How can I increase my 458 Ferrari HP?

If you have a wheel sitting, it shouldn't take more than a minute to replicate the result and snap a pic with your phone. Not saying that you're deliberately fudging the numbers, just saying I think it seems off. Like Ray said, it can be difficult to weigh a wheel for a number of reasons.

 

Looks great. Must be pretty fast too. But it sounds awful, imvho.

Couldn’t agree more with Ray. Super sports cars are more sensitive to weight than most other cars.

I bet the performance difference between two stock 458s may be quite considerable, if one of them has a full tank of gas and no options, and the other has almost all carbon fiber goodies and half a tank of gas or less.

If I wanted more performace, I’d buy a 488. If I wanted to hold on to the 458, I’d probably tune it, delete cats, put a decent sports air filter in place and equally important, look for areas in which I could save weight.

Kind regards,

Nuno.

 

That's pretty ridiculous. I asked my dealer for weights of front and they told me 18 lbs which is stellar.

 

No body was ever suggesting Exoticar's numbers on the wheels was off - they are of our best Sponsors here. My only point was that in the original reference link above, the weight was mentioned at 18 lbs, whereas sometimes when it's actually on a scale, it might be 18.1 or 18.2 lbs or something, depending on which scale and how accurate, etc. I recently weighed my car battery and one time I weighed it, the bathroom scale said 19 lbs and the other time it was like 19.2 lbs. I didn't bother to use my more accurate scales, but for the carbon fiber rims I mentioned before, I used a gram scale that was accurate to 10 grams +/-

Anyway, the only reason I suggested we might get a photo of a wheel on a scale, was because then - whatever the weight is - then maybe we could the result in something other than lbs and/or to one decimal point or something.

When you are just trying to gauge the approximate weight 18 lbs is fine. But if we are splitting hairs between Specialie wheels vs. Vossen wheels, we might want to know it to ounces or grams or something.

Anyway, I'm sure if Andrew has a wheel around, and there is a scale within reach, he'll post a pic. If not, 18 lbs is good enough for me.

The real question here is what's the exact weight of those big red Vossen wheels!

Ray

 

So, me wanting a bit of confirmation after spending years researching and running light wheels, as I don't think it fully adds up, is ridiculous because your dealer told you something? Did it ever occur to you that your dealer got that number from that other thread? You should know that Ferrari does not publish wheel weights anywhere.

Ray, you're right. Let's not send more energy on this. It's not that important, and not something worth getting bent out of shape over.

 

So had a spare moment, and emailed Vossen. Weight for those rims in 9x21 and 12x22 are as follows. 27 and 31 lbs. minimum depending on offset, so can be more. Like we guessed, heavy wheels. If we do the total math for a set of these with tyres compared to the standard 458 forged star wheels, it's quite the weight gain.

A full set of forged 458 wheels with tyres will be around 202 lbs. The complete set of Vossen wheels with PZero rubber will be a whopping 244 lbs!
Considering those additional 42 lbs are not only unsprung as well as rotating, a lot of that added weight is in the outer most circumference of that rotating mass. The negative impact on performance will be huge. I reckon it will be the equivalent of adding 250-300 lbs of mass to the chassis of the car. And this doesn't even take into account the negative effect the 28.7" diameter rear tyre will have on acceleration due to the change in final drive ratio.

 

Wow! I'm glad I have the Speciale wheels! I just like the LOOK of them but the added benefits are crazy if other wheels would be adding 250-300 mass to the chassis! I've never quite understood the whole thing with unsprung weight and how it relates.

