• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR6 How to improve the handling of my TR6?

Share this page

SCguy

SCguy

Jedi Warrior
Country flag
Offline
I have a 1974 TR6. I'd like to improve it's street handling. The suspension (front and rear) was rebuilt 15,000 miles ago using TRF rubber bushings. I have tube shock conversions in the rear. The rear springs are stock with 10,000 on them and the front are stock with 140,000 on them.

I was thinking of changing the springs to Moss Comp. springs. Whatwould you do? Do you think that the TRF rubber is still good 15,000/6 yrs. old? What about front (uprated) and rear sway bars? Over kill?

tr60pm.jpg
 
Hi Larry,

There's a lot you can do. It all depends on how much you want to spend and if you are willing to live with a harsher ride, as a trade-off to improved handling.

If you replace those old front springs with stock rate, that would likely help, bringing the front up to spec with the rear.

If you go to competition springs, I'd suggest try to get a matched set of 4 for your car, front and rear, all from the same source. The British vendors like Revington TR, Cambridge Motorsport and Racestorations all offer packages of matched springs. Otherwise, you can make yourself crazy buying one set for the front from one vendor, another for the rear from a different vendor, and never get a nice balance.

In the U.S., maybe someone like British Frame & Engine, Ted Schumacher or Kai Radicke specializes in TR6, although I haven't been able to find his website.

In fact, there is a lot of handling and sway bar info at Ted's website, www.tsimportedautomotive.com

And there are various "competition springs". Some lower the car a little. Others actually raise it. Ask. If you your looking for better cornering on paved roads, you'll probably want to lower the car a little. If you are going rallying, you might want it to sit higher.

It sounds like you already have a front anti-sway bar. You could go to a heavier or lighter bar there, depending upon what you are trying to change, and you could add one to the rear.

Also, some bars came with rubber fittings, you can change these to polyurethane to get a better feel. Change both ends to make the roll bar as effective as possible, removing most play, or just one end left rubber while the other is polyurethane will allow about 1/2" play before the bar begins to take effect.

A rear anti-sway bar can help an IRS car like yours alot.

I'd also look into replacing the rubber parts in the front suspension with polyurethane. I'm not familiar enough with your car to say if the same should be done at the rear. Polyurethane bushings in front will definitely make the car more precise handling. In fact, it's possible to go to even harder setups, but they are probably too harsh for a street car.

There are different grades of polyurethane, softer and harder (durometer), too. But, many vendors only offer one. Ask about it. This can really be used to "tune" the suspension. I have soft urethane bushings in my off road Rover, but semi-hard in my TR4.

Lower the car. This can be done with the springs, as already mentioned. Also, the front, lower control arms can be inverted pretty easily, to drop about two thirds of an inch.

Don't overlook tires, tire pressures and alignment. These can make a huge difference.

You didn't mention what type of shocks you are using. There are improved types, depending upon what you want. I like Koni, but some like Spax or other brands. Be sure to set up the front pair first, if only working in pairs, then the rear if you wish.

Hope this helps.

Alan
 
Alan,

Thanks for the great info! I think I'll start with new/matched springs all around and new tires 205/70/15. Does anyone have any expeience with the Comp. Springs that Moss is currently selling. They say they don't lower the car? They used to offer some blue ones that did lower it slightly. I guess I'll give them a call.

Also, how hard is to change the bushings in your front end? I had a shop do it six years ago, but if no special tools are needed I'd think that I could do it myself.
 
Larry, don't overlook a little company called British Parts Northwest (bpnorthwest.com). They are very knowledgeable about springs, ride height, bushes, etc. I went through several vendors for springs before these guys set me straight and got me into the comp springs that worked for me. I lowered my ride height about an inch, run Michelin Hydroedge tires and stayed with rubber bushes everywhere. Check'em out.

Bill
 
Don't forget Goodparts as a source of performance add-ons.

SCguy - don't know what your budget is. Rear trailing arm bushes should at least be polyurethane; nylatron (Goodparts) is better. Mr. Good also has uprated springs that lower the ride height 3/4" to 1". You can get spacers to lift the spring if it's too low for you.

A rear antisway bar works wonders, too. Now it's time to get that rear wheel camber where it should be. Again, Goodparts has some adjustable trailing arm brackets that will probably save alot of time getting the camber right. I got lucky and was able to use my existing brackets in a different configuration. And no affiliation with Goodparts - just a satisfied customer.
 
