About to replace springs in my late 1988 328 GTS, s/n 78698. Ferrari published no spring specs for this application. So, I have to approach this empirically. I've had my existing springs documented by Coil Spring Specialties in Kansas, who measured free length, wire diameter, coil diameter, number of coils and spring force. I want to get as close as possible to the original ride height from the factory. However, my car has sagged a bit in its 28 years, and for my car, ride height is slightly different at each of the four wheels. So, I hope those of you FChatters who are 328 owners will help me out with this little survey. I'll compile and publish the results here, in case anyone else finds it useful. Please measure ride height at each of your four wheels, as shown in the photographs. I'm looking for three measurements per wheel: ground to bottom edge of center cap, ground to top edge of center cap, and ground to bottom edge of wheel flare. If you'll report here your measurements, as well as a few details about your car, I will compile all of the information and post it here, along with my analysis and conclusions about what specs I'll have my new springs custom made to match. Here are my Car's stats and measurements: 1988 328 GTS - s/n 78698 65K miles bone stock with targa roof in place and spare tire, tools, and jack kit in boot tires inflated to spec parked on level concrete 3 days LF 26-1/4" (667mm)..........RF 26-3/32" (663mm) LF 12-11/16" (322mm).......RF 12-7/8" (327mm) LF 10-1/2" (267mm)..........RF 10-3/4" (273mm) LR 26-3/8" (670mm)..........RR 26-3/4" (679mm) LR 12-3/4" (324mm)..........RR 12-13/16" (325mm) LR 10-11/16" (271mm).......RR 10-11/16" (271mm) Image Unavailable, Please Login Image Unavailable, Please Login
Tim, the rear spring is common to some other models. I can probably come up with some specs from sources we didn't look at prior. The front springs are late 328 only but I sent an email to someone who might be able to help.
Those should get you the numbers that matter - center of hug (cap) to fender lip (wheel flare). You don't care about ground to wheel flare, because those will vary with the particular tire - size varies slightly by manufacturer/model, and by how worn the tire is - you will easily get 1/4" to 1/2" variation in radius between differing tires, which will drastically skew your ride height measurements for spring comparison purposes. By measuring (or calculating from the measurements above) center of hub to fender lip, you eliminate tire diameter variable from the calculation. You should really just ask for measurements from centre of cap, or from each of top of cap and bottom of cap, to bottom edge of fender lip.The hub center to fender lip distance doesn't change no matter what size tires are on the wheels.
Thanks GordonC; Of course, it's obvious that the only measurement I really need is center of center cap to fender lip. It's very difficult for a person to eyeball the center of a disc, and being off by even a 1/4" would make a big difference. That's why I'm asking for ground to top and bottom edges of the center cap - I'll do the math to establish the center, and that will halve any measurement errors, to boot. Then ground-to-fender lip, again, because it's easy to measure accurately, and I will do the math to find the distance between the calculated center of the center cap and the fender lip, which is, of course, the dimension I need. As you point out, this takes out all variations of the tire and gets me the most accurate ride height. I think it also gives the most consistent data from person to person measuring car to car, because they can easily eyeball their ruler or tape measure from ground thru center cap, to fender lip, giving a more consistent readout than if they tried to eyeball from center of center cap to somewhere on the fender flare, that will not necessarily be the same spot from car to car.
How does the ride height on a 328 vary from a 308? Are they also different for all the different 308"s? I would guess they must be...?
Also wanted to throw another ringer in here! From working with many people on race cars over the years, I believe that while ride height is important and needs to be consistent, it is mainly appearance related. What makes a car handle better is checking "Corner Weights". RHS to LHS Front and RHS to LHS Rear. I am not sure what the weight balance is on a 308, front to rear. I do know that getting the corner weights right makes a lot of difference to the handling.
It is not adjustable on the 308 or 328 nor most of the Ferrari models ever made. For street use we have managed for 131 years without corner weighting street cars and it has served us just fine.
