Suspension and Brake Upgrade Time

Mike,

Just curious why you mixed and matched in the first place.

 

Mike & Spang308, Thanks for sharing your knowledge and experience. It's people like you that make this such a great place and I appreciate what you and others have done on this site that make owning and working on our cars possible (for me anyway).

 

Mike,
I'm glad you got that sorted. I have some miles on mine now and have had no issues.
My set-up is as follows: QA-1 shocks front and rear. 10" 350lb. front springs. 12" 250lb. rear springs. Front shocks set on 3. Rear shocks set on 4. The car was lowered 1" and I am running 1/4" of rake in the ride heights.
I haven't taken it to the track yet, but in some very spirited road driving it is balanced nicely. I still have the factory ARBs on, but will be upgrading soon.
The car's handling is GREATLY improved and the ride quality has not suffered so I am pleased so far. I also upgraded to 360 Brembo brakes in the front with two piece slotted rotors, stainless lines front and rear, and Ferodo DS3000 pads all around. Both handling and braking are greatly improved.

Next up, more H.P.

To anyone thinking of doing these mods, I HIGHLY recommend it. Well worth the $$ for me.

Thanks for your input Mike,

John

 

Mike,
Sorry to hear that. I got halfway through your last post and was so mad I had to walk away from the computer.
And now, with around 200 posts on this board, I don't think I have trashed anyone, but here it comes. Rob, I'll try to be diplomatic. ;-)

Tristam Buckley is a wannabe, smack talking, idoit, twit. I e-mailed him about a year ago inquiring about the shocks, swaybars, and brake upgrades that he had listed on Ebay. His reply was so condescending and arrogant that I vowed I would rather burn my Ferrari than give him a pennie of my money. Something along the lines of "anyone serious about upgrading their suspension and brakes would be using wheels larger than 16" in diameter. I know because, blah, blah, blah." Pissed me off to the point that I did my own research and calculations on 308 suspensions. I corner weighed my car PRIOR to modifying anything and calculated roll centers, measured things like bump steer, shock inclination angle, and of course ride height and rake. I contacted QA-1 to inquire about the internal valving of their shocks before I purchased them (just to make sure). You see Tristam, I know all this crap because I know how suspensions work. How do I know?? Because I spent the better part of my adult life building, designing, setting up, testing, and racing sports cars. I got PAID to do it. You are a putz pedaling product with no real working knowledge. When I contacted Excelsior via Ebay, I was a buyer for your goods. That was until your smart azz reply. I'm glad your such a pompous idiot, because you saved me the trouble of redesigning the crap I would have bought from you at nearly three times the price that I paid.

Now time for school. Shocks are to dampen spring motion. PERIOD. They are NOT to stiffen a given corner as you replied above to Mike. That's what springs are for. And the two work hand in hand. The springs hold the chassis off the track and the shocks control the speed at which the springs compress or rebound. Tuning them is really simple IF YOU UNDERSTAND THEIR PURPOSE AND HOW THEY WORK. There are many other variables that I won't dive into because I'll lose you with a glazed look on your face anyway, but Ferrari designed these cars 20+ years ago with what working knowledge they had at the time and the tools, parts, and materials at their disposal. Also keep in mind they were designed strickly as a road GT car. Saying they can't be improved upon is the same as saying Schumacher's F1 ride is no more advanced than Lauda's.
Another factor to consider. 308's have limited ground clearance from stock, especially with a euro front air dam as both mine and Mike's have. If you lower ride height (as your kit certainly does) and don't increase spring rates, you are gonna have some serious issues with bottoming. Why do you think we/they run 2000lb.+ springs on Indy and Sports Prototypes? To keep the chassis off the track when speed+aerodynamic downforce conspire to compromise ride height. I ran my car on a very sprited drive Sunday on some not so friendly roads, and never bottomed or hit the spoiler once. Not only that, the ride quality is balanced nicely with handling and even after 4 hours in the car I wasn't getting beat up by a harsh ride.
Moral of the now long story--You don't know your azz from a hot rock. My set up is posted above and works nearly perfectly. It's based on calculated data not BS.

Mike, I am truly sorry you have to deal with this idiot. If there is anything I can do to help you PM me as others have in the past. Same goes for others doing suspension mods. If you want I will send you my number.

Irritated and possibly banned from F-Chat,
John

 

Thanks Mike. If the above post keeps just one good F-chatter like yourself from dealing with that moron, I will consider it time well spent typing it.

It's interesting to note that I generally subscribe to the "run the softest springs you can theory" when dealing with low or no downforce cars. It aids greatly in generating mechanical grip. However IIRC, 308's have 180lb. rated springs on the front from the factory. Way too soft, especially with a lowered car. At our ride heights, you would have SERIOUS clearance issues both with the chassis/ground and tire/fender. I'm running 350lb fronts on the street and would probably be running no more than 450lb. on the track where ride comfort is not a factor and the lateral forces and G loading is increased.

