I have been having a hard time trying to diagnose a ride height difference visually between the left and right front on my 97 Spider. The car has been at the Ferrari dealer of Hong Kong for two weeks trying to reset the ride height to the factory settings, as the previous owner had lowered the car at the front which caused me to knick my driveway and damage the bumper. The car is totally balanced from the workshop manual's point of view - the A arm bolt centres to the floor. However looking at the car, the drivers side bumper and wheel well is a tad bit lower than the passenger side. (Im a RHD btw) I had the dealer place the car on the cellette bench to check the chassis, and all came out alright. Per the records, there was never any major accident to the car. I have read here that sometimes the anti roll bar can cause this to happen? Does anyone have any experience with this issue that could offer some advice as to what could cause this? Thank you!
not the most technical explination.. but sometimes, on any car in general, the drivers side suspension can appear abit lower due to your weight on that side of the car constantly..
To get this best understood a Cellette bench is a very old system and if not updated to a new laser measuring system is only as good as it's unrights were calibrated. I am sure they have it dialed in to measure suspension mounting points per factory specs. Hopefully they had an overhead bridge to check shock tower location not just undercarriage. If you have any pictures of it on the machine I can better see whats going on Most measure systems produce their own set of "blueprints" for the end user they sometimes get from the factory or they simply measure a known good specimen. Even if all is perfect which it most likely is. Even the slightest height difference, a few MM will cause the fender gap to bow and be different side to side. They only true way to tell is do a full 3D measuring of the car with a modern system. Again a cellette bench is one of the first benches designed for unibody and we've come a real long way since then Hope this helps
Thank you both for the reply. Apologies if it wasn't technical enough I was just trying to explain as much as I could in brief. To be honest, the service advisor at the dealer mentioned it was a cellette bench, but since this is Hong Kong I'm not sure if that's actually what the official Ferrari service has. Anyway they said they had tested the chassis on the so called jig they have and it's fine. In terms of the fender gap bowing, do you mean a slight difference in the height of the a arms would be enough to cause a larger distance gap between to two fenders? I'm at a loss of ideas, do you have any suggestions I can give them to help? Cheers
A picture with the car on the machine I could tell a lot more The suspension can be spot on perfect but the part where the fender mounts to which is just a weak sheet metal can be off a bit. Either from when new or even hitting a bump while braking hard can "settle" the weaker parts of the car slightly. Most likely the car had a very minor accident or fender replaced that is causing this. Again if the suspension mounting points are correct and the alignment is correct with ride heights set then the car put on corner scales (scales is optional) you should be good to go If it was in my shop and the customer insists I would check for replaced fender or bondo fender. Pull the fenders and bumper off the car and do a proper measuring of the front section Fender mounting points, front support. I would assume one side is slightly off either swayed to one side or height is off. I would use a spec sheet similar to this to check it out, ferrari does not offer this because they suck LOL It goes into more depth Hope this helps Image Unavailable, Please Login
I just lowered mine 3 turns and it appears higher with more gap on the passenger side. I attribute it to weight and load differences over time. It's similar on my Miata. The paint marks on the perches were the same and appeared unaltered before i moved them. There is no record of an accident for this car and two shops have said nothing of the kind. It MIGHT have been curbed during a spin or the drivers emergency brake is just squeaking. I do hear some undulation from that hub while driving but it is fine. I had it checked at the major last year. My Miata did get some bad whacks from potholes on the passenger rear. I saw about a 1/4 inch difference in strut mounting height-fender gap when I lowered it a couple years ago. Allignment is fine and it tracks well but vertically there was some displacement in the top hats or strut wells. Rides super nice now on new Dunlops.
After the ride heights are adjusted, you roll the car up onto 4 sets of scales and measure how much load each tire is carrying. If the left-to-right weights are not similar, you adjust the spring perches to get them as close as possible while maintaining the ride heights. This process requires teh wheels to be removed, the perch wrench attached, and a trial adjustment. Wheels back on, roll car back onto scales:: repeat until the corners weight correctly and the cross axis weights are balanced. This process is called corner weighting (google it). One can move 25 Kg pounds from left to right with a fraction of a turn on the spring perch (less than 1mm ride height change). Overall it is better to have the ride heights off by a fraction of a millimeter than to have the corner weights off by 10 Kg.
Thank you all! I really appreciate your help. I have tried to find someone with good scales in HK, not even the dealer has them. I am quite upset at the level of service in Hong Kong, we have no engineers, no mechanics, just part fitters who guess what's wrong and order new parts based on their guess, when that doesnt work, same step repeats until problem is solved. My request to have the throttle intake butterflies balanced and was met with blank faces, so I am sure some of you can understand my frustrations.
So I'm at the Ferrari centre in Hong Kong and they are arguing the only way to check measurement is by the graphic in the attached photo. I am saying the next page of the manual shows to check on the ground using the lower control arms is the correct way. They don't understand how to do this... Unbelievable Image Unavailable, Please Login
As per the workshop manual, does anyone know which pick up point to measure the height from? Is it the bolt on the inside side of the a arm, or the actual a arm middle mounting point itself?
