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Interesting. Ill have to go back through this thread again, I could have sworn going with ISC tops in the rear was the way to go... I would use shocks as they came off the car, same clip location.
Originally Posted by Bronson M
...the only way you'll have tire to hard part interference is if you don't take the time to cycle the suspension with the spring off and cut or shim your bump stops to maximize travel while preventing rubbing.
If you put NB shocks on a NA you'll find your rear bump stop ends up being less than 1/2" in height which makes for harsh engagement......add 1 1/2" top hats and you can now run a 2" bump stop that has a much softer engagement.
Swanpuppy - I would wade back through the thread, but I think Bronson has the long-and-short of it here. Going to extended tophats, particularly for the rear, is more of a necessity for an NA - even with mine, I have NB top hats, but may end up going to extended hats in back. Your NB with stock tophats should have sufficient travel unless your only concern is to be low (which likely correlates to not caring about how the car rides and handles).
But regardless, everyone here will continue to repeat to you that you need to cycle the suspension without the springs to determine/adjust bumpstop length. If money is no object and you just want to have the security of not needing to do the job twice if you decide you want to go to extended hats, then just buy them. The worst that can happen is you finding you DON'T need them and just sell them from the forum for a large portion of their original price (perhaps to me?). Likewise, if you want more travel but they end up having TOO much travel (tire contact, coil bind predicted, or threaded sleeve contacting the top hat), then you will just need a shim above the bumpstop to effectively "shorten" the hat depth.
I hear that going with 1.5" hat in rear may cause issues. I was planning on 1" hats for my NB.
You heard wrong. They work fine to add a bit more travel if your bumpstops are sized appropriately. You always size the bumpstop height to match your wheel and tire combination. Just like setting your ride height you assemble, test, adjust as necessary. We don't all run the same wheel and tire.
Originally Posted by 2slow
OEM circlips?
Moving grooves on shocks?
new OEM or FCM bushings?
Revalve or new seals/oil in old shocks?
Yes
No, they should already be in the bottom groove which is perfect unless you get really short adjusters.
OEM is fine for performance. Spend your money elsewhere.
If they are worn out, yes. Otherwise there is no need.
Originally Posted by Swanpuppy
1.5" in the rear has issues? I don't recall reading that, what effect does the extra .5" do?
See above. 1.5 works fine.
Originally Posted by 2slow
Depending on weather you use stock criclip location or not, what size of wheel and tires, possible contact between wheel and liner if your springs are not stiff enough. Again, I don't know this for a fact, but read in other coilover threads/sites. I'm about to do Bilstein build myself and most people told me to use stock hats in front and back, but I feel like adding 1" for a bit of extra travel may be a good idea.
Again, only a problem with a ridiculously short bumpstop height or really large wheels/tires. This is a custom arrangement so do check every setup for appropriate operational clearances with your chosen tires and wheels. What works for 225/45 may not with 245/40, etc. Choose or modify a bumpstop that fits your clearance needs.
Originally Posted by Bronson M
You're way out in left field here, the only way you'll have tire to hard part interference is if you don't take the time to cycle the suspension with the spring off and cut or shim your bump stops to maximize travel while preventing rubbing.
If you put NB shocks on a NA you'll find your rear bump stop ends up being less than 1/2" in height which makes for harsh engagement......add 1 1/2" top hats and you can now run a 2" bump stop that has a much softer engagement.
But regardless, everyone here will continue to repeat to you that you need to cycle the suspension without the springs to determine/adjust bumpstop length. If money is no object and you just want to have the security of not needing to do the job twice if you decide you want to go to extended hats, then just buy them. The worst that can happen is you finding you DON'T need them and just sell them from the forum for a large portion of their original price (perhaps to me?). Likewise, if you want more travel but they end up having TOO much travel (tire contact, coil bind predicted, or threaded sleeve contacting the top hat), then you will just need a shim above the bumpstop to effectively "shorten" the hat depth.[/QUOTE]
I must have missed this conversation entirely. I was under the impression most people simply trim to 30-35mm for their bump stops and have no issue. I do not need "max low flat brim hat yo" ride height. I thought I read with 7" springs in the rear NB's were almost stuck at stock ride height, but with ISC's in the rear you were able to achieve about a 1" drop around the car.
