is 2007 base SL55AMG with 517 hp that will be 600 hp pluss with 180 mm weistec Pulley, Kleeman headers. special air intakes ,intercooler extra, tuning ECU, remove all cats, and resonators. kit is Misha Design with some small modifications.

Very special Nutek wheels 777 series with 6,5 inches lip in carbon

nice build.
600 hp at the crank is possible with those mod, but at the wheels forget about it.

we use 98 octan fuel, so will se after tuning how it will be, will try get on a dyno when finished . this model has 80 mm trottle body, earlier model have 74 mm only

80mm throttle body way too small

You will see a giant hp LOSS using those giant wheels (trust me I did same thing on my misha build, big wheels kill hp/tq I lost 40+ whp easily vs lightweight 18" setup) you'll be hard pressed to see 450 whp or 550 at Crank after these mods.. Sell the fashion wheels if you want more whp..

If diameter of wheels & tires (with smaller widewall) end up being about the same as 18" setup, would there still be power loss?

Yes, there will still be a power loss. The more weight you get further away from the center point it will reduce power. he new larger diameter wheels could weigh exactly the same and have the same overall height and width but the larger diameter wheels and tires will sap more power than the smaller diameter wheels.

That seems odd for power loss if the overall diameter of wheels & tire set up equals about the same as the 18, especially with new light weight wheel materials. However I am no engineer or wheel/tire expert. First hand experience like you had though is valuable, even though it may register odd in my head.

nice project , great build

Plan not go wide with tires,, to avoid loose to mutch power, i have 295 in back and 255 in front. but is 20 inch. standard is ofcourse 18 inch. hope this not take to mutch hp, sinse i not go to wide

Came out great lower it a bit & you're set... Welcome to Widebody/Misha club! Mines in black... The tires aren't your major point of loosing power it's the big Fashion 20"s they look good, but come @ a hp/tq loss, what did the "Rears weigh each w/out tires?" if anything over 30-35 lbs? They are killing a lot of power... What width & weight?

i had 20 inch 295 on my old car, and took them off before sold ,and put the 18 back with also set of 295 and drove 2600 km.. for deliver car,cant say i felt any difference in the power, and i was drive hard all the time. this new 20 from nutek is center alu . think they are lighter than old 20 inch i have. But i will measure. Was thinking going wide kill hp more than the diameter.. have someone ever measured the difference? But for shure this new 20 inch are heavier than the standard 18

You can't just go by the feeling, I actually dyon'd pre-post.. Yes the width def adds to the hp losses as it adds hugely to overall size/weight of the wheels..

The further the weight is from the centerpoint the more power it takes to turn. You can have an 18" wheel and a 20" wheel that weight exactly the same but the 18" wheel will make more power.

http://www.w8ji.com/rotating_mass_acceleration.htm

Yup... Besides that the larger you go from the STOCK diameter which was 18" on these SL's possibly 19" on 07' up? it retards your gear ratios IE making the car indeed slower still. This is in addition to new Horsepower losses from extra weight/width etc.. OEM gear ratio on these cars is 2.65 which is a very tall gear setup to begin with, adding still taller wheels IE 20"s makes the gearing even taller equals much slower 0-60 mph.

You want to keep the overall Diameter/height @ least same as OEM. What guys do to reclaim this ratio w/20"s is add super skinny low profile tires which RUIN ride comfort/handling & leave those pretty new wheels open to massive damage, IE hitting a pothole w/low profile hard tires = bent/cracked wheels on top of everything else..

Trust us, you get used to the hp loss very quickly in a 500 bhp car. Your gas mileage will suffer too.. The entire big wheel trend is Form over Function.. Unless you're a slave to fashion, and enjoy the looks of said wagon wheels over performance? Sounds like you want Function though so ditch the Rap Video wheels

Love how you flushed the spoiler

I switched from stock 18" wheels to 20" forged lightweight wheels as well as went for PSS tyres. The stock 18" wheels were 29lb rear and 27lb front(quite heavy) and the tyres were almost the same.Total rear 58 and 54 front. My new 20" setup were rear wheels 23lb front wheels 21lb and tires rear 26lb front 23lb. I had also gone 20mm wider on the rears. Total rear 49lb and front 44lb.
So the new setup was 9lb lighter in the rear and 10lb in the front and has the same diameter as stock but end up lighter than the stock wheels and tyres so will actually increase the performance.

The OP has installed a Widebody kit & needs wider wheels/tires to fit new wider bodywork.. Yes oem wheels can be heavy vs some of latest aftermarket 20"s (and that has nothing to do with this thread)

We're mainly talking about stock Diameter 18"s vs huge WIDER heavy 20"s the OP has bought for his build, not STOCK wheel weight vs the latest lightweight narrow 20" wheels on market that wouldn't fit the new Widebody fenders w/out spacers which would have to be huge & not the proper way to finish his build..

Although you think the new lighter 20"s you found are ONLY increasing perf you are mistaken, you added low profile skinny hard tires to compensate for the larger wheels to keep @ OEM overall Diameter/Height, this does (2) negative things in perf.. (1) Traction will be greatly reduced w/new minimal Sidewall making rock hard rubber bands = much slower 0-60 mph, you wont be able to hookup from a dig or a slow roll (2) You've now made the ride/handling much rougher, suspension isn't the only component making these MB's ride so well in OEM trim. The 18"s leave room for 2-3 times more tire sidewall thickness making the ride infinitely better/smoother etc..

Your 1 positive if you can tolerate new rougher ride is it will be faster after you achieve traction IE top end will be better. But since your new 20" Sidewalls are so thin/hard you will now be bending/cracking wheels IF you hit any decent sized potholes etc.. There's zero cushion or give between the road & wheels now..

