Alter K Coil Rates real world feedback

Posted By: jcc

Alter K Coil Rates real world feedback - 03/26/13 06:11 PM

So I'm getting closer to getting my Alter K road ready. No drag use, strictly street and track day car b body RB. I got 550lb coils and a 1+'? sway bar. Although there are likely many more Alter K users over in the drag forum, not sure their experience correlates to my use.

Their are only 2 ALter K listed in our handling registry, so what rates have you used and how did they perform, including sway bar?

Posted By: jrlegacy23

Re: Alter K Coil Rates real world feedback - 03/26/13 06:22 PM

Subscribed

Posted By: abodyjoe

Re: Alter K Coil Rates real world feedback - 03/26/13 06:40 PM

damn i forget what i have on mine.. i'd have to go out and check. i have a small block dart so it probably wouldn't help ya much anyway.

what does bill recommend?

Posted By: TC@HP2

Re: Alter K Coil Rates real world feedback - 03/26/13 11:23 PM

What's the motion ratio on the AlterK? Knowing that, we can calculate wheel rates to be compared against known t-bars rates and back into comparable coil rates.

Posted By: jcc

Re: Alter K Coil Rates real world feedback - 03/27/13 12:40 AM

I could contact Bill tomorrow, or if we knew distance of LCA pivot to wheel centerline?, and distance from LCA pivot point to coilover attachment point on LCA, and we knew or guessed coilover inclination, we would have a number/factor to compare my 550lb coils with a typical TB set-up, for a relative starting point?

When these coils were obtained, years back, they were mutually agreed upon by Bill, along with brakes, etc but a lot has progressed since when .96" TB's were worried about being "harsh".

Posted By: TC@HP2

Re: Alter K Coil Rates real world feedback - 03/27/13 02:58 PM

Quote:

or if we knew distance of LCA pivot to wheel centerline?, and distance from LCA pivot point to coilover attachment point on LCA, and we knew or guessed coilover inclination, we would have a number/factor to compare my 550lb coils with a typical TB set-up, for a relative starting point?

Exactly. Its high school level geometry at that point. Once we know what the applied wheel rates are, we can compare apples to apples.

For simplicity, a lot of wheel ratings are calculated at the ball joint rather than the wheel centerline. Obviously wheel offset impacts that actual applied rate the tire sees and the more accurate you calculate this distance, the more accurate your results. I just wouldn't want other potential AlterK users to follow along and end up with different results because they chose a different wheel than you have and then wonder why things aren't the same.

Posted By: Devil

Re: Alter K Coil Rates real world feedback - 03/28/13 03:06 AM

I'd read this for street use....

https://board.moparts.org/ubbthreads/show...e=0&fpart=1

Ryan

Posted By: TC@HP2

Re: Alter K Coil Rates real world feedback - 03/28/13 03:04 PM

Thanks Devil. We all know you are an ardent E-burg supportor and think the AlterK is one step above scrap metal. Unless you have relevent info on motion ratios, there is nothing to see here...

Posted By: G_T

Re: Alter K Coil Rates real world feedback - 03/28/13 04:01 PM

Im interested to see how this works out for you. When I bought my system, I spent quite a bit of time talking to Bill. He typically recommended the 450lb in front, but since i had the viper motor and intended to autocross, we stepped up to 550lb (btw sway bar is 1.25").

Bill did say he would do a free swap with me once if I wanted a different spring rate.

On the car, it feels quite stiff - but car isnt fully assembled or driveable (mock up), so I cant give you a real world testimony for a while.

My car is lowered, and I have found that springs supplied are too short under full rebound - so I'll need to adjust accordingly down the road. Just something to consider that if you intend to run a lot lower...

Posted By: jcc

Re: Alter K Coil Rates real world feedback - 03/28/13 07:09 PM

Quote:

Im interested to see how this works out for you. When I bought my system, I spent quite a bit of time talking to Bill. He typically recommended the 450lb in front, but since i had the viper motor and intended to autocross, we stepped up to 550lb (btw sway bar is 1.25").

Bill did say he would do a free swap with me once if I wanted a different spring rate.

On the car, it feels quite stiff - but car isnt fully assembled or driveable (mock up), so I cant give you a real world testimony for a while.

My car is lowered, and I have found that springs supplied are too short under full rebound - so I'll need to adjust accordingly down the road. Just something to consider that if you intend to run a lot lower...

Yes we have many things in common on our builds, yours sounds really nice and well balanced.

Recently received RMS email motion ratio is wheel weight x 1.3 equals spring load. Measuring my Alter k mock up with a tape measure with my selected wheels, I get 1.6 x wheel equals spring load or 343lbs/in compared to a TB. FWIW my swaybar is not 1.25", as it was not offered at the time, and yes Bill has made very accommodating offers on changing springs rates

These springs are 2.5"ID x 9" and offered in numerous 25/50lb rates by a number of manufacturers.

As best as I can tell, RMS measures from the ball joint with their ratio, and mine is from the wheel centerline I have chosen.

Posted By: TC@HP2

Re: Alter K Coil Rates real world feedback - 03/29/13 04:57 PM

So there you go, about equivlent to a 1.19 or 1.20 t-bar with your current set up.