355 Current market pricing for 355 challenge speedline wheels

It’s not, I had to measure them.
I’m having wheels built and I want them to be built in the same spec as my challenge wheels. Getting it wrong will be a very costly mistake.

 

https://www.ferrarichat.com/forum/threads/355-speedline-challenge-wheels-strange-offset.506358/page-3

I guess I was being lazy and re-posting bad info.

Anyone have a confirmation Speedline Challenge wheels were actually 18 x 10 +77.9 at some point? Most pics I’ve seen, the wheels sit further out than OE. I believe +68 is correct. But of course, open to possibility +77.9 exists.

 

I run the fronts with 11mm spacers and they look about the same as yours to me. I think you should go with +49 to be sure.

 

The original speedline decals on my white wheels are long gone. In 2017, when I came to Pocono Sportscar, I put these speedline and 37 decals on the wheels...


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77 would be odd looking

 

All challenge wheels on BaT are +49/+68

 

That’s why I had to pull mine off to measure them. Even though you said that the offset you had was (+77) I didn’t believe that that size was possible.
Now we know most are probably +49 and +68.
But like most of this old Ferrari stuff I believe there’s probably a few variations. Like some of the sizes you posted earlier

 

Yes, but the faces also changed with the sizes.

 

I can tell you this. I also ran my fronts with 15mm for the longest time. 4mm more than it is now. I think it’s perfect the way it is now and I wouldn’t run 15mm again.

+49 is 4mm more aggressive than +45. Challenge wheel fronts are convex, so the spokes poke out more than the wheel. You can probably get away with it with a different style wheel, but I did bend my fender with the 15mm spacers.

 

Here’s my other 355 when I ran 15mm spacers front, 11mm rear. If you think yours sits less aggressively, it’s probably a +49. I was one of first to run 15mm spacers in the front with challenge wheels.


The recommended setup at the time from Hill Engineering was 11mm front/15mm rear. I switched it around on purpose out of curiosity. I now feel 15mm is too aggressive front or rear. 11mm is perfect if one wants spacers.






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Your black car looks great,
11mm is perfect for me. I’ve had to repaint my fenders already with 11mm. 15 won’t work at my ride height. I’ll assume my front wheels are the regular 49mm, I must have measured incorrectly and thought it was 45mm.

 

Thanks for all the input and info in this thread.

 

*+45 is 4mm more aggressive than +49.

 

With Ken’s permission I stole his knowledge and distilled this tread into a blog post / buyers guide. Please let me know what I missed and what typos I made.

https://348s.forsale/2025/06/04/speedline-challenge-wheels-buyers-guide-sl886/

 

That’s good.

 

Powdercoating is “ok” as long as the shop knows how to powdercoat mag wheels properly and do it with minimal orange peel and the orange peel is satisfactory to you. The problem is finding that shop. That’s the risk. It’s hard to correct once it’s done was my point. Painting doesn’t have the same risks.


I posted info on two shops in Japan who “specialize” in restoring mag wheels as an example. Both powdercoat. One resulted in a relatively smooth finish. Not as smooth as paint, but pretty good. The other resulted in orange peel like you wouldn’t believe. Most powdercoat shops have a noticeable level of orange peel imo.

I also posted a link to Chips in FL. They paint the base color, then apply a powdercoat clear for durability. Sort of a hybrid finish I guess. Why paint? Paint is thinner than powdercoat. It’s not gonna orange peel. Powdercoat clear can probably orange peel, but like regular clear, it depends on the skill of the sprayer.



Btw… the photos you used for “standard” (no spacers) are probably bad examples as those are the first iteration challenge wheels, which most don’t have, and probably can’t get. Best to post samples of regular challenge wheels most are familiar with.

 

*the black wheel you used to show “smooth paint” is actually powdercoated.

 

These wheels were powdercoated recently.


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Regarding lug seats for restoration. They can be popped out and re-used. Or you can simply buy replacements from Hill Engineering.

https://www.hillengineering.co.uk/wheel-inserts/wi-355-ch


Rookie mistake #1 is restoring wheels with lug seats/inserts still in place. Don’t make the same mistake I did.


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Were the 77's for early 348 fitment?

Here's mine, I sourced these from fchat ~13 years ago.

 

I doubt those rears are 77mm judging by the fitment. They look far too flush.

 

I think mine are standard 68mm. Which I got backwards so wouldn't make sense for an early 348 - they'd have even less offset (lie 63?).

 

Question for Ken: do we *know* if Speedline/Ferrari made wheels specifically for the 348? It seems to me like the SL886 debuted on the 355C and where retrofitted to some/all 348s for the seasons they overlapped.

 

The lower the + offset number, the further they push out. Any reason early 348’s would be more pushed out than 355?

 

Oh man, that’s a great question and something I’ve never quite understood. The later 348s (spider, gtb, gts) are supposed to have the same rear geometry as the 355 yet the 348s have lower offset wheels. Why?

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