95' Junker Drag Truck

[Big Blue24]

Different turbo, this was a VGT turbo off of an 07.5+ 6.7 Cummins. It was fully functional using a spring and drive pressure to control the variable geometry.

During the burnout, boost was hovering at 32psi, which is less than the 40 ish psi it makes driving WOT down the road because spinning rubber doesn't fully load the motor.

 

[mondtster]

What are you going to do for a turbo now?

 

[Big Blue24]

I really wanted to stick with the HE351ve for a bit to help quantify the HP increase from the 215 injector and rack plug. I can't justify spending 200 on a HE351ve when I ultimately plan to install the He351cw over HT4B twins and I need just $200 worth of parts to build the twins.

I have an extra He351cw on the work bench that I was saving as a spare for my daily driver but I don't want to blow up a $400 turbo just for fun.

I might just go back to the stock turbo for a few weeks/ months. I'll bet the stock turbo will still run 13's with the recent fueling upgrade.

I'm hesitant to build/install the twins until the truck's chassis is ready for speed. Right now, I don't feel comfortable over 100 MPH. I need to get new tires for the front and replace a few more worn front-end parts before I push this thing over 100 MPH.

I don't think the stock flex plate and stock input shaft and stock aluminum planetaries will handle the added HP/Torque of compound turbos.


Before I do anything, I need to dissect the blown turbo and see what happened.

 

[ewatts2003]

I've got an Amsoil 6" inlet filter if you might be interested. Pm me if you want to.

 

[Big Blue24]

Well, there's not a lot of turbo carnage to show in the pictures. The compressor wheel made contact with the cover. The exhaust turbine wheel also made contact with the exhaust housing. The thrust washer looked fine and the shaft was not broken. The rear most journal bearing was seized to the shaft. The compressor wheel was also seized to the shaft. In trying to remove the nut that holds the compressor wheel to the assembly, the shaft broke before the nut ever loosened up. After the shaft broke, I removed the compressor wheel and front half of the shaft and was not able to pound the shaft out of the compressor. I then tried to remove turbine wheel and rear half of the shaft. The rear-most journal bearing is seized onto the shaft and prevented removal of the turbine wheel.

The shaft portions that are visible are not blued from excessive heat so I'm not sure exactly what caused this turbo failure.

Possibly a chunk of weld broke loose in my home-fabbed adapter and it momentarily stalled the turbine wheel and caused it to push over to one side and wipe out the rear journal bearing.

It's also possible that this turbo suffered an oiling failure however the thrust washer/brass wear plate looked to have minimal wear making me think they had adequate lube.

During the 5 mile limp/drive home, the turbo ate 1.5 quarts of motor oil. I found about 1 quart in charge air cooler.


Also, my home-made flange warped a little when I welded it up and I didn't have a belt sander to make it flat so it wiped out a stainless steel gasket.

 

[Big Blue24]

I decided to go back to the stock turbo for a while. The stock turbo is actually a WH1C although I hear they are the same measurements as pre 98.5 HX35's. I ported out the wastegate to 15/16". The stock wastegate was .762" or just a hair over 3/4". I also drilled a 5/8" hole through the divider to make both volutes wastegate and thus allow the front 3 cylinders to wastegate properly.

I went with 5/8" because quick math showed 5/8" to be equal to 1/2 of the surface are of 15/16" hole.

I chose 15/16 for the wastegate hole because the stock puck measured exactly 1.125" and I wanted 3/32" overlap for a good seal.

I also adjusted the stock wastegate actuator I full turn shorter/tighter.

The result is that boost maxes out at 38 psi. So even with this additional fueling, the stock ported gate is large enough to stop boost creep. I'm going to adjust the gate even tighter since I want to run about 45psi on this turbo and drive pressure is opening the gate at 38 right now.


Overall driving impressions, the truck is down a little on power. It also spools slower than the He351vgt did. The stock turbo spools fine, it's just a little slower. I get about halfway through first gear before it fully lites and blows off the tires. The He would light almost right off the line from a dead stop and it would spin the tires through OD.

I think with good traction, the truck is capable of high 13's. We'll see in another week or two when the track opens again.

 

[Nick]

Did you find the broken pieces of your compressor wheel or do you think they made it to the motor?

 

[Big Blue24]

Did you find the broken pieces of your compressor wheel or do you think they made it to the motor?

Nothing broke off the compressor wheel, it just rubbed and deformed a little bit.

The truck is back up and running with the stock WH1C and it is running as good as ever, just down a little bit on torque & HP from the smaller turbo that spools a little slower than the VGT did.

 

[Big Blue24]

**Update**

I made it to the track tonight. All that has changed since my last outing is I removed the HE351ve VGT turbo since it blew up and reinstalled the stock WH1C turbo with a modified wastegate, basically this is an HX35 internally with a v-band compressor cover clamp instead of a large snap ring clamp.

I also added used 215 injectors that I picked up on Ebay for $65. And I installed a 2095 rack plug, $15 part as I recall.

New best pass:

13.68 @ 100.8 MPH

That calculates to an additional 62 HP at the rear wheels. My 60' times were pretty consistent all night in the 2.17 to 2.28 range.


The attached time slip was a pretty close race against a newer C-6 corvette with a well practiced semi-pro driver. He later admitted that the traction control was left on during that pass to help him maintain traction, that's why the Junker lead the race till almost the 1/8th mile mark.


All-in-all, I'm pleased with the progress and I finally reached the goal of 13 seconds for less than $1500 total parts investment.

 

[nilsson]

So you never tried the HE351 VE with 215 injectors and 2095 plug?
//nilsson

 

[Big Blue24]

So you never tried the HE351 VE with 215 injectors and 2095 plug?
//nilsson

The He351ve VGT blew up before I got the 215's and rack plug installed, so no, I never tried it.

 

[Nick]

Thats great!

 

[9712valve]

congrats, nice times! how much faster do you want to go? 12's 11's?

 

[Big Blue24]

Ultimate goal with the twins, more billet parts in the tranny, slicks, weight reduction, etc, is anything 10.99 or quicker in the 125-130 MPH range.

I'm a man of small means so it'll take a while before it gets to that level if ever.

I hope to see 12's in the next 6 months or so.

 

[Big Blue24]

Home-made caltrac style traction bars:

 

[Big Blue24]

2095 Rack Plug/Cap:

 

[TTR 21]

Nice build you got going on there man. im starting a 94 2wd sleeper beater build too but just need the time to get working on it. only thing i have had time for is 4k gov springs and 60 lbs valve springs with pump tuning and straight pipe exhaust and tinted the windows haha. also did gauges. i picked mine up for $3200. only 125k on the odometer and it already had an afe stage 2 intake! power everything on the interior.

Didnt read everything here but what are you hoping to reach for track time and HP.

Here is what mine looks like right now.

 

[Lostnwalmart]

how did those bars help your hook up?? make in some progress bud

 

[Big Blue24]

My best 60' to date is 2.12 seconds with the bars installed.

Without the bars, I had one freak 60' of 2.17, but average non-bar time was 2.38 to 2.5.

Now it runs consistent 2.14 to 2.22 60' times. The truck spins out much smoother and more controlled when it does spin. I haven't played with the adjustment height or preload so it might have some 1.95's in it with proper setup and good driving technique.

 

[Hurley]

Any strength concern with your front mounts when it comes time to get some real tires?