Wicked Weasel

I am running hardbar penske coilovers and t1 bars. I think the t1 bars are too big but would like to hear people's opinion.

My reasoning is I bought these great coilovers why connected them with this strong bar. Any thoughts?

Thanks.

gkmccready

Stock bars are cheap. Throw some on and test! A good test is worth 1,000,000 opinions.

I have stock C6 Z51 bars with my HardbarUSA Penske 8100s and the car handles great. I've been thinking of trying a base model rear bar, and I've also contemplated throwing the Pfadt Pfatty front bar on to check it out, too.

A good portion of my fun with this hobby is experimenting with things...

Wicked Weasel

Valid point and usually I do testing, but I wanted to be headed in the right direction before starting out although swapping out sway bars is not much work.

redtopz

I had the exact same question except with pfadt coilovers. I've had advice from several different suspension gurus. Some say use the stock bars and some say use the T1's. I have tried both and even used the T1 front bar and stock rear bar for auto-x, which felt good. For my last 5 track days I've been using the stock bars and I've become comfortable with that setup although my rear inside tire gets pretty light on corner entry. Out of curiosity, I put my T1 bars back on for a track day next Monday to see how they feel. When I was using the T1 bars before my car felt really stiff and the rear end liked to come out, but I'm not sure if it was the suspension or my driving, since I'm pretty new to the sport. We shall see .

fatbillybob

Wicked,

Good question. The theory is that you delete the sways and tune the car for the track you run and thus the springs you need for the that track. Then sways to control roll, then shocks to fine tune. How you do all that in real life I have no clue. But these suspension guys are supposed to be able to tune the springs to the car by some empirical means with chassis frequency and other parameters. Then I guess it comes down to roll control for your tire chosen. I guess if your tracks are smooth you can up the spring derived wheel rate and use a smaller sway. If tracks are bumpy I guess you use a lighter spring derived wheel rate and then up the sways and add more shock rebound. Well that's the crap going around in my 6th grade brain anyway.

redtopz

Well this obviously is not a popular topic, but just to follow up my earlier post I thought the T1 bars with the pfadt coilovers were great. My car felt like it had tremendous grip and did not feel too stiff. The rear end did not feel loose like it did before. So I guess it was me, not the bars .

GettReal

Wish I could give an opinion but I'm a month away from running a Penske / Hotchkiss set up. My Race shop said the T1 would be too much bar and the Hotchkiss should be good.

Davinss

I would go even further and say that testing is essential! It's crazy to me that people on this forum will spend thousands on parts and not spend any time/money/effort on testing and tuning...

Wicked Weasel

We will eventually test, but I wanted to see if my logic made sense. After some other reading I see that it does make sense and going with a smaller swaybar should improve handling.

The testing now will be what size swaybar to go with. I can easily change the swaybar on my car in a 2 day event and see what happens, but it is all feel which is important, but proves little. I think I want to add some data logging to my car and then start testing.

I have stock C5 bars and I believe C5Z bars around. I can probably get another set or 2 of bars and go from there.

95jersey

Aren't the new rear T1 bars adjustable? You may want to buy the adjustable PFADT bars. Then you don't have to switch out bars, but simply make adustments on the fly. I think those PDFAT bars are simply gorgeous, but too rich for my blood.

I use the T1 with 750lb coil-overs and it is STIFF, but I must say it does work well, even in bumpy conditions. Even though it is much stiffer than stock, the car is less twitchy over the bumps than with the stock suspension.

Let us know what results you get.

Wicked Weasel

I don't think the adjustment is big enough on the bar to make a comparison. I think a less stiffer bar needs to be used to see what happens.

I am also not sure if stiffness is a proper way to determine if your car handles well. I say this only because I would think you always want as much tire to be in contact with the ground which means it has to flex to do that. Of course you also don't want too much body roll so stiffness would be needed. And getting deeper into it what about torsion. If the front of the car is flexing I still want the back of the car to not be flexing until it needs to or adjusting for it.

Any way So far Based on my findings a stiffer bar (t1) would be used with shocks and leaf springs to help with overall handling. As you change to coil overs with adjustments a stiff swaybar actually is counter productive thus you would swap out to a bar that was less stiff allowing the coil overs to be more independent as they were designed to be.

Of course this is me thinking out loud and I have not one ounce of data to support it... Lol

ghoffman

With the setup you have I recomend the stock bars, or perhaps the Pfadt SS bar (not Pfatty). Bigger is not better when it comes to sway bars, especially with your setup.

95jersey

I agree that stiffness itself is not the way to improve handling. I personally know so little about how suspension really works that I completely stay away from complex set ups (like adjustable sways, adjustable shocks). I personally would probably screw it all up and make it handle worse.

I can't speak for Penske coil-overs, but if it means anything for this discussion, Lou has publically recommended T1 bars with his coil-over set up. Now, I know we are talking about 2 completely different brands of coil-overs, but it has to have some relavancy. I would think based on Lou's reputation that there is something behind that recommendation...what, I have no idea. Maybe I am too trusting. Maybe like stated earlier it is just "different" schools of thought. I have no idea either, maybe Lou can chime in (not to put him on the spot).

gkmccready

Remember, if you hit the bump with both left and right at the same time the swaybar has no effect unless you've got too much friction in the bushings. If both sides move up, or down, at the same time the bar just rotates in the bushings and provides no added stiffness, its when one side wants to move a direction opposite to the other side that they get involved...

Somewhere on the forum there was a thread about this before and somebody explained that springs provide the front-rear stiffness, and left-right stiffness, and you should only use enough swaybar to provide any further left-right stiffness you require.

That made sense to me when I look at the light springs, big bars set ups. And I see the folks with heavy springs thinking they may want less bar...

bowmanized

I just happen to have a Pfadt SS bar. Brand new in the opened box.

It also has the upgraded pfatty end links.

Let me know.

Thanks

Wicked Weasel

Matt in my research I came across a post from lg which basically stated stiff springs / soft sway or soft springs / stiff sway. It stated stiff springs and stiff sways was not a good choice. This is part of my reasoning for questioning the whole setup.

Here is the post

Http://forums.corvetteforum.com/1568225764-post221.html

95jersey

Wow, good to know I have seen them say they recommend T1 bars with their coil-over set up, so not sure what is going on, maybe I am wrong. Maybe I should put my C6Z sway bars back on the car

Also, I guess we have to determine what is considered stiff? For a pure race car, 750lb springs may be considered soft. We are comparing our coil-overs to OEM spring rates which may not be the correct way of looking at it. In any regards the conversation is pretty interesting and looking forward to the outcome.

Wicked Weasel

Funny I was just editing my post to say "I am not sure what defines stiff springs or stiff sways"

gkmccready

Pfadt has published a nice chart of relative stiffness of various swaybars:
http://www.pfadtracing.com/photos/da...ph_with_SS.jpg

ghoffman

Guys, it really is not that hard to deal with adjustments (at least ones that actually do something). It does require that that you A) have been provided some data (like shock dyno, or sway bar rates, etc) and B) go to the track and do some homework. The small sway bar thing is not my idea, it is really basic, basic, physics, and guys like Gordon Murray (google it) have advocated it for alot longer than I have. If your shock supplier does not or will not provide you dyno data, then you really are better off with a non adjustable and hide your head in the sand and "believe".