putting GS wheels on a 4200 messes up the the msp and asr and speedo??

[karatemaserati]

was advised not to do it by a dealer. does this happen?? is it easily rectifiyable??

 

[Woody]

Later 4200s could be spec'd with GS allows and I believe they bolt straight on. I would think that so long as then rolling surface is the same, the speedo will be fine.

 

[Woody]

Ps have you got a set lined up? They're not easy to come by.

 

[Woody]

Pops no clue about the MSP and ASR. No idea why that would cause problems.

 

[CraigWaterman11]

The wheel speed sensors do not read off of the rims or tires. I would find it hard to believe that if all of the tires are spec'd correctly at 19" instead of 18" it would mess with the MSP/ASR that read from those sensors (one sensor is still reading the same wheel speed the other sensor is on the other hubs). Now the height from a 265/35/18 to a 265/35/19 (these are the rear tires) is just slightly different but nominal at best. It might mess with the vehicles calibrated speed-o-meter but it would be nominal amounts. I run into this a bit when I am lifting trucks and going from 265/70/17 to 305/70/17, most don't care because they want the truck lifted. But for a Maserati you can google a tire chart and see it's not going to make a huge difference. I have GS rims that I already had media blasted I am about to paint hopefully within a week going on my Spyder.

 

[CatmanV2]

Sounds like twaddle to me. Craig's more convincing, though

C

 

[mjheathcote]

Complete BS!

 

[CraigWaterman11]

Complete BS!

+1 on the brief version of what I said! lol

 

[Andyk]

Yep, they were an option on the last face lift 4200's.....

 

[BJL]

There are plenty of apps that give you info such as rolling circumference, height and radius. As long as you maintain the rolling circumference balance between front and rear then the only problem you would have is speedo error which is about 3.5% increase per step up in rim size on identicle profile or 3.5% increase on profile increase alone. At 100 mph it would read 103.5 assuming the speedo isn't undereading to start with, which they are by upto 5%.

MSP can only detect rolling circumference differential caused by an uneven increase in RC

 

[davy83]

The only thing that will upset speedo, ABS and ASR is if the rolling circumference changes. You cannot put wheel tyre combinations on the car that are much different in total circumference (or rolling radius) without it causing problems. I would think +/- 2% in rolling radius is perfectly ok, 3.5% is pushing it a little ,and you need to watch the tyres don't start hitting bits of the body. Bigger diameters will potentially reduce acceleration as if affects the final engine to road gearing.

 

[hodroyd]

Dealers do not know everything and use BS to confuse..!!

 

[karatemaserati]

hmm thaught as much.

 

[zagatoes30]

As stated their are apps to calculate tyre / wheel combinations. Normally if you move up on one you should move down on the other but even if you don't you can work out the difference and see how that compares. Never changed the wheels on the Maser but I changed loads on Alfas, VW, Audis etc all with no issues.