Chapman Report

Published by the Golden Gate Lotus Club

February 1999

 

February Meeting

Friday, February 19, 1999

 

News Flash!

The track event at Thunderhill May 16 is confirmed. No more excuses!

 

 

Lotus Calendar 1999

February

19 Meeting Don and Betty Nester’s – Danville

March

13-14 Club Lotus at Donnington Park, England

19 Meeting – John Zender's – Menlo Park

27 Sierra Foothill Tour to DBE & Denhard's

April

16 Meeting Victor’s – Burlingame

18 Lotus Dyno Day and swapmeet/grand opening/BBQ at Spencer’s shop – Hayward

25 Dream Machines show - Half Moon Bay

May

16 GGLC Track Day at ThunderHill

21 Meeting Joel Farber’s – San Jose

June

13 Zender Rallye – Woodside Hills

18 Meeting Hamai's - Palo Alto

July

16 meeting TBD

16-18 LOG 19 - Lotus Ltd Corning NY

August

20 Meeting TBD

27-29 Lotus corral at the Monterey Historics (featuring Auto-Union)

Sept

11 British Car AutoX (tentative)

12 All British Car meet – Palo Alto

17 Meeting

October

15 Meeting TBD - Nominations

Nov

19 Meeting TBD - Elections

Dec

5 The Toy Rallye -Fremont

?? GGLC Holiday Party ,TBD

 

 

The President Beats the Rap

I can honestly say that 1999 has started off well and I hope it continues. We had a great January meeting with a good turnout and I thank all of you who were able to make it on a night with such bad weather and traffic problems. Those of you who didn’t make it missed out on our host Tom and Cherie Carney’s yearly feast of hors d’oeuvres, and we all helped Mel Boss celebrate his 11th consecutive 39th birthday as well!

 

The day after the meeting I received some news that I had been waiting to hear about for a couple of weeks and I thought I’d share it with you all since I think everyone can benefit from it. The big news for me is my victory over the California Highway Patrol. This is regarding the ticket that I mentioned at the November meeting when I was so desperate for help. To recap what led up to this, my brother and I have a friend who lives in Holland who came over in October on business. Rob is a fellow car fanatic who owns a Lancia Delta Integrale Evolution I, and it was understood that while here, we would go out for a day of Lotusing.

 

We took to the hills and drove up to Skyline Blvd with my brother in the Europa and Rob and myself in the Seven. We had a great time and I got a good chance to put my boot into the Seven for the first time since its maiden drive to the British Car Meet in September. Those of you who saw my Seven at the meet know very well that it wasn’t exactly finished when I drove it down. Well, it wasn’t finished very much more by the time Rob arrived either and I hadn’t gotten the speedometer hooked up yet. As a result, paranoia dictated that I not get too carried away that afternoon and that I take the "back roads" to wherever we needed to go.

 

As I said, we had a great time and when it came time to leave, I made the decision to leave Alice’s restaurant and go down highway 84 to Canada Road and take that back. Knowing full well that a Europa and a Seven cruising down the road together is a magnet for attention, we cruised home as carefully as possible with my brother in the lead to establish the speed. As we drove down the road a CHP passed us going the other way. I had just enough time to look in the rear view mirror to see him turn on the lights and pull one of the quickest U-turns I’ve ever seen. He pulled us both over and proceeded to tell us that he had nabbed us with radar doing 62mph in a 50mph zone. Yes, that’s right, CHP with radar. We better get used to hearing it too because they’re using radar on more and more highways in the bay area.

 

Now I’ve heard of people sweet-talking policemen out of tickets but no matter what we said, Johnny Law wouldn’t have it any other way. He wrote us up while I stood there thinking that if he only knew that my Seven had no speedometer, no handbrake, and the gas tank was bungie-corded in, this ticket could be even worse. Still, it was very disturbing to us since my brother had said the Europa indicated 52mph at the time and Johnny wrote the ticket for "60+mph"!

 

We received the standard lecture of how "unsafe" we were, but doing 10mph over the limit on an isolated road, in perfect daylight, with not a cloud in the sky and no other cars on the road can hardly be considered dangerous. So, wrongfully accusing the Smith’s speedometer in the Europa, we had the accuracy checked and were surprised to find out that it was only off by 2mph at 50mph.