Hope all turns out well for you and at the very least you get the car corrected so you can enjoy it. You'll forget about the $400 a little more with each passing smile.

Take care,
John

 

PRIOR to getting into this, I would note that I did "go to bat" for Michael. When he told me of his problem I contacted both the shock manufacturer and the spring distributor and explained the situation. I explained the problem to the spring distributor and they agreed to inspect Mike's springs. I coordinated with the spring distributor told Mike to send them his springs and that distribitor was expecting them. Pursuant to my request, the spring distributor examined the springs and concluded there was no evidence of a manufacturing defect. It should also be noted that Mike bought his suspension from me at was essentially my COST. I spent my time putting his kit together and did not get paid for it as the money went to pay the distributors for the shocks, springs, swaybars, and associated hardware, etc. So, seeking reimbursement from me for springs that the manufacturer says were not defective is, I believe, unreasonable. (I've included my replies to Mike's emails for reference)

Well, Sprang308, calling me a “wannabe, smack talking, idoit, twit” reflects well on you, a person I’ve never met and apparently a person whose never used my sway bar, shock and spring set. As I own what is probably the fastest normally aspirated 308/328 street car in the world, one which will surely out handle most 308 race cars and out brake them as well, I’d hardly say I was a “wannabe”. Perhaps you’d like to run your GTB against my 2600 pound GTS with its tuned 355 engine and six speed transmission, 380mm brakes, 8 piston brake calipers and 25mm (Front) and 335mm (rear) tires, etc, etc. The proof is in the pudding. Call me a wannabe if you like. Whatever. By the way, anyone reading this thread who may have a 512 TR or M drive train please let me know. I’m putting one in 2500 pound, GTO bodied 308.

You are simply incorrect when you proclaim: "Now time for school. Shocks are to dampen spring motion. PERIOD. They are NOT to stiffen a given corner as you replied above to Mike. That's what springs are for."

FACT: Ferrari, Mercedes, Lamborghini, Corvette, etc., all use “adjustable” suspensions. We’ve heard of these as “modes”, e.g., “sport mode” or “comfort mode”. These cockpit adjustable suspensions allow the driver to stiffen or soften the car’s ride and handling responses. How? By changing the car’s springs as Sprang308 implies? No! They vary the setting of the shocks’ resistence. Now, if you start with a very stiff spring it doesn’t matter how hard or soft your shock setting is. You will be unable to make it ride in a comfort style mode because your shocks will have to be set stiff enough to control the stiff spring. Thus, you have a stiff ride. Bottom line is you can and manufacturers do use variable shock rates to control the ride and handling of their vehicles. Sorry Sprang, you are incorrect.

You also speak of upgrading 80’s technology yet you ride on 16” wheels and tires? Talk about bad engineering! Name one performance car made today that rides on 16” wheels! None! Last time I checked every Ferrari and Lambo now made has 19s. And yes, there are good reasons for the larger wheel / lower profile tire, as you, a self proclaimed sports car engineer should know.

I used to sell aluminum radiators for the 308/328. Then one Ferrari chatter said his wouldn’t just drop in. However, rather than send it back to me for a replacement he decided to take it to a shop, spend (if I recall correctly) a hundred dollars or so on having the radiator modified, and then demanded that I pay for it. Of course, my response was that he should have sent the radiator back and it would have been fixed by the manufacturer or replaced at no cost to him. This is the normal course of business no matter what you purchase or from whom. However, he was upset and posted his feelings on Ferrari Chat. So I decided simply not to sell the aluminum radiators. Too bad really because they were made by one of the leading manufacturers in the USA, weighed just 12 pounds and cooled the Ferrari dramatically better than the OEM radiator. Oh well. Now I don’t offer them for sale. Not worth the hassle. Perhaps the suspension for the 308/328 will meet the same fate as the radiator.

Enough said. I’m including my entire and unedited reply to Michael Charness. In addition to my emails, I spoke with Michael about his issue as well as the shock manufacturer and spring manufactuer. I did indeed "go to bat" for Michael.

I shall include the entire reply to Mike's inquiry. Mike conveniently leaves out portions of my reply that are relevant.

EMAIL REPLY 1

Hello Michael,

Well, as you surely can understand, if the manufacturer and expert reviews the springs in person and states there is no manufacturing defect there's not much I can do. For example, if you blew your motor or your shocks in a new vehicle and brought it back to the dealer the dealer would then see if the damage was covered. If they manufacturer says it was not a covered damage then the dealer would simply relay the official company position. I suppose that's why they are called manufacturer's warranties.

