maxG

hhmmm... ok so i understand the "it depends" response. I was just told, before i do any suspension mods or get a more aggressive alignment i should stiffen up my suspension bushings with at least poly. But maybe for a season or two ill just stay with rubber until im ready for stiffer. How much does rubber really hold one back, or take away from confidence and degrade suspension kinematics and dynamics? Will I not benefit from a set of coil overs and anti-roll bars just because i still have rubber or poly bushings? I have been in other cars that i know have rubber bushings and was still impressed. thanks again for the feedback.

Werks

There is a right order to do things. Throwing a bunch of money at your suspension to improve handling and getting a "competition oriented" alignment when your stock rubber bushings are going to be flexing so much that your -3 deg of camber in the front is going to be +1 deg on the outer tire when cornering does not make any sense and is arguably a waste of money.

If you want to do things right and really want the best performing car that you can have first get a camber kit from LG, Hardbar or one of the others, then upgrade bushings, then get a track alignment, then sway bars, then shocks/coilovers. You first have to build the foundation for the house before you build the house on top of it. That imho is the order that you should be doing upgrades in. If you don't really care just do whatever, will you car handle better than bone stock? Sure, just know that you are not receiving the full benefit of the upgrades that you are doing.

maxG

Thx Werks for the feedback.
I have the $ and tools for the bushing upgrade, what I was surprised to learn and what is causing reserve is I have had mixed feedback on poly and delrin. I have seen many people discuss the stiction in poly if not regularly lubed and I haven't heard enough informed positive feedback on a kit without this problem or at least zerks to address it. Also replacing them every couple of years isn't a good trade off for my car per its current goals, its not a trailered race car I don't want to trade one issue for another larger one that is a constant hassle. I also have a vehicle /aerospace/materials engineering background so its hard to accept the "trust me" feedback I get on forums and from vendors selling their product. I appreciate and value tribal knowledge but need to understand it or see it with my own eyes if possible. Too many times I have trusted others to end up struggling through issues not foreseen ruining the original intent of the car "modification" where OEM was almost better off and a lot less hassle. Just trying to do my research I'm also a numbers guy, I like quantitative analysis. I hear claims of losing 4 degrees of camber in roll but has anyone done the research? I appreciate vendors that do and present it to the customer. I know this isn't a huge indicator but my tire wear is pretty even and doesn't pass the shoulder arrow indicator, I have also taken tire temps with a probe and short of realtime IR sensors I have on average been able to get a 15F spread inner to out decreasing.

naschmitz

I've autocrossed and tracked my car with stock rubber, poly and delrin (80,000+ total miles; 7000+ of those are data logged track miles).

Of all the things I did to my car to make it a better track car, replacing rubber bushings degraded ride comfort the most. It was absolutely fine for me, but some passengers would complain.

On poly vs delrin, delrin is better in every way except for cost.

Werks

Touch base with Anthony at LG, I remember him posting a video of just a dyno run with the camera under the car pointed at the rear suspension arms and you could visually see the tires toeing out under acceleration due to the rubber bushings deflecting. It's a known issue and not. In regards to switching from rubber to poly/delrin I did it about 3 years ago and frankly did find any noticeable degradation in ride or NVH when used on the street. The car felt tauter and was noticeably more responsive to steering inputs etc. I went on several 400+ mile trips with my S/O and she never complained about the car being rough or noisy or anything like that. In the last 2 years my car has become about a 90% track car so 2-3 months ago I switched over to LG Sphericals which have again improved handling noticeably on track, on the street I not every bump etc is directly transferred to the suspension so the ride is for lack of better words "harsher" but is by no means unacceptable to me for the noticeable performance gains that I have seen on track. If you are serious about tracking and plan on doing that a lot I would skip the cost of the Poly/Delrin bushings and just go straight to spherical's. If you are going to occasionally track the car and plan on switching to stiffer sway bars, coilovers with heavier rated springs etc. to improve handling all of that is going to affect the ride of the car anyways and frankly the poly/delrin bushings are going to have a much smaller effect on ride (if any) than your decision on what spring rate to run on your coilovers or the damping settings that you decide to run them at.

In regards to stiction with poly if not regularly lubed, I had Pfadt ones on my car and once we finally figured out how to install them properly lol I never re-lubed them in over 2 years and had no issues.

Nowanker

Pfadt urethane bushings... zero noticeable change in ride quality. Dead quiet for 2 years on the original lube, just now giving an occasional groan. "Not enough to address at this time".
Agree with Werks on the ride quality... (IMO) stock suspension is already toward the harsh side for the street, but totally inadequate for the track. I'd imagine anything remotely track worthy would make monoballs a non issue.

maxG

So what vendors/brands do you guys recomend for poly or delrin? What's the positives and negatives of each? I don't want to buy poly only to realize I should've bought delrin.
Areas of concern:
-Serviceability
-maintenance requirements
-Durability/replacement intervals
-Availability; pfadt is gone
-Would a hybrid setup be best? ie is one material better in certain suspension locations than the other
-proper installation difficulty

Thx!