 

There's a lot to explain, but here's a simplified explanation. As far as unsprung mass goes, you should look at it as a mass which has no damper and spring to control how it acts upon the unevenness it encounters. There's nothing to absorb the energy, thus it upsets the car.
What is much worse is the weight that is rotating. Not only do you need to move the added weight forward in a straight line, as was it part of the car, you also have to factor in the fact that it has to rotate faster or slower. The heavier the wheel, the harder it is to stop and get spinning. Lastly, there's the gyroscopic force. The heavier the wheel, the harder it is to turn once it is spinning. This has a huge effect on how the car steers. As an added issue, where the wheel is heavier greatly affects how bad all these things are impacting on the cars performance. Imagine holding a 1 kg ball in your hand and swinging your arm. Then tape that ball to your elbow and swing your arm again. It's the same weight, but the force it takes to control the swing is very different. Let's take the rear wheels for instance. There's 7 lbs of difference between the PZero 335/25R22 tyre and a MPSS 295/35R20. This means that you add 7 lbs at the outer most circumference of the wheel where it has the greatest effect. The weight is in the tread mostly, so it is about as bad as it gets. In the same way you also add weight with the wheel. But when you add weight going from a 20" wheel to a 22" wheel, you're not only adding weight, you're increasing the diameter thus moving the added weight away from the hub. If the weight was added to the hub, then it's of little issue all things considered, but there's a good chance that a lot of that additional weight is in the outer part of the spokes as well as in the rim flanges, lip and barrel. All in all, it's about as bad as it gets. On a side note, this is also why the weight of spacers don't affect wheels that badly, but why switching to iron rotors will have a negative effect. Both discs have a similar alu hat, but the metal rotor places all the added weight in the rotor disc itself away from the center of the hub. Of course it is not as bad as with heavier wheels and tyres, but it's still worth considering when people think about going to steel rotors.

 

Yes, you are spot on there with your analysis there. I had to teach myself all this some years ago when I got into motorcycles.

As far as the Vossen wheels: yes, it's definitely something to be aware of all right. Even if they are 20" wheels, I would suspect the weight would be around 25 lbs per rim. Even if it's only 25 lbs, that's potentially 7 more pounds per wheel as compared to just buying some Speciale wheels and painting them ruby red. It doesn't seem like a lot of weight, but when you look at it from a moment of inertia standpoint, it can start to really make a big difference. Maybe not as large an impact as with a motorcycle, but nevertheless, we are talking about rotational mass here.

As you also correctly point out, the weight difference of the rubber tire itself can have large impacts as well - and certainly at the most critical point. The MOI formula takes into account distance from the rotational axis (and I think it's factored as the square isn't it?), so that becomes a huge, huge issue. This is why I always used to weigh my motorcycle tires before purchase

Anyway, if Warren is interested in going fast, he would definitely want the lightest possible wheel/tire combo there is. So many people go out and buy glitzy wheels and tires, without even a second thought to the weight they are potentially adding. Not all wheels - even forged wheels - are created equal. They don't offer CF wheels for the Pista for nothing!

Ray

 

Every single high revving NA car gains power from this simple formula, more air in and more air out.
The common most effective path in any high revving NA engine, especially with ram air, is to get bigger throtle bodies (599, ff, f12 for example), filters, and then work on exhaust size, remove cats, 76mm piping for any 2 liter up to 3 liter will make power. 458 has around 2.250 per bank so it will make power for sure just with it. I wouldn't mess too much with headers, expensive, no one in Ferrari upgrade market is competent enough to make proper headers, so don't bother.
Do a decent tune (just adjust air fuel ratios and maybe advange timing a tiny bit if you have good quality fuel) and you are golden for at a bare minimum of 600hp. To be honest, on a 2 liter with similar yet lesser quality internals, revving to 8500, similar mods would easily equate to 35-40 hp. So 70hp gain would not be dreaming that high.

 

It will be difficult to get more out of the 458 engine without serious modifications. Aside from a tune, you can also add a set of Challenge heads which flows more and bump the compression a bit. Then add a set of Speciale cams. I'm sure any good engine builder can cut the valve seat for valves that are 1 or 1.5mm larger in diameter. Farrea can then make Ti valves for the intake and Inconel valves for the exhaust. All in all a very expensive operation for maybe 80-90 hp.