I'm pretty sure my parts list mimics quite a few of these set ups, if I don't need the hats in the rear I'm fine with it, I just thought that made the ride a bit more plush.
Is there a specific post that talks about cycling the shocks and what to look for for the ideal bump stop sizing? What to watch out for etc? I'm rereading...
You're either over thinking this or not reading what we posted..... No one with half a brain Just cuts to some arbitrary bump stop length way too many variables to do that. The extended top hats only move the upper shock mount up not the springs so no ride height change.
You need to stop posting and go pull a wheel and just look at your suspension it'll all start making sense.
I am definitely overthinking this Bronson. 845 posts of information can be overwhelming, especially when I'm waiting on parts to arrive to get started. Ill see what I can find out.
I am definitely overthinking this Bronson. 845 posts of information can be overwhelming, especially when I'm waiting on parts to arrive to get started. Ill see what I can find out.
+1 !
I feel the same and also waiting on parts. Once they come in I'll be able to pull old suspension out and try a few things.
If you change nothing but the tophats and leave everything else stock the major difference would be you could go over larger bumps without bottoming out because of increased bump travel. And a little body roll because the stock springs are so weak.
Unfortunately, I can't give you more to reference than the pictures here.
I plan on upgrading my setup now that I have serious, proper grippy tires. My current setup is 450lbs/in front, 300 rear on OTS NB HD shocks. 7" springs all around and stock NB Top hats. Like I mentioned earlier I have just over 1/4" before the bump stops engage so I am basically running on the bump stops the entire time. My ride height a 12.25" Front, 12.75" rear (Measured from the hub to fender), a relatively modest ride height compared to a lot of people. My Bilsteins are also using the stock circlip. I have a few more questions before I start buying parts again.
What is the benefits and drawbacks of going to a shorter spring? Based on what I can gather by looking at the suspension if I went to a 6" spring that would lower the car assuming I left the spring perch in the same place. Do shorter springs just help allow more adjustment if your goal is to get lower? I still have about an inch of threading left to go on my sleeve. Currently on my setup on a 7" spring I have close to 2" of space between the spring and top hat when completely unloaded.
Speaking of so much dead space between the coil and top hat, should I be thinking of running helper springs? If I examine the threads on my sleeves I can see where the top section has been worn down quite a bit and there is bare, smooth metal where threads should be. To me this indicates that the springs are coming unseated and rubbing quite a bit.
Finally we come to top hats. I want to continue to run this ride height. I think it gives my car a nice look without being hella slammed and scraping on every little thing. I don't want to have compromised handling for this ride height though. For general street driving the car is very comfortable even for being on the stops 24/7 but I imagine as soon as I hit a mid-corner bump at 10/10 on track I'll be going right around. I'm thinking of ISC 1" rear top hats and TSM 3/4" front tops hats. The reasons being I'd have around 3/4" travel front and back if following 949's recommended rake. 3/4" of travel was recommended to me earlier. Just running this by the experts first incase I'm thinking wrong.
I'm also planning on upping the spring rates to a 550/350 setup. When I first bought all the equipment I was afraid of stiff springs so I chose a compromised softer spring. A few of you guys mentioned that 550/350 is around the sweet spot for OTS HD's. Obviously it isn't as ideal as 700/400 but without a revalve I do not want to DD that setup, I know what it feels like and I don't have the budget for a revalve. After I get the hats I'll trim the bump stops to see what I need to do. I'm going to get very good at replacing suspensions.
So there is my plan. Should I run helper springs? Are my top hat choices good? What length spring should I choose if I aim for a 12.25"/12.5" ride height?
I run 550/350 in 7in on NB Hard S. I run 7in because it is the longest spring that will still let me get down to my desired ride height. The longer a spring is, the further it can be compressed without binding. From rest, a 7in spring can be compressed further than a 2in spring, for instance.
