ISC top hats and billies.
 

I have some R Package billies, high mileage, still have not had them rebuilt/revalved. But getting tired of blown shocks and bottoming out the shock and going to install them this weekend.

Just picked up some ISC top hats a few hours ago, 2" and 1 1/2"

Using Tein s tech springs, and the r package billies. Will I have any problems with the tophats, I am worried that it may be too much length.

I think 1 inch ISC tophats would work better unless you are sub 12 inch ride height.

I am about 12" front and rear as the car sits now. So would it be completely unbeneficial for me to use them? Maybe the 1.5" in rear and sell the 2"?

Or they wont help at all, and better off using the stock na hats for the time being?

I had also planned on getting new bumpstops from fatcat, but that hasn't happened yet. Really not wanting to spend $100 on 4 bumpstops.

Would I be ok just using the stock bumpstops for the time being?

I'd try the 1 inch in front and 1.5 inch in rear at your ride height. You do lose droop with those top hats so it would be a good idea to measure to see how much you end up with.

A do apologize for my lack of knowledge...

Installing the 1 1/2" top hat on the rear spring/shock I can push the spring down enough with my own weight to compress the spring to get the nut on the shock.

With the 2" I will need to compress the spring much more using a spring compressor. Would that be in issue? And at 2" is that considered to be a big decrease in droop?

2 inch top hats reduce droop by 2 inches. You should use the ISC top hats with adjustable sleeves to reduce preload. You can get 46mm bumpstops from Ground Control for $12 each plus shipping.

Thanks for the tip on bumstops, I will be sure do check them out. Much better price than fatcat...

I dont have adjustable perches at the moment, installing tein lowering springs on stock r package bilsteins.

Correct me if I am wrong, installing the 2" rear top hats will reduce droop by 2" understood. But the increase in preload will give a similar effect of stiffer springs no?

My shitty paint picture below...

I don't fully understand suspension terminology or completely how things work. But my understanding is.

In the middle you have a spring of 245mm, with a stock hat the spring compresses 15mm which is your preload. Now using a extended tophat, originally intended for lower cars that lost travel and want to regain.

In my case, I haven't lost very much travel at all with the lowering spring, but with the extended hat I am compressing the spring at a much greater rate, compressing it 45mm. So a much higher preload. My understanding is an increased preload would make the spring seem stiffer?

This is what I have figured out

Specs for Tein S-Techs

Front/235 Rear/168

Now the rear spring length is 245mm, with the 2" tophat the spring is now 197mm.

How would I calculate the spring rate with the amount of preload? I am worried that with the 1.5" tophats on the front it may have a bad spring rate in relation to the rear.

Installed the 2" rear and the 1 1/2" up front, used a jack to lift up the lca with the tire on. Lifted until the car started to lift, car sits higher than it did before...

The taller the top hat I think you have more potential for coil bind.