Weber starvation in left hand turns using radial tires

[Ohmess]

For forum members into Weber carburetor trivia, I noted an interesting tidibt in the Batmobile BAT comments today. Auction is here: https://bringatrailer.com/listing/1973-bmw-3-0-csl-8/

During the process of turning one of the original 110 batmobiles into a race car, the builder discovered that the car was starved for fuel in left hand turns. They added little "towers" to the top of the carbs underneath the jet inspection covers. see pic 136/258. Here's the seller's explanation:

@mercurykg7h during testing we found the car starving for fuel in left hand corners. We (by we I mean the extremely talented mechanics) found that adding those little towers solved the issue. It was a perplexing problem at first and difficult to diagnose. A Weber expert met us at Laguna Seca and explained the radial tires were making far more grip than the Weber’s could handle. He suggested we switch to the slower bias-ply. Slow wasn’t what we were after. The towers solved the fuel starvation problem. I can say with confidence I have no idea how they work ️

@Stevehose had a somewhat similar problem with right turns. See here: https://e9coupe.com/forum/threads/what-did-you-do-to-your-e9-today.17735/post-380842

 

[Stevehose]

For forum members into Weber carburetor trivia, I noted an interesting tidibt in the Batmobile BAT comments today. Auction is here: https://bringatrailer.com/listing/1973-bmw-3-0-csl-8/

During the process of turning one of the original 110 batmobiles into a race car, the builder discovered that the car was starved for fuel in left hand turns. They added little "towers" to the top of the carbs underneath the jet inspection covers. see pic 136/258. Here's the seller's explanation:

@mercurykg7h during testing we found the car starving for fuel in left hand corners. We (by we I mean the extremely talented mechanics) found that adding those little towers solved the issue. It was a perplexing problem at first and difficult to diagnose. A Weber expert met us at Laguna Seca and explained the radial tires were making far more grip than the Weber’s could handle. He suggested we switch to the slower bias-ply. Slow wasn’t what we were after. The towers solved the fuel starvation problem. I can say with confidence I have no idea how they work ️

@Stevehose had a somewhat similar problem with right turns. See here: https://e9coupe.com/forum/threads/what-did-you-do-to-your-e9-today.17735/post-380842

Typically those cover towers are used to solve fuel sloshing in hard turns, not starvation. They cover emulsion tube extensions which lift the air correctors well away from the jet deck so fuel can't enter the air correctors and stall the engine. I have no idea how they would be used to solve a lean issue as he describes. Another intersting hack on those carbs is the connecting by a tube of the float vent/idle circuit air holes on the face of the carbs, which then has it's own filter. I find this amusing since there is no filtration over the trumpets which would account for 99% of the dirt entering the carb once off idle anyway.

 

[Arde]

Wow, NASCAR tracks are only left turns... is that why we do not see E9s in NASCAR ?
Don would probably blame Coriolis forces before blaming tires, and then tell you to convert to fuel injection.
Imagine dealing with carburetors in small airplanes, I once hired en engineer whose previous job was to design the fuel tank sensor for airplanes, mind boggling when the plane could be upside down...