Dodge or Ford intercooler. Will try by-passing the intercooler today if I have time.

I had to laugh at the tire kids at the tire store. They only put in 35 psi. and looked puzzled at the somewhat flat tires. They went to check their compressor pressures. Then I told them what I had in the front for weight. Sure glad i bought the 7 ply tires. I have a feeling I'll be rotating these often to get the miles out of them.

 

[Idually]

Very nicely done.

D. W. Can you answer a couple of quick questions? I'm sorry if you covered this in the past. Did you change axles on your RAM, or is it a 3/4 ton already? Did you do any frame mods for strength? I have a chance to get a 78 Ramcharger and I've toying with this very idea. Thanks



Andrew

 

[LAlessi]

out of curiosity can you post transmission, axle ratio, and tech info in one post?

i have had good sucess with a LOT of intake restriction and

cpl858 105hp 265tq no inner/aftercooler

38" tires

4. 56 gears

nv4500 transmission (. 73 overdrive)



no lugging issues. good mpg. 24+@70mph 30+@55



have since downgraded to 35"tires to save my mud tires, but not enough miles to really have an opinion except they are almost 1/2 the weight of the other tires and wheels so accelleration is now MUCH better. havent towed anything though

 

[HoleshotHolset]

i have had good sucess with a LOT of intake restriction and

cpl858 105hp 265tq no inner/aftercooler

Could you expand on that sentence a little?

I'm curious what you mean by a LOT of intake restriction and the specific success you've had by implementing that.



Thanks,



Matt

 

[driverswanted]

Andrew,

It's a 1/2 Ton Ram Prospector with 3. 54 gears as far as I can tell. Have not done a driveshaft rotation count with the rear wheels lifted yet. It has aftermarket limited slip and a set of lift springs that bring it into the 3/4 ton weight range. It has the standard nv4500 from a 1995 Dodge.

I did re-inforce the frame rail outside, bringing a 5/16" plate forward to the original cross member. That is stitch welded in place up front and bolted through in the back to the engine mounts. My engine mounts are mid-engine. Here's a photo of those. You can see the plate on the frame with gray primer on it.

Your really don't have to move the engine back like I did. There's room to put it over the original cross member. It would save some grief with the exhaust too.

 

[driverswanted]

LAlessi,

I'll give my numbers but first an update from our sponsers. :-laf

1. HY35W

2. Bosch 190's; Timing per Pastor Bob@ Piers Diesel.

3. Saab 900 intercooler

4. 2. 5" stainless intercooler lines.

5. Full size 6bta Dodge diesel air filter box (w/ K&N)

6. Air horn with heater grid from 6BTA.

7. VE settings:

Smoke screw in 2 turns.

AFC star all the way down

AFC washer shaved from . 169" to . 121"

AFC diaphram ~10 degrees from full power



Readings at these settings before turning up the Full Power screw:

heavy acceleration from 35 mph to 65 mph = 12. 6 psi and 964 F. No smoke to speak of yet. Performance is about the same as my stock ( no turn up except slightly advanced timing) 0ne ton '91 350 Cummins.



AFTER turning up the Full Power screw 3/4 turn:

Idle went up to about 925. turned that down to 850.

Performance w/o boat:





Good acceleration with smoke. smoke cleans up once speed is reached. Good pull away With normal acceleration I get about 5-6 psi boost and 550 F EGT.

With hard acceleration I get 10-14 psi boost and 800-950 + F.



Performance with 2 ton boat behind:

Normal acceleration pull away same as without the boat (good) and slightly better than my '91 one ton.

Running up what I guess is about a 50 percent grade (22 dgree) hill I can hold speed in 4th ( about 2200 rpm)but not in 5th (about 1700 rpm)at 60 mph. Shifting into 5th on the hill with about 9 psi the boost In 5th drops as the rpm's drop .

It accelerates in 5th on hills of up to about 8 percent grade (with boat of course).

The acceleration on level to 8 percent is slightly better than my one ton. With the 28" tires I can now accelerate nicely from 50 mph in 5h without transmission vibrations picking up.



G

 

[LAlessi]

Could you expand on that sentence a little?

I'm curious what you mean by a LOT of intake restriction and the specific success you've had by implementing that.



Thanks,



Matt

lol, it was intentional from the standpoint i have about 6 feet or more of intake tube. its so i can run under water. id rather not have it, and im willing to bet i would have some performance increase from not having so much tube

 

[bgilbert]

Those 1/2ton Rams also came with 3. 23 gears, which could explain your low rpms in 5th od. No id tag on either diff cover?

 

[driverswanted]

There was no tag. I do have aftermarket limited slip (which is working quite well btw; left two black streaks taking off with the boat yesterday) but don't know what it was changed to.

I guess I can lift the rear end up and count the shaft revolutions per one tire revolution. Strangely enough a road speed caclulator showed about a 3. 35 rear end when i plugged in my actual road speed from a gps and my engine rpms with a 31. 6" for the tire size.

 

[driverswanted]

I went back to the calculator and the numbers match a 3. 23 better than a 3. 54. The 3. 23 gear shows about 1708 rpm at 65. I was closer to that than the number for a 3. 55

 

[Forrest Nearing]

did I read correctly that you've got a Saab 900 intercooler!??!?!? that thing is paper thin!!!



you'll probably run better without an intercooler than with that!



Forrest