Don't have a set of QA-1 yet but here's mine with 1" lowered spring perch, at least for now. Image Unavailable, Please Login
Hallo friends ,i would like to fit Q A1 springs and shocks in my 308 GT 4 m.y.1978.I would have the same spring rate and lenght of original, for street use ,i asked to Summit and to QA 1 but nobody was able to give me the answer ,QA 1 asked to me some tecnical questions i am not able to give . Somebody fitted Gt 4 with QA1 shocks and springs? If yes ,tell me please the result ,spring rate for street, spring and shock parts number to order to QA1.Any help will be appreciated , thank you v. m. regards Antonino (Italy)
Sorry I took so long to respond Shashi. I was looking for a picture I thought I had measuring the height with a tape measure. I know i can't get two fingers.
Sorry, but I am getteing a little confused now. I see 250/300, so in percentage that is 100/120. I also see 350/400, in percentage that is 1,14, so another ratio relatively softer at the back. In the same factor as the 250/300 setup I would expect a 350/420, so what is the reason to stick to the 50 difference instead of the 1,2 factor?
The reason the front spring rate is higher on the front has to do with the geometry, (not to be confused with the alignment). The front springs are inclined much more steeply than the rear, (which are closer to vertical). Check out the angle of the front and rear springs in the photos below. This gives the suspension on the front more leverage on the shock/spring, so you need a stiffer spring on the front for proper balance. I went with the 400/350 springs and find them fine on the track, but a bit harsh on our back roads. If I had it to do again, I would go with the 350/300 springs. I was one of the "lucky" ones that got the 25mm/22mm saner antiroll bars, which I found gave too much understeer with my current tire set up, (225/40-18 & 255/35-18). I now run 22mm f/r with the front full firm and the rear soft. A much nicer balance at speed. Because you can adjust the height of the spring on the shock, it is important to make the height adjustment on a set of scales. This not only changes the height of the car on its suspension, it transfers load diagonally across the chasis. I have included the scale corner weight readings after I did my adjustments. For a street car with a bit of track use, this is ok. It took me most of a day to build a set of ramps and two level platforms to accept the electronic scales and make the spring height adjustments. When doing this you need to first disconnect the anti roll bars and place a few bags of sand in the drivers seat, (to simulate the weight of the porky driver . After the weights are close to diagonally similar, you can adjust the anti roll bar drop links to slip on without any preload on the bars. The front brakes are 14 inch F-50 units and the rear is a full floating 13 inch 360 brake set up, including the parking brake - (which works just about as well as the stock 308 parking brake :-( hth, chris Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
I doubt it, springs in these rates go in steps of 25, so the combination 350/425 would seem to be more logical than 350/400 if your starting point is the 250/300 setup . Is all plays a role in how the car wil behave considering over or understeer. That also will be depending on stabi- bars, if you make them stiffer all around in the same rate or front or rear relatively harder/ softer. And the car will become more critical with or without spacers or increasing the ET of the rims. In theory the combination 250/300 ( 20 percent harder in the front) will induce more understeer or less oversteer depending how the car basicly is set up off course than the 350/400 which is relatively softer in the front ( only 14 percent harder in the front) . Reason I ask is just being interested since I learned a lot the last years from changes to my (Alfa romeo) racecar where a 10 percent difference in springrates makes a lot of difference in behavior of the car, and requieres also a big difference in shock adjustment ( stiffer springs need other shocksetting too)
If you send eMAIL to: [email protected] I'll send you the white paper I've pulled together to help people considering using QA1s. It also has links to most of the more relevant Fchat threads about QA1s. chrismorse and luckydynes both have a lot of serious track experience using QA1s, so their posts should be seriously considered. VEEP, You have raised some very good points about the softness of the frequently chosen front to back ratios not scaling. Unfortunately, a lot of the spring rate selecton has not been very scientific, and the end results aren't always reported.
I have the 350/300 setup which I tried for the first time today. I have to say the car was definitely less squishy but not too firm. The car is lowered and the shocks set at 4 position. I wasn't able to really put the car through its paces as I need a four wheel alignment first.
