95' Junker Drag Truck

[gunslinger]

Just finished reading all the 92 and half pages. Oh man, what a ride.

 

[haulinass97]

Really nice job took me two weeks to read only a couple pages at a timegave me a lot of idea what to dowith my first gen that is getting a ppump industrial motor.

 

[wert842]

I joined this forum for this type of thread. I read every page and looked into just about everything you did to your truck. You explained thoroughly what you did, if there was gains to be made, and so much more. Thanks for taking the time to making this thread with so much info for everyone to see! I'm so pumped to get my truck on the move and get some numbers put up!

 

[SCHMITTY]

Any progress ?

 

[Big Blue24]

Update: Pump Flow Data

Racing season is right around the corner so it's time to install some much needed upgrades on the Junker Drag Truck. First off, the factory 160HP P7100 injection pump has been a limiting factor for quite a while. It has been a fun challenge to extract as much fuel as possible from the original pump.

Zach, owner of Hamilton Cams provided a new pump cam and springs to help maximium the potential of this factory original 12mm pump. The old pump, along with the new cam and upgraded tappet springs (also from Hamilton Cams) were sent to Seth Farrell, owner of Farrell Diesel Service for the cam upgrade work and back to back flow bench testing.

Seth Farrell did a phenomenal job at cleaning up the exterior appearance of the pump, including professional packing, return shipping, and proper warning labels to inform the customer about pinned timing and pre-lube requirements for the pump itself.

Seth resealed the pump using genuine Bosch seals and plugs, but all of the original hard parts were retained with the exception of the factory cam and tappet springs. We wanted a fair test on the flow gains and hp gains from a cam/spring change only.

Still the factory original 160 HP 838 pump housing, plungers, barrels, governor, etc.

The factory original delivery valve holders cleaned up pretty nice. Zero modifications were made to the holders.

Here's a couple pictures of the old stock cam, it's easy to see why they struggle with refill in the upper rpm range, they have so little re-fill duration it's astonishing, almost as if the factory was designing them to be compatible with reverse or forward rotation motor setups....

Now for the important technical information, how much did the old pump flow????
With 40 psi supply pressure and 105*F fluid:

At 1000 RPM, the old pump flowed 490 cc's
At 2000 RPM - 480 cc's
At 3000 RPM - 440 cc's
At 4000 RPM - 330 cc's
At 5000 RPM - 110 cc's

After the Hamilton pump cam swap:
At 1000 RPM - 490 cc's (0 gain)
At 2000 RPM - 490 cc's (10cc gain)
At 3000 RPM - 450 cc's (10cc gain)
At 4000 RPM - 430 cc's (100cc gain)
At 5000 RPM - 430 cc's (320cc gain)

Now for those concerned with total flow, we are utilizing the same comp cut delivery valves and set the pump for identical delivery at 1000 RPM (engine rpm) so we could perform accurate back to back testing showing the gains from the camshaft alone in the form of upper rpm performance and hopefully more HP due to increased injection rate. With full cut DV's, this pump would be capable of over 500 cc's of fueling but that was not the targeted research/test parameter.

I know there are guys out there wondering about the home maxed barrels and the overall balance of the pump. The pump had a 20 cc spread at low idle which is pretty far out of spec, in fact, the new cam setup has a 2cc spread at low idle. However, the full throttle balance at 3000 rpm or around max power had a 30 cc spread which isn't too bad, the new cam setup has a 20 cc spread at the same 3000 rpm WOT condition.

I'd like to recognize both Hamilton Cams and Farrell Diesel Service for their help and support!!!

The new pump install is nearly complete and track testing will come soon!!!

 

[97$moker]

That jump in cc's is definitely impressive. Cant wait to see what it does at the track.

 

[CorneliusRox]

So does this mean that you're going to be switching you transmission shift method? I hear it's hard to get 47rh's to shift much higher than low 3000's RPM, and it seems like you're going to want to shift closer to 5000RPMS now.

That pump does look sexy as Hell after being cleaned up though!

 

[97rada]

So does this mean that you're going to be switching you transmission shift method? I hear it's hard to get 47rh's to shift much higher than low 3000's RPM, and it seems like you're going to want to shift closer to 5000RPMS now.

That pump does look sexy as Hell after being cleaned up though!

Couldn't you control it with a manual vb a lot easier even with a rh

 

[crackerman]

He has lightened governor weights to prevent earlier shifts in 1,2,3 gears. Overdrive is the mystery.

