Welcome to ISSPRO’s Performance Diesel Blog

Come view this page periodically to see updates about everything from upcoming ISSPRO products to updates on the build of my new race truck, racing results and the behind-the-scenes thrashes needed for all of the above!

Michael Pliska (ISSPRO Engineering Manager)


Race Truck Build Report:

If you missed any of the earlier blog posts about this build, they are available here.

Episode 29:

Sorry for the long time between updates, I’ll go into that a little more towards the end, but suffice it to say that life got in the way again!

Back to the firewall structure, I realized that the tube I was working on at the end of the last update would have an exposed end, and it would be much stronger at the joint if I capped the end so the tube would not deform so easily.

First I needed a circle cut out of 0.100″ thick 4130, I used some 1″ strap material, drew a circle on it, and sheared then ground it down:

It was easier to clamp it and weld it to the “stub” bar before welding that bar to the chassis. After tacking the end cap on while in the clamp, I welded it fully on, then carefully positioned, tacked, and welded the tube to the chassis.

Next up was a vertical tube, notched, positioned, tacked then welded in:

The next 3 tubes were tricky as they needed to run together at the same spot for the optimum strength. I notched them and mocked them up before welding any of them.

I ended up deciding to leave a small gap between the two that come together on the same side, so I could fully weld without too much trouble. Unfortunately once I tacked the far side the weld draw pulled the end down, requiring a little help to hold it in place for welding!

This photo gives you an idea of how tight it was in the junction with the pillar bars, there are a lot of tubes coming together there! Now I just need to figure out how to work in a cupholder ;)

Speaking of cupholders, I started worrying about driver and steering wheel placement a little more as I finished up these areas, so I spent a bunch of time mocking pedals, seat, and steering wheel into place while seeing where everything felt the most comfortable to me. I may have even made a few “Vroom, Vroom” noises while doing so. Interestingly I found that I was most comfortable with the steering wheel centered 1″ to the left of being on the same centerline of the seat. Later I checked my Vega out, and of course it is 1″ to the left and seems to have trained my brain into thinking that is the most comfortable!

I took the final measurements and went back to the CAD model, to figure out the best routing of the steering column through the tubes, trying to leave room for the front tires as well as the exhaust manifolds.

Here is my first positioning, which avoided a tight space in the double frame rails but started to eat into the space for the front tires.

After a few iterations I found a position for the U-joint which would have shallower angles for the joints and more tire room, but it really “threads the needle” as it passes through a gap in the double frame rail tubes.

At this point I ended up with several competing priorities that have cut into the race truck time. Probably the most high-profile one was my appearance on the Motorhead Garage TV show, that chewed up some time making all the arrangements then flying out to do the show. That said, it was an awesome experience and it was great to work with Sam Memmolo and Dave Bowman, I’ve been watching those guys on TV for literally decades!

I had previously added a new exhaust system and associated mounts on my Vega. One of the first times out with it I discovered that the front crossmember had broken off the chassis, requiring a bunch of grinding out of old welds, rewelding and gusseting.

After adding all the weight of the new exhaust to my Vega, I figured it was that much closer to the 2800 lb minimum weight for the Super-Street 10.90 index class. While my car is one of the slowest in the 9.90 index class (running around 144-145 mph on the throttle stop), I could probably run 10.90 @ 142 and have the tactical advantage of being the faster car through the top end. After spending way too much time building weight bars and scrounging up lead to melt into them, I ended up missing the race with a sick kid!

Speaking of that kid, you might remember that she crashed her Jr Dragster two years ago, and we had been using a borrowed chassis. I returned that chassis at the end of last season, so the next project was rebuilding her wrecked car.

I straightened the chassis main tubes, then built a new left front spindle assembly along with an insert for mating it to the old tube, set the alignment angles and welded it back up.

The cage was damaged in the wreck, and she was getting too tall for it anyway. I left parts of the original cage in place to hold the parts of the new cage, but this shows how much taller the new cage is.

After way too many hours I had rebuilt the front end, cage, and even rebuilt the rear section of the frame so that the engine assembly mounted at the correct height and 15° angle rather than using adapter plates and spacers, and added a beefy tensioner for holding chain tension. I even added a hook for holding the helmet on the return road, and a slide-in mount for the safety flag.

When I finally did some racing myself this year I was fortunate enough to win a few races, including the Siskyou Diesel Fest, and the highest payout portion of the Woodburn Night of Fire event.

With racing at a slight profit for the year I decided to enter my first NHRA national event since 1993, running in the 9.90 Super-Gas class. I was mostly going so I could see the event as a spectator (and better yet, one with a restricted area pass and on-site camping). My daughter had voted for this choice since she had a longtime online friend that lived 2 hours North of the track, figuring we could work out a way so they could visit while we were up there.

I surprised myself and got the car sorted out to a 9.906 within our two qualifying passes, but first round I managed to forget something I had long ago learned about racing Super-Gas: Most of the cars in Super-Gas are very low with long overhanging body panels, which trip the finish line beams instead of the tire. My car is very low BUT the body panels in front of the tire curve upward, so the tire is always what trips the beams. I haven’t raced Super-Gas all season, and none of the cars I run against in bracket races are built like that, so I was used to cutting the finish line close compared to the other car’s front tires. I managed to take what works out to about a 0.004 sec (9.2″) margin in front of the other guy’s front tires, but since his body panels tripped it he crossed by 0.002 in front of me, and adding up the incremental timing results and datalogger info it appears I would have run another near-perfect 9.906 if I would have just stayed on the throttle!

After all that, at least I was “visible” in many of the TV shots, showing up in the background as I hung out in the restricted area (see me just over the right shoulder of the guy with the white beard):

Unfortunately the race also added even more delays to the race truck construction, courtesy of a spectator in an F250 apparently trying to “Roll Coal” as he passed by my pit spot. He ended up showering me with gravel, and some metal fragments that were in the gravel ended up embedded in my cornea, requiring surgery to remove them and the associated rust. This has cost me another two weeks of productivity, and nearly cost me my rare 20/10 vision (at least in that eye). Ironically I am a real stickler for eye protection for myself and anyone around me, as I’m known as the “Safety Glasses Nazi” at work. Only 30 seconds before that truck passed I had been wearing safety glasses since I was working on the race car, but I had just put them away to go pick up my daughter. While much has been written about the negative effects of diesel owners “Rolling Coal”, here is yet another reason to disapprove of the practice. With my eye healing up I should be back out in the shop in the next few days, resuming work on the race truck.

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