Skip to main content

If I were interested in buying a device to measure my air/fuel mixture to tune my carbs, what would be my best bet?

Is this the one? http://vwparts.aircooled.net/I...-p/innovate-3837.htm How hard is something like this to use? Do I need a lap top? Be gentle, I still have a flip phone.

My only problem is that my exhaust from cylinder 1 and 2 never joins 3 and 4 until the very end. It's a Seduction thing. I'll have to weld in a bung for each side. There is a nice spot right before the mufflers.

engine comp

Thanks,

CG

 

Attachments

Images (1)
  • engine comp
Original Post

That's an Innovate LM-2. It replaced the Innovate LM-1 I've got. Summit Racing has them for $246. No, you don't need a laptop. I just look at mine while driving around to see what's going on. The information it provides will be a benefit in getting a perfect tune.

Others might not agree-- but with carbs, whatever you do to one side you're doing to both, so you wouldn't need to weld a bung in both pipes. I probably would anyhow, but it'd just be overkill and redundancy.

Your mileage may vary.

$246? That's an awful lot of coin for that device today. My Innovate MTX-L turned to junk after a few uses, then sat on the shelf for a couple years. Tried to use it and the screen went dark. Never worked again. They won't get any more of my money.

The one Ed references is $150 today. I recall it being less when I bought it

Last edited by DannyP

@Carlos G all of the 4:2:1 Spyder exhausts of that design have the same issue and have for the 15 years we've been using them.  L&R don't blend until the tip, and you'll find that with a tailpipe sniffer you can get it into one side or another, BUT you can get some odd readings at times, plus you will get a huge influx of fresh air sucked back into the exhaust when you lift off the throttle.  you can get a descent tune this way,  but nothing beats having o2 bungs further up the system, just before the mufflers is my preferred spot.

Two bungs would be the way I'd go. I would think this would aid in tuning seeing that I'd be reading exhaust gas from two at a time versus all 4. But what do I know.....

I don't think my exhaust blends very much at the tip. My tip is just a band to keep both ends together.

exhaust 2

The spot I also thought would make the most sense would be between the flange and the muffler. One question though, does the two pipes coming together before the flange going to mix enough before hitting the sensor?

exhaust 1

I've got a bit of an exhaust leak on one side. When I take the exhaust apart to weld in the two bungs, I was thinking of using some kind of exhaust sealing paste to make a better seal. Is there a better way?

exhaust 3

Attachments

Images (3)
  • exhaust 2
  • exhaust 1
  • exhaust 3

Yes, Carlos, I used NAPA exhaust system sealer on my old exhaust. My new one doesn't leak thankfully.

My exhaust bung is in the last 6 inches of the final outlet. But I also have a Vortex cone insert in a 6" extension on top of the regular exhaust. My gauge readings are steady and not too jumpy to read and/or dial in. Plus there isn't any drone when cruising, it's actually quiet enough to converse. Until I put my foot down. Then it sounds like every other Spyder at full song.

Thank you, Ed. I took an hour and a half solo ride yesterday, it was above 90 and a bit humid. The back of my shirt was soaked. Why, you ask? Because, Spyder! 

But also because it was the first time since last summer's rebuild that I drove it that hot out and that aggressively. Temperatures stayed right where they should, 180-185 on the oil. Fan came on infrequently, like it's supposed to. I was trying to get it hot to see what the limits are, if any.

Once it got really warm, I had to richen two cylinders and lean the other two and boost the idle speed a couple hundred rpm. Purring along at 900-950 hot idle now.

I'll say it passed the test. Soon, I'll be installing 4 CHT displays to go with the K-type thermocouples that are already on the engine.

@DannyP posted:

Thank you, Ed. I took an hour and a half solo ride yesterday, it was above 90 and a bit humid. The back of my shirt was soaked. Why, you ask? Because, Spyder! 

But also because it was the first time since last summer's rebuild that I drove it that hot out and that aggressively. Temperatures stayed right where they should, 180-185 on the oil. Fan came on infrequently, like it's supposed to. I was trying to get it hot to see what the limits are, if any.

Once it got really warm, I had to richen two cylinders and lean the other two and boost the idle speed a couple hundred rpm. Purring along at 900-950 hot idle now.

I'll say it passed the test. Soon, I'll be installing 4 CHT displays to go with the K-type thermocouples that are already on the engine.

Teby and I drive Saturday. My fan comes on at 190 degrees and it only came on a couple times and for not very long. Outside temps were nearing mid to high 80’s by the time we got done. The 2110 Pat Downs built for me runs exactly as it should. Glad to hear you got out. 

Add Reply

Post Content
×
×
×
×
Link copied to your clipboard.
×
×