The DelSol Prerunner....

Erin1

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So I've come to the realization that I should have built the car from the middle out instead of from the outside in.

Redesigning the front end gave me the opportunity to do just that. I was able to link the two ends of the car by building the 4 tube "spine" made of 1.5" x.120" DOM pictured below. It fits nicely into the exhaust tunnel of the DelSol and I was able to build it with no bending or notching so it went together quickly. The square tubing is there just to help hold it all together as I welded it up and if you look close enough, you can see that the spine mounts are notched to allow room for the AC hoses.

The top 2 tubes will carry coolant to the front of the car and this required building the small bulkhead pictured below which allows me to terminate the 2 upper tubes at a point in the back of the car where I'll have enough room to actually put hoses on them. Its shaped like that to keep mud out of the tunnel. From there, it all bolts into the stock DelSol rear suspension mounts allowing me to use the body of the car for structure. Not pictured are the skid plate mounts and the shifter mount. All this structure is pretty much eating up all the space under the car where the stock fuel tank was but there should be just enough room for the batteries...maybe.

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The rear cross-member is built at 5 degrees and I've started on my trailing arm design, keeping the following points in mind...If I'm wrong let me know now!

1. The axles and the trailing arms should be the same length to minimize axle plunge. To achieve this means lengthening the wheel base a few inches but I suspect that the improved geometry will be worth it.

2. The trailing arm pivots and the inner CV should pivot in the same plane to further minimize axle plunge. I can do this but ground clearance will suffer....I was hoping to have the bottom of the car "slick" from one end to the other but to get everything pivoting on the same plane out back will require that the ring and pinon sump hang a couple of inches below the rest of the car. I can skid plate around it and with 38"s, I don't think I'll have much of an issue with it but whats more important? Good geometry or ground clearance?

3. While I've heard that 3" is about the right distance to offset the inner and outer CVs when everything is level to help minimize axle plunge, that works out to 2.5" as my car will only be 84" wide. The goal is to not have the outer CV in front of the inner CV at full droop which shouldn't be hard to do.

4. At full pack, the rear shocks should be working at a right angle to the trailing arm pivots.

5. A decent rule of thumb for lower shock mount placement on the trailing arm is roughly at a distance 80% down the trailing arm from the pivot and as close to the tire as you can get it without hitting it. I can't remember exactly how I came to this conclusion but I believe it was in a thread about shock/wheel travel ratios.

6. Unfortunately, I'm not going to be able to use "off the shelf" axles unless I'm cool running this thing at 88" and that's a little too much ass for the places I go. Kartek can shorten them up so I guess thats the plan at this point.

The new front end is going together now and I was able to addresses a lot of nagging little issues I had with the old one.
Update? Pics?
I have an old Del Sol and would love to find someone to do this for me!
 
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RDC247

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Damn that's harsh! I've been working out of town for 3 months so I haven't touched it in a while.

For the most part, I got the front-end mocked up and I was able to keep it short enough for my approach angles to work while being long enough for my Vue style steering booster to fit and still work with the stock Delsol steering column...but just barely. I was able to keep the total width down to 83ish with the wheels bolted on so it'll be just narrow enough for most of the trails in our area but too wide for some of the tighter stuff which is fine. At this width, total travel is limited to about 14" but the airbags are really the limiting factor here as they don't articulate but about 6 or 7 inches. I was able to keep the front end square with the factory body mounts without the use of a dedicated frame jig so I was happy with that.

The shock towers still need to be boxed but they bolt on so I can modify or move them later if need be. At some point, I'll probably ditch the airbags, put a coilover/bypass combo on it, widen it up and take it out west but this setup should work OK for poking around in the woods closer to home.

You can barely make out the radiator/fan/condenser mounts in the back there but I was able to squeeze it all in between the firewall and the shock towers without too much drama and still make enough room to service it all. I had to cut the supports out of the stock DelSol hood but everything fits and the hood closes to match the factory angles of the car so I'm hoping it won't look like a pregnant roller skate. An aluminum 3 core 65 Mustang radiator was sourced because it's square, cheap and because it should be up to the task of keeping a stockish 5.3 cool, especially with the coolant capacity this thing is going to have. I plan on using the stock Delsol AC condenser and I'm using an 16" Spal fan. Hopefully it'll be enough but a mild LS with an aluminum block is a fairly cool running engine as long as it isn't under boost or cammed to death.

You can also see I still have a couple of tubes that need to terminate in the back but I haven't forgotten about those. This is the only picture I have on my current phone but the structure is actually triangulated pretty well and I still have a couple of bars to go.

