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Discussion Starter #21 (Edited)
I'm not certain that you will see a difference on the dyno by reducing unsprung weight. The dyno is measuring HP and Torque. Not rate of acceleration. You will certainly see a difference on the track though.
Apparently it actually does show up on the dyno (as whp/wtq recovered from loss). There is a video from a mustang guy showing how a 17 pound heavier (Per corner) Wheel and tire combo lowers whp by 5% on the dyno. Another one replaced rotors (dropping only around 10 lbs total) and unlocked a similar amount of power. And a driveshaft 7 lbs lighter than stock recovers around a dozen hp at the wheels on the Q50.

The big question is one of value.Wheels, tires, brakes and driveshaft will cost around $4,000 installed. Is it worth it to destress the drivetrain, increase the whp by a few dozen without risking the warranty For that amount of money?

Then again maybe these mods plus a tune put the car 50 whp/wtq up on cars with just a tune without stressing the transmission any more?
 

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@Ohthatguy - Which trim + packages Q50 did you end up getting?
 

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I have 2 piece brake rotors and 20 lb forged rims. I put both on at the same time. In the front that's a huge weight reduction.

It was an immediate improvement..

For an example imagine holding a race bicycle wheel and get it to spin fast..then use your hand to try to stop it.

Easy to get going fast, and stopped it might burn your hand a little bit..

Now try an old big ass balloon tire of a 50 bicycle.. heavy and harder to get going as fast and a bitch to stop fast.

Now a motorcycle tire, not a good idea.. a Q50' tire on a balancing machine.. try to get it to spin fast and worse try stopping it by hand. Not really doable.

Same with your lighter wheels. ROTATIONAL Mass is a big deal. LOTS of stored energy.

Now regarding suspension. Try the above examples of wheels and try to lift them up & down 12" quickly. The inertia of the heavh wheels is a bitch trying to change direction.

Once in motionan object.....

Fighting inertia takes a huge amount of energy. Brake pads and shocks fight the stored energy, inertia.

Moral is rotional stored energy & weight savings is much more advantageous than sprung weight savings. 5 lbs off a rim is like X times more, where X may be 5 or 10lbs.

5 lbs unsprung rotational mass may equal 25-50 lbs of sprung weight.
 

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Discussion Starter #24 (Edited)

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Discussion Starter #25 (Edited)
Did a little R&D by taking a scale down to discount tire to see if the continental sport contact 6 tire was really 22 pounds in a 255/35/19 size. Tire Rack lists this tire as being 22 pounds. The other day, discount tire told me their system showed 26 pounds and today their system showed 25 pounds. All for the same tire. I weighed it in the parking lot and it was 25.0 pounds exactly. So now I’m going to add back a couple of pounds to the plan and just go with a wider tire.

The 305/30/19 Falken FK510 arrived and, as expected, they’re falken huge. 1/8th shy from being an even 13” wide unmourned and they weighed 28.4 lbs on my bathroom scale.
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maybe i'm lost or semi retarded (no offense to anyone).

let's go on a rs400 spec's, 400crank hp, about 350whp, stock. follow me. so the motor is using 50hp to rotate the trans, wheels/tires, axles, driveshaft and rotors. wouldn't lightening up these items allow the motor to actual have to use less HP to rotate them, ie, you having more WHP ??? i'm not saying like 20-30whp, but maybe 5-7whp freed up ???

someone chime in, i'm trying to make sense of this. cause them z1 2 piece rotors are hella expensive, alu or cf driftshsfts are $1000+ for some weight savings.
Yes, by cutting weight in those area's you are effectively reducing the amount of power that is lost via inefficiencies in the drive-train. Most of the chatting in this thread is just us discussing how we think those benefits will manifest on the dyno because the wheels (where power is measured) is already in motion and accelerating.

The real benefits to cutting un-sprung weight will show in acceleration (60ft time in particular), braking distances and how the chassis/suspension
responds/changes in direction and road impacts.
 

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Discussion Starter #27 (Edited)
At nearly 13” wide, forced perspective shots make them look extra yooooog. These FK510s are going to be mucho wider than my prior Hankook 305’s and not too far off the MPSS 325’s when mounted to 11” wide wheels but shave about 4 lbs.

(looking at my old data, the 325 MPSS’ were only .44” wider unmourned.)
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Discussion Starter #28
Just showed up at the shop to get my baseline runs in and was told that their Dyno was out of commission. I believe this is the only one in my area so I might not get a baseline run in before the parts are on.
 
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Take both sets with you.

It does you no good to do a dyno run after knstalling lighter wheels unless there is another mod on its way and you need a baseline.
 

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If only those FK510s were not squirmy on straight and has a bit more traction off the line...
 

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Discussion Starter #31 (Edited)
Found another dyno to try on Saturday. So the tentative plan is to get answers on this soon.

Sat 7/25 stock dyno
Tues/Weds 7/28-7/29 Light rotor Install (may decide to only do fronts due to $ vs gains)
Thurs 7/30 aluminum driveshaft install
Friday 7/31 wheel and tire install
Saturday 8/1 Re-run same dyno
———
I reserve the right to wake up to to the stupidity of throwing this much $ at a depreciating asset and stop the insanity at any time ha ha.
 

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Here is what I had and then what I got new. I could tell the difference but I did not put it on a machine.