 

A friend of mine suggested that since the ticket was so bogus, I should contact a traffic attorney. I’ve heard of lawyers specializing but I thought this was amazing. I contacted a local motorcycle shop to see if they could recommend anyone and I spoke to a young man who hired a San Francisco attorney who had "gotten him out of a pretty hairy ticket and a failure to appear". She sounded like a real Perry Mason and just the kind of person for me, so I asked for a continuance on the ticket due date and made an appointment for a consultation. I gave her my side of the story and she said that several factors were in my favor, namely the conditions and the proof of accuracy of the speedometer. She said she thought I had a good case BUT, there were no guarantees of course. Knowing full well that if she did lose, I would have to pay her fees and the ticket, and receive the point on my record, I decided to take a chance and hire her. On January 11th she walked into the arraignment in the Redwood City courthouse, worked her magic, and got the charge reduced to "local San Mateo ordinance 3.38", whatever that is. I haven’t been able to find out what exactly this is, but in a way I don’t care. It cost me $275, but considering I had two tickets on my record already, the cost of the attorney was less than the increase in my insurance that I would have had to pay if I had been convicted. It was all so easy, I didn’t even have to appear with the attorney.

 

I’m breathing easier now and just hoping that I won’t have to use her services again anytime soon. But it’s nice to know that we have one more weapon in the war against the hypocrites who label us as criminals simply because we own sports cars. Happy Lotusing and see you at the next meeting!

 

Scott.

 

 

The Editor

Well, here I begin my second year with the CR. Daren did a great job on his first issue last month and gave me a wonderful break. Taking turns on the CR will go a long way in minimizing editor burn-out. Having last month off was wonderful. It seems that when you’re doing it every month, like the deadline is always coming up¼ it is!

 

With Daren’s ideas and input the CR will change and improve over the next few months. One of our primary objectives is to have the CR in your mailbox during the first week of the month. If you don’t see it by the 7th, then we’re late and you can hassle us all you want. It might not help, but it probably won’t hurt either.

 

Something else I would like to see with the CR is to get someone to write an article on a monthly basis that will continue each month. This might be a fictitious story, advice column, cartoon, gossip, or whatever. Even a single paragraph every month will be enough. Any takers out there?

 

Progress on the Ultimate Europa was slow this month. I completed the rear section of the cage including the rear braces, main hoop and x-members, and the roof halo. This job has turned out to be much more difficult that I anticipated. You really have to think ahead as you build the cage to avoid painting yourself into a corner. Hopefully, I will have the cage complete by the middle of February. That will give me most of March to do the motor brakes, dash and wiring and still get to Bean’s on the 27. If not, then you’ll definitely see it at Thunderhill in May.

 

John Z.

 

 

Rebirth of a Renault Tranny

Or how to build a racing 395 transaxle

by Mike Schlicht –Vice Prez

 

This is the first in a series of articles about the Renault transaxles used in the Europa. The main focus is on what it takes to race prepare the 395 variant which was used in the Renault R17's. Most of the information except that pertaining to the shift mechanisms is applicable to the 365 transaxle as well. This first article will talk about some basic transaxle stuff. In the next article I will go into what it takes to retrofit the 395 into a Europa. Subsequent articles will go into the details of doing roll pins, modifying synchros, changing gear ratios and fixing a few known problems.

 

A little history;

Lotus first used a Renault transmission in the S1 Europa. The Europa at that time was Renault powered so the choice was obvious. Later when the Twincam version of the Europa came out the Renault transaxle was retained. Along the way the transaxle went through several versions. Starting with a side shift 4 speed and ending with a rear shift 5 speed (365). The basic internal design stayed about the same with only the shift mechanism including the rear cover changing significantly. Various final drive and gear combinations where tried. By the time the Twincam came along the split housing had gotten stronger mainly by using more ribbing. Rumor has is that the improved housing was for the Twincam but my sources in Renault indicate that this was not so. During the late 60's and early 70's Renault was using this transaxle in rally cars. At the 95 Lotus convention at Laguna I had a chance to talk extensively with some of the guys from Renault who where there to support the Renault powered F1 cars that where there for the Historics. Several facts came to light:

 

1. The turbo powered Rally cars where putting out over 200 HP and 200ft/lb of torque! The cars would regularly get several feet off the ground and then come down hard with the engines redlined! Occasional U-joint and drive shaft failures would result but they never saw a stubaxle or internal gear failure! After a little prodding they admitted that the input shaft extension (the part that actually goes into the clutch) would sometimes fail but this was considered almost a normal thing as it is designed to be the weak link in the transaxle.