I'm thinking of ISC 1" rear top hats and TSM 3/4" front tops hats. The reasons being I'd have around 3/4" travel front and back if following 949's recommended rake. 3/4" of travel was recommended to me earlier. Just running this by the experts first incase I'm thinking wrong.
I have some concern here, as the TSM hats are call out at 3/4". Is that 3/4" deeper than stock NB hats you're running or 3/4" absolute depth? I am guessing it is just 3/4" absolute depth. If that is the case, then they are exactly the depth of stock NB top hats (3/4"), per my measurements. Therefore, if your current setup has 1/4" travel all around (is that true?) and you want 3/4" at the same ride height with the same bumpstops, you need 1/2" deeper top hats or a combination of deeper hat/shorter bumpstop. But that is assuming you would still need to check for tire contact at full compression. But this is predicated on my first question of the top hat depths (as advertised) being absolute. Someone want to verify?
After ~3000 miles, a trackday, and a couple autocrosses on my 7" spring/NB hat/MSM shock setup I can surely say that I wish I had sprung for extended rear hats.
550/400 at 12"/12.5" and I bounce off the bumpstops on every Midwestern freeway expansion joint sized dip. Below 50mph the car is Cadillac comfy. Freeway speeds make it feel like I assume racelands feel.
After ~3000 miles, a trackday, and a couple autocrosses on my 7" spring/NB hat/MSM shock setup I can surely say that I wish I had sprung for extended rear hats.
550/400 at 12"/12.5" and I bounce off the bumpstops on every Midwestern freeway expansion joint sized dip. Below 50mph the car is Cadillac comfy. Freeway speeds make it feel like I assume racelands feel.
Are you completely on the stops at 12" in the front? I have the slightest bit of travel on my setup at 12.25" so I want to move to extended top hats up front as well. I've heard it's a concern of coil bind in the front though when running extended top hats. I'll have to check the math for 7" springs. It looks like your spring rates handle the height fairly well at low speed which is nice.
Originally Posted by JoeTheZoe
I have some concern here, as the TSM hats are call out at 3/4". Is that 3/4" deeper than stock NB hats you're running or 3/4" absolute depth? I am guessing it is just 3/4" absolute depth. If that is the case, then they are exactly the depth of stock NB top hats (3/4"), per my measurements. Therefore, if your current setup has 1/4" travel all around (is that true?) and you want 3/4" at the same ride height with the same bumpstops, you need 1/2" deeper top hats or a combination of deeper hat/shorter bumpstop. But that is assuming you would still need to check for tire contact at full compression. But this is predicated on my first question of the top hat depths (as advertised) being absolute. Someone want to verify?
Very good question. I decided to do some google fu and found a (Maybe) answer on Clubroadster of all places. Looks like the TSM mounts are indeed extended 3/4". Are ISC mounts extended 1", or 1/4" taller than NB mounts?
Through my research I'm starting to be interested in 1.5" ISC rear mounts and either TSM (3/4") or Garagestar (1") front mounts. Oddly enough Clubroadster has a lot of people running 550/350 7" springs on 1"/1.5" F/R hats with great success. Adding helper springs just furthers the ballin'. 1" Front mounts shouldn't bury tires in fenders right?
I am currently inquiring into the TSM mounts with attached isolators. They told me they are "standard 1" added travel" and their description says 3/4" extra travel compared to the stock NB hats. From what they are saying, is its an EXTRA 3/4" above and beyond the stock NB hats.
So it seems like TSM mounts would make for a good setup on the front of my car then! That should provide for a good amount of travel especially if I can trim the stops a little bit more. ISC 1.5" hats for the rear will be ordered soon!
Another question on tophats - I've talked to GoodWin guys and they say that the Feal hats they sell have built-in bushings (pressed in) so that there is reduction in vibration. It seems that the quality, built-in spring locator, pressed in bushing and lack of need to install OEM bushings makes it a rather good choice. It's more expensive than ISC, but not by much after you take all those pieces into account.
07-28-2016, 08:43 AM
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