Competition Springs, Which to use??

[gmagana]

Hello, I was hoping someone on this list could help me out. I have a 67 2000 #79 that is undergoing restoration. I am looking at putting some comp springs in the front. I currently run some of the recent springs that Nissan had made through their Nismo department on my 67 2000 #222 and 64 1500. They have 860 lbs of compression rate. Mike Young offers some that are 1/4 of an inch shorter with the same compression rate. I have acces to a set of NOS original Nissan Comp springs that apparently have a progressive?? spring rate that goes roughly from 640 lbs to 860 lbs. Has anyone ever ran original springs?? What is better?? I am looking at making this a nice riding car that is streetable as well as good in any type of autocrossing/ Racing/ mountain road driving situation. Just would like some insight what the differences and preferences are for the different comp springs.
Thanks, Gerardo

[spl310]

Hi Gerardo,

I have some of the original Nissan comp springs on my 2000. I was disappointed that they did not lower the car as much as I had hoped, but such is life. They do stiffen the front end up quite a bit.

I would like to try Mike Young's springs one day.

[gmagana]

Hey Sid, Happy New Year, I am curious about this "progressive rate" Do yours do that?? It seems like the ball joints would wear better with a progressive rate rather than a fixed compression of 860lbs.
Thanks, Gerardo

[spl310]

Back at ya Gerardo!

I don't know about the whole progressive rate thing. I had them lying around, so when I put in new shocks, it seemed to be a neat idea to put them in. I should have sold them to take the temptation away, but they are installed now and I doubt I will take them out any time soon.

[Import_sounds-of-mid-GA]

Heres what you need to do.... jack up your car, turn the wheel, break out the saws-all and cut a round or two off, well, cut about half way thru and drop the car REAL hard.... that'll break it, then take the round out, then cut your bump stops most the way off and BAM your car is magically lowered............. j/k DONT do that, only I can do that

[spl310]

Evan,

I think that when you take the car out on the streets for a serious drive, you will come to regret lowering the car as much as you did. I can see fender damage in your future....

[67 1/2 1600]

I see something worse than a fender .

[S Allen]

The NISMO competition front springs do not drop the car down at all. It is even more evident when you put the rear competition springs on. I was very disappointed at the end result. I have installed Mike Young's springs in several cars and driven them. The stance is nice with a slight rake in the front with stock rear leaf srings. The cars handle well in the twisties of Sonoma County. I also have a set of Mike Kerr's heat shortened front springs on my stroker and they make the car sit lower in the front as well. I like the ride and handling with them too! Mike K is no longer in the business to the best of my knowledge so that leaves NISMO and Mike Young's springs the only alternatives. Hands down I would use Mike Young's springs but that is only my personal opinion. Progressive is an insurance company isn't it?:roll:

Steve

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[gmagana]

Alvin, I do have two of them, so yea, I think that vintage racing might be a part of #79's future. Now on to progressive springs:
In a normal spring, the coils are evenly spaced and compress at the same rate. In a two-step linear spring (or one-step progressive), about half the coils have shorter spacing. As the spring compresses, the coils move closer. At a point, the shorter spaced coils touch You then have a spring comprised of only the longer coils.
Several things would be seen with a spring with a progressive rate.
1. Braking would be improved as the car will not dive, resistance starts when the spirng compresses after it's initial compression
2. It would increase your ride comfort as you drive around town because it would only compress as you needed it for bumps as you mentioned.
3. You would get better road handling as the spring is able to adapt for various conditions.
My understanding is that the original Nissan springs were progressive in nature. The most recent ones that Nissan made have a fixed 860 lb rate without any change in rate with spring travel. Mike Young has these that bring the car down 1/4 inch lower than Nissan with the same rate. Finally I have access to a set of original NOS springs that are the progressive type. I am curious how you like the ride in your civic with the progressive springs and wonder if you would like that type of ride in your roadster for street and track??

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[gmagana]

Makes me want to go out and road race, where is the next autocross?? I think I need to try the Miata out and see what it does!!

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[Import_sounds-of-mid-GA]

Evan,

I think that when you take the car out on the streets for a serious drive, you will come to regret lowering the car as much as you did. I can see fender damage in your future....

uhhhh, fender damage.... im tuckin! Yeah, i can see a set of mike young comp springs in my future.... hopefully not a busted oil pan, if thats what joaquin was referring to. But for now its my contribution to our collection of driveway art.

[RockFish]

You guy's have peaked my interest in front springs.

Based on what's been written so far, and the note I read at:

http://www.311s.org/tech/susp/dsfrtsprings.html

it sounds like my ideal spring would be a progressive rate spring with the same ride height as the Mike Young springs. Does a spring like this exist ?