I note you did say that Varishock rebuilt your shocks for free on Ferrari chat.

I would also note that I sold you the shocks and springs at basically my cost.

I would further note that I did try and dissuade you from using springs other than the springs I use and include with the kit. If you recall, you wanted springs that I stated to you I had no personal experience with. You're the first person I've sold these to that has had a problem but most every other customer took the shocks with my springs. You basically customized my application with different springs. What I can tell you is people with my kit who drive their cars nearly daily, and I know of one locally in particular, have not had any such problems.

Of course, I'm not in the business of selling these parts and frankly, the Ferrari chat community sources out their own Varishocks and QA1s. So, it's not like I control that market. They're doing it on their own anyway. I would note that the springs rates everyone on ferrari chat is using are dramatically different than what Ferrari chose. My spring rates are close to OEM specs and my ride quality, track or street, is adjusted by the shocks. Guys running their shocks on 3 or 4 never take advantage of the stiffness capability of the shocks and thus never make full use of "soft" ride settings and "track" settings.

My suggestion continues to be to use my springs and not these springs that are tossed around on the Ferrari chat. I don't think Ferrari's engineers were so bad that they were so far off yet this is exactly what these Ferrari chat spring rates are when compared to stock.

Regards,
Tristram

EMAIL REPLY 2

Well, first, I don't know whether or not the springs were "bad". I have never sat them up straight to see if they tilted. For all I know all the springs may have had a tilt. The springs are to seat on a collar which should center them.

Second, springs and sway bars are entirely different. Springs stress the chassis far more as they act directly upon the chassis itself, transmitting all road loads directly thereto. Shocks which can be stiffenened can then control the amount of and frequency of spring compression without overly stressing an already weak chassis (which the 308, particularly in spider form, is).

On the other hand, sway bars act on the opposite side A arm helping to level the car so all four wheels, instead of just the outside two, apply contact to the road effectively. For instance, hit a speed bump and a rollbar increase affects chassis load little if at all. On the other hand, stiff springs are a direct one to one relationship on that impact with that bump.

Apples and oranges really. Which is why I recommend stiff sway bars and not going excessively stiff on springs.

 

Mike,
Sorry about your crooked springs and the jerks that would not back you up. But, I gotta do a slight hijack here to ask John about his ride.

John,
I too have a 308 with QA-1 shocks and 350 springs on the front. I differed from your set up by using 300 lb on the rear QA-1s, but still reatain the stock bars, (with black poly bushings on both the bars and arms).

A few questions:

1) How did you deal with the shock bushings?? ( I asked Unobtanium Supply's own "Il Duce" to help and he produced some fine fitting parts, IIRC with the help of Atlantaman.

2) With stock bars, are you also running stock 16 inch QV rims, or have you gone wider on the rear? You mentioned that the balance is good? I am considering going to 17 inch Ronal wheels or perhaps the 7.5 & 10 inch by 18 inch 360 wheels and am wondering about balance and front to rear tire sizes, (i am also open to changing the bar sizes but don't want to go too stiff for a "reasonable" touring ride.

3) How close did you get with the corner weighting?

4) Can you give us a bit of detail on the 360 front brake conversion and what was done to the rear to achieve a satisfactory balance. How much better is the 360 set up over the 355 front brake conversion that QV London does?? I haven't been able to find out what size rotors the 355 uses in the QV set up or what size the caliper pistons are, (I am assuming that they are stock 355 brembo units).

I have only put about 2000 miles on the car and am trying to bring up the maintenance and improve it as i go.

Any advice you could give would be appreciated. (by me and others)

chris

 

Chris--beware of going too big on wheel width.........I just put on 8x18 and 9x18 wheels on my 308 and am dangerously close to running out of room near the springs. and if i add more offset , it looks stupid with the rubber coming out past the wheel wells.

I went to 225/40-18 in front and 265/35-18 in back
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Chris,
I'll try to answer your questions in order.
1. Shock bushings were made on a lathe similar to the designs used by Verell and Atlantaman. I used steel sleeves and aluminum spacers. I believe they used all aluminum which may very well work great. I used steel sleeves with concern to them deforming, but the aluminum ones are probably fine. I usually go a little overboard on designs. I saw an earlier post of their stuff and it looked very nice.

By the way Atlantaman, cool rims. The car looks great.

2. I'm running on the stock 16" QV alloys as is Mike the last I saw. See Atlantamans post concerning wheel/tire sizes. I am trying to do mods to my car without altering it's appearance too much. Increasing bar size won't hurt your overall ride quality nearly as much as springs will. I am working on some tubular bars with sliding collars and rod end adjustable links. This will effectively make fine tuning easier than the 3 hole option currently available.

