Project: Commodore powered buggy

[maddog]

Not a huge amount of this project relates to Holden Commodores, but the powerplant will be, so I'll create a thread here about it.

I'm building a tube chassis 4WD buggy for competition. One of the most important decisions on how to build the buggy is what engine to use, and where to place it.

As such, I ended up deciding that a V6 3.8L motor out of a Commodore VS/VT would be the go. Why?

It's a nice short motor, will be easy to fit into where I'm going to put it

Easily supercharged with the factory pump (6PSi from memory) to give it a bit more get up and go

Light compared to some of the other motors I was considering

Easily available, and easy to get parts for

I'm left with some questions which you guys might be able to answer:

- Are the VS and VT motors the same?
- Where's the best place around Sydney to get either an engine with computer/wiring harness etc or a front cut? I'd also consider getting one from QLD or VIC if it was cheap enough. I have a car trailer for my competition Jeep.
- What would I expect to pay for a front cut of a VS or VT?
- There's hardly any room to run an exhaust. Basically the extractors will just taper off to open air and run that way. Any forseeable problems?
- Is there anything else I should consider?

[mattman]

- There's hardly any room to run an exhaust. Basically the extractors will just taper off to open air and run that way. Any forseeable problems?

No idea on the rest.. but doing this it's bloody loud! I've seen a vid of someone running a block part lifter out of the engine, no extractors or anything, and it was bloody noisy..

Plus you'll have no cat.. so you'll probably end up with carbon monoxide poisoning (or the guy behind you will at least).

[maddog]

Good point re the fumes. Might have to run some form of pipe down and dump it somewhere. Just won't have much room to run too much piping.

If it was rear mount engine, it wouldn't be a problem, but at this stage I'm pretty sure I want to make it front mount engine.

[HoZy]

Run the headers and make up a bracket and go "Manifold/Headers/Cat/Resonator"

Pretty much one after the other no joining pipes if possible
So it just looks like a jumple of sound restrictors/monoxide,

Cheers
MaT

[burnz]

i personaly would use a rodeo v6
lite, lotta grunt, loves forced induction
no need 4 cats a set of zoomies go well

[maddog]

i personaly would use a rodeo v6
lite, lotta grunt, loves forced induction
no need 4 cats a set of zoomies go well

What capacity is it?

I'll have to see if I can find a wrecker that has one. I spoke to a guy this afternoon who's getting a price for a VT 3.8 motor for me.

[elljay]

You'd be betta off with a rear mounted engine wouldn't ya??

[burnz]

What capacity is it?

I'll have to see if I can find a wrecker that has one. I spoke to a guy this afternoon who's getting a price for a VT 3.8 motor for me.

3.2ltr alloy motor

[burnz]

You'd be betta off with a rear mounted engine wouldn't ya??

i hade a 253 went very well

[maddog]

You'd be betta off with a rear mounted engine wouldn't ya??

That's more like what I'm going to build.

Front engine is better for climbing up vertical walls, and it saves me having to flip the diffs over and all the hassals that come with that. The front or rear mount debate can go on forever when you're designing a rock crawling buggy, but in the end I decided to go with front mount.

I've spoken to a wrecker this afternoon who's got a VS motor with computer and wiring for $990. What do you guys think about that price? Is it reasonable?

[burnz]

sounds about right

[elljay]

OMG!!! Very coooooooool!!!

[maddog]

I've spoken to a few people today about different motors.

Can get a VS with 200,000kms, wiring loom, computer for $800 from a diff wrecker.

Private sale guy has a VN motor, wiring loom, computer, box (assuming T700 or T400) for $400.

Question. Is a VN V6 the same as a VS/VT V6? For some reason I thought the VN was only a 3.3 or a 3.6 or something? Also, can it be supercharged as easily as the VS/VT motor?

[vh-holden]

what would happen if you turned the exhaust manifolds upside down and had smoke stacks going up over the car?

[burnz]

I've spoken to a few people today about different motors.

Can get a VS with 200,000kms, wiring loom, computer for $800 from a diff wrecker.

Private sale guy has a VN motor, wiring loom, computer, box (assuming T700 or T400) for $400.

