Dyno time can be expensive and is a great way to tune at WOT. But what about where you spend most of the time? Part throttle tuning is where you can really feel a well tuned carb and maybe even save a few bucks in fuel.

This is how the service would work:

The Innovate Wide Band O2 meter with additional data collection capabilities would be the heart of the system.

I would weld an O2 bung onto your exhaust if needed and also hook up several simple sensors.

We would take the car out for a test drive doing some stop and go stuff plus some moderate accelerations on the highway.

I would download the data and print out a graph or as I like to call it, a map of what your carb is doing and when.

The following data would be collected and graphed:

Air/Fuel Ratio
Manifold absolute pressure (MAP)
RPM
Primary valve location
Secondary valve location (Very helpful with vac secondaries)

This information would take a lot of the guess work out of tuning your powervalve/piston, accelerator pump cams/squirter dia., vacuum secondary spring size and jets.

By having a proper air/fuel ratio you will be able to optimize your timing. You won't have to pull back on initial timing to cure knock issues that may be the result of a poorly tuned carb.

I figured I would charge about 50 to 60 bucks for 2 sessions. (or beer) I thought I would throw this idea out for some scrutiny. I may be the only person in Atlanta that cares about this stuff.

 

How would you get these two data values:

Primary valve location
Secondary valve location (Very helpful with vac secondaries)

 

Position sensors that are linked to some location on the throttle linkages to note their movement. I have made two that work with a typical Holley 4150 with vacuum secondaries. I would have to make others for Q-jets and Performers.

 

I would take you up on that but I'm more than a long day's drive away.

 

With the wide band O2 sensor couldn't you just make a clip to clip ino the rear exaust pipe?

 

Innovate sells a clip already...

Not a bad idea for service. I'm guessing you would drive to the customer's site or meet at a mutually agreed upon location. I'd set up a fixed fee and offer a certain number of runs for that fee - say two runs with a data dump between the first and second.

If your analysis shows an area for improvement, will you charge to adjust the carb too, or does the customer do that? If you adjust it, maybe you could do a package deal - One 20 minute run followed by adjustment, then a follow up run to insure the changes were effective...

How does Lars charge?

 

If you could use a clip (don't want to weld a bung in my sidepipes) I'd do it. Just to see a map of what my carb is doing.

 

i could go for that myself, except you're a long way from me...but the idea is spot on...

 

would you consider coming all the way to Guam to do my 82 and 69 ?

 

I am willing to try this , I believe that I could set up a group if you are willing to travel to Huntsville or Athens Al.

 

The drawback with a clip on sidepipes is that the opening on the pipes is fairly large and could draw back some fresh air and contaminate the data from the O2 sensor. I just welded a bung into my pass collector and its not visible from the outside

 

1st- it's a great idea.
But, where did u get the idea that dyno tuning was all that good at WOT? it is notoriously inaccurate with carbs. (fuel slosh, G forces).
Most guys here want max power, and that is WOT. So u don't need a TPS. WOT can be inferred from vacuum. So it's easier to hook up. Even part throttle testing doesn't need a TPS. y'll see it at higher vacuum

 

I think you have a great idea and I would take advatage of your service in a heartbeat, but I'm in New Jersey.

 

Thanks for all the feed back guys, it is a big help. Great ideas as well. The package deal sounds like the way to go. As far as a TPS, yes Innovate sells one to work with the sensor. The only concern I have is routing the wires for a highway tests. I guess a few zip ties could work, but the sensor and data collection unit cables are fairly large in diameter and as a result have to locate all the "stuff" in the engine compartment. I wish they had a "ribbon" type cable so I could run them by the doors an into the car. With a lap top computer, I can show real time information. The other issue with a tail pipe sensors is if you have cats. For accurate data the sensor is best placed before it.

 

Ur talk'n like what the pro-teams use. The big time racing teams monitor all that stuff for the entire race. BTW Edelbrock sells a Data Acqusition set-up but u still need to adapt it to what u want to monitor.
Well i applaude ur efforts but my perspective is that close is good enough with a carb. Every time the air temp/density changes the mixture will change also unless u have an electronic control like the electronic Qjet or electronic FI which already has the O2-A/F controller.
Most of us have a hard enough time just getting the advance curve right and changing sec-metering rods let alone removing the top hat and screwing in new pri-jets/replacing rods/custom pump shot.
What i would like to see is someone prove the wide-band senors really make a jet change choice any closer/better than the narrow band O2 monitor from Edelbrock or K&N for <$150. Sence there is a limited number of sec metering rods availible and the sec jets are fixed/unchangeble is the wideband getting u any closer? Once the air vlv opens ur choices are limited.
I can see where getting everything right on the pri side would be nice but man in just one day? Ur talking removing the top hat, replacing pri-jets, then tuning/replcing for metering rods, then for power piston and or spring, then for pump shot lever position, drill or plug and drill pump shot holes for best transition. That top hat may R&R many times. Man that's a bunch a work. But if ur only gonn'a adjust idle mix then its quick.
Well i have a mounting hole in each collector right now for my Edelbrock O2 sensors but no place to mount the boxes - yet. I guess i will need to play with my narrow band sys 1st before i can say that its all that bad or not good enough.
But if u feel up to it y not get something like a lars touring & tuning party going as a corvette get-together is always fun. Or even just show up at the local car shows offering tuning service - probly make a few friends there.

 

Yes. How is that for a reply? Close is about as good as one can expect with a carb but I bet many folks out there are even close. And I can imagine the smile on their face when they feel the improved performance by making some simple changes. I am not talking drilling or anything like that. Leave that to the carb tuning experts like Lars. But, that being said, if you give the print out to someone like a Lars, they could recommend what needs to be done. Anyway.... The real reason why I want to do this is not to make money but meet people like yourself and just have fun talking about something other than sports, not that sports are bad....

 

Actually, that is exactly what we use to tune our race cars. The lap top is vital to data acquisition and storage of data. Sadly though, this type of tuning never makes it to our hot rods. The only extent of our tuning on the hot rods is limited to time on the chassis dyno (Dynojet)where we get a chance to adjust timing and carb settings.

Good luck on this project!

 

Matt,
I think I misunderstood TPS as tail pipe sensor not throttle position sensor in your reply. Yes, I agree that vacuum give lots of info and on carbs with mechanicl secondaries you can get a good idea of where your throttle blades are. At part throttlle type acceleration, knowing when your vacuum secondaries open is a bit harder to tell. Another big problem with vac secondaries is they don't always open all the way at WOT. The graphs will make it easier to reduce lean or rich spikes during the transitions from one circuit to onother. This is where fine tuning the accel pump and power valve rating and restrictor hole diameter come into play.

 

Cardo4,
I used the Edelbrock unit for about 2 years and it was a big help. The problem with narrow band despite the many diods on the box, is it only tells you if you are lean or rich. The three primary readings I got was all green with one yellow or flickering yellow, that meant I was in the ball park, all lights on RICH or all lights off LEAN. It is a great way to make sure your engine is ok . It was a big help to me with setting up my idle system as well.

 

I would do that for free! Just let me sleep on your couch for a couple of days!!