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Discussion Starter · #1 ·
I'm thinking of getting a set of track-only rims/tires for my GS & was wondering if anyone else has done this. Of course, the GS now has a 19" Pirelli P-Zeros but, an owner of a tire store recently told me that Toyo Proxes R-888 R series tires mounted on 18" rims would be the best setup he would recommend. He also said to not worry about what the rims look like but, to get the cheapest, lightest I could find. I don't know anything about lightweight rims. Tips?

 

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I think your tire guy is right. 18's seem to be the sweet spot for optimizing width versus weight. I looked in to this myself and found that there are plenty of good manufacturers but almost none publish wheel weights (for good reason as they are heavier than they look).

Once thing was clear though - light wheels cost serious $$$. If you wnat the ultimate, go for BBS RE magnesiums. Otherwise, HRE C series, Rays, Volk and Racinghart make nice light stuff.

I have attched an interesting site to help you. Good luck.

http://www.wheelweights.net/

P.S. Don't worry about the looks. You will end up with a slighty higher profile tire on the 18's to keep the same OD so there won't be a gap in the fender. Also, the coupes/ spyders all came with 18's and they look fine.
 

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Discussion Starter · #3 ·
Thanks Flash! It's a beautiful day here in DC (~70F). Sunny-side up in the Spyder. Can't wait till spring to get back out on the track. I'll def check out the rims you suggest & stick w/18".
 

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No problem Vicenzo.

It is beautiful here in Calgary too (+8 degress C which is warm for us) and sunny. I would try driving too except there is a lot of snowmelt and the roads are a mess.

I am envious but spring is only another 3 1/2 months away in this neck of the woods!
 

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I would rather keep the 19''. The GS set-up was designed around the 19 inch rims. I would not change it. I think there is a lot to be gained with the following mods (which I intend to do):

1) Sway bars tuned for less understeer
2) Racing brake pads
3) Road-race tires (lots of choice available in 19 inch size)
4) (optional) lower and stiffer springs - but remember that stiffer is not always better - as in fact the F430 Scuderia is a lot softer than the old F360CS, which was way too stiff, and the Scud handles far better around the track.
 

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I would rather keep the 19''. The GS set-up was designed around the 19 inch rims. I would not change it. I think there is a lot to be gained with the following mods (which I intend to do):

1) Sway bars tuned for less understeer
2) Racing brake pads
3) Road-race tires (lots of choice available in 19 inch size)
4) (optional) lower and stiffer springs - but remember that stiffer is not always better - as in fact the F430 Scuderia is a lot softer than the old F360CS, which was way too stiff, and the Scud handles far better around the track.
Not quite sure what you mean by "designed for". The car is certainly optimized for a certain wheel/ tire outside diameter (OD) - that would not change with a switch to different rim size as long as the proper tire size is selected to keep it within +/- 2% of the OEM OD. The carcass stiffness of the tire (higher for a larger diameter) should in theory be used to optimize the spring rates and damper/ rebound settings but these are cars are so poorly set up from the factory that I seriously doubt that any of it was even considered.

I do agree with your list of suggested mods but I would suggest reversing the order - springs first then the sway bars (Formual Dynamics also recomends this sequence). The reason, to put it bluntly, is that the OEM springs are garbage. They are too long and too soft for a car of this weight and border on dangerous for high speed driving. The new springs help curb roll but will also stop the riduculous amount of bow planing and nose dive when accelerating/ decelerating (respectively). If more roll roll resistance is needed, the sway bars can then be added. The springs are also cheaper so they make a good Step 1 improvement.

BTW - I have done every one of the mods that you suggest plus some. If you need more info let me know,
 

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Discussion Starter · #7 ·
I would rather keep the 19''. The GS set-up was designed around the 19 inch rims. I would not change it. I think there is a lot to be gained with the following mods (which I intend to do):
Maranello - I agree that the 19" look great but, I was only thinking of the 18" setup for track days (so, I'd have two sets of tires & rims). I track my car about three to four times a year. I've already done your list (items 2 thru 4).
 

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Maranello - I agree that the 19" look great but, I was only thinking of the 18" setup for track days (so, I'd have two sets of tires & rims). I track my car about three to four times a year. I've already done your list (items 2 thru 4).
Vicenzo, you should consider the sway bars as well. The difference is as significant as the springs - which as you know is huge. They do not really degrade the ride quality much either.

The exotic car club here in town has set up about 1/2 dozen scheduled track days for 09 plus there are usually a few unscheduled ones - I am looking forward to an interesting year. Hopefully I can make it through on one clutch...
 

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Not quite sure what you mean by "designed for". The car is certainly optimized for a certain wheel/ tire outside diameter (OD) - that would not change with a switch to different rim size as long as the proper tire size is selected to keep it within +/- 2% of the OEM OD. The carcass stiffness of the tire (higher for a larger diameter) should in theory be used to optimize the spring rates and damper/ rebound settings but these are cars are so poorly set up from the factory that I seriously doubt that any of it was even considered.

I do agree with your list of suggested mods but I would suggest reversing the order - springs first then the sway bars (Formual Dynamics also recomends this sequence). The reason, to put it bluntly, is that the OEM springs are garbage. They are too long and too soft for a car of this weight and border on dangerous for high speed driving. The new springs help curb roll but will also stop the riduculous amount of bow planing and nose dive when accelerating/ decelerating (respectively). If more roll roll resistance is needed, the sway bars can then be added. The springs are also cheaper so they make a good Step 1 improvement.

