Lotus289

iTrader: (1)

Possible, but my passenger door is actually going up a bit. Probably about 50% of the time the window on that side closes on top of the weather stripping instead of under the lip. I'll wait to adjust anything until I get my SFC's on. My guess is cutting the roof supports off was a bit of a shock to the system when the car was used to being so rigid for 85k miles and the chassis isn't used to handling all the torsional strength; even though it's built for it.

usmc320

iTrader: (3)

I just install my UMI 3pt bolt in SFCs earlier this week and had the same results. The car feels much more solid in all conditions, especially rough roads and turns. Worth it in my opinion.

JD_AMG

Your window has multiple adjustments on the door, use them. And the simple fact that you did the t-top swap means that the t-tops may not be aligned correctly either.
The extremely thin steel that you cut out provides no structural support. These cars are built as a t-top originally and then made into a hardtop.
SFC's are not a bad thing, but they are not even in the same universe as some people describe them to be. If you (and others) want that solid feel you need to fix what give these cars the sloppy loose feeling in the first place, the stock shocks. I've been in a couple of fbodies with SFC's, one of which I've been in multiple times before the SFC install. I could tell no difference in terms of "flex" compared to before, or compared to my car. What I (and others) have noticed is the rear of the car is more harsh over bumps for whatever reason (probably has to do with the fact they connect to the LCA mount, and use the bolt there, which then requires more torque than before and probably causes some binding).
The said car had more rattles after install due to the added harshness, and didn't feel any more solid (and still felt much less solid than my car because of his stock shocks).
Add it up guys:
Car with SFC's -> still rattles
Car with no SFC's, but quality shocks -> no rattles
Coincidence?

UMI Performance

iTrader: (77)

It is great to hear everyone is happy with them

We appreciate the positive comments... it is always good to hear our hard work has paid off!

Ryan

ws6_z28

iTrader: (7)

I have two f-body...one with sfc, lca, stb and one without...night and day difference. I also have nothing both UMI suspension parts...

usmc320

iTrader: (3)

You're crazy if you think SFCs make little to no difference. I don't think anyone would argue that shocks will make a bigger difference, but they should for the price of quality shocks.

I've had 2 F-bodies myself. The first had SFCs and stock shocks. It handling remarkably well for a live axle muscle car. When I got my 2nd F-body (w/o SFCs) it felt sloppy and I lacked confidence in it's ability in corners (especially on rough roads). I put in SFCs and the handling is back to where my 1st F-body was.

As far as rattles those should be tracked down and fixed not covered up. That's an issue in the car's build quality.

Oh and for the record I think SFCs AND shocks should be done, but I chose to do SFCs first.

JD_AMG

They should because the factory shocks are so bad.
Again I don't think SFC's are bad at all, but from what I've experienced they show no difference on the butt dyno. I'm sure they stiffen the chassis some, but I don't think they stiffen it enough to justify the added weight and lighter wallet. I'm honestly not surprised that manufacturers don't give us any figures for how much they stiffen the chassis...

Thank you for the extremely vague story.

Completely agree, track down what causes the rattles -> too much shock compression. No different than if your tires were filled with cement, causing the car to ride like crap and making rattles appear. You get real tires and fix the problem at the root.

I thought like this before, but after riding in a 4th gen with SFC's I'm glad I didn't waste my money. All the things that I wanted to fix about the car I found from searching, and it turned out to be the shocks...

usmc320

iTrader: (3)

Maybe I'm lucky. I don't have the kind of rattles you're talking about. I have 1 that shows up occasionally(rarely) in the front of the center console/dash area. Nothing worth fixing right now to me and it certainly doesn't justify $600+ shocks.

How much clearer do I need to be for you? You have no intention of getting SFCs anyway. Good for you. I've driven both and know what the difference is and of course they're not the magic fix-all for all of the F-body shortcomings. Neither are shocks.

I could feel the flex in the body on freeway on-ramps with open joints especially. Now with SFCs it doesn't feel like the back is going to kick out like a truck. It feels more like my RX-8 did on the exact same on-ramp. (Note: I am comparing these 2 cars in this situation only which I deal with on a daily basis.) I call that a significant improvement.

3-point SFCs may or may not be overkill compared to 2-point, but they fixed everything on my car I expected it to at half the price of shocks. I call that a win-win situation for me. One day, I'll still get the shocks though. I don't doubt that will improve the ride, but I'll do that when I do springs so I can match the 2.

