Performance mods for the Q

[StarPD]

I see a lot of good ideas for improving handling and acceleration in threads throughout this forum. One thing I don't see though is much addressing weight reduction. It improves acceleration, handling, ride, and fuel economy. Altering weight distribution while reducing it further improves handling and ride, kind of a "twofer".

There are a number of ways to cut and redistribute weight, some relatively inexpensive, some expensive. Those with F50s are ahead of the game to start with, considering that they are approximately 250 lbs lighter than G50s and have depending on how you view it, anywhere from 25 to 40 more HP stock.

If you have towing on your insurance, and don't drive much where punctures are common, removing the spare tire can drop 25 to 45 lbs, depending on whether you have a standard spare tire or a space-saver.

Replacing the batery with one of the lightweight gel type batteries is another. That can save up to 25 lbs. Relocating the battery to the trunk improves weight distribution too.

A lighter exhaust system may not help HP much, but will certainly cut weight too, perhaps as much as 75 lbs or more.

Lightweight tires and wheels can chop another 40 to 60 lbs.

Running 1/2 tank of fuel rather than a full tank can drop another 75 lbs.

For the hard core enthusiast, replacing the power front seats with lightweight Recaros or other premmium fixed seats can drop a considerable amount of weight too, while providing excellent driver support and comfort.

Not counting the seats, and being conservative, these things combined could reduce weight by around 240 lbs, bringing for example, an F50 down to around 3750 lbs. Assumng 300 HP to the rear wheels as an example, the power-to-weight ratio goes from 13.3 to 12.5 lb per HP. That's almost a 6% improvement in HP to weight, with a commensurate improvement in acceleration and fuel economy. These figures are not etched in stone, but are reasonable estimates. Math majors can calculate the gains better than I can, but these numbers shouldn't be too far off. Handling and ride are more difficult to quantify, but they will surely improve considerably too.

If one wanted to improve performance even more, considering the improvement in fuel economy, one coud use a lower rear axle ratio to improve acceleration even more, while maintaining fuel economy close to stock, a win-win situation.

Another benefit would be greater component life for the engine and chassis, certainly important for the guy who wants to keep his Q for a long time and save money, time, and effort maintaining one.

There are other little tricks to cut weight, and if engine/trans mods are added, overall performance can be improved even more

Then, dropping the car 1-1/2 to 2" would also improve aerodynamics, increasing performance and fuel economy and handling more yet. Not sure what a such drop would do to cd, but it would certainly be another plus.

Now, picture an almost stock appearing 3750 lb F50 that could stay with a BMW 550 or other high performance luxury car, handles at least as well, would give great fuel mileage, and ride better than stock, without compromising comfort, reliability, or durability. That would make the Q into a true "Q-ship".

Think about it.

[sijoko]

I can definitely see your line of reasoning. One of the things I would like to do is take a 90 Q and lighten it. Mostly remove the heavy seats and spare tire. Also rip out the sound proofing stuff. There are a few other things that can also go.

A new stainless single exhaust would also save a good amount of weight. I figure if the curb weight is brought down to around 3600 lbs and hp is taken to the 340 level the car should be a screamer.

[midnightsliding]

my cars weight is still unknown, and i made 360Ft. and its moves.

[gammer_ghn]

Very nice point of view but than the curb weight is still not considering your own weight so if you 220 pounds like me your car will still be overweight but u will go faster its not a bad idea but i just wish they had weight reduction kits for these cars like fiberglass hoods fenders and trunks shaves about 200 pounds in total but no one cares for the Q sadly and no way in hell your gettin 300hp at the wheels you should be happy if you get 240RWHP if your lucky and oh im going to dyno my car soon so we shall see sheets from me = ]

[StarPD]

Very nice point of view but than the curb weight is still not considering your own weight so if you 220 pounds like me your car will still be overweight but u will go faster its not a bad idea but i just wish they had weight reduction kits for these cars like fiberglass hoods fenders and trunks shaves about 200 pounds in total but no one cares for the Q sadly and no way in hell your gettin 300hp at the wheels you should be happy if you get 240RWHP if your lucky and oh im going to dyno my car soon so we shall see sheets from me = ]

You are correct of course, but the weight savings is still the same, and so are the improvements in performance, handling, ride, and economy.

Be sure to let us know how your car dyno's out. Is it an F50 or G50?

[gammer_ghn]

Neither its a 1999 Q45 which makes it a FY33 (FYG33) i like the looks better than the F50 and the G50 and when i pay off the car im thinkin of slipping in a nice Nissan Titan motor my friend has one on his G50 and his is a monster but i dont know he did too many mods to the chassis.... but in this whole sence im just in a thought of evearything ive had the car for 7 months only and i have been in love with it from the first time i saw it 3 years ago...

[Skibane]

Lightweight tires and wheels can chop another 40 to 60 lbs.

Reducing the weight of tires and wheels pays double dividends in acceleration, since it reduces both the weight of the vehicle and the mass of rotating parts. IIRC, every 10 pounds of weight reduction in wheels/tires improves the acceleration by roughly the same amount as dropping 20 pounds in non-rotating parts.

(BTW, this trend also applies to other rotating parts - driveshaft, wheel hubs, brake disks, rear end internals, engine flywheel, etc.)

And, of course, tire diameter also has a significant effect on acceleration: Bigger = slower.

[gammer_ghn]

good man looks like u know wussup but larger tires pay off when you are in higher speeds bigger rotation area gives you more distance per turn so if you got big motor with big tires = more mass of an area achieved per tire rotation = ] but light weight rims do help but to be honest i came to the conclusion of gettin something with a smaller motor driving on 1/4 tank because your broke sucks so ya i dont know why im saying my life story here but im in depression haha but Q45 is my life live it enjoy it and push it true code of Q45!

[tkd_q45]

Though I understand the logic (and share the desire) to get our G50s to go faster - I see my G50(s) as a luxury vehicle and am a big fan of noise reduction/comfort. If I wanted a light wt fast vehicle, I'd opt for an NSX or 3rd Gen RX7.

[Skibane]

I agree absolutely!

However, if an opportunity for improving performance ever presents itself (without detracting from the Q's main appeal as a comfortable, quiet luxury cruiser), there's no harm in at least considering it.

[xerexabante]

great point!

[elwesso]

Removing weight= free HP.

Very good post on easy ways to reduce weight. However remember especially for G50s that low fuel likes to kill fuel pumps, so take that with whatever grain of salt you wish...

On the point of the diff, lets say you have a G50 and you putin a 4.08 for a 15% change, thats pretty much gonna change your fuel consumption by 15% which turns out to be a few MPG. NOt a huge deal but for some it may be. IMO high stall torque converters win over rear end gears because you get the extra torque off the line but dont sacrifice anything else.

[gammer_ghn]

Dr Phil sould come on and get onto this subject so much love man haha got to love our cars!!!