 

3. It was not uncommon for the cars to finish a race or stage with holes in the casing, gear and pinion faces badly scored but still running! The transaxle was not considered a high priority item in keeping the cars running. The term used by the French was "bullet proof". They just laughed when asked about the supposed "weaknesses" of the transaxle.

 

By 1995 I had been racing with a 395 Renault transaxle for over 5 years and had experienced no significant failures. This is not to imply that all was perfect, just that the basic design and materials would easily work with engines of up to 260HP and 160ft/lb of torque. This does require a slightly different 1st and 2nd gear tooth design than found in a stock 395 (stub tooth). With less HP (200) you can go a little higher with torque, maybe 200ft/lb. It turns out that the actual instantaneous torque that the engine puts out can be much higher than the average torque. In a typical street car with a light (26lb) flywheel/clutch and rubber engine mounts the peak torque is typically 150% of the average. In my racecar with a low mass low weight flywheel/clutch (12lb) the instantaneous torque is about 300% of the average. This works out to a peak torque for a stock Twincam of 165lb (110 * 1.5) and 474lb (158 * 3) for my car, 2.87 times as much.

 

Besides limited slip and pinion wear, all of the problems that I have experienced have to do with shifting and the synchro springs. Jeff at JAE has told me about problems with first gear failures when drag racing a ell tuned Europa Twincam. I have used a stock transaxle for years Autocrossing (drag-race starts), without any problems. I suspect that the transaxles that failed where not maintained properly. If the stub axles are not shimmed correctly the spider gears will wear abnormally eventually shedding small bits of metal. Additionally, I have almost never seen a transaxle that had the ring and pinion backlash setup correctly. If this is way to loose (the norm) the pinion will wear abnormally eventually shedding small bits of metal. If any of these bits get between the gear faces it will damage the gear teeth. If this goes on long enough a gear will fail! First gear being closest to the final drive will usually get the most damage.

 

Transaxle design highlights:

The basic layout of the transaxle is very conventional for a street transaxle. There are two shafts that carry the gears, the Input shaft and the Pinion shaft. As it implies the pinion shaft also ends in the final drive pinion which together with the ring gear and spider gears makes up the final drive unit. Overall a Transaxle is the most efficient way to package a complete drivetrain and the Renault transaxle with bell housing weighs only about 95 pounds. The Shaft spacing is 70mm or 2.756". This is actually considerably less than all of the other transaxles that I have seen for this power range and contributes to both the lightweight and much lower rotating mass.

 

In my opinion the lower rotating mass more than makes up for the slight disadvantage posed by using synchros verses dogteeth in shifting. The following is a real world example of why I like synchros:

 

You are heading for turn 2 at Laguna when making an inside pass on someone that you have been chasing for several (eternal) laps. You are coming into the end of the straight at about 125-130mph, you go way to deep into the corner and stand on the brakes, the car initially pulls down at near 3 G's but as the brakes heat up and the car slows they start to lock up (oh-shit!), at this point you are modulating the brakes for all you are worth to save Y O U R L I F E, you leisurely pull the shifter back and to the left, step on the clutch, apply a little back pressure to the shifter and wait a second or two for that reassuring clunk as the synchro does it's J O B and the transaxle drops into second gear, while you are still modulating the brakes for all you are worth to save Y O U R L I F E, just on the off chance the Lotus achieves the miraculous and slows down enough WHILE STILL ON THE PAVEMENT to make the corner, (oh yea, wasn't I passing someone way back there?!! God, what a lousy pass, I'll have to apologize to him after the race for almost hitting his car at least once never mind running him off the race track!), finally get off the brakes, blip the throttle and let the clutch out, accelerate smoothly just clipping the apex and out of the turn (phew!), check the rear view mirror to see if the poor slob is still there and not flipping you off (what? what's this, he is giving me the thumbs up for a good pass, YEA!).