Oh and you probably won't tell much of a difference "riding" in a car with SFCs. Try driving one around corners/joints and see. Although comparing your car with upgraded shocks to one with just SFCs will admittedly be that much harder for you to tell the difference with SFCs. Yours SHOULD do better. You paid alot more for it. Either way, it sounds like both of us got what we wanted and expected out the mods we chose. The only purpose of this post (or any post about mods on any forum) is so others can read it and make informed decisions about what they want to do.

Cliff notes: If you have realistic expectations and don't expect miracles from them, SFCs are a good buy for the price.

JD_AMG

For significantly better handling (grip, feel, balance), and a much better ride for $800 I think that's a steal, especially considering you cannot get the both for any less money.

You mentioned two different Fbodies without saying any mods you had, or what kind of options they had.
If someone could prove to me that they significantly stiffen the chassis with some actual real data (like torsional rigidity) then I would consider them, but no one has and I think there is a good reason for that.
The deal here is the stock Fbody chassis is not that weak, and no where near as weak as some pretend it to be. It has the torsional frequency of a C5 convertable (which is plenty stiff). The stock decarbon shocks on the other hand ARE a problem with the car because of the valving.

I think I know this "flex" you are talking about. How the rear of the car skips over the bump and crashes? That's due to too much shock compression my friend. One of the cars I rode in (im going to leave the other out because he had QA1's, so ofcourse the car felt like a boat) with SFC's I had ridden in many times before the SFC install (on stock shocks and springs before and after, and no other mods after the SFC install). And on the same road with various imperfections (potholes, road construction, dips, joints) the car's suspension still crashed, and the car felt like crap. No difference than before the install when it comes to "solid feel". It actually rode a bit more harsh in the rear. My car on the other hand feels perfectly solid and balanced on that same road, but that's just a coincidence right?
And you know that disconnected, floatyish feel at higher speeds? Not enough shock rebound. And how the rear kicks out when you are pushing the car hard? Shocks. Sloppy, loose feeling? Shocks...
Starting to see the big picture here?
Let me ask you, would you feel comfortable taking that same on-ramp turn hard on throttle now that you have SFCs, or is the car still too loose?

Both cars were driven hard, one was around some corners and on those joints.

Mine should be better because I fixed the problem, not tried to cover it up.

usmc320

iTrader: (3)

That's funny, because SFCs fixed that problem 100% for me.


I wouldn't take that particular on-ramp any faster or at full throttle in my RX-8 and it's handling is 10 times better than an F-body and it doesn't even have enough torque to kick the tires out so no worries there.


But not driven by you. That's the point I was making.

Anyway I'm not saying that shocks are a bad investment. If I had unlimited funds to invest in my car I would have a set of Koni's already. Unfortunately I have other priorities. SFC's were in my price range and they fixed what I expected them to fix as I knew they would from past experience.

I do appreciate your insight though. It makes me feel confident that when I am ready to upgrade shocks they will make a vast improvement. That's good to hear. Though quite honestly I'll probably do more power mods/9inch before I get around to them.

LS1Aggie09

iTrader: (25)

I just finished installing my UMI 3-pt. SFC's this past week. I have been driving my car for about 65k miles now and at first I really couldn't tell a difference, but that was when my gf was in the backseat (5'8"~125lbs.) and my dad was in the front (6'2" ~225lbs.) plus I didn't really drive it that hard. I was beginning to think oh well, I'm glad I wasn't the one who spent 280 bucks on them (my gf bought them for me after she hit my car). After I have been driving it now and putting it through its paces, let me tell you what, I WAS WRONG!

I absolutely love my SFC's and while I'm glad it wasn't the first thing I did, cause I wouldn't appreciate them, I am thrilled I have them now. The traction still feels similar, but everything definitely feels tighter. I have no new rattles at all and I even have 125k miles on my car. The handling is not a tremendous difference, but I feel much more confident taking turns and I can feel what the car is doing and what the road is like much better than before.

I am hoping to do shocks (most likely Bilsteins w/stock springs) in the next several months and I have no doubt that they will make a bigger improvement than what the SFC's did in the handling department. But as far as stiffening the chassis, they can't do that...physically impossible. I recently got in a rear-end collision and I was lucky in the fact that my bolt holes lined up perfectly which made me happy and I feel much more confident if I get in another fender bender.

Thank you UMI!

Anyone needs to buy UMI 3-pt. SFC's if they can afford it!

