73 Twin Cam at speed

[rjbaren]

Hello all, I have another question.  I have been driving around a bit more in my Europa and getting used to the feel, sounds, and smells.  I have also noticed at about 70 mph it gets a little squirrely.  Are these cars pretty stable a highway speeds?  I have only been on two lane highways with 45 and 55 mph speed limits and pushing it a little.  But I don't think I would feel comfortable driving at 70 mph or above on the freeway...yet.

The shop that installed the drivetrain said they did an alignment but I don't believe they have an alignment rack.  They are racers and they do race an S2 Europa so I wonder what kind of alignment they did do.

Should I maybe go to a Goodyear and have it checked?  Will they have the specs?

[tedtaylor]

proper alignment (front & rear) with respect to specs from the workshop manual are critical.   additionally, all the front end parts need to be good, not worn.....links, tie rod ends, trunions, steering rack, etc.   Tires and wheel balancing as well.
the only issue i ever had at speed with my JPS twin cam was the Lotus factory alloy wheels and their infamous centering issue.  regardless of balancing, i could never fully get rid of wheel vibration 50=70 MPH.
I've had my car up to 90-100 and drove straight as an arrow, fully confident in handling/steering, so you definately have some issue to fix.

[rjbaren]

Thank you.  I have new tie rod ends, ball joints, lower control arms, bushings, tires, wheels, inner and outer bearings, calipers & pads, and trunnion kits.  Steering rack is original and untouched with only 45k miles and new rubber bellows too.   
I will get it to an alignment shop.

[1970EuropaGuy]

My S2 feels great at high speeds as well. My only complaint is front lift so I'll be adding a Twin Cam type spoiler.

[BDA]

I would also make sure your front wheel bearings are properly adjusted. Grab the tire at 3:00 and 9:00 and try to wiggle it. It shouldn't move.

[Kendo]

It doesn't sound quite like what you describe, but when I first got my Europa I couldn't believe the front tires should only be filled to 18 Lb. So I went higher, around 30 PSI. They bounced around quite a bit at speed. Back down at 18 PSI the car behaved much better.

[rjbaren]

I saw something tonight that might be a part of the problem.  The shop put a 185 70 13 on the right front and a 175 70 13 on the right rear.  The other side has a 175 70 13 on the left front and a 185 70 13 on the left rear.  I will switch the RHS tires and then check all the tire pressures.

Where is the best place to jack up the car using a floor jack both front and rear?

Also, can I jack up the rear of the car from under the transaxle to get both rear tires off the floor?

[BDA]

First jack up one side behind a front wheel. Then put your floor jack under the cross and jack the front up and put stands at either end of the 'T'. Then jack up the rear by the tranny. Put a prop under the rear hoop or tranny, whichever gives you a good prop support. If you have a 365, the rear hoop is flat and you can use a stand there but you might want to make a rear prop to work for your rear hoop.

[jbcollier]

The best places to jack are the rear hoop at the back and the under the chassis "T" section at the front (with a bit of wood to spread the load).

Get a four wheel alignment!

Especially watch for:
- camber. Off? Something is wrong, worn, bent, etc.  Find the problem.  Don't use adjustable links to hide the problem.
- front included angle (or KPI)  Off?  Something is bent, most commonly the upright.
- rear toe in.  Don't go too close to the minimum spec.
- rear thrust angle.  Adjust the rear toes until it's very close to zero.

[surfguitar58]

The consensus seems to be a suspension set-up issue, but I have to say, 70 mph is my comfortable upper limit in my TCS because above 70 it sounds like its revving too high for sustained driving. Handling is just fine, but the noise is grating. I have a 4 speed (352 trans) and that is one of the reasons I am planning to upgrade to the 365 trans with overdrive. Maybe the header on my car is tuned to kick-in at that rpm or something, or I am just a revs wimp, but sustained high revs on the highway just feels wrong. Spoiled by modern cars maybe.
t

[surfguitar58]

I saw something tonight that might be a part of the problem.  The shop put a 185 70 13 on the right front and a 175 70 13 on the right rear.  The other side has a 175 70 13 on the left front and a 185 70 13 on the left rear. 

Just read your post more carefully. This is almost certainly your problem.
t

[jbcollier]

Most certainly, but still get a 4 wheel alignment.

[jbcollier]

The Renault engine thrives on revs.  As long as you keep under the redline, you're fine.  It will happily exceed the redline but cam and follower wear increases significantly.

TC/S engines like to rev but their short valve guides are the weak link.  They're going to wear out any way so you might as well enjoy it.

The 0.86 5th in the 365 does help but it still revs at speed.  I have 0.86 equipped 395 and I wouldn't call it quiet or long legged. Larger tires also give longer legs and help all the way through the range.  Finally, ear plugs or noise canceling headsets make it all peachy on long trips.

[rjbaren]

Changing the tires around and putting both 185s in the rear and adjusting the pressures made a huge difference.  50 and 60 mph are just fine now.  70 is also good but you begin to realize that 70mph is pretty fast.  I did run her up to 90 for a second or two and I'm not sure how accurate the speedo is, but she went and she was still pulling.

I am going to get the specs together and take her for a four wheel alignment.

[BDA]

That's great news! Let us know about the results of the alignment.