Lowering Springs?

[gdcwatt]

I drove a slightly lowered '91 Civic Si for 300,000 kms; a typical "bad" week of mixed highway/city, with enough stop & go traffic, would see me using 7.2L/100km, and 6.5L/100 km in a "good" week: both are "excellent" numbers, considering.

Car & Driver magazine listed the tested top speed of this car at 108 mph, or almost 175 kph . With aftermarket Tokico blues, a mild drop with some Eibach street springs, Lightspeed header, 2" exhaust, free-flow cat, but no cold-air intake, this car would do an indicated 205 kph, top end, make it a BMW 325 beater at Shannonville (well, actually, the other guys had more to lose), and able to lap Mosport at respectable 1:53's, on shaved 185/60-15 street tires on skinny 6" steel rims.

The drop must have helped the car reach this speed, and approach the higher level cornering potential offered by the new suspension bits. In addition, however, I found that, with the improved suspension, I didn't need to slow down as much for corners, saving precious fuel since I didn't need to then speed up again, and could go through many corners in a higher gear, say 3rd instead of 2nd, or 4th, and just wonder why everyone else was slowing down soooooo much.

The other thing to consider is that a stiffer - or rejuvenated - suspension will help your car's tires hook-up better, for starting, stopping, and cornering; you'll have less useless wheelspin, plus your more controllable car will thus be more predictable, and safer. It is not uncommon for a car with 80,000 km (50,000 miles) to be in need of new shocks; I replaced the struts on my Acura 16 months ago, and the car is much more controllable in snow, too, that it was, say, 24 months ago, an interesting development since the same winter tires are now [at least] a year older.

I conundrum is, if the former Big Three were working sooooo hard to improve their corporate average fuel economy rates, why didn't they just lower all of their SUV's and trucks, so many of which never venture off road, unless it's an unintentional result of having heavy vehicles, with sloppy suspensions, which should lowered, and drivers who don't really understand what they are doing.

Oh, and while you're at it, my suggestion is that you should add a stiffer rear sway bar, to go with some new shocks, which you'll need with those shorter springs...and then some sticky tires, so that you don't have to slow down for corners at all! And racing school - everyone should do that, because if more people actually knew how to drive well, traffic would flow better, and we'd all be using less fuel!!!!

[gdcwatt]

Originally Posted by California98Civic

If struts last anywhere from 50K to 150K miles, you'll know in a few years if you got the full use out of yours since the lowering, no? I ask because I'm genuinely interested in your full assessment, not to contest your claims. I'm thinking of lowering with clamps, but I just replaced the struts about 30K miles ago. They were costly. If I needed them again, I would learn to do the job myself, but still... costly.

You should be able to find very detailed "how-to's" for strut replacement, posted in chatrooms specific to your model of car, complete with photos, and tips, and maybe even links to your car's service manual. Then, look up "How to replace the struts on your Mazda Protege", on youtube.com, plus more generic videos, for shocks and brakes. In particular, I liked the video entitled, "How NOT to replace the..." and think about the suddenly unrestrained spring going shooting across the road; watch several, and if they all seem to be telling you the same thing, then perhaps you really shouldn't release the tension on that top nut until AFTER you've got the spring compressor on. And wear your safety goggles!

Here in Canada, we often feel that we're getting suckered by manufactures/dealers, but I saved $1,300 replacing the struts on my two cars [although a big part of that savings was buying parts from a US Acura dealer whose web-business shipped to Canada and handled all of the paperwork, too], less the cost of a few more tools.

Oh, and remember to buy those endlinks before you start, and a grinder and a nut-splitter, and remember that you can do this, and then you'll start doing brakes, again, and then... I figure I'm $2,500 ahead, including my daughter's boyfriend's car; going slow, that's 2 -4 hours a night over 14 nights!

[drmiller100]

lots of tailgunners on this thread.

Lets say your car is 45 inches tall. Then you lower it 2 inches.

Your frontal area is a function of how high your car is, and how wide.

one way to measure it is simply divide the numbers -

2 inches divided by 45 is 4 percent.

so you should expect about that much better mileage.

[camry25]

it also helps downforce; less air under the car, it felt better even at highway speeds. but wears down struts quicker.

[Frank Lee]

Cutting Coil Springs - Eaton Detroit Spring

If these long-time Detroit spring guys don't know springs, who the hell does?

NOW... since they are doing bidness commercially, they are exposed to liability, which makes them play it super-safe to limit exposure. Not only that, they are in bidness to sell springs (I'm not sure why they put out the truth about home cutting them... maybe they are just that honest?) I'm not in the biz, but even if I was, I stand by my heat-reshaping of the spring seat. Think of it, they state that heating above 400deg = annealing, and annealing = steel too soft to support the vehicle. Well look at that last coil on the square ended spring- that last coil is basically sitting there and it ain't flexing... if it is flexing, it's only a wee percentage as much as the coil above it and the others above that. All it has to be is strong enough to keep the spring seated squarely, not bear the weight of the vehicle for the entirety of that last coil.

[Fat Charlie]

Originally Posted by drmiller100

Lets say your car is 45 inches tall. Then you lower it 2 inches.

Your frontal area is a function of how high your car is, and how wide.

Unless you've got something like a solid axle hanging down there that will get tucked in by a drop, lowering the ride height won't affect frontal area beyond showing a little less tire- the gap between the undercarriage and the road is what's being reduced. Ride height adjustments are about controlling airflow, not reducing area.

[California98Civic]

Originally Posted by Frank Lee

Cutting Coil Springs - Eaton Detroit Spring

If these long-time Detroit spring guys don't know springs, who the hell does?

NOW... since they are doing bidness commercially, they are exposed to liability, which makes them play it super-safe to limit exposure. Not only that, they are in bidness to sell springs (I'm not sure why they put out the truth about home cutting them... maybe they are just that honest?) I'm not in the biz, but even if I was, I stand by my heat-reshaping of the spring seat. Think of it, they state that heating above 400deg = annealing, and annealing = steel too soft to support the vehicle. Well look at that last coil on the square ended spring- that last coil is basically sitting there and it ain't flexing... if it is flexing, it's only a wee percentage as much as the coil above it and the others above that. All it has to be is strong enough to keep the spring seated squarely, not bear the weight of the vehicle for the entirety of that last coil.

Two friends are rebuilding a 240Z, installing a roll cage, fiberglass hatch, dynamat, new wiring, transmission... the works. I'm in their garage recently and tell them I am considering lowering the car. He says I should cut the springs. I say I can't reverse it. He says, "but you don't want to reverse it." She's just looking at me as he suggests that buying replacement stock springs would be much cheaper than buying aftermarket lowering springs, and I think of Frank Lee again. I have no idea if I'll do it, Frank, but it's amazing how much space in my head you are renting for free when it comes to this idea! Thanks for the link.

[mcrews]

THere is an angle of slope on the front of a car that reaches an 'optimal angle' in relation to air flow.
Someone had a thread or post on it.

When I lowered the front of the Q45 1.25" I did see an improvement on the trip to texas.
Not sure if the mustang 'angle' is even close to the optimal - even with the lovering

[drmiller100]

cutting the spring means the car is lower but the spring is stiffer.

torching the spring means the car is lower and the spring is a LOT softer.

which one are you after?

[user removed]

The problem with cutting springs is when you get to the point where the shocks are bottoming out all of the time. The bump stops get beat to pieces and your shocks are the next to go. As long as you do it to a reasonable point, shortening the spring by about 10% of the total length is one of the best ways to get it lower, within reason.

regards
Mech