Lotus Elan

shock action noise question

PostPost by: mac5777 » Sat Aug 13, 2005 5:58 pm

Hi, I may have found my answer by going back through old posts. I want to set my 67 elan S3 coupe up for street use, only, with a soft, quiet ride. Webers and exhaust noise are Great.
Here are my questions- While driving down the road and hit a small bump it sounds like the springs or diff. are real loose. They are not! I can push down on the rear of the car and it moves quit easily for two pumps and then gets rock hard at the bottom and then slowly releases back up. This, to me, may be why the car gets race car hard through the bumps making all of the noise. WHAT IS NORMAL??

The old post said that I may have shocks that have two adjustments, up and down and they may need to be set or balanced. My car is in the shop for final tunning after engine breakin and I can not get to it to inspect until after this weekend. I thought that all shocks should work the same in both directions. WHAT DO YOU GUYS THINK??

The front shocks are good spax and the rear are new spax, installed by my british mechanic's shop. I have noticed that Spax in front and Koni in the rear seem to be the choice of most. Is it because they can be adjusted for better track use and will it make any difference for my needs?
Thanks for any light you guys can shed.
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PostPost by: type26owner » Sat Aug 13, 2005 6:44 pm

That's called 'bump jacking'. Soften up the rebound adjustment (that's the only the adjustment the Spax have). Bad to have that happen on the racetrack! It's a good way to go off course and not know why. Carroll Smith's book explains this effect IIRC.

I run the Spax on the four corners of my car. They work fine on the track if you know how to adjust them. The trick is use as little dampening as possible. The inside dampers goto the end of travel in rebound when cornering. Best to let the weight transfer happen as quickly as possible. Having to wait for traction sucks especially when jumping on the brakes. Because the Elan does not have anti-dive you have to wait a moment for it to dip it's nose before really pounding on the brakes.
Last edited by type26owner on Sat Aug 13, 2005 7:02 pm, edited 1 time in total.
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PostPost by: mac5777 » Sat Aug 13, 2005 7:01 pm

Thanks Keith, now I can name the problem. I'll get that fixed right away and will have a quiet, tight rolling elan.
How is your painting going? Let me know when you are ready I can drive down to you for the weber tunning. Thanks again, Sarto
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PostPost by: type26owner » Sat Aug 13, 2005 7:06 pm

Sarto,
I'm supposed to moving furniture but as you can see I'm playing instead.

Give me full rundown account of how your Webers are behaving. If the folks that installed them did a good job then my tuning services might not be required.
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PostPost by: type26owner » Sat Aug 13, 2005 7:33 pm

I have a little announcement. Mike Ostrov's next tech day is Sept 15 and I promised to be there awhile back and do a demonstation on how to tune DCOEs using an AFM. Unfortunately that's also the time my son is moving away to goto graduate school. I'm under orders not to make any other commitments. :( If I can make at all it will be on short notice. One major drawback is don't have a laptop to run Logworks on.

Mike, I know this is long shot but do you have a computer at your shop by chance? The cable has a serial port connector and not a USB.
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PostPost by: mac5777 » Sat Aug 13, 2005 8:08 pm

Keith, I have been asked 3 times this morning, when is the lawn going to be cut? Now it's time for the lawn.
Rich Kamp installed the 40 DCOE 151s. The tach needed to be re-calibrated, so he did not do much to fine tune them. The shop is installing the tach among other things now.
The car has much more power with the new webers even without the final adjustments. There is no rush, as I am having to much fun with all of this new found power but I still would like you to have them tuned to there full potential.

-Sarto

their not there potential--I hate it when my fingers can't spell.
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PostPost by: type26owner » Sat Aug 13, 2005 8:24 pm

Sarto,
The real bummer is I'm going to miss the next GGLC trackday on Sept 13 at Thunderhill.

The good news is my son has earned a fully paid ticket to a doctorate degree in bio-physics. That means I've got more money to 'waste' on the Elan! :D

Okay, should be no big deal to get the Webers purring then. Do you want best power or fuel economy? Best power only costs about 5 miles less per gallon though.
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PostPost by: mac5777 » Sat Aug 13, 2005 8:46 pm

Keith, I see we are both still playing around. Feeling this new power is intoxicating and if you can add to that, I'm going for the extra power.
I have been getting approx. 28 to 32 miles per gal. Five miles per gal is a small price to pay.

-Sarto

And congratulations on your son!!
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PostPost by: type26owner » Sat Aug 13, 2005 8:52 pm

Sarto,
You're getting slightly better mileage than I am right now. I've got it set for maximum power but have a 3.9 diff and 21.5" diameter tires. I indicate close to 5000 rpms at 80 mph.

My helpers have not come back from lunch yet. :x
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PostPost by: mac5777 » Sat Aug 13, 2005 9:05 pm

Keith,
I have 22.6 diameter tires, semiclose trans. and just had a new 3.55 diff installed by Rich Kamp. I had another elan owner drive mine and he thinks that I have more them the stock 105 hp. The rebuilt engine was just standard, nothing special was added. Once I have a tach that works, I'll know more about the RPM's etc.

-Sarto
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PostPost by: type26owner » Sun Aug 14, 2005 12:06 am

My guess is most folks have never driven a well tuned pair of Webers so most have no feel for the REAL performance the twinkcam is capable of. My 7000 pound van V8 only has 100 hp for a comparison. :P
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PostPost by: type26owner » Mon Aug 15, 2005 3:43 pm

Sarto,
Jon Rosner has asked me to tune his DCOEs on his cloned Super7 with some Toyota engine. They have all the classic problems and are screwed up in everyway. I'm in tuner heaven. :D

The auxiliary venturis are literally rattling around in their bores causing a huge flatspot. I could barely get it to rev up past the rpm flatspot teasing it with the idle speed screw it's so bad. Going to make up some of the coil springs to replace the horrible P-shaped springs that originally are intended to securely hold the auxiliary venturi in place but don't.

He needs to get his car to pass the rolling road smog test. I'll tackle your DCOEs next.
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