Lotus Elan

GGLC Tech Session Oct 1st

PostPost by: khamai » Mon Sep 26, 2005 4:45 pm

The Golden Gate Lotus Club will hosting a Tech Session.

Our guest will be "Type26Owner". Keith will be going over Weber tuning.

Many of us on LotusElan.net have read Keith's development on Webers. Here's an wonderful opportunity to see it being done!

RSVP is required. For more information please visit the GGLC website at www.gglotus.org

Cheers,
Kiyoshi
GGLC Webguy
User avatar
khamai
Second Gear
Second Gear
 
Posts: 181
Joined: 20 Oct 2003
Location: NorCal

PostPost by: type26owner » Mon Sep 26, 2005 7:29 pm

Kiyoshi,
I'm fairly certain I've cracked the code and can tune the Webers to the desired affect if the engine parameters are not whacked out of bounds like having too large an exhaust manifold for instance.

I posted this morning the stuff I learned over the weekend here. Articles 42 and 43 are both mine from this morning.
http://www.innovatemotorsports.com/forums/showthread.php?p=11897#post11897

Sarto, be prepared to do a WOT blast in second gear getting onto the freeway by Mike's house over and over again the same way each time. I'll explain the testing procedure in detail to you on Saturday morning. Piece of cake!
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: type26owner » Thu Sep 29, 2005 2:36 pm

Hey Kiyoshi,
I'm expecting for you to test drive my car this time...No excuses! It would be better if it were done on the racetrack though. :lol:
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: khamai » Sat Oct 01, 2005 11:57 pm

Today's session was a GREAT learning session.

Keith (type26owner) went thru how to tune a weber. The information that he shared was invaluable. I've read a number of books/manuals on Webers, but never has it been as clear and easy to understand how to tune them.

After driving Keith's Elan I'm convinced that Webers can be made to run stumble & hesitation free.

Thanks to Mike for sharing his shop and Keith to share his knowledge and save us from the pain of doing all the work that he's had to endure.

Cheers,
Kiyoshi
User avatar
khamai
Second Gear
Second Gear
 
Posts: 181
Joined: 20 Oct 2003
Location: NorCal

PostPost by: type26owner » Sun Oct 02, 2005 3:24 pm

Unfortunately I was not able to improve the tuning of Sarto's Webers other then the quality of the idling and at WOT. They would not repond to emulsion tube changes in the way I expected to tweak in the partial throttle mixture. Found one carbie had the the fuel level set to low by 6mm and the other 4mm. One interesting feature was immediately after the fattening caused by the accelerator squirt there was a moment were the mixture went off scale too lean. When it did this it would backfire presumably because it takes a moment to suck the fuel up the 6mm and 4mm up the well. Swapping the emulsion tubes and plugging up holes did change the magnitude of that lean hickup. Bottomline is the fuel level must be set correctly before doing at fiddling. With both carbies out by that much it would have taken me all day to correct that situation so I pressed on as if everything was okay. I could not have demonstrated how the AFM worked along with the analysis software otherwise.

The fuel level problem did not prevent the dialing in of the WOT mixture jetting via the main and air corrector jets though if you ignored the backfire. That responded just fine and was set at 12:1. Suppose with hindsight I'm glad to have learned that with the fuel level set to low it mainly just affects the partial throttle cruise mode only. Another myth proved to be wrong.

It was decided folks wanted me to do another demo and in the meantime Sarto is going to have the person that installed the carbies adjust the fuel level like they should have done to begin with. We'll nail down the sweet spot next time I promise. :roll:
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: type26owner » Sun Oct 02, 2005 5:47 pm

Kiyoshi,
I demonstrated the typical mixture one gets if you set the idle mixture by the famous 'Lean Best Idle Adjustment' method. Do you recall that value?

Another myth which is wrong.
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: khamai » Mon Oct 03, 2005 6:20 am

type26owner wrote:Kiyoshi,
I demonstrated the typical mixture one gets if you set the idle mixture by the famous 'Lean Best Idle Adjustment' method. Do you recall that value?

Another myth which is wrong.


Keith,

I think it was about 17:1 or maybe 22:1. I can check the vid to find out exactly, but it was WAY off!!!

BTW... have you ever posted or made a sketch of the optical tool you made to measure the fuel level. I pretty sure you've discussed it on the forum, but I don't recall seeing a pix or diagram of it.

Thanks again!
Kiyoshi
User avatar
khamai
Second Gear
Second Gear
 
Posts: 181
Joined: 20 Oct 2003
Location: NorCal

PostPost by: mac5777 » Mon Oct 03, 2005 6:54 am

Hi, I wanted to post earlier, but I just returned from Niello Concours at El Dorado Hills CA. where Frans with his perfect early Lotus Elite took another award.
I want to thank Kiyoshi and Golden Gate Lotus Club for hosting the Tech session and Mike Ostrov for having us.
Guys,,,, for those who missed it, you don't want to miss the next one!!
Keith (type26owner) worked on my elan and unfortunately my float levels halted the final adjustments. Even with that , my elan now idles smoothly and has more power than it has ever had. I can only imagine what it will do after he completes his final adjustments.
Keith sent me out on several runs, doing the same each time. We were able to watch Keith interpret the data on his equipment and the effect of changes he made to the webers after each run. It was like a professor dispelling myths and proving it.
Keith I'll let you know when Rich complete the float level adjustment.

