Center to Center Measurement for Coil-over Shocks

Jeff,

In my opinion QA1 shocks are the best cost/function compromise available., I have them on two Pantera's and the GT40.

The QA1's are available in single adjustable or double adjustable and when I contacted QA1 Tech they recommended what is now the 501 model, either DS501 (Single Adjustable) or DD501 (Double Adjustable). Note: These are the part #'s for bearing mounts, alternatively the 502 model is a poly bushing.

They have a 16 7/8" uncompressed length and 11 5/8" compressed and a recommended ride height of 13 1/4" to 14 1/2". They use a 12" long spring available in multiple rates. Summit Racing sell the shocks (bare shock bodies $220 single adjustable, $320 double) and springs at $71 ea. making obtaining springs for rate changes pretty easy. There is a mismatch in the eyelet size as the Pantera is M12 and QA1 shocks 1/2" so stepped bushing inserts require to be fabricated or alternatively ream out the Pantera shock mounting to take a 1/2 dia. bolt. I have a dimensional drawing to fabricate the stepped bushings if needed.

Spring rate recommendations seem to be as individual as Pantera's themselves dependent on your use. Larry regularly races (ORR and track) his narrow body Pantera and has 375# Fr with 400# Rr spring rates. Personally, I will start out at 350# Fr and 450# Rr and go with a 1" solid sway bar with the ball ends on what will be a wide body car that is intended to see some track use.

Lastly here's a thread with some  measurements that might come in handy.
https://pantera.infopop.cc/top...ck-compressed-length

Julian

Thank you very much Joules for the information, it is very much appreciated.

I am trying to achieve the same stance for the car as Jim Demick’s 1971(attached). My concern is that I’m running 245’s in the front and 335’s in the back on 17” wheels. Will I be able to set the car at a lower ride height with my current tire configuration without having issues with the wheel wells?

Also could I please have your dimensional drawing for the step bushing in case I need it?

Thank you again very much,

Jeff

Jeff,

Unless you have a weird offset/backspacing you should be able to run 17's with 335 tires and get the rear a-arms parallel with the ground. I sent the drawing in a reply to your PM.

Julian

A couple of things I experienced lowering my car :

- if you have the factory windshield wiper motor cover, it will rub and, worse case, gets dislodged from its mount and lodge itself between the right front tire and fender. It’s best to remove it for now until you can fab another. If it happens while on a test drive, make sure you are equipped to allow removal of the tire.

- You may also experience rubbing of your wide 335 rear tire(s) against your exhaust as the tire tucks in (negative camber). I experienced rubbing on the driver rear with my Mindtrain exhaust and the mufflers are narrower than the ANSA. Ideally you want adjustable upper rear control arms when adjusting ride height.

- you can’t blow thru speed bumps now that your car is lowered. You’ll see.

BTW - I have the same tire size and wheel combination. The wheels are Boyd Coddington replicas from Pantera East. 17x9 fronts with 245/40ZR17 tires and 17x11 rear with 335/35ZR17 tires Kumho Ecsta.

You can minimize or even eliminate rubbing by using the correct tire sizes, wheel offsets and shock absorbers. One common problem area is using a shock absorber that is too short. This can cause rubbing because the suspension compresses too far. It can also shorten the life of your rear-upper ball joints and even ruin the top tapered hole in the upright . If your shocks are any shorter than the ones recommended by Julian, earlier in this thread, you can solve the problem by adding an extra bump rubber per shock absorber. Bump rubbers don't last forever, so keep an eye on them.

If you have rubbing problems at the front, it might not be due to tire width. Rather, it could be due to tire height. If your tires are taller than 24.8", they are too tall. A 235/40-17 is much less likely to rub than a 225/45-17. Keep in mind, our much beloved 225/50-15 Pirelli P7's were only 23.9" tall! Naturally, I'm referring to what works on a narrow bodied Pantera.

Thank you Liv1s and David.

I’m running 245/40/17 in the front. Another Pantera owner that I’ve been talking to (1971Pantera), is running 235/40/17 on the front of his car. His car has been lowered by about 2 inches and he’s running QA one shock absorbers. my concern was that the 245’s might be slightly too wide for the front if I were to lower the car some. I guess since the QA1’s that I’m going to order are going to be adjustable, if I do experience rubbing, I can always elevate in 1/2 inch increments until the problem is resolved.

Thank you everyone for providing information. Since I’m a first time owner, any information is going to be nothing but helpful no matter what the perspective.

many thanks,

Jeff.

Jeff, I had 245/40-17’s (on 17” x 9” wheels) on my Pantera and only experienced minor rubbing at full lock, when parking. Otherwise, I had no rubbing when driving and my car was quite low. Also, my fender lips are rolled flat. I would have preferred 235/40-17’s but I couldn’t find a matching rear tire. A matching 335/30-18 does exist but there was no stock in North America and the manufacturer had no idea when they’d be in stock. I ended up using BFG Rival S tires and was quite happy with them. Made in USA too!

Thanks David for sharing your experience. This forum is turning out to be one of the best source for first hand information on these cars. I’m going to give Michelin Pilot Sports a try once I’m ready to buy new tires. I’ve heard that they have phenomenal grip and cornering ability.

Which Michelin Pilot Sports are you referring to? They make many different versions. The ones I'm the most familiar with are the PS2's. Great tire but keep in mind, they were designed to be good in the rain, which doesn't really matter to most Pantera owners. It does matter to most Porsche 911 owners, where the PS2 was probably the OEM tire.

Your biggest challenge will be availability of the sizes you want, particularly if you're after a matched set. Don't think The Tire Rack is the be-all-end-all. I know of a few Pantera owners that were able to find supposedly unavailable tires on Amazon and eBay. Just make sure you get date codes before you pay for them. After all, various Pilot Sports have been made for over 30 years and PS2's for more than 20 years.   

These are the tires that my local shop is going to order for me.