BLP CARB SHOOTOUT Your input please !

[Brad Hawk]

Sweet... what an event!

In addition to my last post inquiring about more details of the SB results, I'm also curious how the BLP baseline carbs showed in comparison to the other entries in their respective classes.

[razor66]

Sweet... what an event!

In addition to my last post inquiring about more details of the SB results, I'm also curious how the BLP baseline carbs showed in comparison to the other entries in their respective classes.

I have a good feeling from watching a lot of both events on the Webcast that the BLP baseline carbs performed quite well.

[Mike Laws]

Congratulations to John, Jay & Jeff of Team AED for backing up their excellent S/B Shootout performance by winning the OOTB side pot and the main-event in the B/B Shootout. Jay and Jeff were stellar in their performance and also in their professionalism and attitude. The engine and intake manifold combination baffled many of the teams; however not these guys. The tune-up they brought to the inertia dyno was strong from their first to last run.

Congratulations to Team Braswell for a very close 2nd place finish in the B/B Shootout. Dave & Doug also had little issue with the engine combination and were very impressive.

Congratulations to John & Randy from APD for their win in the most closely-scored contest (2.130” side pot) of the B/B Shootout over Karsten and Team KB.

The B/B Shootout Elite-8:
AED
APD
Braswell
CFM
DaVinci
Holley
KB
POW

[jmarkaudio]

What a wild few days this has been, I had an amazing time and it was an honor to be around a fabulous group of carb builders. I can’t stress enough the job the guys at BLP did to make this happen, considering some of the glitches that came about they did a flawless job at keeping things running smooth. I think for the first year you could not have asked it to run any better. Tony and Scott did an awesome job helping everyone in the dyno room with changes and getting the carbs on and off.
The BB supplied by Steve Schmidt made a lot of power and performed very well for the shootout. It came equipped with eight O2 sensor locations in the primary tubes and all were used, the small block only had one in each collector. The parameters were that you could not have any O2 go 14.0 to 1 or over on the BBC. The intake chosen was used to make any reasonable carb be able to be adapted for the shootout. It proved however to throw a curve into the mix that had EVERYONE making changes to try to get the O2’s equal . Even those with experience and dyno time with that intake had to make changes, some significant, to make the fuel curve work as well as possible for the engine. I think the top for the intake played a big part, but having different tops also made it work different for the different carbs as well. Most had an issue with #2 but not all. Had the engine been equipped with only collector O2’s the fuel used would have been averaged, jet and bleed changes made to tailor the curve, and everyone would have made more power with the engine. While the engine likely would have survived, we would not have known the importance the top played into the intake as a whole, and would not have known that a couple cylinders were running closer to the danger zone. It also taught me the importance of having a properly designed intake, even the best heads will not work as well if the intake used is unable to provide the correct fuel distribution to the heads. And it goes back to the carb, no matter how perfect the fuel metering is leaving it the manifold has to do it’s job to distribute it. The smaller carbs seemed to fair better overall, the higher vacuum generated under it improved early vaporization and subsequently made better power in some cases. AED and Braswell used the same top, their choice in that and the tuneup they made with it proved to be the best choice for the engine used, they deserved the win and runner up spots. AED overall did a fabulous job with a win and runner up, they brought quality stuff to work with for both classes. John and Randy at APD did a great job as well, made the right changes to make an already good carb work with the engine to win the 2.130 class. I think I was hampered by my choice of tops, a homemade piece, but I feel good that we were able to make some modifications to it (drill bits and die grinder) as well as some major calibration changes to make a safe pull even though we ended up around the bottom of the field. And everyone started helping each other, making suggestions to help overcome the issues we had, that too was amazing to see. With enough time I’m sure everyone could have improved their tunes even more to make the engine run better and make the field tight like the small block was, but looking back now I’m glad it ended up the way it was because it made it a real challenge for everyone even though I ended around the bottom and I was in good company down there. I will recalibrate the carb back to my original setup, and I’ll run it on some engines to test and refine it to learn some more. It starts, idles and comes up on the converter clean so I can’t fault it, just need the right engine to work with it. I plan to start on my SB2 soon, it will make a good test engine to try it on as well. I had a great time, learned a lot, and made a lot of new friends. The ones that truly missed out are the ones that didn’t attend, maybe next time the field will expand and of course new challenges to work with. Thanks to all and congratulations again to the BB winners.

[dieselgeek]

Interesting observations, every N/A V8 I've tuned recently (using 8 O2s) has at least a 1.5-2.0 point spread in AFRs before we start trimming individual cylinders.

How about a carb-vs-EFI shootout in the future with these same (obviously very qualified) guys putting on the competition?

[razor66]

Thanks Mark for the run down on what kind of things were going on behind the scenes at the Shootout. Sounds like it was a blast and for all the great builders there helping one another is just fantastic!

Congratulations again to all the winners, runner-ups, Elite 8 as well as everyone else who participated in the small and big block contests as in my mind you all came out as winners as did all of us carburetor end users out here.

[Unkl Ian]

Congratulations to everyone involved.