67Riviera

Also interested in hearing real world durability/replacement intervals. Love tracking my car as much as I can, but I also daily drive it and often drive long distances 35k+/- per year. Poly is so much cheaper I find it hard to justify looking at delrin or spherical.

Also regarding the Pfadt Poly recommendations - what would be a currently available equivalent? I've seen several posts regarding the poor quality of Energy alternatives because of low duro, poster got replacement yellow higher duro bushings from the company, but I can find no sources for them.

Werks

I think that a lot of the stuff that you are asking again has already been covered by people in the last 2 pages. At a certain point I think that you are going to be best served by taking some time to do a search on here and researching things a little your self by reading through all of the threads on this subject (I'm sure that there are a lot of them) and contacting some vendors to discuss things. At the end of the day it is your money and you are going to have to make the ultimate decision on which direction to go.

Bad_AX

There are quite a number of sources for polyurethane bushings and I would choose a product from a vendor that races successfully. There are only two or three vendors that offer Delrin for the C6 Corvette.

Phoenix Performance
610-482-0141
jfaphoenix32@aol.com
A whole big thread on Phoenix Delrin bushings: https://www.corvetteforum.com/forums...-bushings.html

Vansteel - Corvette Suspension Brakes & Steering
727-561-9199
800-418-5397
Email: vansteel@vansteel.com
Maybe better known for suspension for the earlier generations, this company has been around for a long time and their products are backed by results on the track. I saw their Delrin bushings at Carlisle, and they look the business in terms of quality.

Werks is right about the order of "improvements". Personally, I am taking the advise of those with much more experience and burning through a couple of sets of street-type tires and brakes before going crazy with modifications. This is only my second year of tracking my car, and I have come to appreciate how much the alignment can move on the stock bushings as I'm pushing the car harder. Thus far I've done modestly improved brakes/pads, DRM Bilstein shocks (excellent bang for the buck), Michelin PSS tires, high spec fluids thoughout, and a more track oriented alignment (for the 3rd time). Next stop for my ride is seats, bushings (most certainly Delrin), brake cooling ducts, and T1 bars (or the LGM version). My hubs are still tight, but that won't last long if I go to stickier tires. The following was posted last year, and I think it's spot on advice.

https://www.corvetteforum.com/forums...n-upgrade.html

chetly

What does a castor/camber kit consist of for a c6z? I have -3* camber and plenty of castor. What am I missing?

rfn026

This is what Polyurethane looks like after two years of track use.





You need to give some serious thought to using Delrin.

btw - Energy Suspension manufactured some new bushings for me that use a much harder urethane. They've been working just fine. VBP has never gotten back to me. I'm still waiting for their email. I've been waiting 2 years actually.

Richard Newton

Werks

You should probably expand on that statement a little, that's what the bushings that you got from VBP looked like after 2 years. I ran Pfadt ones for 2 years, and frankly I'm about as anti-Pfadt parts as can be nowadays and their bushing never looked like that or gave me any issues once we figured out how to put the things together properly.

67Riviera

If the new Energy urethane works, why do you still recommend Delrin? Can you tell us how much the higher duro Energy bushings ran you and how you went about getting them?

As was previously stated, ride quality and preference is highly subjective. I'd love to ride along with some people who have the setups in question so I can get a better feel for them. Anyone around Pittsburgh/East Ohio, Mid-TN, or Atlanta?

w00tw00t

I have a set of LG monoballs on the way that Anthony is assembling for me. I'll post up a review once I get them, however my thought process was to wait a bit, save up for it and go straight to the best monoball setup available (LG) and not muck around with poly/delrin ....

Werks

I just had my second track day about 2 weeks ago with my new LG monoballs, you are going to like it. The car handles so much better it's hard to describe! Here is a little video from that day where me and a buddy were also testing brake pads, I'm the orange Z with the wing and video is shot out of my buddies car. Once we get through traffic and picked up the pace it just felt like the car was on rails!

w00tw00t

nice!! That's Mike (mikymu) and you correct? You guys are crazy fast! I'm looking forward to getting these installed and hitting the track soon for a winter-track-day here in Seattle..

derekdj87

I just saw in the STU build in this forum the main poster building his own Delrin bushings on a lathe. I thought I had previously read that something about the bearing geometry was weird on corvettes making so you had to machine them offset?

Derek

Werks

Yep that's me and Mike aka mikymu playing around at Thunderhill 5 mile track with the new 2 mile addition. You are going to really enjoy the spherical bearings once you get them in!

w00tw00t

Very cool! Can't wait to have mine on! I did t-hill a few years ago, perhaps next year I'll do a road trip down there with some track buddies. Have to try out the new section!