Springs/Shocks - Upgrade or OEM?

[TRixie7]

My TR7 seems to sit a bit low in the front - she bottoms-out on what seem pretty minimal bumps in the road - and after 33 years I don't think the shocks and springs have ever been replaced. I think this because  they appear to be original and I'm the second owner and the first owner didn't recall having replaced them. So I am considering making springs and shocks the next bits to replace and/or upgrade.

My question from you guys-in-the-know is this: Should I go with standard OEM shocks and springs, or should I go for an upgrade of some sort? The roads around Arizona are pretty smooth, overall, and I don't drive her on dirt ever. We have some twisty roads to drive, but overall she is gently driven. I like a tight, grippy feel to the road, but I don't want it to feel like I'm driving a go cart.

Any suggestions you have are immensely appreciated!

[Chriss]

Hi Trixie

Nice car, pretty well the same colour scheme as mine!!  

I have a 7 on 15*195*60 tyres and springs that are uprated 40% on standard all round, polybushes and adjustable dampers, Koni at the front, AVO at the back.  The car is used for track days and CT endurance events and is judged to be one of the sweetest handling 7s there is. I find that on bumpy or rough roads it may be a little too stiff.

The TR7 was designed for the USA and although some in Europe said it was too floppy in original form my conclusion is that the spring rates were about right for normal use, even in Europe.  Where it could do with some tightening up is in the bushes, damping and anti-dive. My suggestion would be to fit new poly bushes all round, including the gearbox mounting, standard rate springs, adjustable dampers that you can tune yourself and an anti-dive kit.  I did not notice if you had 15" or 13" wheels before I started writing this, but keep the ride height standard.

My dampers were fitted about 7 years ago and things have moved on since.  Theo have you a recommendation for dampers?

[Beans]

Not much to add there to Chris' advise.
Although my DHC with 200lb springs and Koni dampers feels a little soft in my opinion.
But that cars sits on the original 13" wheels and has original spec tyres fitted.
With track tyres fitted it feels much tauter, without being to harsh.

Chriss wrote:

... Theo have you a recommendation for dampers?

I'd go for Koni's all round, but they seem to be difficult to get in some parts of the world.
I'd definitely not go for AVO or Spax, they are both to long at the rear.
Best alternative will probably be GAZ adjustables or KYB, although no experience with both.

As an afterthought, Howard B's TR7 has original spec springs and dampers with 15”wheels,
and that car drives and handles rather nicely, so maybe that he can add some info?

[Rust Restorer]

All a matter of personal choice I think.
If you are not doing trackdays, but still want good road holding may be best to fit the cheaper Spax. For serious track stuff or really hard driving then follow Theos advice and fit Konis/KYB/GAZ.
My own experience with both a FHC and DHC on Spax with uprated springs was OK unless I used 15" wheels and low profiles which made the cars a very harsh ride.

[Pete TR7]

This is my own experience as a novice, I use the car as daily transport during the summer so not a weekend or track car.

When I bought my TR it was on standard springs and adjustable spax, the ride was very soft, fun but not great.  I found out the rear shocks had gone and replaced with AVO - dont do this they are too long and bottom out.

During a rebuild I fitted uprated lowered springs all round, kyb front shocks because the front spax had also failed, polybush throughout, front strut bearings and the antidive kit.  The result was not good.

The car was almost undriveable, the suspension was very hard with lots of vibration and although the rear was lowered the front ride height was increased and did not settle.

I ended up going back to the original springs and KYB all round, this is the current set-up and the car is so much better, it does have a firm ride and the handling is excellent for me.

Changing to polybush does firm up the suspension well but as in my case transmits vibration much more.  I have a high speed vibration at 70mph, I have managed to reduced this to acceptable levels, I suspect the remaining problems are tyre/wheel related (I have the factory alloys).

Agree, you will probably need to change the gearbox mount and remote extension bushes, I also had a rattle fromt the gear stick because the cap locating it to the remote extension was broken.

Although my car is pretty standard I am very happy with the suspension and handling for how I use the car, the vibration is annoying on the motorway - unless I happen to accidently exceed the speed limit  ;D

[Chriss]

Pete have you seen the thread on Wheel Vibration?  You may find an answer there.

[Beans]

Rust_Restorer wrote:

All a matter of personal choice I think ...

Fully agree on that, absolutely love my FHC with 336/240 Lbs springs  F/R and custom made dampers.
But these will probably be a bit too harsh for most  TR7 drivers  ::)

[Chriss]

Theo

Changing the subject  slightly, you see from my list of cars that I have 3 Saab Classic 900s.  While on the face of it they are similar, underneath they are very different and all are modified.  Leaving the engine mods aside they each have different springs:  Standard, Turbo and Turbo S.  There is about 30% difference between S & T and about 60% diffference between T & T S.  I find the T S springs are too hard for daily use on increasingly rough British roads.  T springs are the best overall but the Standard springs provide roadholding that is hardly inferior for road driving but gives good ride.  I have made all the cars handle well on the road by fitting anti-roll bars front and back.  My thoughts for a good road car is to have springs no harder than necessary, but to increase the roll stiffness.  This has meant that the cars are prone to understeer if taken on a track, but this may be a good thing on the road.  I am about to experiment with my Turbo S by disconnecting the front ARB to see if that reduces understeer.