[jmarkaudio]

Interesting observations, every N/A V8 I've tuned recently (using 8 O2s) has at least a 1.5-2.0 point spread in AFRs before we start trimming individual cylinders.

How about a carb-vs-EFI shootout in the future with these same (obviously very qualified) guys putting on the competition?

If you are injecting the same amount of fuel in every cylinder why would you have the AFR that far off unless each cylinder is not pulling near the same amount of air? Especially on a sequential system, I might see that happening on a batch fire. I would not expect a N/A engine with a quality intake and a carb to stray even at most half a point, but I have seen it get really strange. I will say that seeing the difference between 2 collector O2's and 8 primaries is real eye opening.

[dieselgeek]

Interesting observations, every N/A V8 I've tuned recently (using 8 O2s) has at least a 1.5-2.0 point spread in AFRs before we start trimming individual cylinders.

How about a carb-vs-EFI shootout in the future with these same (obviously very qualified) guys putting on the competition?

If you are injecting the same amount of fuel in every cylinder why would you have the AFR that far off unless each cylinder is not pulling near the same amount of air?

You answered your own question here, other than there might be reversion/crosstalk/whatever causing fuel from one injector to end up in another cylinder (manifold issues?). I always start the tuning off with safe AFRs on the minimum cylinder then start building VE maps once the rough tune is close.

Especially on a sequential system, I might see that happening on a batch fire. I would not expect a N/A engine with a quality intake and a carb to stray even at most half a point, but I have seen it get really strange. I will say that seeing the difference between 2 collector O2's and 8 primaries is real eye opening.

I agree, I didn't expect what I saw either. One was Dan Miller's hemi which was sequentially injected (phasing optimized), had 100% isolated runners so no injector crosstalk, it needed 15% differences and also the differences changed dramatically with RPM through a pull. Another was CDMBill's big block N/A Ford making ~1010hp it was a bank-fire injection strategy with a common plenum/tunnel ram, dual TB config with injectors at the base of the runners, it displayed similar characteristics as the EMC engine. Another was a 499" Hemi 99/prostock that had a compromised common plenum manifold sorta like a TPI intake, injectors at the base of the runners, sequential injection - still similar differences. It's also been common to pick up as much as 10% power at different places in the curve once all the cylinders are running proper AFRs. This year was the first year I started using 8 O2s on engines I am tuning. I can't believe what I've been missing all these years! EGTs do not even come close to being as clear/obvious as AFR plots for each cylinder, IMO.

[razor66]

Interesting observations, every N/A V8 I've tuned recently (using 8 O2s) has at least a 1.5-2.0 point spread in AFRs before we start trimming individual cylinders.

How about a carb-vs-EFI shootout in the future with these same (obviously very qualified) guys putting on the competition?

If you are injecting the same amount of fuel in every cylinder why would you have the AFR that far off unless each cylinder is not pulling near the same amount of air? Especially on a sequential system, I might see that happening on a batch fire. I would not expect a N/A engine with a quality intake and a carb to stray even at most half a point, but I have seen it get really strange. I will say that seeing the difference between 2 collector O2's and 8 primaries is real eye opening.

Mark, what kind of differences did you see between the collector's O2 readings and those in the individual primaries? Thanks.

[Doug Schriefer]

Interesting observations, every N/A V8 I've tuned recently (using 8 O2s) has at least a 1.5-2.0 point spread in AFRs before we start trimming individual cylinders.

How about a carb-vs-EFI shootout in the future with these same (obviously very qualified) guys putting on the competition?

If you are injecting the same amount of fuel in every cylinder why would you have the AFR that far off unless each cylinder is not pulling near the same amount of air? Especially on a sequential system, I might see that happening on a batch fire. I would not expect a N/A engine with a quality intake and a carb to stray even at most half a point, but I have seen it get really strange. I will say that seeing the difference between 2 collector O2's and 8 primaries is real eye opening.

Mark, what kind of differences did you see between the collector's O2 readings and those in the individual primaries? Thanks.

The small block only had O2 sensors in the collectors while the BB only had them in the primaries.

[Steve Zicht]

Just started a new thread in the Speed talk general discussion titled ' Carb Shoot Out 2012 '. Lets talk about taking the the next Shoot Out over the top with more ideas from all of you. Fell free to discuss about whats on your mind. Kudos to all of you that contributed to this thread. Whew ! 20000 hits on this thing. See you in the other chat column ! Steve Zicht

[razor66]

If you are injecting the same amount of fuel in every cylinder why would you have the AFR that far off unless each cylinder is not pulling near the same amount of air? Especially on a sequential system, I might see that happening on a batch fire. I would not expect a N/A engine with a quality intake and a carb to stray even at most half a point, but I have seen it get really strange. I will say that seeing the difference between 2 collector O2's and 8 primaries is real eye opening.

Mark, what kind of differences did you see between the collector's O2 readings and those in the individual primaries? Thanks.

The small block only had O2 sensors in the collectors while the BB only had them in the primaries.

OK, got ya - I misunderstood what Mark was saying. Thanks for the clarification.

[A Atwood]

Who's 4150 carb placed highest on the small block test?

ARN

[Dan DaVinci]

I am all in for next year all competitions. Dan DaVinci