02-20-2007, 06:40 PM
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Location: santa clarita, ca
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 Quote:
Originally Posted by George Willet
Bryan: you certainly have put a lot of thought and work into this thread. I would have to say this will definetly be one of the most outstanding efforts on this bulleten board.
And those that have tried "it", and now know what works and doesn't work (and when) are sure adding to the quality of this thread.
I'll add to it when I can help. Thanks for your effort.
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To those that have tried "it"... please keep the reviews coming!
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02-20-2007, 06:55 PM
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Ride Height
With all the discussion on springs etc, it would be nice to have a common definition of "ride height". I propose that front ride height be measured as the middle of the lower a-arm chassis pivot. It's easiest to measure on the front to the middle of the grease cup. At the rear, I would propose measuring to the middle of the trailing arm chassis pivot. It's easy enough to measure there. For example, what ride height do you get with Alfaholics fast road springs, or Centerline, or International. Of course the weight of the car will affect ride height some, but not dramatically.
As a starting point, my GTV race car has 1200 pound, 9.5" x 5.5" circle track springs. On the bottom, the rubber seat is retained, but since the spring is ground flat on one end, the top rubber seat was removed. The car also has 1 inch drop spindles. With the set up, the front ride height is about 6 1/4 inches (I've since lowered it with spacers under the spring pan). In other words, putting these springs in a street GTV without the modified spindles should give a ride height of about 7 1/4 inches. My street GTV has stock geometry with the International springs. I will measure it for reference soon.
Erik
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02-20-2007, 07:28 PM
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Location: Christchurch, New Zealand
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Quote:
Originally Posted by genericwood
With all the discussion on springs etc, it would be nice to have a common definition of "ride height". I propose that front ride height be measured as the middle of the lower a-arm chassis pivot. It's easiest to measure on the front to the middle of the grease cup. At the rear, I would propose measuring to the middle of the trailing arm chassis pivot. It's easy enough to measure there. For example, what ride height do you get with Alfaholics fast road springs, or Centerline, or International. Of course the weight of the car will affect ride height some, but not dramatically.
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I guess its somewhere to start though.
Last edited by dzine; 02-20-2007 at 07:30 PM.
Reason: more info came to hand ;)
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02-20-2007, 08:23 PM
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True. Although I'm not sure that the inflation and the temperature matter very much! For the record, the example I gave is with 225/50-14 tires with a diameter of 23.0 inches, at 70 degrees F and 28 pounds of pressure!
My point was that many will say that a spring combination "lowers the car 1" from stock ride height". Well what the hell was stock ride height? It depends on the year of the car and the market it was sold in. On the other hand, if someone knows that their car is currently at 7" ride height and they want it at 5", they can choose a certain combination of springs and tires to get there!
Erik
Quote:
Originally Posted by dzine
But surely the huge variation in people's tyre choice changes makes this measurement a bit pointless. Unless you are running the same wheel tyre combo (and inflated to the same amount, at the same temperature).
I guess its somewhere to start though.
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02-21-2007, 04:50 AM
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Location: Oakville ON
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Quote:
Originally Posted by dzine
But surely the huge variation in people's tyre choice changes makes this measurement a bit pointless. Unless you are running the same wheel tyre combo (and inflated to the same amount, at the same temperature).
I guess its somewhere to start though.
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Ken Lee
Oakville, ON
1974 GTV 2000 - Ruby (I'm never selling this one, honest!)
1973 GTV 2000 - Rowdy (or this one I hope)
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02-21-2007, 05:38 AM
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You are right, most of our tire choices are pretty close. I run a 205/55-15 on my street car. It is almost exactly the stock diameter.
Erik
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02-21-2007, 12:19 PM
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Tyre size calculator
Here is a good tyre size calculator. You would be surprised at the difference.
Tyre diameters.xls
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02-21-2007, 03:50 PM
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Actually, not surprised at all, although the calculator is useful. The 205/55-15's I run on the street car are 1/4" different from the stock diameter. A 205/60-14 is about 1/2" different than stock. A 1/2" difference in tire diameter only equates to a 1/4" difference in ride height. So from a ground clearance and appearance standpoint, I stand by my statement that a standardized ride height measurement point is useful, not "pointless".
As I said before, I will measure the street GTV later this week and post the measurements for the International Sport springs. I'd be interested in other's measurements with different set ups. Might prevent some experimenting for those contemplating a change.
Erik
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03-06-2007, 06:34 PM
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So the mystery springs are indeed a set of OK parts springs I used an online calculator to find the spring rates (sort of). The fronts appear to be 440 Lb, and the rears are roughly 170 lb, however the rears are progressive rate. The bottom small coils I can compress with my hands, but I can't compress the full spring by standing on it, I'm about 190lbs. The fronts lower the car 35mm, am I going to run into issues with the oilpan finding the ground or is the spring rate high enough to get away with. I emailed OK parts and they just confirmed that they did the springs. They would no tell me the spring rate however. I'm hoping to do the suspension this weekend, should I go for it or get a set of performance springs from John Norman at Alfa parts. I'd go with a set of Centerlines, but they won't be here in time.
Will
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1969 1750 105.51 GTV AR1530324
1969 Datsun 2000 roadster (the track car)
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03-07-2007, 11:34 AM
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Measuring from the center of the hub to the fenderlip is the easiest way to get a "ride height" comparison. That doesn't change with wheel/tire sizes.
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Per Schroeder
1974 GTV
Classic Motorsports magazine
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03-07-2007, 02:28 PM
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Quote:
Originally Posted by CMSPer
Measuring from the center of the hub to the fenderlip is the easiest way to get a "ride height" comparison. That doesn't change with wheel/tire sizes.
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Erik
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03-07-2007, 04:14 PM
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ahh, good point!
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Per Schroeder
1974 GTV
Classic Motorsports magazine
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05-03-2007, 09:37 AM
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I had the OKP springs in my car and had oilpan issues...
Look at the pictures at my link below...
I changed the front springs, the rears are still the OKPs.
Regards Clemens
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[URL="http://www.alfabb.com/bb/forums/showthread.php?t=16555"]My 1750GTV 2.0[/URL]
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05-03-2007, 08:29 PM
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Quote:
Originally Posted by clemensh83
I had the OKP springs in my car and had oilpan issues...
Look at the pictures at my link below...
I changed the front springs, the rears are still the OKPs.
Regards Clemens
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I took your oilpan issue into thought when I did the work. I sold the springs. I now have a set of Centerlines in the front (still with 37 year old dampers) and the stock springs in the back. The Alfa has been put on hold for a little while. Its for its own good, I'm trying to get my track car going again, and trying even harder to not turn the Alfa into the track car. I think I'm going to try a set of Performatec rear springs. I'm going to do the whole rear end at once, 4.1 LSD diff, (with long wheel studs) springs, dampers, trailing arms, and bushings. It will be a big project so I need to have the other car ready to go. The car drives a little on the strange side right now, the high roll center in the back is a strange feeling. Its like the car is hinged in the middle, not confidence inspiring at all.
Will
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1969 1750 105.51 GTV AR1530324
1969 Datsun 2000 roadster (the track car)
Last edited by BlpltGTV; 05-03-2007 at 08:34 PM.
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01-31-2008, 10:40 PM
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WOW Bryan how did I ever miss this thread?
Lots of great info here guys. When I get ready for new springs this is the thread I'll come back to.
Thanks!
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