 

I attempted the above scenario in the same place once with a "crash" box and it crashed several times, loudly! I have talked to a few well-known drivers that in private admitted to the same reluctance to try and use heal and toe techniques while they are "braking to save their life". I have driven various racecars with both types of engagement mechanisms and if properly done they can both be made to shift quickly. A synchro transaxle will be more temperature sensitive and in my car the shifting is quite stiff (slow) until the transaxle gets up to temperature which only happens on the racetrack. I will go into more detail on the ins and outs of synchros in a later section.

 

The five-speed transaxle has 5th gear reversed in that the synchro gear is on the input shaft. This is actually quite clever as it makes the design of the shifter setup simpler. When taking a transaxle apart it's obvious that the 5 speed was a derivative of the 4 speed. 5th gear is outside of the main case, tucked inside the rear cover. In a stock transaxle 5th gear is the only interchangeable gear and for racing can be changed without removing the transaxle from the car. Due to interference with the shifter selector pivot the ratio that I now use for 5th (1.25 instead of a typical .86 overdrive) is about as high a ratio that will fit.

 

The final drive ratio in the 365 and 395 is 3.777. Other ratios are in theory available but I have not been able to find any that are a drop in. For reduced gear load a higher ratio like 4.11 would be better. However this puts more load into the pinion which is not a good idea from a wear standpoint. In the racecar, besides the limited slip the pinion is the only part that shows any wear when using Red Line 80W140 synthetic oil. My guess is that a 4.11 ratio would not last more than about 25-50 hours in my car. In addition a 4.11 ratio will require larger input shaft gears slightly increasing the rotating mass. As I have found out the 3.777 ratio is about the best overall compromise.

 

The 365 as used in the Europa is a rear shifter. Unfortunately what this really means is that eventually it will become a "no shifter". Years ago I did a stress analysis of the shift rod that comes out of the cover. It turns out that there is a lot of side load on it and the simple and too short bushing used to hold it will wear out in short order. Since it is the lowest part of the transaxle it will also leak oil forever! While it is obvious that the case has provisions for a rear shifter, somehow I can't believe that Renault actually designed the rear cover that way unless they did it under duress?

 

The 395 transaxle on the other hand is more like the early Europa, a side shifter and in my opinion a much better way to go. Not only does it work more smoothly and doesn't wear, it is spring biased like a "modern" transaxle. In neutral the shifter is held between 3rd and 4th gears by a spring arrangement. In racing this means less than on the street but I find it still helps if for no other reason than it tells me if the shift mechanism has gone out of alignment or is broken.

 

The final drive stub axles that come out of the differential are splined. The inboard U-joint yolk is held in place on the spline with a roll pin. In true Lotus fashion the drive shaft does double duty and is part of the upper link of the rear suspension. This means that the roll pins (as well as the U-joints) always have some side load on them. There are many misconceptions regarding the often-maligned roll pins. If setup correctly they will last a long time, but not forever! In the later Europas the roll pin is a single one. The good ones are made of 0.04" thick steel rolled about 4 times such that there is only a 0.05" diameter hole in the middle. I have seen cheaper ones that use thinner steel where the hole is about 0.1" diameter. Don't use them! In my opinion the roll pins are at the center of one of the most critical areas of the cars performance!

 

With tight tolerance U-joints, high quality roll pins, correctly shimmed stub axles with some roll pin "preload" and above all else tight fitting yolks on the stub axles, the rear suspension can be made to work very well even with 11 inch wide tires. I add about .1 degree of camber to compensate for the slight play in the U-joints. I also use taper roller bearings in the uprights but that is the subject for an other article.

 

The standard differential is an open type with 2-spider gears in the 395 and 4 in the 365. While the 2-spider setup will work on the street it will wear out quickly on the track! Do not use it. The 4-spider diff will work on the track but it too will wear out. It took about 25 hours in the racecar to wear the 4-spider diff to the point where small pieces started braking off of the worn edges! Quaife makes a Torsen type limited slip. It works quite well. Like all Torsen diff's it too will wear out the worm gears! At the last race of this past season the Quaife (with about 25 hours on it) would suddenly start to slip when the engine was at peak torque. It felt as if the clutch was letting go, the engine would just race up and down with the car going down the straight. I am still checking into this "problem" and may get an answer from Quaife before the next article.