I'll get you my measurements tonight, Tim. Brian: Eventually I'll have to do the same thing to my '87 (#71403). I already know I can get the Koni's rebuilt. The springs, though, I want to keep set up for road-going use like Tim. To me, the car has just the right balance of ride quality and stiffness. Suggestions for the earlier 328's ?
IMO the only measurement that matters is the spec for new spring length. Measuring the distance as proposed is fraught with the potential for inaccuracy, just based on each individual's method of reading the tape. Also, in most cases, people will be measuring cars with springs that are just as old as the ones in question so such measurements are just an "average" of the suspension height of cars that are nearly 30 years old. I'm not saying it might not be "interesting" to do such measuring but it shouldn't be taken as an assumption that it reflects the height the cars originally sat at when in the showroom. RifleDs attempt to find the OEM spring spec seems to me to be the only viable method...Obtaining/installing a new set of OEM-spec springs on the car will produce the "original" ride height. It seems to me that absent a factory spec showing the distance of some portion of the frame to the floor/road, the only way to tell if there is any sag would be to install a new set and check the difference. OTOH, in reality, since the springs on most 3x8s probably haven't been stressed much, if at all, I really wouldn't expect any difference over the years. Coil springs "wear" from cycling, not from sitting. And heck, the fact that cars often go 100's of thousands of miles on the original springs makes it seem almost impossible that a typical 328 could ever NEED replacement of suspension springs due to "sag" unless the owner is looking to alter the suspension for whatever reason. The above PRESUMES that the suspension springs are of some reasonable quality in the first place...
Much of what you say is true except for the fact that Ferrari had a very long history of buying coil springs from the low bidder and the springs go bad as a result.
When I was a teen I "knew" (in my own mind) that every component on a Ferrari was undoubtedly of the best available. Hey, I was young and stupid...
You ain't the only one. The stuff made in house is good. When they have to pay an outside supplier the wheels fall off.
Doesn't know if it helps, but as an example I have this S.B ("Circolare tecnica 331", december 22, 1978) for 308s; isn't it an equivalent for the 328s? ("Giappone" in the second group of cars is Japan in Italian) Rgds Image Unavailable, Please Login
One factor to check if ride height is different on different corners of the car is that the bushes are not in a bind condition ie the wishbone bolts have not been tightened with the car jacked up.
Much of what you say is true except for the fact that Ferrari had a very long history of buying coil springs from the low bidder and the springs go bad as a result. Hey guys! I thought that this was an open forum...? Just a bunch of people trying to help other owners who may or may not have the "technical expertise" at times. No need to blow off a constructive comment on "corner weights" as unnecessary because that's how thing have been done for the last "131 years". Boy! Do we have to present credintials first. Lighten up mate!!!
IF the values obtained at the mandatory french "contrôle technique" scales are to be believed (note: IF), and if my maths are not too rusty, it is about 47% of the weight on the front axle / 53% on the rear axle, when the car is on their scales, for both my '89 328s (GTB and GTS) Rgds
And just how is that inaccurate or negative? We can go on flights of fancy all week long but it gets us no closer to the goal. We are talking about technical specifications for springs for street cars here. Not tuning suspensions on race cars. If you are going to be hypersensitive you need to check yourself in somewhere and let the grown ups talk.
Tim, according to SB60-5 which applies to the spring PN 113516 Spring flexibility .28 mm per KG Unladen length 341 mm Coils 11.5 External diameter 102.5 Wire diameter 12.5 This part number is listed as front or rear in a 328 depending on which year pats book you look at. I cannot imagine that to be correct so measure what you have and match it up. I cannot find any source for the other spring. If this post offends anyone call someone who cares.
Interesting, as the same spring, # 113516, is listed on the "Circolare tecnica" that I have enclosed a few posts back: for 308s, this spring was used at the front for "USA-Japan-Australia" GTBs. Of course we know that Ferrari often carried over parts from one model to the next (that is, if the 328 is indeed &a "next model" to the 308, rather than an evolution...) Rgds
Yes 113516 was used in 308 and 328. It remains to be seen if it was used in the front and rear (doubt that) as the books suggest or the front or rear.