3. I'm within 1% side to side on both axles with 1/2 tank of fuel and 150lb. driver. Took some adjusting on the collars to get there, but it's doable. Phillip (pma1010 i think) also got his carbed 308 very nicely balanced. It just takes some patience. I was surprised how nicely these cars weight out for being a street car. My ride heights are within 1/16" of my target.

4. I'll possibly be letting the cat out of the bag on this one. The 360 Brembo caliper is the exact caliper used in the Brembo GT Big Brake kit. That being said, everyones driving impressions of that kit will apply to mine as well. My set up is 360 front calipers with one off hats made from 6061 T6 aluminum billet and gas slotted, directionally vaned race rotors. Front rotors are 12 3/16" and 1 1/8" thick. Basically that crosses over to stock 355 rotors and the rotor size that comes with the Brembo kit. It's within a few mm anyway. This is as large as you can go with stock 16" wheels. My rears are stock for now with Ferodo DS3000 pads. Stainless lines all around. Again, I have yet to go to the track with this thing, but my initial impression is that it's balanced nicely the way it is currently. The pedal travel is slightly longer as others have experienced, but much easier to modulate than before. My feeling is increased piston size in the rear is going to necesitate a master cylinder change. Something I'd rather not get into if it can be avoided. I will wait until after I do a track event and truly get to abuse the brakes. With stock tire size, going larger (brakes) in the front is not necessary as they will lock if enticed to. The question I won't have answered is whether or not they fade with heavy abuse on the track and how the stock rears hold up with just upgraded pads. I'm not after Bling-Bling, so if the brakes have stopping power, are balanced, and don't fade in 1/2 hour sessions, I'm leaving well enough alone.
As far as the QV London 355 conversion, I suspect they are using 310mm diameter rotors if they are doing this conversion on cars with 16" wheels as that is about all that will fit and that is the stock diameter for 355 rotors. I don't think 355 rotors will bolt up due to offset differences, but again I haven't tried or even looked into it so I may be full of doo doo there. I think I read their kit uses 355 calipers front and rear which would cause you to lose the E-brake unless they are using a dedicated e-brake caliper. If you search F-chat I'm sure you could find the piston bore sizes.

I think you are on target or close with your rear spring rates. I am doing sway bars next and will be tuning on them before I make any further changes. I MIGHT go up to 275 or 300 in the rear, but more than likely will end up staying put at 250.

Good luck with your updates. I had fun doing my mods and plan to keep upgrading as I go similar to yourself. Fire back with any other questions.

Have fun,
John

 

Mike--you may want to call Brian W. on this issue---he is as high ranked expert on this stuff as you can find. Cosworth and lola had him in England last year for 8 months designing their new suspension system.

lol--he is the is the only guy i know that travels with a shock dyno----

 

Spang--we should chat----

I still have my OEM 16 wheels and have a very large custom brake kit on my car.--one that i designed from scratch----

now that i have gone up to 18" wheels I am redesigning the brakes again, going up to 13.5" rotors.

 

Funny. Before I decided on a bigger blower, I was thinking 512TR, had the car measured and almost pulled the trigger and bought an engine/trans/subframe on ebay. I finally decide it was too much cutting for my taste and just upgraded the supercharger instead. Good luck with it, it should be a rocket.

 

I mathed everything and 350/250 is the first setup I tried (although fitted to stock shocks) and I thought it seemed to make the front push quite a bit....I guess that could have been tuned with the swaybars though.

I've since changed shocks (ohlins) and went up to 450/400, which I like a lot better...although the rear seems a bit stiff I think, I might try 375 or 350....but I need to do swaybar too. I guess that will be the winter project and brakes will wait another year.....

Oh, if you want to see how the heavy springs ride on the street, we should hook-up sometime. I think the ride is fine personally.

 

Mark,
Are your Ohlins shocks independently bump and rebound adjustable?
If I have one complaint with the QA 1 units, it is that they have a single adjust set up on them. I knew this going in and it's hard to argue the quality of them for the price (cheap). I'm used to triple adjustable shocks and am not wild about the single adjust units. OK for a street car but I would like to be able to set bump and rebound independently.
We definitely need to get together some time soon. I'm dying to see your boosted beast. Any auto-X's at Park City coming up soon?

John

 

John,
I've only got rebound, althought it does act a little on bump they say, 90% rebound/10% bump. For indendant adjusters I would have needed to spend another $170 pre shock if I recall, and I just didn't want to.

Parkcity was last week, but I didn't go, house stuff to do. The next one is 9/25, I'll start a thread in the mid-atlantic regional
http://www.scca-susq.com/calendar.html

 

I should be able to make it 9/25. See you there.

John