How to improve the handling of a TR6? Trade it in and buy a Miata /ubbthreads/images/graemlins/wink.gif .

Sorry, bad joke, but somewhat honest.

Before you start throwing tons of money at the issue, try to assess your goals. If you're talking about improving the handling of your car because you plan on racing it in a vintage class, that's one thing. If you're trying to make it handle much better than a stock TR6, because you want a great handling sports car, then you have to be honest with your goals.

When the TR6 came out in 1968 (calendar year, that is, 1969 model year,) it was so archaic in design, so out of date in technology, and built on such a tight budget, that it was playing with one hand tied behind its back. Triumphs were never class leaders in handling -- making up for handling issues with great torquey engines. Guys like Kas Kastner made-up for the shortcomings by figuring out the best spring rates and adjustments for racing applications.

As with all cars like the TR6, which have frames that flex like an Olympic gynmanst on a balance beam, the only way to get great handling is to add extremely stiff springs. In 1984, the Corvette Z51 package did just this to attain 1g skidpad numbers, but the car was deemed unlivable on the street, and those who ordered the option usually ditched the springs and shocks for standard issue parts.

On my '59 TR3 about four years ago, I installed uprated springs and found the car still understeered like a dumptruck going 50mph into a hairpin. (Okay, not that bad...but it was hard to get it to transition into a four-wheel drift, or oversteer in dry conditions.)

The amount of cost in parts, labor(if you're paying a shop,) and in physical therapy bills for back rehab from making a TR6 handle well, you can pretty much buy a used first-gen Miata...or certainly a Fiat X19 or Porsche 914 -- all cars that in bone-stock trim not only handle better than a Triumph, but actually are more fun (give better feedback to your hands and tush) in tossing them around corners -- unless, of course, you're like me and prefer to exit corners with your trunk/boot somewhere along side of you.

Just food for thought.
 
As pointed out, one of the major problems with trying to build handling into these cars is that as the springs get stiffer, you mostly induce chassis flex, which then behaves as an undamped spring. One way to quiet the chassis flex somewhat is to add a roll bar (not a sway bar), which strengthens the chassis side to side quite a bit (at least if it is mounted correctly).

I'm also wondering about Sammyb's experience with drifting understeering dumptrucks. Wouldn't a load of gravel help induce some oversteer? /ubbthreads/images/graemlins/lol.gif
 
Hi again,

SammyB makes some good points.

Perhaps it would have been best to ask you to define "better handling".

Some folks define it as one thing, others look for something else. I suppose it depends on if you are drifting, autocrossing, road racing, hill climbing, rallying or taking a Sunday drive with a picnic basket strapped on the trunk rack.

Frankly I'm pretty amazed at how well TRs handle and perform. They are pretty crudely designed and built by today's standards! The IRS models tried to add some sophistication, with good success in the marketplace but some compromise and age-related difficulties.

Still, all models can be tuned to a pretty impressive level, if that's your goal and your wallet is fat enough. The earlier ladder frame cars are tough little cars, relatively easy to set up with their simple suspension. IRS take more thinking and fiddling to get to really stick in the corners, but likely have more potential. At one time, the IRS cars were shunned for racing, because of the more complex suspension. But, now many prefer the IRS cars because there is more tweaking possible.

On the front end of the car, it's relatively easy to swap out the rubber bushings for polyurethane at the most important point: the upper fulcrum. The main concern is the front spring. Depending upon what's installed, it might be necessary to retain the pring while removing the upper a-arms and upper fulcrum, to install poly bushings. However, if you are swapping out springs, that's the ideal time to do this job as well. The front outer joints are not rubber, and the lower inside joints are nylon/steel, so no change is needed. I'm not very familiar with the rear suspension of IRS cars, so can't really advise you there.

It's true that some people don't feel the rubber is a problem. However, I've seen a lot of rubber bushings that are torn, mishapen and damaged within a very short time. Polyurethane will hold up and retain it's shape far better. If you feel they are too stiff, get a softer poly bush. Oh, and some poly bushings tend to squeek... use a little synthetic grease on them during installation.

If you have an original factory installed front anti-sway bar, the mounting points at the frame might be rubber, too. I'd suggest changing those to poly, too.

A roll bar in the cockpit is a good suggestion, too. It could be very helpful reducing frame flex, with one big caveat. The "ideal" mounting points are the outriggers, where the body bolts to the frame, and other points connecting to the frame. Most "street" bars do little good, either reducing flex or in an actual roll over, because they are only mounted to the body itself and in no way attached to the frame. Plus, a roll bar should have a diagonal or crossbrace to significantly reduce flex. Actually, a full roll cage is the best way to make the car rigid, but likely is more than you want to do.