 

Good point.
But in practice where are no big throttle body and RAM intake for 458 on the market.
Cat-back exhaust gives almost nothing.
And Fabspeed headers and decat, with proper tune gives 50+ hp, and - 0,5+ sec 100-200 time, at almost equal price.
It’s best gain for a buck, and only 1 real life way to noticeably change the acceleration, without dreams about SC or TT, or challenge heads, or about big difference in acceleration with light wheels.

 

I believe you're right about the MOI.

For ease of use, I've personally used the following as a guideline.

Modern large brakes 14" or more. Added weight x 3
Wheels 16"-17". Added weight x 3
Wheels 18"-19". Added weight x 4
Wheels 20". Added weight x 5
Wheels 21"-22". Added weight x 6
Tyres 25"-27". Added weight x 8
Tyres 28"-29". Added weight x 10.

Of course it is not very scientific, but it isn't that far off. I asked one of the techs at Dymag a few years ago what he thought, and he concurred that it was a good list to use for a ball park number.

I will never understand why people buy a car like a Pjsta and then put wheels on it, that looks like they belong on a chariot.

Best set up for speed in a 458 is the lightest 19" wheel you can find with tyres which reduce the overall diameter with about 1/2" an inch. It may not look as snazzy, but it will definitely be fast.

Sent from my SM-G930F using FerrariChat.com mobile app

 

personally in my opinion there are no slow cars. just slow drivers. The 458 does 200mph for crying out loud... turn off traction control and push it on your favorite back road. Bonus points for feeling the back end shimmy at 60mph coming out a corner.

if thats not your thing and you prefer straight line racing... then you got the wrong car.

 

I wonder what happened to the OP.

 

I could probably write another novel here, but lets just say that most of what people think is wrong. Unless you plan on taking a car apart and rebuilding it, replacing almost every part (which you should figure will cost at least 4 times what the car stickered for these days) you are just throwing away your money and your time.

 

Some people have too much money But I agree.

 

I did it is 2006 car was apart for a year and a half. It started life as a 2006 997S, it is now (as the Porsche dealers call it a kit car) not really that. It weighs around 2200lbs over 650hp, no nannies, and is probably the most fun (fun is for you normal people I see it as my best work on a car) you can have (if you have a weak stomach you will throw up), in a car. The cost was over 3 times its 102K 2006 sticker price (that includes the stuff I blew up building it). Taking 10lbs off a car that weighs over three thousand pounds is not going to do a thing, Buying low weight batteries for a street car is just dumb and you are throwing your money away. Wheels smaller lighter is always good but dropping 3 lbs per wheel on the same size wheel is probably not something you are going to feel. This is a modern car, not a MGB or a Spitfire (you would probably feel it in those cars), and if you want lighter go buy a 4C (that's what I'm doing it), and put a bigger engine in it. Will be a lot less expensive and a lot more exciting.

 

@Il Co-Pilota Thank you for the detailed reply. That explanation makes sense now. It reminded me of what I friend told me that ships exotic cars. He told me he saw a guy one time strap an exotic in a trailer from the control arms and other parts and wrenched it down super tight. That meant the suspension of the car was super pulled down low and when you'd hit bumps, the car wouldn't move and that wasn't smart as the car needs to fully use it's own suspension and that's why you already strap them in at the wheels, NOT the suspension. So, in my mind a super heavy wheel would be weighting the car down is a bad way. I know this isn't exactly the same comparison, but made me think of this.

@RayJohns - And your comment on the tire weight is why I like Michelin tires, usually lighter. I talked with a Michelin rep years ago where he said many times other tires are joined together and are heavier due the the seams, etc, and Michelin likes to use one piece which is lighter and makes for better a better ride usually. I know it's true on the Lambo, as anyone that has P Zero tires hates the way they ride and it's a known thing now to toss those and go with Michelin PS4S for much better handling and ride quality all around.