QA1 DD403 FRONT Shocks, what springs?

[Just 1 More]

For the guys that swapped to the QA1 DD403 front shocks, what springs did you go with?

[33fromSD]

I'm running 300# 9" long springs in the front with my QA1 DD403 coil overs. Very comfortable ride.

Jim

[JimLev]

I did pretty much the same as Jim, QA1’s
Front - 9” 300 lbs
Rear - 12” 275 lbs

I did get some 8” 250 lbs springs from Jim that I decided not to use.
I’ll be giving them away and then selling the Koni coilovers that came with my hotrod.
(The Koni’s were sold)

[FF33rod]

I went down to 220 on the fronts. A lot nicer than the original... I left the IRS springs as is.
All I do is cruising. If you want to AutoX, you actually need to go the other way!

Steve

[Just 1 More]

So what's the deal going with shorter springs? Aren't these supposed to be 10" springs?

[RoadRacer]

The springs touch if you lower the car on the longer springs. I’m running 800/450 springs now and all 7” ;)

[JimLev]

Springs all depend on the weight of the car. The back won’t change much but the front can depending on the size of the engine and if it cast iron or aluminum.

[33fromSD]

So what's the deal going with shorter springs? Aren't these supposed to be 10" springs?

The springs that come with the FFR kit are 8" long, I went up to 9" in the front and 12" in the rear.

Jim

[Just 1 More]

The springs touch if you lower the car on the longer springs. I’m running 800/450 springs now and all 7” ;)

800/450??? Dang, I would think that thing rides like a brick

[Just 1 More]

The springs that come with the FFR kit are 8" long, I went up to 9" in the front and 12" in the rear.

Jim

Thanks, For whatever reason, I thought they were 10"

[33fromSD]

Thanks, For whatever reason, I thought they were 10"

No problem, for some reason FFR's spring were short little things (8"), that's why in the rear most builders have their Koni's adjust almost to the top of the threads to get the right ride height. Even in the front the 8" seems too short which is why I switched to the 9".

Jim

[Mastertech5]

They sent me 9" fronts and 10" rears. I had to wait a couple of months for the front springs to show up.

[33fromSD]

They sent me 9" fronts and 10" rears. I had to wait a couple of months for the front springs to show up.

Sounds like they started to listen to a bunch of the folks saying 8" were not long enough. That's great.

Jim

[RoadRacer]

800/450??? Dang, I would think that thing rides like a brick

You’re not wrong.. but after 2.5 years of tweaking I finally have a car that plants the outside tire correctly.. which equals speed! First in class last week :)

189782

[Dgc333]

The springs that come with the FFR kit are 8" long, I went up to 9" in the front and 12" in the rear.

Jim

What is the advantage of longer springs assuming the same spring rate?

I got daring yesterday and took my Speedstar for a drive out of the neighborhood. It gave me a chance to get up to about 50 mph and go through the gears. One thing I noticed was the back end was pretty jarring, the front didn't seem bad.

Since the spring is way up the body of the shock there is plenty of room for a longer spring. Maybe a progressive wound spring or dual rate springs.

Also, what are folks running for air pressure on the hot rod. Saw a post where the recommended air pressure for the roadster is 22-23 psi. Don't know how much heavier the the hot rod is but based on this I should have a lot less than the 35 psi currently in the tires.

[FF33rod]

What is the advantage of longer springs assuming the same spring rate?

I got daring yesterday and took my Speedstar for a drive out of the neighborhood. It gave me a chance to get up to about 50 mph and go through the gears. One thing I noticed was the back end was pretty jarring, the front didn't seem bad.

Since the spring is way up the body of the shock there is plenty of room for a longer spring. Maybe a progressive wound spring or dual rate springs.

Also, what are folks running for air pressure on the hot rod. Saw a post where the recommended air pressure for the roadster is 22-23 psi. Don't know how much heavier the the hot rod is but based on this I should have a lot less than the 35 psi currently in the tires.

Roughly 1 psi per 100 lbs - so 24ish is the right range. This changes the ride significantly.

As for springs in the rear, what rear are you running? the IRS is quite different from the straight axles....

Steve

[Dgc333]

Roughly 1 psi per 100 lbs - so 24ish is the right range. This changes the ride significantly.

As for springs in the rear, what rear are you running? the IRS is quite different from the straight axles....

Steve
I have the three link and the kit came with 250 lb/in springs for the rear and 400 for the front.

[Just 1 More]

Aren't the Koni springs a 2.5" spring? Same as the QA1? If that's the case, Can't I use the Koni 400# on the QA1 as starting point?

[RoadRacer]

Aren't the Koni springs a 2.5" spring? Same as the QA1? If that's the case, Can't I use the Koni 400# on the QA1 as starting point?

Yes, same diameter 2.5". springs are interchangeable.. and let me know if you need different springs, I have a box full :D

[Just 1 More]

Yes, same diameter 2.5". springs are interchangeable.. and let me know if you need different springs, I have a box full :D

Thanks James, I'll start with the 400's and if I ever get this thing on the road, i'll adjust from there.

[JimLev]

400 in the front are pretty stiff.
I changed my front and rear springs, see post #3.
I still have 8” 250 lb springs for free if you or anyone else wants them.

[Just 1 More]

QA1 recommends a 10" for the DS403 shocks. The ones I have from FFR are 8" .. should I go with 9" or 10"? Keep in mind, i'm installing these inverted with the more cone shaped QA1 top retainers 9018-113

[Just 1 More]

A little more measuring, I can see with the std shock top retainer that a 10" would be correct, with the more tapered top retainer the 9" should be the ticket.