ISC tophats VS. NB tophats
 

I just installed my Bilstien/ebay coilover sleeve/ QA1 spring coilover combo today. The car rides much better than stock, however I'm too high for my liking. F 12.75 R 13.25ish. That's wound all the way down.

The ISC top hats apparently drop you an additional 3/4''. Do the NB tops to the same thing? NB's are significantly cheaper and OEM Mazda, which I like.

I know the springs will settle a little bit, but not enough to bring me to the height I want. I want to be ABLE to go to 12'' if I need, but I'm planning to run F12.25/R12.5.

What spring rates did you go with?

What spring lengths did you use?

Did you use NA or NB Bilsteins?

NB drop 1/2" from what I recollect.

NA Bilstiens. 550F 350R

Spring length?

I want the same ride height from NA Bilsteins and Shaikh told me 6"F/7"R springs.

6'' front 7'' rear.

From what I'm reading it's a lot trickier to make the NB tops work with Bilsteins over Konis...

So I my go with ISC.

Did you see the FCM installation instructions? Unless I'm missing something, it doesn't look difficult.

http://www.fatcatmotorsports.com/FCM...U_bushings.pdf

It's not the install... it's finding the right shank nut or something?

It may be that FCM includes the hard to find parts, but I didn't see anything related to difficult in the NB tophat install.

http://www.toughnutz.com/refills.mgi

10x1.25

TNZ17?

There are a few... M10x1.25

Tnz17

Is there a how to on MT here? There was a DIY on miata.net with all of the part number and it had photos but they are all dead now.

Apparently there is an energy suspension bushing kit you can use?

http://www.amazon.com/Energy-Suspens.../dp/B000CN5GEA

Cut them down to size. You need upper and lower bushing and upper and lower washer from NB. Go to Rosenthal Mazda for them.

I'm having a hard time deciding on polyurethane or MCU.

just go to http://www.finishlineperformance.com. you need the tophats, upper and lower bushings, and upper and lower washers.

With my konis, since the threaded is so short, I could only use the lower bushing.

I would do ICS rear hats and nb fronts for max travel.

Hey... so with the upper and lower washers/bushings all I need then is the shank nut listed in a post above?

Then assembly like the FCM kit?

What about a shock isolator for the top? Is it nessicary?

not sure with the bilsteins to be honest, but I'd assume so. Since the konis are adjustable if I used that nut I'd have no way to adjust the suspension (not like I do alot) with some custom knob to reach down...

I like the isc stuff better since you actually get more travel. I just sold off my nb tophat setup and replaced them with isc. Once you buy the tophats and the associated bushings, washers, etc. It's not that much cheaper.

What are you planning on running for bumpstops?

I can have a set of 4 NB tophats for $80 CAD. So it is a fair bit cheaper than ISC.

Not sure on bumps yet... I'm just running cut stock ones right now until I either order some ES or FCM bumps.

I've driven the car a fair bit over the last two days and it's settled a bit. Right now I'm at about 12.5 in the front and a hair over 13 in the rear. The NB will bring me down to my ideal 12.75 and 12.5... perhaps a bit lower.

In regards to the shock insulator on the top... it is needed for the NB tops? How will that effect the overall lowering the NB tops give you?

Anyone know where I could get some allen bolt style locking collars for a threaded sleeve? Right now I'm running two that are "butted up" against each other. Going to one with a locking bolt (like FCM uses) would give me an extra 1/2'' of adjustability.

koni sells some...not sure if it'll fit your threads.

How do ISC mounts attach to the shock. Are they the same as the stock NA tophats... piston->spacer ring->bumpstop->tophat->washer->nut? I assume so... just with a large cylindrical spacer on TOP of the tophat under the nut?

Or are they more like the NB tophats with a shit load of hoakey washer/spacers/bushings holding it together?

I have a washer on the shaft > tophat > bushing > washer > locknut.

I've come to the decision that they provide too MUCH travel, like Shaikh can said: with proper bumpstops you can put the rear tire into the fender on stock mounts...

Not with the sleeves I'm using.

First thing I'm going to do is unbolt all the shock mounts and re-torque them while the car is on the ground. I didn't do this before and it may even things out a bit. I'm having someone local fab up some top mounts for me.... hopefully.

Buy set screws at local hardware store. Nylon tips if it makes you feels better.

Drill in alignment with a ridge on the threads, so the hole sits square on the center of the sleeve's thread.

Tap.

Assemble.

Drink beer.

Thats exactly what I was thinking of doing..

Or... wait are you saying to use set screws right into the threaded collar? I'm thinking like the FCM ones that have a gap in the perch and a bolt "sqeezes" the perch to gether to tighten onto the collar.

I was thinking right into the collar. The squeeze-together type is a lot more complicated to get right, because the angle between the unthreaded and threaded portions changes when it compresses.

1. yes. 2. no.

I bought some ISC's local for a good deal.

Still figuring what I should do for the front. I'm running NA Bils with a 6'' 550lb spring. When putting the car down, before the spring starts compressing it seems as though at least 3-4'' of piston is already being pushed down. Should I go NB, ISC 1'' or ISC 1.5''?

With those rates the front springs will compress an 1" give or take; depending how light the car is. You dont need that much travel in the front, and it's very easy for the front tire to go into the fender wall at less than full compression in a lot of cases.

So what do you suggest I get? Or keep it stock?

I kind of need the extra height adjustment the ISC's give though. Should I get the 1'' ones?

really? I had 7" 550s on stock NA perches and i got it low enough. NB fronts might just work for you...i dunno.

If I didn't have the second locking collar I could get it low enough. It's at 12.75 righ tnow. I am going to loosen the lower shock bolts tonite and retorque. I did them in the air last time.

ohhhhh, that'll drop it a good .5", just put that corner on a jackstand, then jack the tire up and unload and retorque.

Sweet... I'll do that tonite. As well as put my rear ISC's in.

So I threw the rear ISC's on.. it's alright. Low enough I guess.

As for the rest, I retoruqed all the lower shock bolts with the corner fully compressed and it didn't really do anything.

They were brand new shocks and I guess the bushings are very stiff.

I need front ISC's... Or real ground control sleeves.

how much have you driven...after a few good miles on them they will settle another .25" as well.

I've had the whole thing in for about a week. Ive put about 400kms on them. Put the ISC in last night and the rear is just perfect now. However I won't be able to get corner balanced unless I wind them up a bit.