 

[SCHMITTY]

He tested your old 160 pump at 40 psi ? Weren't your pushing 90 psi into it ? Just wondering if there was a difference in cc's with 90 psi. Are you going to push more than 40 psi fuel pressure into your new pump setup ?

 

[YOUNG GUNS15]

With as much messing around with springs and weights the will does, I think it would save a lot of stress and time to throw a ratchet shifter in that thing, modify the VB for manual second gear lockup and go racing!

 

[CorneliusRox]

Couldn't you control it with a manual vb a lot easier even with a rh

It would be, but he has kept it as a full auto for this long because of repeatability. The manual VB (especially TFOD-3 kit) would have always been the easy way out.

 

[madmikeismad]

I can't believe the drop off in flow is so dramatic on the stock cam. Seems like trucks should actually be slowing down at full throttle LOL

 

[Big Blue24]

Couldn't you control it with a manual vb a lot easier even with a rh

It would be easier but much less consistent for testing purposes to do a full manual VB. It's time consuming to constantly swap shift spring and play with the governor weight but I've been learning a ton about governor and VB setup on this trans (learning is good!)

He has lightened governor weights to prevent earlier shifts in 1,2,3 gears. Overdrive is the mystery.

Yes, I lightened the weights, then I swapped in a V-10 governor assembly which is even lighter weight and it bumped shift points up to 4000+ rpm. I went back in with the stock 1-2 and 2-3 shift springs and the V-10 governor and it's almost back to where my old lightened governor and custom spring setup was. 1-2 is down to about 2800 rpm now and 2-3 is around 3400 rpm now.

He tested your old 160 pump at 40 psi ? Weren't your pushing 90 psi into it ? Just wondering if there was a difference in cc's with 90 psi. Are you going to push more than 40 psi fuel pressure into your new pump setup ?

Yes, however the test stand is only setup to easily test at 40 psi so that is where it was tested. Honestly, with the way power drops off above 3000 rpm as evidenced by the loss of boost, it's pretty clear where the pump loses peak flow even with 110 psi lift pump pressure. What's great is I still have the high pressure lift pump setup so it will be easy to perform back to back pressure testing on the truck with the new pump cam setup.

With as much messing around with springs and weights the will does, I think it would save a lot of stress and time to throw a ratchet shifter in that thing, modify the VB for manual second gear lockup and go racing!

The thought has crossed my mind, especially since I have a spare VB to mutilate with the TFOD-3 kit. I don't have a rachet shift though and that $300 expense is not within the "ultra cheap theme"

It would be, but he has kept it as a full auto for this long because of repeatability. The manual VB (especially TFOD-3 kit) would have always been the easy way out.

Very true, well said!!

 

[Chrisd91]

Ratchet shifters can be had used for ~$100

 

[YOUNG GUNS15]

brand new my B&M pro ratchet was 200 ish, I think once you figure in your man hours to mess with everything (double for being in a garage with no lift, rolling on the floor with ATF dripping in your face) I think it would be worth the investment to save you some time in the garage.

If the turbo system ever gets upgraded you dont have to pull the VB down again to change shift points, just mentally tell yourself to hit the shifter a little later LOL

Can you tell Im partial to manual VB's? haha

 

[CorneliusRox]

I would think a better solution would be to grab a 47RE (or 48) and make a stand alone unit. I've been toying around with that for a while. If I had an oscilloscope and more time in the day, I'd have a better understanding of it and be able to iron some details out. Anyways, from what I've found, the solenoids use about 2A max, so you can get a solid state relay and use an Arduino as a controller, and add some inputs from TPS and CSS, and could potentially do whatever you want. The PWM on the solenoids is the thing that's tough to pin down.

I've often wondered if an easier way would be using a TFOD-3 kit, and then making an actuator to shift for you and be controlled by an Arduino.

 

[SCHMITTY]

Do you think your 351/4b setup was capable of more hp ?

 

[Big Blue24]

Do you think your 351/4b setup was capable of more hp ?

I wholeheartedly believe this truck was/is still fuel limited on it's quickest passes. Look how clean it is on this 10.95 @ 126MPH pass!! I'll bet it could burn another 50-100 HP worth of fuel.

[ame="http://www.youtube.com/watch?v=Ef9B63yl_g4"]http://www.youtube.com/watch?v=Ef9B63yl_g4[/ame]

 

[1-5-3-6-2-4]

Late to the party. But if anyone wanted to see the governor tubes. I swapped a 4wd 47rh to 2wd.