Sarto
lotus elan 1966 S3 FHC
36/5785
LHD
User avatar
mac5777
Fourth Gear
Fourth Gear
 
Posts: 576
Joined: 05 Jul 2004
Location: Northern California

PostPost by: type26owner » Mon Oct 03, 2005 1:31 pm

Kiyoshi,
It was idling at 22:1 at the LBIA. I have no idea why the engine will even idle at that mixture level but it does. If you wanted your engine to overheat quickly that's the correct setting for you.

Here's the optical fuel level gauge. You can and should measure the fuel level with the engine idling. When the bottom surface of the acrylic rod is pushed slowly down and is wetted the top end darkens a bit to let you know. The tool is removed and the distance from the sliding bushing to the bottom of the rod is the real fuel level. This is a direct meansurement of the actual level due to the buoyancy of the floats floating in the fuel, not some air gap above the floats.

Sarto,
You'll have carbies that perform like fuel injection next time. Would you like me to make you an optical fuel level guage so Rich can do it with very high accuracy? The level needs to be set to 25 +/-0.5mm. I set the level 1mm lower than the Lotus manual says otherwise you'll get the popping on overruns and at othertimes because the fuel sloshes over the brim. The brim of the passageway leading down to the auxiliary venturi is 23mm btw. Sarto's were set for 31mm and 29mm. Hey, it didn't run all that badly even though the level was way too low. Sure screwed up the partial throttle tweaking with the emulsion tubes though.


Image
Image
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: mac5777 » Mon Oct 03, 2005 2:15 pm

Keith, YES! I would like to use the tool for fuel level. Doesn't hurt to be accurate with less trouble.
Frans car was a two tone type 14 at the concours.

Sarto
lotus elan 1966 S3 FHC
36/5785
LHD
User avatar
mac5777
Fourth Gear
Fourth Gear
 
Posts: 576
Joined: 05 Jul 2004
Location: Northern California

PostPost by: type26owner » Mon Oct 03, 2005 3:23 pm

Sarto,
Found my emotions for wanting the carbies to perform well gave me no ends of trouble. I was strongly biased and as a result my day to day judgement of tuning changes was impaired. Therefore, I personally must rely on the recorded data to substantiate whether or not there is more power. My wanting it to be so clouds over my ability to tell by seat-of-the-pants feedback alone. The numbers don't lie and since there is a timing stream running along with the data you can see it without any bias. Getting from point A to point B in the quickest time is always the best measure. Do a timed run over a set distance since we put your old jetting back in. After we're done tuning it again you can confirm if it's improved or not.

In the meantime I'm going to build a new tailpipe fitting to mount the O2 sensor. The one I bought from Innovate blocks off nearly half the area of the 1-1/4" inner diameter tailpipe. That can only be creating more back pressure at WOT. I'm concerned that the main and air correct choice is screwed up as a result.
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: mac5777 » Mon Oct 03, 2005 5:18 pm

Well Keith, without the tail pipe sensor in, even with the old jets my trip to El Dorado Hills was a dream. What ever the results of the work we could do, the car seems to be more responsive. Now I want to get it on a track and do some timed runs. Or maybe when Mike Ostrov ran the compression test and it showd 195.200.200.200. I was so pleased that I just thought it ran faster. We'll talk later.

Sarto
lotus elan 1966 S3 FHC
36/5785
LHD
User avatar
mac5777
Fourth Gear
Fourth Gear
 
Posts: 576
Joined: 05 Jul 2004
Location: Northern California

PostPost by: type26owner » Mon Oct 03, 2005 6:16 pm

Good thing I had you do a baseline run and recorded the data before we started to tweak anything. The partial throttle mixture was about 13:1 to begin with so it ran okay cruising down the freeway. Any weaker than that and it would surge btw. What's wrong with the 115 main and 200 air corrector is the WOT mixture. It begins at about 12:1 at 2000 rpms and at redline it's at 17:1 or higher. My carbies behaved in exactly the same way with those jets. Not good for making power at the topend of the rpm range! Lotus kinda muffed it there. That's the jetting everyone has if it hasn't been changed from stock.
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: type26owner » Fri Oct 07, 2005 5:16 pm

Hey Sarto,
The backfire was caused by the spark plugs wet fouling for a moment at WOT is my best guess. The lean spike we saw in Logworks2 was the unburnt oxygen that collected in the exhaust manifold just before it reignited. I've explained it in more detail over on the http://www.innovatemotorsports.com/forums/index.php forum.

Send me your snail mail address offline and I'll pop the optical fuel level tool in the mail tomorrow.

I'll post the Logworks file here next week so folks can pickup on the technology.
type26owner
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1616
Joined: 18 Sep 2003

PostPost by: mac5777 » Sat Oct 08, 2005 5:29 am

Keith,
I had just sent you an E-mail w/ phone numbers as I will be in your neigborhood Sat. and can pick it up. Let me know if that will work for you.
Rich agreed with you about the level being 1mm lower than recommended setting. I will wait to hear from you.

Thanks, Sarto
lotus elan 1966 S3 FHC
36/5785
LHD
User avatar
mac5777
Fourth Gear
Fourth Gear
 
Posts: 576
Joined: 05 Jul 2004
Location: Northern California
Next

Total Online:

Users browsing this forum: No registered users and 6 guests