OEM Dumbflop A/S is 31 pounds vs Continental Extreme Contact 24.7 OEM wheel 30.86 vs Konig 20.94 Total overall weight reduction is 25.2 + 39.68 = 64.88. Rotational Inertia old: 15.967 kg-m2 Rotational Inertia new: 11.780 kg-m2

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Here is what I had and then what I got new. I could tell the difference but I did not put it on a machine.

OEM Dumbflop A/S is 31 pounds vs Continental Extreme Contact 24.7 OEM wheel 30.86 vs Konig 20.94 Total overall weight reduction is 25.2 + 39.68 = 64.88. Rotational Inertia old: 15.967 kg-m2 Rotational Inertia new: 11.780 kg-m2

View attachment 93969
Following you with tenths, then hundredths, then thousandths; and pounds to kilograms per meter squared hurt my head!
 

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Discussion Starter #34
Here is what I had and then what I got new. I could tell the difference but I did not put it on a machine.

OEM Dumbflop A/S is 31 pounds vs Continental Extreme Contact 24.7 OEM wheel 30.86 vs Konig 20.94 Total overall weight reduction is 25.2 + 39.68 = 64.88. Rotational Inertia old: 15.967 kg-m2 Rotational Inertia new: 11.780 kg-m2

View attachment 93969
That’s a huge change. How did it feel driving on the new set up VS a OEM? Which konig model?
 

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Discussion Starter #35 (Edited)
Edit: Drove 40 minutes to the closest functional dyno and couldn’t get a pull in. Unfortunately, I won’t have a baseline run done prior to the parts going on this week (40 lb lighter wheels/ tires).

I decided to put the brakes on getting lighter rotors for now due to cost and their being closer to the hub possibly minimizing the impact of the 30 lbs of unsprung weight reduction.

I pulled the trigger on the CZP aluminum driveshaft though. After watching Gilbert keep up with / beat some very quick cars so many times with basically similar mods to lots of other Q owners who don’t get spectacular times at the track, my hunch is that a few X factors play into why his car was so much quicker than the other Q50s/60s. This list doesn’t include the fuel upgrades which obviously added another level to the power gains.

Three things jump out at me about his build: 1. light wheels and tires: his size and brand of wheels and tires for roll racing cane in around 185.9 lbs. The Achilles 245/40/18 he ran up front were only 25.1 lbs. and the Enkei 18’s were crazy light. (I’m dropping 40!lbs off the OEM set but his set up was another 22 under that).

2. Decreased tire diameter. This impacts gearing and Improves acceleration. His front tires were way smaller than stock at 25.71” and his rear Toyos around 26.2” (I’m going to be around 26” on my tire set up)

3. The CZP driveshaft. Not a lot of people are running these upgraded drive shafts and he gave this mod a lot of credit for impacting the acceleration of his car.

A bunch of parts are inbound now:

This week:
Wheels: $800 (27 lbs lighter)
Tires: $950 (13 lbs lighter)
Hub Rings: $100
Next week:
BMS Smooth Inlets 5hp? $100 ($50 labor?)
Heat Exc: $220 ($472 labor)
Used BOV Kit: $380 ($210 labor)
Megan LDP: $180 ($210 labor)
In 2-3 Weeks:
CZP Driveshaft: $800 ($105 labor) (7 lbs lighter, built to order in 7-10 days)
Next Phase:
Light Rotors Installed $1,300 (30 lbs lighter)
Ecutek Tune: $1,250
 
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From my experience with other cars, you will be quicker at the track. I never dynoed after changing wheels, driveshaft, etc. So the results will be interesting.
 
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Discussion Starter #37
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Got some baseline pulls in today in 100 degree heat. I’ll put the car on the same dyno after the lighter wheels/ tires/ driveshaft go on to see what changes.
 

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Discussion Starter #38
From my experience with other cars, you will be quicker at the track. I never dynoed after changing wheels, driveshaft, etc. So the results will be interesting.
Yeah, I’m interested to see what happens on the dyno tomorrow. If you google unsprung weight wheels mustang dyno you’ll find a video of a guy who recovered +5% on whp by dropping 34 lbs off the driven wheels of a stock 5.0 mustang. If my loss of 20.8 lbs on my driven wheels holds this ratio, my 318 corrected whp will jump by 3% on the dyno tomorrow.
But the improvements seem to be more dramatic on lower displacement cars. Another article showed that just a combined loss of 9.3 Lbs from a swap to four lighter rotors on an AWD import (wrx or similar) recovered an amount that would equate to an 8.275% gain over my 318 whp tomorrow.

So it looks like my 318 whp will increase to something between 328-344 corrected whp on the dyno tomorrow.
 
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You have a difference of 5whp and 8wtq when you compare one specific run to another.

You will have to find 10whp or it will be inconclusive.

Are those runs in order?
 
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Discussion Starter #40
You have a difference of 5whp and 8wtq when you compare one specific run to another.

You will have to find 10whp or it will be inconclusive.

Are those runs in order?
The runs on my sheet from the other day we’re all done in order within around 45 minutes. The car heat soaked but remained consistent in a tight range for the last few.
The pulls today will be on the same dyno, with the same fans, same tech, same correction methodology, different day with different weather/ DA.
They’ll do a few pulls and it’ll follow the same pattern of heating up then settling into a range. It’ll be easy to identify any gains.
 
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