I'll be upgrading my A Arms soon for track only use with 8" slicks at first and possibly up to 12" slicks in the future. Has there been enough people running the A Arms with extended pins to correct the geometry on lowered cars, to know that the longer pin can withhold the strain from serious racing?

This car is powered currently by a stock Chevy LS1 350 crank hp V8, and likely to be upgraded with relatively minor power mods to about 450hp. So the suspension will be strained by both slicks and torque filled power.

Please help me with actual experiences.

Thanks,

Steve

 

I've kind of wondered this. I'm sure Travis from Rennbay will drop in with advice/hard info on the new pins. I've had them on my car for some time, but it's only been on the track a couple of times. And maybe some "spirited driving" on the Ozark backroads at the Rentreffen event last year.

For what it's worth, I saw an S2 at the track break the balljoint out of a set of Fabcar arms on Saturday at Heartland Park in Topeka, KS.

Hmmmmm, I'm interested in the other reply's as well-

 

Travis' pins are not designed for track use, to the best of my knowledge.

-Jon

 

There was a very good discussion on this subject on the DE/Racing forum here about a month or two ago. The general consensus was that the right way to go in your situation is with charlie arms, or equivalent, where the arm is corrected for the lower geometry, and not by simply using a longer pin. Also, the larger diameter (19mm?) pin was recommended by several people in the discussion. I myself am a little concerned about having more material machined out of my spindle to accomodate the larger pin, though.

Travis' stuff is topnotch though, so he may have some comment about the pins strength. I think the discussion I mentioned above just addressed arms and longer pins in general, but were not specific to the Rennbay products.

 

We have just released a 19mm pin version of the GCK pins. You have to machine your spindle pinches just like with Charlie arms. We offer the 19mm pins in standard length as well. All ball pins are 4140 Chromolly, cut hard at 30 RC then hand polished.

Check them out

These are recommended ridiculously fast cars with sticky tires.

 

I stand corrected, nice work, Travis, as usual.

If I can make a couple of suggestions for future products: 1) poly steering rack bushings (not delrin, and not rubber) 2) A means of lengthening the tie rod pin to account for the change in geometry that the GCK creates

That's stuff that I'm interested in.

-Jon

 

Working on an uplink kit for the tie rods. I could have went with the traditional "tie rod drop link" but I try to make everything so it will fit as much as possible. With a tie rod drop link you cannot run 15" wheels (for the NA guys). So, we are making a tie rod uplink that moves the tie rods up at the rack ends.
Have a few working prototypes that I like a lot. If there is much more call for them we may start production soon.

 

Sounds pretty interesting, does it replace the entire inner tie rod? Just curious.

Thanks for bringing more cool products to market.

-J

 

Nope, just steps it up. Bracket mounts to the rack and tie rod mounts to the bracket. It does play hell with steering boots but I guess you take the good with the bad. Still working out the bugs. May come with larger boots when & if it ever hits the market.

 

Steve,

I didn't have good luck with longer pins on my track car. Be very careful!

West

 

Thank you all for your help.

West - what arms were you using and what failed?

Tifosiman - Thanks for the reference to the previous thread, however I just saw a long thread from 2004, and I didn't any discussion on the change of geometry in the actual A-arm? There was discussion on the long pins though. Was there another thread you're referring to?

Thanks to all,

Steve

 

Steve,

I'm hesatant to bash anyone, so I'll just say that I believe any long pins in stock arms are a big mistake regardless of what they are made of. I have some theories about why they fail (it's a geometry thing), but let me just give the facts. I had run stock arms rebuilt by Dynamic European in Houston for 2 years, 2 drivers 12 events per year. I tried a pair of the long pins in a set of arms that had been assembled by the pin manufacturer. One of them failed in the first run session, and the other side was showing signs of bending. I was at TMS, and fortunately the failure happened on the inside straight and not the 150MPH banking so all it cost me was a fender and a tire. I suspect the manufacturer believes I assembled them incorrectly, not properly torquing the connection to the strut. But, I went back to my 2 year old rebuilt arms, assembling them exactly the same way, with the same struts, and have been running them without problems for another year now. YMMV, but buckle up tight.

West

 

West, just to clarify, are you saying that you had a kit for longer pins that were installed into stock arms?

If so, then it doesn't necessarily rule out the Charlie arms...

??

Steve

 

My failure was with a kit that used long pins in stock arms.

I know Racer's Edge just came up with some new arms, and perhaps Charlie has some long pins. I have no experience with either of them.

I've decided not to argue with 2 years of success, and am just sending my arms back to be inspected and refurbished.

West

 

Steve, check out this discussion:

https://rennlist.com/forums/racing-and-drivers-education-forum/178029-944-a-arm-advice-to-newcommer.html

Regards,

Jeremy