I completely agree. Although no popping noises yet. Using stock end links. Liberal lithium grease on bushings.

 

Z51 with MRC here. I recently purchase the Pfadt sway bars kit. Quality is top notch and have had it for about a day. I haven't really taken it to the limit yet to see if it's understeering much but it's definitely much tighter around the corner than I remember.

I'm curious as to how they determine the adjustability on these.

Stock C7 Z51 with MRC
Front 28mm
Rear 31mm

Pfaftd
Front 35mm
Rear 32mm

It looks like they beefed up the front ALOT more than the rears. Knowing that almost all cars come from the factory with understeer, woudn't increasing the front bars that dramatic compared to the rear cause it to understeer even more? I'm hoping to have a very balanced setup for my car but am confused what the best way to setup the adjustment holes on these bars.

I understand the non-MRCs have a much smaller rear bar. Is it because the spring rates in the rear are much stiffer compared to the MRCs so the ride is balanced out? If that's the case, would adjustments on aftermarket sway bars be much different on an MRC vs a non-MRC car?

 

I have run every combinations of factory sway bars on my base car. The MRC setup was the best of the stock setup variations with the least amount of understeer. Still, I did not like the softness of the front end, resulting in a noticeable dip an delay in response at the turn-in.

The Pfadt set fixed the soft front end issues. Turn-in is much more precise now. I am using the softer of the two front bar setup. At the rear I am using the mid-position. The car still displays mild understeering tendencies but, being in the right gear at the right RPM during cornering allows for the torque to be used to control any understeering tendencies. Besides, on a street-driven car it is always a good practice to tune-in some mild understeer for safety.

The one thing I ended up doing was re-installing the factory end-links at the rear bar. The Pfadt rear bar does not line up properly enough with the control arm mounting holes and their end-links were binding, resulting in some popping noises. Since putting back the factory links, no problems.

 

I haven't experienced that endlinks issue. It mounts up fine and so far haven't heard any noise. You mentioned you have a base model. Which originally came with a different size stock bar than mine. I'm assuming that GM put that bar on for a reason and adjusted the dampers and springs to balance out the car. With an MRC car, they've increased the rear bar size probably because the dampening and rebound are adjusted differently from the base model. So since there are so many variations with our cars in terms of sway bar sizes, I'm just curious how aFe did their tuning on these bars. I'm thinking if I were to use the same settings you are using I would get a totally different result considering I am using a different damper than you are. That's why I'm very curious which car aFe used to test their bars on.

 

IMO - GM decided NOT to use a rear bar on the base model, due to the expected customer profile who would purchase the base. That would be a relatively unskilled driver and as such, they can benefit from the extra safety provided by the heavy understeer of the no-bar setup. This driver is not expected to make quick, spirited drives over mountain or canyon roads but, more a "wax and coffee" style customer.

The smaller rear bar on the non-MRC Z51 car follows the same philosophy, making the car for the moderately skilled driver who values more precise handling and will actually lightly use it over winding roads.

The MRC was made for the top tier drivers who might even take their cars to the track and demand the most neutral and quickest handling that GM is willing to release. But, GM being conservative and wishing to avoid lawsuits over a nearly neutral handling car and its consequences, still retained a somewhat soft front end that discourages hero-driving.

I would not worry about which model the Pfadt bar was tuned for. That is why it is adjustable to give you a wide range. I use non-MRC Z51 shocks with the base springs. I am not convinced that there is much differences in the spring rates between the base and Z51 models. Also, I always favored softer springs and stiff sway bars for best surface compliances. Same as I prefer the 18&19 tire combo over the 19&20 for better tire sidewall compliance as well as for rim protection. For me the above setup provided a great improvement over the MRC bar setup. So, I suggest to start off with my settings and keep testing the car on a winding road until you find the combo that you feel comfortable with. I am a very aggressive driver, with decades of SCCA track racing experiences and am rather happy with this setup. If I raced the car, I'd go stiffer with the suspension, in general.