At this point, I've got an S2000 master cylinder mocked up and have eliminated the factory brake booster using a booster eliminator kit that relocates the stock brake pedal pivot for added leverage. Honda made master cylinders in 5 different piston sizes in this bolt pattern so the plan is to keep swapping those around until I get the best brake feel and then install a Wilwood with remote reservoirs. Wilwood makes masters with this bolt pattern so once it's sourced in the proper size, I think the setup should work alright. If doesn't, I'll keep hacking at it until I get it right but I'll take the easiest path available to me as long as I can take some reasonable stab at success.

Moving towards the back of the car, I've got the batteries, shifter, winch, package tray, turning brake, steering column and the pedals all mounted. The winch is mounted behind the seats in the middle of the car, the batteries behind the seats on either side of the car and a package tray covering it all up. In a perfect world the winch would live up front but there wasn't room for it so we'll give this location a shot and see how it works. There are some overlanders using interior mounted winches and they seem to work OK for those guys but I'll call the winch a gamble worth taking at this point. I'm using two Walmart side post batteries because they're cheap, easy to source and in my experience, the Optimas weren't worth the coin.

I was hoping to get the rear trailing arms done before I left town but I ran out of time. Even though I was able to get the lower frame rails/engine cage built and get the fuel cell mounted, I discovered that my rear cross member is about 6" too far back so I'll have to slide it forward a bit. The way the frame is built, it shouldn't be to difficult to do, just time consuming.

I got the accessory drive done which was easy enough as I'm not using power steering. I went with an f-body oil pan and corvette spacing on all of the accessories. A Sandan style AC compressor will work with the style of pressure regulating the Delsol came with and finding mounts to bolt one to an LS is as easy as an internet search. I'm running the stock truck intake turned backwards so the filter points to the front of the car but I can't build the airbox until I shorten the car up.

I'll be using a Holley Terminator X kit for engine management because it allows the most flexibility with engine configurations going forward. I'll be using DBW so the only worry here is harness length. Holley is pretty emphatic that you shouldn't mess with any of the provided cable lengths and as their setup is made for front engine applications, the throttle pedal cable might be a bit short. The only way this setup is going to work without cable modifications is to mount the ECU behind the seats and hope that the cables all reach.

As a side note, I used Steel-it for the first time and that poop is a revelation. Absolutely love that stuff....

Thanks for the interest.
 
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RDC247

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Been working in Vancouver BC for the last 4 months and on the way home, I detoured to Moab to meet friends who trailered their VW based trail buggies out there. It was our first time in Moab and based on this trip, I need to tweak a few things....

First, the radiator needs to go out back instead of being mounted out front like I originally wanted. We rented a new CanAm Maverick for a few days and while it's hard to complain about how competent a trail rig the thing is, it got uncomfortably hot on the slower trails . This is partly because of the air blowing off the radiator and partly because of the proximity of the engine/turbo to the passenger compartment. Moving the radiator out back will also make things considerably easier to package and give me a ton of storage space up front.

The winch....I was going to use a 5k winch but after seeing all the winching going on out there, I'd better step up to an 8k. We got stuck on "Hamburger Hill" and while we could have eventually stacked rocks and gotten up it, winching was the best way to get through that mess, This was clearly demonstrated by a group of heavily modified Land Rovers who rolled up behind us. One of them told us we got stuck because we brought "knives to a gun fight" while another laughingly asked "how in the world did we ever expect to get up that with 2wd?". After that bit of A-holeness, we watched as they proceeded to winch their entire party up the whole thing...geez.

But the trip cemented in my mind that I have some things right for what is now getting further and further away from a true prerunner and more and more into the realm of a dual sport machine...

Keeping the width of the DelSol down to 82 to 84 inches is going to be a win for not only the riding we're doing here but for places like Moab in general. At that width, it should be narrow enough to get around most of the obstacles we faced in Moab but anything much wider than that wouldn't go down some of the stuff we rode. Boulders made natural gates in many places and you weren't going to crawl over or around them period...

And while the temps weren't really that hot out there, the sun was relentless. We're used to shade and while we didn't resort to fist fighting over it, there was some bumping and pushing going on trying to get into it. AC is going to be a win in an environment like that so working hard to keep it will be time well spent.

Work and a Cummins powered square bodied Suburban I picked up in Vancouver have put a temporary dent in progress but I hope to be back at it in a few weeks.
 

RDC247

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Before going too much further, I decided to mock up the rear of the car and have spent a significant amount of time sourcing parts and researching how to integrate the factory air conditioning into the entire package. The biggest victory here was finding fittings that adapt the Honda evaporator to easily sourced #6 and #10 fittings, making the AC integration a bolt on affair.

In my travels, I came across a DelSol being parted out and I took the time to cut the rear quarters off it. While I knew the car had a substantial amount of roll protection built into it, it's hard to see it from inside the car. I was rather surprised to see how well engineered the car is from this standpoint.


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