BTW - I have done every one of the mods that you suggest plus some. If you need more info let me know,
Please let me know about all the mods you have made. Interesting about the springs, I'll remember what you said. I know Formula Dynamics has good prices for the parts, but how much is the labor cost for installing springs and sway bars?

As for wheels/tires, I have seen in Germany a Gransport with Michelin Pilot Cup tires (available in exactly the correct OEM size for 19in rims) lapping easily 2 seconds a lap faster than a GS with "ordinary" tires. However, they are lethal in the wet. I am worried that by modifying the springs, sway bars and adding extreme tires I will make the car totally undriveable in the wet. What is your opinion?

Also, I was thinking of doing the DBW and engine ECU mods as well. The car does deserve more power. But as it is still under warranty, I am reluctant about touching the engine. Is it really true that the ECU mods can be removed without leaving any trace? Is there the risk of the ECU throwing any codes because of the mods?

Thanks
Andre
 

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Please let me know about all the mods you have made. Interesting about the springs, I'll remember what you said. I know Formula Dynamics has good prices for the parts, but how much is the labor cost for installing springs and sway bars?

As for wheels/tires, I have seen in Germany a Gransport with Michelin Pilot Cup tires (available in exactly the correct OEM size for 19in rims) lapping easily 2 seconds a lap faster than a GS with "ordinary" tires. However, they are lethal in the wet. I am worried that by modifying the springs, sway bars and adding extreme tires I will make the car totally undriveable in the wet. What is your opinion?

Also, I was thinking of doing the DBW and engine ECU mods as well. The car does deserve more power. But as it is still under warranty, I am reluctant about touching the engine. Is it really true that the ECU mods can be removed without leaving any trace? Is there the risk of the ECU throwing any codes because of the mods?

Thanks
Andre
Andre,

Pease see the attached posts that describe most of the mods.

The other things that I have done since are to de-pack the pre-cats (the ones at the front integrated in to the headers) as well as install hi flow main cats. I relocated the O2 sensors from the front to fore and aft of the main cats when I did this.

The install for the springs was about 4 hours of labor. The sway bars were more - at about 6 hours. My feeling is that the installed cost is still pretty reasonable given the comparable cost of Ferrari and Aston parts.

Your comment about tires is completely valid. I don't doubt that adding a stickier tire like a Cup Sport will increase lap times significantly especially in the hands of a very seasoned driver but frankly my feeling is that unless you are a trained race driver, getting that kind of improvement without other changes is not easy. I have the sway bars, and springs and I run Goodyear F1 GS-D3s. These tires are one of the best rated wet performance tires and I find the car handles very well in damp conditions and is way faster than stock in the dry (due to the suspension changes). I think any good wet rated tire (like a Michelin PS2) combined with the other changes will make for a good set up on both street and track. I really can't say enough about the springs and sway bars. These two changes compeletely transform the car's handling and will improve your confidence immeasurably.

The FD ECU/ DBW mods attach to the harness outside of the ECU so you are not really touching the engine (they are actually installed under the carpet in the passenger side foot well). They come with a bypass plug as well. If a factory tech starts poking around the ECU, he will probably see the mods but all it appears as is a few spliced wires. I have never heard of any thrown codes coming directly from the DBW/ ECM and in any event Jeff is very responsive to ensure that everything works. I wouldn't worry about this given everyone's very positive experiences on the forum.

The relocation of my O2 sensors is another story though. I would think twice about doing this if you de-pack your cats.


http://www.maseratilife.com/forums/showthread.php?t=4099
http://www.maseratilife.com/forums/showthread.php?t=5453
 

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yes, definitely go for light weight wheels if you are into tracking the car. Reduced coner weight, reduced rotational weight, and reduced unsprung weight, all make the car handle better, react to surface faster, and less weight gives you better power/weight ratio which makes you go faster. The down side is that you cannot mix light weight, strong, cheap together. You can pick two...

I felt the stock suspension is fine for street tires. Yes it's softer, but that's classic italian sports car setup. The gearbox can use some update... the dip when the clutch re-enage during braking-downshift is annoying and took longer than expected, but knowing it, one just need to learn to time it accordingly... granted, it'd be nice if it is more perfect :)

I've never been in a FD DBW modded car so can't comment on it, I hope to have it before next track time.

Personally I'd go for 18" strong light weight wheel for R compound tires if I go that route.... when that comes, then fd springs are likely to be needed to cope with additional grip. Will see, one change at a time.
 

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ps. I do like toyo's, T1-S and T1-R both have been consistent, can take abuse, do not overheat and loose grip, and last forever. They do squeal more than most other tires to give impression that one is pushing the car hard, but I felt right amount of squeal tells me i am in the right zone before over pushing the tires. That said, do let us know what you think of the R888 :)
 

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18" Wheels are best for the track, 19's are 2nd best. There is quite a good selection of track tires in 18" as well.

Be wary of claims on wheel weights from manufacturers. They usually measure the smallest size available for the wheel and quote that as the wheel weight. You may have a completely different weight by the time you're through. So tell them beforehand that you'll be weighing the wheel and that it better be very close or you'll be unhappy. This may force them to be a bit more dilligent before selling you the wheel and quoting the weight. Then of course weigh the wheels once you have them to be sure.

FWIW, the GS wheels are very light @ 25lbs. Also, keep in mind tire weight. Most people focus on the weight of the wheel and leave the tire out of the equation. However there are big differences in weight with different tires.

Of course another big factor is where the weight is located. The closer the weight is to the center of the wheel , the better for you. The further away it is from the center the more it will slow you down. So ideally, you're looking for the lightest tires that offer the proper grip and life, then the lightest wheel with a design that places more of the weight towards the center.

Best Regards,
-- Jeff
 
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