Don't skip corner weighting it. It may look level & feel pretty good, but with adjustable coil-overs it won't be right until that is done.
I wish I had scales to corner weigh my car... I've been happy with my 300/250 setup (again, as suggested by a QA-1 engineer). Keep in mind that the stock spring rate the 308's came with were something like 175 or 180 lb/in.
I am having the car corner balanced at the shop that I work with (Group 2 Motorsports) Thanks. Plan is to go ahead with the 350/300 springs.
Or just split the difference and get 300#/300# QA1 springs. ~6000 miles after installation and I'm totally satisfied with the overall balance between response and ride comfort for 90% street/10% track on my '85 GTS. Normally have the shocks set at 3 or 4 out of 12, but for auto-x or track driving crank it up to 10 or 12. Think it was Hans who suggested this set-up. After much reading and agonizing about 50lb more or less front and/or back pulled the trigger on the 300s and never looked back. This is a great time to also do the suspension bushings ("Hard Rubber" set from Superformance worked for me) and tires BTW.
Hi guys, anyone, I need some help here. A while back I purchased the "paper weights" from Verell, a few weeks back I purchased the QA1/Einbach set up from Summit...Try installing them yesterday and I realized that I m missing all the rubber bushings except for the ones that came installed in the " paper weights ". I do not remember if the "paper weight" kit came with all the bushings necessary to complete the installation..I emailed Verell , have not gotten a response thus far. Best regards,Ted.
It's been a while since I did mine, but...aside from the QA-1s and the paper weights I purchased from Verell, I don't remember any other rubber bushings.
Yes. Verrel has a bushing set that you need in addition to the paperweight. In the ecatalogue it is under the paperweights. QA1s won't work without them. Believe they are small diameter hole where the shock fits to a arms.
Ted was asking about the black polyurethane bushings for the QA1 shocks. Apparently his shocks came without them! Anyway, he's got them on order. Sorry to be slow in responding, was camping last week w/o internet access. Came back & my eMAIL had 8000+ "new" messages. Have spent 2 days getting it sorted out. Learned more than I ever wanted to know about Outlook mail files.
Be warned: on a GT4, you need a 1" shock extension in the rear!! (Aluminum Shock Extensions | QA1 Shock Absorber Extensions | Suspension for Drag Racing, Street Performance & Street Rods). Apparently, the GTB/GTS have slightly shorter shocks, but if you don't use this one on the GT4, then your shocks will top out at every larger bump. Not pretty. And indeed, I reasoned that with OEM having front and rear the same, why would I change to stiffer front? So I went with 300/300 and love it. Hans P.S. I've found that these guys Autofab Race Cars - Custom fabrications, high performance parts and chassis parts. charge a fair bit less than Summit. In fact, I haven't found anyone who went under their price for QA-1 items. Bought from them twice (once for the GT4 and once for a project car that I am doing) and was happy with their service and prompt shipping.
I've just revised the white paper. Teng found that I had miss-typed the front shock p/n for the GT4. It should have been DS402. Also I've clarified a some sections & fixed some formatting problems.
Hello all, A couple of notes/questions on the QA1s for the gt4: I went with the DS602 for the rears (sorry Verell forgot to report back until now). I thought that this would be like the DS502 with a 1" extension but I forgot one critical calculation: the max travel. On the driver's side it's not an issue but on the passenger side there was definitely potential for the half shaft to want to sit on the exhaust pipe at full droop. It just so happened that (at full droop) the spring collar would sit up against the lower a-arm and limit the travel so the half shaft didn't touch the exhaust. This was with my particular spring height/value, others might not see this with a different setup and would have to find another way to limit the travel (if they went with the DS602 on the gt4). Under normal operating conditions (the car isn't on jack stands) there are no issues. Which brings me to my question: Hans, what were the symptoms of the shocks topping out and how was it determined that they were topping out? I almost wonder if future QA1/gt4 people can get away with the DS502 in the rear without the 1" extension. Thanks, David
