Project Hellraiser 3

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It's hard to believe that in a few months my existing chassis will be 5 years old. In that time the chassis saw 2 power plants, 2 sets of axles and the addition of a rear bench seat.  I am happy with how it has turned out, especially when I think I only possessed a few grinders, a manual tube bender and a welder when I started it back in June 2004.  I have slowly built up my tool collection and have gained access to some cool fabrication options at work and have been itching to build something to see what I could do now. 

I recently acquired enough 1.50" x .120 DOM to build a chassis and I am currently leaning towards using my Hellraiser 2 chassis as a base for a couple reasons the biggest being to answer a lot of the questions I get about the chassis plans I sell.  Despite the build up info on the chassis plan web pages I sill get asked what engine can fit in the designs, how easy is it to change the design, can different sized tubing be used, etc.  By using the 2 seater chassis as a base I can change things around a bit to show how easy it is for to customize the look and functionality of the chassis. I will also detail the buildup in such a way so it creates a roadmap to building a chassis using my plans.  While you can just follow them and go straight to the end before mocking stuff up, it really is better to stop along the way and check the fit of your selected components.  Doing so will allow you to make key changes that benefit your component selection as well as allowing you to customize your chassis. 

Design specs: 3 seater, front engine, single piece front driveshaft with a front mounted radiator.  The plans assume a two seater with a rear mounted radiator but I want to show how easy it is to deviate from the plans if required. This go around I'd also like to play around with getting the nose as low and narrow as possible, optimize the belly clearance for my drive train of choice and create a roomier passenger compartment. 

To mock up the drive train I picked up picked up what is supposed to be a low mileage 1997 S/C 3.8l off of Craigslist a few weeks back which will go well with the spare TF904 I have in my parents garage. The motor could serve dual purposes - I have been wanting to do some motor upgrades on my 3.8l for a while now and if this motor is truly low mileage I can build it up on the side and swap it into my buggy when it is done. Worst case I can use it for a core if I want to just spring for a rebuilt long block. 

One of the first things I built that I could attribute to this project was a wheeled motor stand so I could move the motor around easily.  With the motor was on the cart I have been slowly picking it apart with the eventual goal of tearing it down to the heads to check out the internals.

Another tool I wanted to make for this project was a simple chassis cart that would allow me to easily move the chassis around during it's construction and to serve as a reference plane for measuring purposes.  The cart is made from some scrap 1.25 x .120 wall square steel tubing.  I don't think it is heavy enough to be a true chassis jig but feel it will make life easier compared to building the chassis on my concrete floor.

The finished chassis cart with scribed centerline.  I also added some tapped holes so I can set the lower chassis width via some pieces of angle iron.

Here's a picture of what I have been playing with on the computer in my spare time.  I took my 2 seater design and lowered the hood line to start.  I am currently trying to configure the belly cross members so I do not need a 2 piece front driveshaft in an effort to save money as well as eliminate driveshaft vibrations in 4 high (common and nearly unavoidable with a carrier bearing driveshaft).

Update 3-9-09

My plans kind of got sidetracked for a week during which I thought I had blown the motor in the 4 seater.  I had been going down the path of prepping my spare motor so I could get the 4 seater mobile again and out of the garage.  One of the mini projects involved porting the supercharger housing. You can see in the before pictures the casting on the blower outlet is very jagged. When the blower spins up the air goes thru the large arrow shaped port at supersonic speeds which builds heat as it passes over the rough surfaces - I have read the temps can hit 300-350 degrees. The slots beside the main port are silencing ports, they allow the air to bleed into the chamber which basically quiets the blower. I have read you can plug those if you want more blower whine but I am not going to try that.

There is a surprising amount of information on the net that covers this, The best stuff was on the Eaton website where they covered what you could do to improve performance. This mod won't add horsepower but will lower the temp of the air going into the motor thereby reducing the chances for detonation. So it really is a supporting mod that will allow you to run smaller pulleys or other mods safer. I chose to emulate the outlet porting done by a shop that has a supercharger dyno figuring they tried a few things and ultimately sold what worked the best. The intake already matches my ported throttle body (72mm opening) and will only need to be smoothed out.

After making a fixture at work this morning I stuck the setup under a manual mill and cranked what you see out during lunch. I am pretty happy with my first attempt.  I'll see how it works in the future and have a spare housing if I need to make any changes to my porting.

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