-Karl

JD_AMG

So in other words you put a band aid on the problem, you didn't fix it. Stock, with just konis I would feel perfectly comfortable taking that turn hard with a joint. Why?
1.) Because the chassis is not actually flexing, its the sloppy stock suspension.
2.) You can feel everything the car is doing with the konis, and if the rear end does step out you know its going to before it happens, and it does so in a very slow and easy to control manner.

Shouldn't need to be, because if the chassis really was flexing you should be able feel a difference on the same road. (the car was driven hard remember?) The turn in was no better, the "planted-ness" was no better, and the ride was no better. The car was the same as before, still sloppy and could easily be mistaken for chassis flex, when its really the suspension.

Just don't expect great ride and handling with a heavier rear end, and probably more drag oriented suspension.

usmc320

iTrader: (3)

Technically by your reasoning, shocks would only be a band aid solution to our live axle setup. IRS and a combination of suspension parts would be the only true "fix" which would be costly and only orient the car towards handling. I don't autocross, so the best for one type of driving does not fit in my goals for the car though.

I don't think you can claim how you would take a corner you've never seen before. I can guarantee the RX-8 stock still outhandles your Koni car, so if that corner is questionable at 70mph+ in the 8, then it's definitely questionable in your F-body. Get real.


Come on man. You don't see a difference between driving a car and riding in one. Driving gives you a completely different sense of the car. Hence the reason professionals don't test and compare cars like that ("The new ZR-1 felt great from the passenger seat." Who would trust an opinion like that?)

Actually the addition of the 9 inch will probably help slightly, only because with it are going to come an adj torque arm, adj panhard, and adj LCAs. Oh and I plan on getting a Fab 9 with the parts mentioned above in chromemoly, so weight difference will be minimal.

Once again I have every intention of upgrading shocks. For me though right now there are better ways to spend my money to achieve MY goals. If extreme handling were a major concern I would have:

1. kept the import that was made for it instead of getting a live axle muscle car
OR
2. bought a C5 or C6

But everyone has different goals.

GMmexican

iTrader: (7)

Did you end up getting the chrome moly ones?

usmc320

iTrader: (3)

I didn't for the SFCs. I think it was an extra $100 or so if I'm not mistaken which makes it pretty pricey for them. For the other stuff mentioned earlier the price difference isn't as dramatic, so I will. I don't go to the track, so I'm not obsessed with shaving every pound off I can. I intend to keep my car full weight.

Joshiedoom

iTrader: (4)

I plan on buying these next

Recently purchased LCAs from you guys and it really woke my 155k car up, ordered UMI lower and upper a-arms as well. Cant wait to get them in!

JD_AMG

Not really. While IRS is a far superior setup, the problem was the shocks because they cause the skipping. IRS with the same shocks would get you the same result, the rear wheels would be independently skipping though.

And this is everyone's excuse, hey I don't auto-x either (not yet I haven't) but that doesn't mean that I don't want a stable, solid car. When you are driving the shocks are always working, its not like they only work well when you drive hard.

Yeah, I haven't seen the corner you are talking about, but I've hit a few good joints with my car, one of which was in a 90 degree turn and I didn't know it was there. Took it faster than I should have but thank god I had the konis...
And I'd hope the RX8 could out handle a stock Fbody with Konis, with all the chassis engineering Mazda put into it it better. But that's not to say with a few select parts the Fbody wouldn't be struggling to pass it in a corner.

I see the difference, and their cars feel exactly the same as mine did when it was stock whether I was driving my own car or riding in it. Again, I'm saying you are mistaking suspension flex for chassis flex.

Im not going to argue with you over this but any extra unsprung weight is bad for both handling and ride quality.

This is not about extreme handling, this is about making the car as stable and solid as it should have been.

Chrisingermany

I just got mine on my mid-tour so I havent driven the car in 6 months so I didnt notice the difference after I installed my UMI 3-point. But then I was doing some other work on the car and jacking it up before when I jacked up the front with the jack right behind the front tire on either side the back wheel stayed on the groung and after I installed the sfc the back tire lifted up off the ground when jacking up the front. I know they made a difference just by that aloan. I would get them 100% again.

2002_z28_m6

iTrader: (10)

Good choice. These SFC's are a great product. I really like them. Its a known fact these cars do flex so these can only help that situation.

ZexGX

iTrader: (28)

This really makes me want to install mine... I've had some sitting in the new packaging for months! Already did shocks and swaybars to my liking, along with a UMI PHB; next upgrades are these, then LCAs.