95' Junker Drag Truck

10's are the original goal for this truck. It doesn't have enough power to run 10's even with adequate traction, but there are planned fueling upgrades such as full-cut DV's that will surely provide the extra fuel to run 10's.

Unfortunately, funds for a roll cage are slowly accumulating, so I don't think I'll have a cage till winter time. It's not just a $350 roll cage, it's padding, SFI seat belts, etc.
 
Will, if you don't mind me asking, how much do you have into the entire truck now? Including purchase price? Just the truck now as it sits, not the extra parts you've acquired.
 
madmikeismad said:
Will, if you don't mind me asking, how much do you have into the entire truck now? Including purchase price? Just the truck now as it sits, not the extra parts you've acquired.
Click to expand...


I have $1500 in base truck plus $2207 in performance parts = $3707.


Total in the truck including purchase price, fluids, and non performance parts like front tires, tie rod end, control arm bushings = $4428.


The cost to play has definitely gone up from 20 years ago when I was a young kid dreaming about owning my first dirtbike.
 
agreed for the power that truck has and the fun you have had its been a great investment
 
***Update***

I put the Junker Drag Truck on the dyno today, it was a dynojet 248 HD. It was 90*F so there is a fairly large 1.07 correction factor.


Here's the video:

[ame="http://www.youtube.com/watch?v=OPEvvLuRAWc"]http://www.youtube.com/watch?v=OPEvvLuRAWc[/ame]
 
I blew up (3) total boots today, two on the dyno and one at the track. Needless to say, siliconeintakes boots and vortex boots are not tough enough to stand up to high boost with high discharge temps.

Siliconeintakes.com 3" to 4" reducer, this one blew at 40psi between stages on the dyno on the first run. Total boost was 80 psi but this boot is the reducer between stages from the He351 inlet to the 3" charge pipe. This coupler lasted about 1 year so probably 75-100 passes at the track.
BlownBoots1.jpg


This siliconeintakes.com 3" straight coupler is on high pressure side on a straight run. It lasted about 10 trips down the track and blew on the 4th or 5th dyno run. Junk in my opinion, plus the fact that upgraded 3" straight couplers are readily available elsewhere.
BlownBoots3.jpg


Here's another angle:
BlownBoots4.jpg


This Vortex brand silicone reducer 3.5" to 3" came from Columbia River Mandrel Bends. It held up better than the siliconeintakes.com reducer but it did still ultimately blow. The 3" charge pipe at this connection laps inside the charge air cooler's 3.5 inlet so there is very little side loading at this connection, it looks like a pure boost related failure. Discharge temps could be approaching 500* at this location so heat is definitely playing a role as well.

BlownBoots2.jpg


Unfortunately, I lost a section of my charge pipe in this explosion that took place mid-track. So this boot cost me about $21 for another 3" mandrel bend 90 and $5 in clamps.
 
Here's a dyno sheet. They didn't hook up the tack sensor so there is no torque graph. I did, however, input the HP numbers to figure out the peak torque.

On the 708 HP run, it put down 708 HP @ 2724 RPM and 1452 ft/lbs @ 2442 RPM.

78MPH = 2000 RPM
117MPH = 3000 RPM

As you can tell by the numbers, this truck has a nice smooth power curve but clearly lays over at peak power and makes a smooth gradual decline as RPM increases. I assume this is related to the reduced fuel delivery as the 160 pump's cam profile does not allow adequate fill time in the upper rpm range.

Dyno542.jpg


Same chart, better lighting

Dyno541.jpg


On the 691 HP run, it put down 691 HP @ 2570 RPM and 1476 ft/lbs @ 2313 RPM.

On the 708 HP run, 140 MPH = 3600 RPM so this truck makes just 450 HP @ 3600 RPM this is why the truck feels like it lays over above 3000 RPM..... because it does!
 
Last edited:
Smoken Gun said:
Any recent changes to the truck for the dyno Will?
Click to expand...

The only thing difference since it last ran at the NHRDA event back in March was I tightened the 5K governor springs 3 clicks tighter for a total of 11 clicks per side. If you watch the dyno video, you can see how touchy the throttle is when the truck is bucking and jerking before the pull.
 
After the dyno event, I went home and fixed the broken 3" straight coupler, I replaced it with a stock 3" boot and double clamped it.

I then went to track for test n tune where slicks are allowed and the track is actually prepped.

First pass I left with a couple psi boost and 21 psi in the Mickey Thompson 29.5x11.5 slicks and cut a respectable 1.87 60' time.

This run resulted in a new personal best run of 11.57 @ 121.45MPH

Timeslip542.jpg


On the second and final pass, I aired the slicks down to 18.2 psi and left as hard as I could with the brake pedal on the floor. I didn't look at the boost gauge but it had to have been 10-15 psi. It did two short hops then hooked up and cut a new personal best 60' time of 1.73. I was well on my way to a low 11.3 pass when I lost yet another boot, 3rd boot of the day just past the 1/8th mile somewhere between probably 700' and 900'. I coasted to an 11.86 @ 93 MPH.

I lost the charge pipe in the process of this blown boot so I had to drive home slowly.... this truck will barely go 60 MPH naturally aspirated sucking through the charge air cooler....
 
I weighed my truck at the track tonight as it has the added ballast, some tools, and full tank of fuel less the few gallons burned on the dyno. Truck came in at 5320 without driver.

With me and all my gear, the total truck weight was right at 5580 so with the 121.5 MPH trap speed, that puts the average horsepower right at 680 HP throughout the run. The dyno runs today seem to collaborate this calculated average rear wheel horsepower number.
 
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