The middle number on the side of your tires denotes Profile or Aspect Ratio, ever notice Race cars? Take a look @ what Wheel/Tire setups they use on some of the most competitive autos the "GT Race Cars" super lightweight 18.0-inch-diameter, forged magnesium wheels are 12.0 inches wide at the front and 13.0 inches at the rear. Making room for incredibly fat sidewalls, giving them ultimate in performance..

for now i chosen test on this tires 295 /25 in back and standard 255 /30 in front

spec wheels if someone want make Misha design kit,, was major headacke to get right measurement , Misha they dont have right measurements, So nutek had to send people measure a car .
NUTEK SERIES 777 CONCAVE: 20x9.0
ET-33 (negative) 5x112 66.56CB
B-Profile Concave (Maximum Lip)

SN377 REAR NUTEK SERIES 777 CONCAVE: 20x11.0
ET-45 9 negative) 5x112 66.56CB
B-Profile Concave (Maximum Lip)

Put on to wide wheels and tires in my opinion is no use , look plenty heavy from behind even with 295 wide, wheel and tire is mutch more out each side , and right angel/ chamber is set for this

Bro I wish you would've posted you were having fitment problems soonerI would've been happy to give you my info.., IDK why Misha would do this? they've done 100's of these SL R230 kits by now, they know the exact Back spacing Offsets for these cars inside & out now.. They had me do the same over 3 yrs ago wtf? It's partly the wheel makers fault they act like these Offsets are National Secrets lol.. But I know for a fact Misha had my info including his very own SL55 that he had wheels made for & the list goes on what the hell

I have had no negative ride impact as the lighter weight has allowed the suspension to work more efficiently I guess. My performance has hugely increased due to the low stiff side walls. The only thing you are correct about is that my 0-60 time may be compromised slightly due to the smaller side wall. I am more concerned with the overall ride and handling which has very much improved. I am running 10.5" at the back and 8.5" front. These would not be sufficient for the widebody without spacers, however good quality bolt on spacers would work fine. The pss 305/25r20 rear and 255/30r20 will work fine with your wheel sizes, however I would recommend going as wide as possible on the front tires as the SL is set up to understeer and the wider rubber on the front will help. OP do you know the weight of your wheels?

I realize you don't care for my posts, but instead of following me around the forum like a puppy dog & adding meaningless/false content etc.. Why not stick to threads you actually can add viable information/help to? Do you actually have a Misha Widebody SL? No.. Guess what? I do, so does the OP who asked Q's about it etc.. The spacers required are 2.5"-3" wide if you utilized the lightweight 20"s you're suggesting, again you're totally wrong. Spacers this large are too large to use as permanent safe fix & would only suffice as a temporary fix until proper sized wheels were ordered..

I actually ordered some & did some testing, the manufacturer noted in the application I was thinking of applying them to would over short time create catastrophic failure in the spacers themselves due to the huge power/torque & severely extending axle width & not to do ANY perf type driving period, Spacers of this size are NOT meant to be used for any long period of time or on any high perf vehicles...



What you think is majorly improved in your suspension right now is ONLY the weight loss, it is making the car slightly faster after say 60mph, you def should feel more nimble @ every speed no doubt. Loosing a good bit of unsprung wheel weight is great! But the way you did it comes at a price using big 20"s.. I guarantee after you get used to it you will indeed notice how much rougher/harder the ride is @ every speed due to the new thin hard lowprofile tires, they will not/can not soak up bumps/cracks/potholes like 18"s w/35-40-45 Aspect Ratios vs 20-25-30 A/R on your 20"s

I'm not only right about your 0-60 being slower due to fractional traction available now, you will also suffer bent/cracked/broken wheels when you hit those pesky unseen potholes or curb it etc etc..

(Besides the weight loss you saw in your particular application vs heavy OEM wheels, the 20" diameter wheels are doing nothing positive to increase your cars OEM suspension setups performance) The ONLY way it works perfectly is when it comes setup from the factory w/20" wheels, they actually have to change everything from adding shorter gears in the differential & change entire suspension setup etc to work in perfect harmony..

Don't you think they would use lightweight 20"s in the GT Race Cars? (pic above) or for that fact ANY of the Pro Circuit racing divisions if they worked so great? How about Formula 1 cars? The fastest most wicked autos on the planet. On July of 2014 they tested 18"s & found they are superior in HANDLING/TRACTION/ACCELERATION & set a NEW record lap time on the 18" wheel/ tire setup -- shaving nearly 10 seconds off the fastest lap . The 18"s are the best compromise period.

When using larger 20" wheels with the lower-profile tires people totally forget there is a limitation to how far you can go. Such are the lateral loads being passed from the tread into the wheel via the sidewalls, that geometry of very short/thin sidewalls on 20"s will make them want to separate from the wheels during hard turns/cornering..
Latest prototype 18" wheels w/latest tires on Formula 1
20"s on up are PURELY a fashion statement which offer ZERO performance over a smaller diameter 18"-19" wheel, again unless fitted w/20"s from the factory..

Custom 3" spacers

At no point have I said that light weight 18" wheels would not be better on the track however i run 405mm front brakes and this is the main reason most performance cars are going to 19 and 20" wheels so 20" wheels are the only option for me. The added performance from the brakes far out perform the small loss from the low profile tires on the 0-60. We both happen to have wide body SL's so I will be looking at the same posts as you and would not waste my time with following your posts as you are the authority on all things mercedes and pay no attention to what other peoples opinions are.

18"s are faster everywhere not just the track... Cool post some pix of the huge brakes & widebody..

I live in the Bahamas. My merc is in England. It is being booked in for a Dyno tune with Eurocharged UK at the end of next week so I will try to get them to send me some pics.