 

I have driven the racecar only once with a locked diff. To say that it acted strangely is putting it mildly. With 11 inch wide tires and 220HP the car would "ratchet" around turn 11 at Sears effectively picking the front of the car off the ground! I spent an afternoon flogging the car around Sears Point and only got to within 2 seconds of my normal times. Even though there are people using locked diff's at the track they are all on much heavier cars. I have never seen a high HPmid-engine formula car with wide tires that used a locked diff that wasn't a bear to drive (they did it because they had to). Several Atlantic drivers have told me about what it was like when the limited slip locked up and the car became unpredictable. Some drivers admitted crashing the car.

 

I don't recommend locking the diff in the Europa if you have wide race tires and or a lot of HP. In vintage racing with narrow tires and about stock HP it will work. It took a while before my lap times improved with the limited slip and even then I would say that at Sears point it is worth about .75 seconds and at Laguna Seca it is only worth about .5 seconds. The biggest improvement to the cars performance was totally unexpected. With the open diff the racecar would exhibit tremendous inside wheel spin coming out of slow (1st and 2nd gear) corners. The acceleration was spectacular, the car was quite stable but the engine was using up lots of gas, tires and dumping large amounts of heat into the cooling system. Without the inside wheel spin the water temp was 15F lower, the oil temperature was 25F lower and the rear tire wear was cut in half! In tire wear alone the limited slip paid for itself in 2 years.

 

 

FOR SALE

 

February

Adjustable lower links for Twin Cam Europa John (650) 368-9105 motofab@wenet.net

 

Parts for Lotus Europa S2: pair of aluminum fuel tanks, set of hub caps and trim rings, brake booster, John (650) 368-9105 motofab@wenet.net

 

Parts for Esprit S2 Engine cover (dog house), complete front and rear brakes, radiator fans and shroud, John (650) 368-9105 motofab@wenet.net

 

1984 Esprit turbo, 37k miles, white with red interior, all new everything, meticulously maintained, brake, clutch, coolant, flushed and refilled every 2 years, oil trans every 6 months. All Redline synthetics. Car is located in Danville area.

$15,000 David Condrack (707) 252-9298

 

1965 Elan S-2 roadster for sale in Texas. Color is

red. Weber head and carbs. Original frame (neither rusted nor wrecked) Transmission & engine. Close Ratio Transmission. Three tail Light configuration. Engine rebuilt less than 500 miles ago with new sleeves, connecting rods & new pistons. New interior. Stainless Steel headers and new exhaust. New vacuum canisters, new dash. New bumpers (front & rear). New ball joints, brakes and cylinders (where needed). New Emergency brake cable. Many spare parts. $12,500.00 e-mail is Scupper@swbell.net. Fax

1-210-829-7708.

 

1958 Lotus XI LeMans Series II Chassis No. 533, FIA Papers. FWA Climax Stage III tune with twin Webers. Wobbly wheels. MGA close ratio trans. DeDion rear end. Appendix "C" configuration. BRG with red interior. $55K/OBO. Greg Mitchell-

gkm@pacbell.net 408-298-1730

 

1970 Europa S2. Ground-up, nearly psychotic restoration! Over a 20 year period, every single part of this car was removed and scrutinized for authenticity and quality. Receipts to prove it- if you have 6 hours to go through them. Heavy duty fiberglass lapwork at the traditional weak spots (pillars, pillions) and finished in nearly bulletproof Imron Alpine White. If you attended the last 2 Palo Alto British shows, you probably saw it. Serial #144R, transmission and engine numbers match ID plate. Interior very correct (I'd never call a Europa interior gorgeous) down to the heater door knobs. All the right name brands: Spax adjustables, Minilites, Weber (plus the original), French Motorola, etc. Tons of spares, including a transmission and rare 2 row radiator. Every time I take this car to show it's the same thing: "this is the finest S2 I've ever seen!" I have to agree. I am willing to concede defeat, but this car is unbelievable, nearly concours. Offering it at $10,800- I'm in the Navy, and it's time to head out. Call or e-mail! Eric Petersen, San Jose, CA 408 736 1437, evenings.

 

January

For Sale: ‘89 Mazda 323 SE, 2-door hatchback. 5spd, A/C, new tires & exhaust, 110k, original owner, $3100/obo. Located in Sunnyvale. Daren (dastone@cisco.com) or wk: (408) 527-5044