My wife bought a '78 280Z and we're making several upgrades.

I have front and rear big brake kits on the way. We went with 16" XXR 513 wheels with the staggered set-up with 16x7 205/55 front and 16x8 225/50 rear. The wheels aren't here yet, so I don't know if I'm going to have spring clearance issues in the back or not (0 offset), but I need to decide what to do about springs. I was going to go with the Ground Control coil-over kit, but here's the problem.

It's my wife's car and she doesn't want a harsh ride. She wants it to handle well, but doesn't want the suspension to be too stiff or rough over imperfect pavement. I was told that the coil-overs with any spring choice will make the car rough riding and since I'm planning, sourcing, making the mods, I don't want my wife blaming me for what she will feel is an "uncomfortable" ride.

I've tried to read a lot about coil-over spring options and many seem to go with (Eibach) 200/225 front and rear or 250/225 or something like that. I would go with one of those choices if it were my car, but I've read that makes for a very firm ride. I read at least one post where a guy had coil-overs with 150/175 front and rear springs. My question is; would coil-overs necessarily be a bad choice for my wife's car or would a 150/175 provide sufficient ride quality and with decent handling?

Your help and advice is much appreciated.

Thanks,

John

I'd keep the stock springs and replace the suspension bushings w/ Nissan rubber. Don't go urethane bushings or it will be a harsher ride. It will be firm, but not harsh and handle fine.

I've seen it suggested, and it seems reasonable, that tire choice can have the biggest effect on smooth road (small bump) ride harshness. The tire sidewalls act as shock absorbers. Next in line would be the shock absorber since its response rate is what lets the wheel move instead of the car body. Then spring rate, since a stiffer spring will also move the body along with the wheel.

The opinion that "coil-overs" cause a harsh ride probably comes from the impression people get when they change three things at one time. Typically, low profile tires, high rate springs (because total shock travel is usually reduced), and "performance" shocks are all done at the same time. Add them all up and you get a harsh ride.

And, the Z cars all come from the factory with coil-over-spring struts (aka coil-overs). What people call "coil-overs" are actually just adjustable spring perches for use with coil-over-spring struts. Typically they also section, or shorten,the strut housing so that they can lower the spring perch and use a shorter shock absorber. A person could add adjustable spring perches, keep the stock springs, and lower the car an inch or so and probably be fine.

So you really need to decide what you're trying to do, and take in to account the condition of the roads the car will be driven on. The right tires could give smooth ride on a lowered car if the roads are in good condition. On the other hand, pot-holes and sharp bumps will give a harsh ride on a car with racing shocks set to a high damping rate (Illuminas on 5 for example).

That's what I've learned over the years. It's the combination of parts that will determine the ride quality, not just "coil-overs" versus stock. And don't forget bump-stops if you lower the car.

Coilovers require sectioning of your struts by someone who knows what they are doing.......Eibachs are a much much cheaper option and can be installed in 4 or 5 hours. Ride and handling are superb. While you have the struts off, I might suggest installing new Tokiko Illumina shocks....the combo works great. I have Ground Control Coilovers in one of my cars and Eibach/Tokiko shocks in the other cars. Handling is very similar for each set up, and if you don't get someone knowledgeable to build your coilovers, you'll create more problems than you solve. I agree with Oiluj......stick with Nissan rubber bushings....urethane can be squeaky and harsh.

Edited December 29, 201311 yr by Diseazd

I want to lower my 280Z by about an inch. The simplist way is to cut the springs, but that will harden the ride a lot.

I am planning to lower it an inch by changing the rear insulator to the 240Z type. The 280Z insulators are about an inch higher. See link to atlanticz tips: http://atlanticz.ca/zclub/techtips/suspension/strutbumperlowering/index.htm

The front will be a different story. For the front I was thinking of lowering the spring support on the tower. That would require grinding the support off and rewelding it at a lower position on the tower.

This way the springs and the spring rate will be the same and thats what I like and want to keep.

It might be an option for you.

PS: why the big brake upgrade and what is it, if I may ask?

Chas

Edited December 29, 201311 yr by EuroDat

PS: why the big brake upgrade and what is it, if I may ask?

Chas

The stock brakes would probably have been fine, but I hate looking at drums and I want the car to stop great for safety reasons. I went with the Silvermine rear disk kit and stage 4 front kit.

Thanks guys for the advice. I'll get the rubber bushing kit for sure. That's a great point about all the components, not just the springs. I bought the KYB shock because I read they were less harsh than the Tockico blues and I couldn't pull the trigger on the cost of the Ulliminas.

So would the Ground Control kit with 150/175 springs, rubber bushings and KYB shocks make for a firmer than stock, but still reasonably comfortable ride? Does anyone know if the rear 16x8 0 offset wheels and 225/50 tires will cause stock spring clearance issues that may force me into Ground Control or other aftermarket coil-overs? If I don't have a clearance problem, what about the Eibach Pro-Kit springs? Will they offer a semi-comfortable ride and can I still buy them?

Thanks again for the help,

John

Reading your two posts one thing stands out - you're building a car for you to look at and your wife to drive. Seems like a recipe for dis-satisfaction on both sides. Your wife's idea of comfort is probably different than yours. What do you two drive now? That's what the new ride will be compared to. Hopefully it's an old pickup truck.

Don't forget that the lower you go,the more things will drag underneath. My car is not really very low and I still drag the frame rail on certain speed bumps if I'm not careful.

p.s. To Eurodat - I cut my springs front and back for about a one inch drop and it did not really make the ride that much stiffer. I figured it was worth a shot and if it didn't work I would get some lowering springs. But the ride was kind of soft to begin with so the cutting just made it better. Plus the lowering had a big effect on handling. I'm actually now running cut stock front springs and Tokico rear springs with KYB shocks. It's a nice ride, in my opinion, but my other car is a 95 Pathfinder.

Reading your two posts one thing stands out - you're building a car for you to look at and your wife to drive. Seems like a recipe for dis-satisfaction on both sides. Your wife's idea of comfort is probably different than yours. What do you two drive now? That's what the new ride will be compared to. Hopefully it's an old pickup truck.

Don't forget that the lower you go,the more things will drag underneath. My car is not really very low and I still drag the frame rail on certain speed bumps if I'm not careful.

Wow, that's very insightful, and a little scary:) If I'm going through all that money and work, it should look cool, right? Actually, she doesn't want the car lowered, so I would be in big trouble if I did so. I was leaning toward aftermarket coil-overs mostly for the adjust-ability, but also in case I need clearance for the wheels. The tires are here and the wheels arrive tomorrow, so I'll know about clearance soon.

My wife drives a Mitsubishi Outlander and I drive a '11 F150 when I'm not driving my '09 370Z that's lowered with 20's:) My other car is a '68 Dodge Dart Convertible, on the ground, pro-touring style, big block. Do you think I have issues?

Thanks,

John

Here's a picture of my wife's 280Z. She wants to keep it stock looking accept for the wheels.