 

I am betting your wrong on almost all your assumptions. You don't build a sports car and hope unskilled drivers buy it. They did it for a few reasons, the sway only makes people uncomfotable so they think about pushing harder. It does not stop you from reaching high cornering limits. The dry sump is required for cornering forces higher then what the base car without rear sway can provide. The car has a natural rear bar subsitute built in. It also saved weight. It has never actually been proven that the base car with z51 bars can pull more g's in a corner. It just makes you feel like it can. There is actually a chance its less capable. We will likely never know as instrumented tests will never be done.

 

Are you serious? Have you an idea on the demographics of the typical Corvette buyers? Porsche drivers? I have been around zillions of people and fast cars in the US and it seems there is maybe 1 in 100 owners that ever approach the performance limits on their sports cars. Most drivers only do occasional straight line blasts, even there never approaching the engine's redlines. I live in the hills with lots of open canyon roads, see lots of sports cars cruising on nice weekends and, over the years only a single one, a Ferrari 458, that was driving as it was meant to be. The rest seems happy keeping up with the local pickup trucks...

I am rather confident that I see GM's strategies correctly. Particularly in lawsuit-happy America very, very few manufacturers dare building a suspension with ultimate handling. Not because they could not, it is because they know that a neutral handling car is dangerous in the hands of drivers with less than pure racing skills. One just have to remember decades ago when Porsche got sued over the truly dangerous handling of its rear-engined 911 that killed a good number of people.

You are also incorrect when you appear to judge the car's handling capabilities on the G-forces that they can pull. Just as, or even more so, important how quickly and how fast the car transitions between left and right turns. A car with insufficient sway bars will lean too much, takes forever to transition from that leaning to leaning in the opposite direction. The car will feel like a pig on wheels. Swaybars actually reduce maximum grip but, more than pay back by allowing almost instantaneous directional transitions.

I will also say that dry sumps are overkill for street cars. For many years I raced cars on high G-force slick tires with wet sumps and never any starvation for oil, never a drop in oil pressure, never any resulting engine failures. That, despite revving those engines to 10K RPMs. The times when oil pans were not constructed to prevent oil starvation during hard cornering have passed decades ago. Much of the reason for dry sumps is rather to be able to install the engine lower in the chassis and to gain minute power by reducing parasitical losses due to the oil tracking paths of a sump car vs. dry sump.

 

Again, disagree. The car does not sway back and forth like a pig. That can be seen by the small difference in maximum g force between the base and z51. The car still grips and corners very hard. It just does it while making the person driving feel uncomfortable and not confident. This would be true if the sways on a base increased handling or not. No lean=confidence. Without instrumented tests before and after we don't know. If you decrease your maximum cornering speeds but your transitions are better, is that better or worse?

 

For me, with all my racing experiences, the base car felt like a pig in cornering. Even as I moved up to the Mag Z51 bars and non-Mag Z51 shocks, the car still took an unnervingly long time to transition due to the overly small front bar. Of course, your and my perceptions differ but, I stand by mine as my suspension choices resulted in a good number of yearly championship wins and in fantastic street car performances.

Real life handling, road or track, hardly ever decided by max g-force grips. Sure, a car with smaller, or no, swaybars may actually show higher grip due to the larger weight transfer into the outside tires but, on a tight winding road or track it would be outclassed by a country mile by a much faster transitioning car.

 

So you think that gm created the z51 package and then priced it at such a low cost for the real drivers? When the C7 Z51 package came out its cost was peanuts. Hell, even after the price was jacked its not a significant cost. What was supposed to keep the timid guys away from the elite sway bars? Suppose the timid guy bought the z51 and wrecked it? Lawyers might not care about that? My point still stands. Beyond feel we don't know what the real world numbers enhancement it.

 

The "timid guy" is looking for the best ride quality and maintenance simplicity. The base model is perfect for him. Costs are always a factor but, so is the harshness differences in running larger sway bars and 18&19 wheels vs. 19&20, the complexity of dry sump. Generally when you could get a base for under 55K you still were looking at paying at least 10-15 percent more on a Z51 with MRC.