Question. Is a VN V6 the same as a VS/VT V6? For some reason I thought the VN was only a 3.3 or a 3.6 or something? Also, can it be supercharged as easily as the VS/VT motor?

3.8 same motor just revised/modern

[phat_com]

hay i just had a bit of a look around for ya (alot cheaper that the others)

$500 vn wgn complete car
http://cgi.ebay.com.au/91-MODEL-VN-W...QQcmdZViewItem

this guy has lots of motors vn-2 vp-1 vt all under $500
http://allclassifieds.com.au/c/ac?a=vi&i=1893417644

[phat_com]

or half cut (rear dam)
http://allclassifieds.com.au/c/ac?a=vi&i=701409487

[maddog]

Thanks mate. I'm actually looking at full VN's and similar now, becasue I think I can use the radiator, auto box and some other bits and pieces out of it. From looking in the trading post it looks like I can pick one up between $500 and $1000. Even if it's not registered, that's not a problem for me.

The only problem I have with the auto out of a VN (T700) is the length and weight of it.

Ideally a T350 or a Powerglide would be perfect, but I don't know if I can get one cheaply. Does anyone have any contacts or know of anyone selling a Powerglide for a reasonable price?

[maddog]

what would happen if you turned the exhaust manifolds upside down and had smoke stacks going up over the car?

You have to run a cover of some material over the engine in competition, so I'm not sure that would work, unless it was dumping out to the side.

[maddog]

Forgot about this thread! Better do some updates.

Well the specs on the buggy ended up changing a bit. We now have

5.7L LS1 motor
Powerglide 2 speed auto
Dynatrac Dana60 diffs w/ alloy axles, CTM u-joints, 5.36 gears and air locking centres

Here's some pics of the running gear











The bottom diff is the one going into the buggy, the one we were holding up was for size reference.



My seat



Hydro steering gear



Cutting the old bracketry off the diffs was the first work we did

[maddog]

A friend of mine who's an architect helped me design the frame in Autocad. It was good to be able to get the design down on paper before starting work on it. Here are some samples of the print output of the drawings.





We dummied up the drive train and I sat in the middle of it to try and work out where things would go



First part of the frame bent up and tacked together, then placed over the drive train to check fit

[maddog]

Most of the main frame complete

[Tasmaniak]

In the picture where you had the wheels, engine and yourself dummied up did you end up going with a shorter wheelbase? In that picture it seemeed as if the projected wheelbase would be rather long.

Also, what sort of transfer case is that? Is it front/both/rear selectable?

Whats the degree of turning?

Nice steering rack btw

Is it going to have individual selectable brakes on the rear?

On my buggy I can select FWD and lock up ONE rear wheel and increase my turning circle immensly.

[maddog]

The wheelbase with just me sitting in the pic is probably a bit longer than it actually is. The actual wheelbase of it is 106" now

T/case is an Atlas II 5.0 w/ HD front shaft, short rear tail housing, 5:1 reduction. It's a twin stick, so yes you can do front/rear/both drive selection.

At last check, we could turn the front wheels at 45 degrees from straight, but I'd have to re-check it now that the control arms are in. The chassis was what was stopping it at a little over 45 degrees.

I have a cutting brake which I'll hook up so I can brake both front or both rear wheels, but probably won't go the route of being able to lock individual wheels. For front/rear digs, I think just locking the opposite end is sufficient.

Got any pics of your buggy?

[maddog]

Bit of an interesting point for the LS1 fans here. I changed the sump to a Corvette LS2 sump. The reasons for this is that the factory sump is a front bulge sump. This means that when you try to drive up a steep rock ledge, all the oil runs to the rear of the sump and away from the pickup.

The new sump is a rear bulge sump with the pickup also in the rear. It also has a slightly larger capacity than the factory LS1 one.

Here are some more pics of the frame as it progresses. There is a lot more cross bracing in the frame as of these pics.

In this pic you can also see how limited the space is inside the cabin for me to sit





You'll notice in this pic that I've flipped the exhaust headers so they're facing upwards. This will leave me room to run the exhaust. Although it's starting to look like I'll need to build a custom header for the right hand side, as running the exhaust out up high like that is going to be too hot in my face.