One more thing... a big part of your perception of a car's handling is the feedback you get through the steering wheel. The TR6 has rubber mounts on the steering rack that absorb a lot of the road feel. There are kits to change these, if you wish, to aluminum. Most folks like this change. Some find it too harsh.

Oh, and any faults in the steering or suspension are more obviouis with stiffer mounts and bushings.

Ride comfort will always be a trade-off for sports car handling, a personal choice.

A load of gravel in the trunk? Hmmm... that might work!

Cheers!

Alan
 
You guys have left one thing out in your discussions of improving the Triumph's handling - the driver. You gotta remember that these cars are organic, unlike a Miata or any modern "sports" car. Everyone that rebuilds these cars or even tinkers with them knows every ping and creak in them, and generally will approach their limit very early on in their relationship with these babies. They are alive! They need constant attention, often have a bad attitude and will punish you if you take them behond their innate ability to handle. Just remember that you can't make a modern, sophisticated driving machine out of these little jewels but you can sure cop an attitude and enjoy every wave and high sign that you will get and deserve. How many Miata drivers can say that? Just beware that when you put space-age materials in the suspension, you may regret losing some of the small amount of comfort left in them. Been both ways and went back to rubber.

Bill
 
I agree with all of the improvement suggestions made so far. I upgraded to the compettion springs & Prothane bushings 4 years ago and never looked back. At the time I added Koni shocks in the front & the VB/KYB shocks in the rear. I would not recomend the use of a rear sway bar for street use. It has a tendancy create more oversteer which is not needed. It would also require increasing the front bar diameter to 7/8". To get the most out of these changes other chassis setting should be done.
Your priority should be tires. This change will make the single most improvement immediatly in handling & braking.If your using stock steel 5.5 rims 205/60 or 65's would be the max I would use. I have 215-65's on 7" racing light weight rims but they might rub in the front. Next time I may choose 60 series to lower the height a bit.
Replacing the bushings on the front/rear & rack will make the car more stable & faster to react to steering changes.
Lowering the cars center of gravity & increasing spring rates will be the next step. I personaly do not find the compettion springs to be uncomfortable for street use. Goodparts or TRF have them.
With the proper changes you will not believe how great the car will handle & still be streetable.
 
Yeah - I did the same to a point. With polyurethane everywhere it could be, and aluminum steering rack mounts, the ride was just too harsh for the crummy roads typical of around here. Ended up with poly steering bushes, rubber back on the rear shock bushes, and one rubber bush on the antisway bar link. That softened it up a bit.
 
What's the possibility of an experienced welder modifiying the fram to make it stiffer without having to make any changes to the body? From looking at the frame, it looks like by adding some cross braces to connect the left and right sides of the frame in more places might help with the rigidity... of course that might mess with the exhaust path.

Adam
 
Not being a engineer by any means, I would suspect the only way to make a real differance would be to weld in a roll cage. This would give the torsional stiffness that a convertable lacks. Adding additional braces, unless it's bolted instead of welded would hinder engine/trany removal.

Mitch
 
Larry I agree with much of what has been written in response to your question, and would second the suggestion that you take a little time to think about your priorities before taking action. Are you looking for more precise steering response? Less understeer? Better grip? Less tendency to jump sideways on bumpy corners? Less of that weird "squirmy" feeling on tight corners?

1)Tyres (tires) with a stiffer sidewall will help in many areas, and while there is no rating for this the speed rating gives a good clue: if "H" rated or higher the sidewall will be stiff enough to give good steering precision for a street car. (A lower sidewall profile than 70 series is also better.)
2) Alan's point about the front suspension upper A arm inner bushings is excellent, cheap and easy, big dividend.
3) All out competition springs are ONLY for track use, the Triumphtune catalogue has "fast road" springs which are a good compromise.Goodparts and others may also offer similar. If you change to a stiffer spring you should change the shocks so they can damp the motions of the stronger springs; adjustables are ideal.
4) It is likely not necessary to strengthen the chassis for road use, but gussets can be welded in corners and the X brace reinforced for track use.

In summary, do the cheaper things first, don't go too radical, a few modest changes can give a lot of satisfaction.
Have Fun! Simon.
 
Back
Top