 

Heres some news...you can probably still get a 16 below 50k right now. Z51 1lt for about 52-54k. This is a sports car that's amazingly capable even in the lowest model. If you are so interested in comfort and not performance, there are a hell of a lot more comfortable options. Onre more time, numbers?

 

There are some SCEAMING buys on the Stingrays these days. I did see a brand new 1lt base linked recently on these forums for 44K. That would still be a substantial amount below the 52-54K of a Z51. Our timid, wax-and-coffee guy will pick the base! I picked the base because I did not want the larger wheels and did not want dry sump. I was certain that I could build up the base to handle as good, or better than the top Z51. I have no direct comparisons to rely-on but, I know that I am darn close... this base handles FAR better than the stock. From my racing, seat-of-the-pants experiences, I had to pick up at least 2 seconds/lap at a track, such as Laguna Seca.

 

springs are the fix for the car. Z06 springs will control body roll.

 

You and I have been through this subject before.

Springs have their roles in the suspension and swaybars also have their roles. Using springs to control body roll is not the way to go. You would end up with springs so stiff that the ride would be unbearable for most street driven applications and even for tracks with less then perfect surfaces.

 

So I finally got around to adjusting the Pfadt bars to softest in front and middle in the rear. The difference between this and the Z51 stock bar is very minimal. IMHO it's not worth the $700 I spent. Going to take the car to the back roads soon to try out some more spirited driving. So far not impressed.

 

Pay particular attention during your test drives to the turn-in. That is where I found a very noticeable improvement by going with the Pfadt bar. For me, totally worth the price. I was not enjoying tossing the car around on roads with quick transitions with the stock bar. Now I really do.

 

Going back to the main question, we have the following:

• OEM FE3 bars
• OEM FE4/5/6 bars (with different bushings per suspension code).
• GM T1 bars (I have them on sale; %40 stiffer up front than FE3; same rear bar as FE4/5/6; unique bushings)
• LG G7 bars (40% stiffer than FE4/5/6 bars, with front having an even stiffer setting with second hole)
• Pfadt bars

Anything else?

 

its been a few years now. do we have more info on sway bars mainly the pfadt bars

 

Originally Posted by Kracka
***note*** The Z06 and Z07 use identical swaybars as the Z51 w/MRC.

C7 base Stingray
Front - 26.2mm (hollow, 7.85 lbs)
Rear - N/A
Rubber bushings

C7 base Z51 ($300)
Front - 28mm (hollow, 7.95 lbs)
Rear - 26.5mm (hollow, 6.9 lbs)
Polyurethane bushings

C7 Z51 w/MRC ($300)
Front - 28mm (hollow, 7.95 lbs)
Rear (Z51 w/MRC) - 31mm (hollow, ? lbs)
Polyurethane bushings

Hotchkis ($400)
Front - 32mm (hollow & fixed, 9.2 lbs) +35% stiffer vs. all Z51
Rear - 33mm (hollow & 3-way adjustable, 9.0 lbs) +20-70% stiffer vs Z51 w/MRC
Polyurethane bushings (reuses stock brackets)
Reuses stock end-links

aFe PFADT ($732)
Front - 35mm (hollow & 2-way adjustable) +??% stiffer vs. all Z51
Rear - 32mm (hollow & 3-way adjustable) +??% stiffer vs. Z51 w/MRC
Polyurethane bushings & CNC brackets
Includes heavy-duty end-links

LG Motorsports ($750)
Front - ??mm (hollow & 2-way adjustable)
Rear - ??mm (hollow & fixed)
+45% stiffer vs. Z51 w/MRC (for the set)
Polyurethane bushings (reuses stock brackets)
Reuses stock end-links
Optional heavy-duty end-links (+$245)

Chevy Performance T1 ($600)
Front - ??mm (hollow & fixed, ? lbs, +40% stiffer vs. all Z51)
Rear (same as Z51 w/MRC) - 31mm (hollow & fixed, ? lbs, +20% stiffer vs. base Z51)
Polyurethane bushings
Reuses stock end-links