Has anyone considered AWD?

[myclone]

I have discussed this with another member somewhat and while Ive never thought of tackling the project myself I can hit the high spots of our coversations for some FYI that may save your sanity.

1. The existing syclone/typhoon chassis is nothing more than a regular 4wd S10/Blazer chassis with some minor differences since they are AWD and not selectable 2wd/4wd. Translation=pick up any 4wd S10 chassis from ~85-94ish swap in the AWD transfer case and a syclone/typoon/bravada left front axle tube and youve got an AWD chassis. The AWD transfer case was used in syclones, typhoons, bravadas, and AWD astro vans so its easily sourced in the bone yard and there are a hand full of companies that offer rebuilt units for ~$500 outright. One note is that the tranfer case in the syclone has a specific output shaft so if you use a syclone unit you will need the correct slip yoke for the front of the rear drive shaft. Other than that all the AWD transfer cases are identical in the above listed vehicles.

2. The existing frame on an S truck is very tall so channeling the body over the frame to get a nice ride height will intrude into the passenger compartment quite a bit (the typhoon/blazer frame is basically the same only shorter in length). Be prepaired to build a custom frame unless youre 5'2" and the loss of head room isnt a poblem using the existing frame. Also keep in mind that a syclone/typhoon looks low due to the cladding(cladding=ground affects to most ppl) fitted around the wheel wells and the rocker panels hiding the frame and the gap between the tire and fender lips. Pull the cladding off a syty and you will note a ride height very close to a 4wd S truck that looks like someone stuck low profile tires on (which is basically what GM did).

3. Packaging the driveline will be a PIA Im sure as the front output yoke on the sy/ty/bravada transfer case hangs down quite a bit so you may have to build a higher trans tunnel and raise the engine/trans/transfer case to get enough ground clearance to even think about driving the car on the street. The track width on the front driveline may require custom A arms and half shafts to fit a decent tire on the front but I dont know the track width of an F body vs an S truck so some research here may turn up more info. The rear track width is simpler due to it being a solid axle so you could swap in a 2wd S truck rear which is narrower to get more rim offset and/or a wider tire to tuck in the wheel opening. 2wd and 4wd rears interchange and all the track width difference between 2/4wd is between the spring mounting pad and the brake backing plate. The ZR2 S truck diff is even wider than a run of the mill 4wd S truck BTW (its a 8.5" diff too compared to the syty 7.6").

4. The 4wd S truck chassis uses heavy/bulky torsion bar suspension and the torsion bars are roughly half the length of the entire truck. A coil over/tubular A arm suspension is available to get rid of the bulky factory A arms and torsion bars but its a tight fit around the steering linkage, half shafts, and other hardware up front. Its not a 100% bolt in deal either and requires some frame mods to install.

5. The GM/Barg Warner AWD transfer case is not easily adapted to any manual trans currently available. The syty crowd has beaten this subject to death and its generally agreed upon that it could be done but you will need a money tree(s) to accomplish it. I wont get into details here but rest assured it wont be cheap or easy unless you have a full blown machine shop at your disposal.

6. Front to rear tire diameter is critical so no big n little look can be pulled off without destroying the tranfer case in a matter of a few miles. Juggling tire aspect ratios and rim sizes has been done but the look is all wrong since the sidewall height of the front tires ends up larger than the rears which looks horrible. Most syty ppl that want aftermarket wheels/tires go with 275/40/17s on the front and 315/35/17s on the rear which isnt quite as noticable and the front/rear rolling diameters are less than 1% if memory serves me correctly. While you could theoretically juggle front and rear gear ratios to allow the running of different size front and rear tires Ive never heard of anyone being able to do it with the current selection of gear ratios available and keep the front/rear driveline speed differences at acceptable levels. Its generally accepted and I agree after seeing how the AWD trasfer case works that any significant difference in front/rear driveline speed will destroy the viscous coupling unit in the transfer case in a matter of minutes not to mention the vehicle will be all over the road and hard to control. Ive actually driven a 4wd that someone mistakenly put different ratio front/rear gears in and to say it was a hand full to control would be an understatement.

Basic S10 FYI stuff.... All S truck chassis are the same from the fire wall rearward. The diff in chassis between 2wd and 4wd models is from the firewall forward as well as the the extra cross member in the middle of the truck to mount the chassis end of the torsion bars in 4wd only models (its bolted in so its easily removed). As was mentioned 2wd and 4wd diffs is a bolt interchange but the 4wd diff is wider. An F body or ZQ8 steering box is a bolt in quick ratio upgrade. Baer makes a 4whl disk upgrade kit for the syty that is very nice but the same could prolly be fabbed up using vette components (thats what Baer used in their kit). I had their set up on my first syclone and it was a night and day difference compared to the stock brakes.

One thing I would highly suggest you do is either find a 4wd S truck in the bone yard or find a friend/neighbor/whoever with one and look over the chassis as well as take some measurements to see what youre getting into before you spend a dime.



Dont get me wrong as Im not trying to scare you off and it can be done with the right amount of money, tools, and talent at your finger tips but it wont be easy. I consider myself a very good fabricator/builder and I wouldnt attempt it and I can assure you any thread of sanity I have would be short lived if I did but if you have the capability then by all means go for it.