[TRixie7]

Thanks all, for your help. She does have the 13" wheels, which seem okay, but the rubber is old and I'll need to replace them soon, too. So with all this new info, I will start looking at those parts you recommend and see what fits for what I'm after. I will definitely change the gearbox mount, since it's pretty much a blob of gum at this point.

As far as buying the recommended parts, I have bought typically from Victoria British and Rimmer Bros. Have you any suggestions for other sources?

Annah

[Pete TR7]

Chriss wrote:

Pete have you seen the thread on Wheel Vibration?  You may find an answer there.

I have just read the thread, my problem is now just the rear, will post on the vibration thread.

Re handling, it does depend on how you want to use the car, another suggestion is to fit a bigger anti-roll or sway bar, improves cornering without compromising ride.

I use S&S preparations as main source of parts and advice, Rick will always find something you to need buy  ;D

[Beans]

I use (in alfabetical order, so no preference order  :P)
• Revington TR
• Robsport
• S&S Preparations
And they are all in the UK.

[Beans]

Chriss wrote:

... Changing the subject  slightly ...

This is clearly one firmly in the area of personal taste, although some people say that ARB’s are only meant for fine tuning the suspension set up.
For example a lot of rally Escorts don’t have any ARB’s.

I too am playing with the idea of ditching one of the ARB on one of my cars, in my case the rear ARB of t Kreng.
If that doesn’t work I’ll have to make up something else as I will be ditching the original rear links.
So no more mounting points for the standard ARB (more info in my Blog).

On the same car I fiited a heavier front ARB and that certainly made a big improvement handling wise.
Together with the 336 lb front springs it gives a very livid but confidence inspiring drive  :)

[TRad]

I agree I think choice of setup is definately personal taste. I found my standard suspension setup actually very good for the rougher events I've done in the past. They also make for a comfortable ride on long road trips. I've since upgraded all the bushes to a dynamic? Kit from s and s, together with 200lb lower springs front and rear and Kyb shocks. I must admit that I did research my options thoroughly and came to the conclusion that with not enough technical know how of suspension set ups, id go for an off the shelf package. Taking the old suspension apart I realise how tired it was and then driving the new setup, it has transformed the handling. Ive since fitted a quick rack to sharpen steering and lowered seat rear trailing arms. The trailing arm mod has transformed profile of car to sit lower at rear than at the front which is opposite to standard setup as I believe they ride higher at the rear. Only thing I've found is that it's a harsher ride on uneven surfaces. 70 profile tyres reduce this compared to my 60 profile tarmac yoks. It is a Tarmac setup I've gone for though which is the majority of what the car is used for. Compromise mods to make car more suitable on a variety of surfaces would be to refit standard trailing arms and run Yok intermediate tyres.

[TRixie7]

Wow, so many ways to go with suspension. A kit or pkg sounds like a good idea for starters. Then I can tweak it later on, if it's not exactly what I want. My first car was a 71 Spitfire (how I wish I still had that one!) and I loved the tight, perky, cling-to-the-road-like-glue way that it drove. I'm thinking I'll probably go for a firmer ride, but I will most likely stick with the stock wheels and tire specs.

[Howard]

beans wrote:

As an afterthought, Howard B's TR7 has original spec springs and dampers with 15”wheels,
and that car drives and handles rather nicely, so maybe that he can add some info?

Not a lot I can add. My 7 has Rimmers polybushes throughout, anti dive kit, standard springs, standard shocks, mgf 15 inch wheels with continental tyres - 185 at front & 205 at the rear. I drive it quickly but have never had it on a track. Ride is good so no problems with speed bumps etc. But handles well and totally enjoys being cornered hard. Unless you want to compete this should be fine for all normal driving.

[TRixie7]

Howard wrote:

Not a lot I can add. My 7 has Rimmers polybushes throughout, anti dive kit, standard springs, standard shocks, mgf 15 inch wheels with continental tyres - 185 at front & 205 at the rear. I drive it quickly but have never had it on a track. Ride is good so no problems with speed bumps etc. But handles well and totally enjoys being cornered hard. Unless you want to compete this should be fine for all normal driving.

Sounds pretty good!

[Beans]

I think standard shocks in this case means aftermarket standard spec shocks.
Don't know their make ...

Howard wrote:

... But handles well and totally enjoys being cornered hard ...

It even steps out the back more or less on command  :X  ;D

[Howard]

beans wrote:

I think standard shocks in this case means aftermarket standard spec shocks.
Don't know their make ...
  ;D

Everything came as a kit on special offer from Rimmers about 5 years ago