Note: The WSM shows how to put the springs at a reasonable location. With brand new components, this will be close to what corner weighting. After 20 years of sitting on those springs, and some collapse of the mounting positions in the car, you really need a set of scales. By googling "corner weighting scales" you will find the needed information, and some options in how to measure corner weights. Put in an hour of research time.
My experience with my 97 355 spider is the springs sag with age. I had my car raised twice during my ownership due to the front sinking. On the second raise, the dealer got it to spec height again the WSM, but said there was no more threads left on the shock, so any further sagging I would have to live with.
dailo, IMO the answer is not to even thing of corner weight. It is an unnecessary job with no advantage on a street car. I would set the ride height per the WSM where they tell you to specifically to read height like at the a-arm bolt center or there about. I forget the exact wording. That is it. If you still have fender gap issues it is possible as tim has said the car was hit. Sometimes they are damaged in shipping and fixed before they are sold the 1st time and no one knows. Sometimes it is the problem of build quality because these cars have some hand built quality to them unlike robot perfect American assembly line manufacture. It is also possible that sagging of the 20 year old rubber bushings can also cause visual as well as handling problems. Those bushings are an 1+" round and sagging can certainly be enough to be visual. It is least likely to be springs. Alignment especially camber can also have visual effects as can tire wear and tire pressure. It is very important to set ride height on good tires preferably new tires at proper hot inflation pressure. Scaling takes it to the next level but is unlikely to solve your chief complaint. Dai lap cheong
I think this dealer in HK just wants him gone for whatever reason Thats why I recommend finding a race shop they like to find things wrong dealers missed
Yeah Tim what you say makes sense. He should ping alex550575430 who is a racer and in HK. I am sure he can get you to a good shop.
Hahaha fatbillybob, Dai Lap Cheong!!! Who taught you that??? Well, I found out what has happened, Auto Italia, the dealer, has lost a few of their senior mechanics who have opened their own shops. Apparently plenty of complaints going on here. I checked the service history, springs and shocks were replaced in 2007. Bushings replaced in 2012 a year before I bought the car. In the WSM it states to measure the ground clearance to the centre bolt, however I am having a hard time figuring out if the bolt is the one on the inside or outside of the chassis on the a arm itself, i.e. screws 25 or 22 in the attached parts diagram. The a arm bolt itself is higher than the chassis bolt. I hope that its just a sagging issue, and not the actual car. Just curious, what is the expected life of springs in this car? Secondly, if the springs have sagged at different lengths than each other, and you alter the perch height to balance the car, are there any balancing issues for example having one spring compressed more than the other side to get the height even? Thank you all for your help, very kind of you! Image Unavailable, Please Login
It is in the WSM. My 355 manual is digital so can't picture grab. My 348 manual is paper sorry for lame photo. You can see the A" dimension front and rear of A-arm has a rideheight spec. You can also see the "B" dimension. if you have the right A but B is off you got problems in the suspension like a spring. If the fender gap still looks wrong with A and B right then you got a bodywork issue. You can do lots of work and take off springs and compression test each to verify rate. If you are trying to get down to the last mm of perfection then you will need to either load the car as driven and scale or load car as WSM states and scale. I never load a car as Ferrari states. If I scale I always load a car as driven with 50% of fuel load for a particular race distance. Read up on how racers do this. You need to then take the time to obtain a perfectly flat floor shimming the floor as needed. Image Unavailable, Please Login
Hi Dailo I too suffer the frustrations of HK, it will be forever stuck as a 3rd rate hole in the ground. Already the machine shops just next to Zhuhai cct have over taken what's available in HK by a country mile, and what i have in Malaysia is space age in comparison to here. Don't even ask if there is anyone who can balance a v8 crank - the nearest is japan. It's so bad here - i'm contemplating setting up a decent engine shop - but then most HK people are too cheap to pay the bill. I race at Sepang/Zhuhai and can probably get the scales from Zhuhai back to HK. But honestly it's probably a repaired fender and they didn't put it on just right - it's HK after all. PM me if you need the scales.
Hahaha Im actually bringing the car this week to the new place, Blackbird Automotive. Ex IMSS team in HK, apparently took all the good people with them. After measuring, it seems the whole right side is lower than the left side, I think its a spring sag issue. Will update you all this week, thanks. I am curious, if you compress a spring on one side further to lift up the chassis, does that affect the car in any way from a handling point of view? Essentially you are loading a spring more to get increased height? Cheers!
Just to update everyone, ordered new springs and currently being set up. Will post a pic when its all done. Thanks for all the comments When the old springs were removed, the free length of the front springs were 2cm shorter than the new ones, rear just under 1cm shorter. Cheers
as far as I can remember it is pretty normal for a car to be lower on the driverside. this is done to compensate for the incline on the roads. 90% of the roads are lower on the passenger side for waterdrainage reasons, therefor the car sits more horizontal on the road when the driverside is lower
