TR6 Anyone use TR6 rear springs in their TR4a IRS?

[tdskip]

I've read that the TR6 springs are a touch stiffer and do a better job of managing the rear of the car compared to the original TR4a softer springs. Any been there / done that experience to share?

 

[tomshobby]

Richard Good might know.

 

[HerronScott]

Tom,

I used TRF's SAH1081 "competition rear springs" in my TR4A back in 1982. You can check out a picture of my car just after the restoration in the thread below.

TR4A/TR6 rear springs

I was pretty happy with the ride height front/rear and how they handled at the time, but then again I didn't have much to compare them to since it was my first car and prior to restoring it, I was driving on 26 year old springs!

Scott

 

[tdskip]

Thanks Scott. I have poly spring bushings/packing that I'll be using with them. I have stock springs in the front. At least the rears are easy to swap out if I get this wrong...

 

[RJS]

I'm still running original stock springs in my TR4A but, new springs, HD rebuilt lever shocks and poly trailing arm bushings are on my ToDo list for next year.

I've compiled quite a list of spring rates by supplier. The stock TR4A springs are rated at 280 lbs. A standard upgrade are the TR6 springs at 354 lbs. And uprated TR6 spring comes in a 390 lbs. Race springs are ~510 lbs.

What I haven't studied yet are how spring rate and spring length impact ride height. I suspect a higher rate spring will either need to be shorter or use smaller packing pieces to maintain the same ride height.

Bob
PS: does any one know if springs "wear out" over time or can one say so long as they are not physically broken, performance will be "as new"? Essentially, if I replace my 44 year old original stock springs with new stock replacements, would I see any difference?

 

[cheseroo]

In my experience with sprint car springs where we'd check them after ever race, springs tend to lose a small chunk of spring rate and static height after a race or two then become stable for a couple of years and then start to slowly degrade. I would suspect that road springs follow a similar path.

 

[poolboy]

If there's something that doesn't deterioate with age, I'd like to know about it.

 

[RonMacPherson]

My desire for speed, and money and physical gratification(family forum, so you can figger the last Ken)

 

[tdskip]

Hey now - we've strayed off topic

Anyway - the "How To Improve Your TR4A" book says use stock TR6 springs, so that is what I am going to do. I'll let you know how it turns out!