V-12 Engine into 308 Build, over on Grassroots

The is interesting and looks to be about what I'm thinking is needed with the changed ride height.....is the ride height on the 288 adjustable in some way?

 

No, just standard Koni coil-overs. I guess if you were serious about tracking the car you would swap the shocks.

Not sure how long those suspension forks would survive being stamped steel and used with sticky tires.

 

I've been having that same thought as I think about how I might want to implement any designs I eventually settle on. Mike's idea of weld-on adjustable has a lot of merit....but we all love the idea of bolt-on stuff. It looks like superperformance is sell brackets that must be just offset versions of stock but the more offset the more twisting, fatique forces are there. Maybe just make it thicker metal or I'm strongly considering new bosses in the frame.

 

The forks need regular inspections when used with oversized or sticky tires. They do break right at the radius on the front suspension. 328 with its bigger tires was recalled for those forks. Ferrari made new forks with a near 50% increase of the gauge of the metal. . What I have seen more was broken rear stub axles. I have advocated for years on 308 track cars having them magnafluxed on a regular basis. They are old cars being used with tires we never dreamed of in the 70's.

 

That was never intended to be used. It was there only to homologate the car to allow it to have adjustable ride height for the class it was intended to race in. A class that was dissolved before the car was finished.

 

Im having new stub axles made that take a larger bearing so I don't watch my rear wheel pass me. Boxer forks look to be billet steel but the integral stud doesn't give a warm fuzzy feeling. Drill it out and run a bolt through it.

 

I have a similar plan, we should compare notes or more accurately drawings

 

Before going to the expense have a look at Mondial axles. Pretty sure some are bigger.


Have never heard of that bolt failing in anything. Have a look at BBLMs and see what they used for forks. That car was mostly off the shelf parts. I have never heard of them having suspension issues and high banks are really hard on suspension. But then the gearboxes broke so much maybe they never had a chance.

 

How do we get this question answered? anybody know the bearing numbers maybe? no point in reinventing things

 

Stub axles again. So a 308 uses a 40mmID outer bearing and it looks like modial8 uses the same axles;

A 348 axles uses a 45mm ID bearing and early cars the same CV joint as 308 so are a possible upgrade option.

328 and 3.2Mondial use a different axle from 308 and 348....anybody know what size the outer bearing size is? I don't ever recall hearing about broken 328 stub axles? so I'm guessing 45mm but would love to know for sure.

 

Mondial 3.2 and T both use 45 mm axles.

 

Thanks! And it looks like the 3.2 mondial and 328 axle PN are the same, and for sure the 348 is 45mm so lots of parts to pick from it looks like.

 

I wonder if going to the park brake shoes inside the rotor hat on the 328 meant they changed another dimension that might throw a wrench into your plans?

 

Maybe....probably the only viable path is update the whole carrier assembly. I think I can get my hands on a loner 348 stub before deciding to buy anything.

 

I found an OLD fchat thread from 2001 that was talking about 308 stub axles and included a 328 that lost a wheel at the track and blamed a poor design with inadequate radiusing and no heat treat, apparently fixed on the 348. I saw a couple 348 left side wheel carrier assemblies on ebay for around $1000-$1300, no rights to go with. It will likely be $2.5-3k if I go down this path. I'll likely end up making stub axles....

 

I know this suspension/stub axles is a little ping-pongy but I don’t want to fix the suspension and then change the wheel carriers and need to fix it again. The 348 stuff is a pretty pricey so kind of refocused on making stub axles and I have confused myself a bit. The 308 uses a 40mm (1.575”) ID bearing, the 328 and 348 a 45mm (1.772”) ID bearings but the 328s still have issues, maybe material, maybe design, probably both.

My plan was grab grab some US diff axles to use as blanks and start cutting knowing they rarely break and ASSUMING that was because they are big and heavy…wrong. The big bearing ford 9” and all the mopar use a 1.564” ID bearing, not quite 40mm. The small bearing 9” and a lot of GM stuff use 1.53”. There are some GM trucks with 1.618”…WTF? These things don’t break without REALLY trying and they are smaller?

Design wise the US axles all have a pretty decent radius between the wheel flange and bearing surface and that must be where the magic happens. For sure the US axles are heat treated and the 308 are not for whatever reason. The ferrari stubs have a nut torqued on to hold the CV flange, that is an extra force I guess.....but it feels like a slight design change will sort the issue. Just not certain the off the shelf US axles have enough metal where I need it, I think so? I probably need to pull mine apart and get some measurements so I can be strategic about what I order.

 

This race car raced 9 seasons pulling 2Gs in the turns using 308 wheel carries and bearings with 4340 stub axles...so it seems a well design axle has no issues.

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I emailed Strange engineering to see if they are interested in making 208 axles or interested in partially finished non-hardened axles to at least save me the annealing step.