Horsepower gain with Webers

[sdfletch]

What is the main diff between a carb and weber cam? Is it easily explained? Thanks.

[Anthony]

Here's weber's own chart for correct sizing of their carbs, based on single cylinder displacement.

[SF_SN888KE]

I've heard that the standard Carb cam is not recommended for EFI. Is the Webber cam the same as for the EFI? But back to the HP issue, assuming street driving and not needing WOT carb HP, which produces more low/mid range "streetable" HP - Webbers or stacked EFI? Is this the same for FE and SB?

[Rick Parker]

If you can actually take yourself back to 1963 and the US Sports car racing scene imagine how the newly introduced Cobra was overtaking the normally victorious Corvette crowd, they didn't know what hit them. The Cobra was about a 1000 lbs lighter, that's very difficult to overcome with any reasonable amount of horsepower increase. The American racing circuits were for the most part comparatively short straights (Riverside excluded) accompanied by a series of turns. The main advantage the IDA's provide is a significant (about 20+%) increase in torque. The increase in throttle response is outstanding, this would consistantly put the Cobras quicker off the turns. Combined with their light weight and being faster off the turns they were destined for Glory. When you drive these cars it is the torque that presses you back in the seat, the car squirts forward like a pinched watermelon seed. It's the acceleration combined with the exhaust note that seduces us all. There are faster cars but none that make you feel the same. Torque wins races Horsepower sells engines.

[Excaliber]

Point well taken Rick! Along those lines I would think a good Weber setup would work well on the street as well. Where low and mid range torque is the most common rpm range. Without consideration to price, or mpg, what is the down side for a street application?

From an mpg stand point it's as much about cruising range distance as it is about economics. I only have a 17 gallon tank! Even a slight improvement of mpg is a welcome relief from constantly having to watch the odometer or fuel gauge for my next gas stop!

[Tom Kirkham]

The pinnacle of carb development had to be the superbike engines of only a few years ago before they went EFI. They all ran IR manifolds...

For our Bonneville run I am sure we will run a single four. It is a lot funner to be running than tuning. Maybe after we get some salt under our nails...

[RICK LAKE]

sdfletch Fletch weber or olberg carb don't like alot of over lap in the cam shaft and a wide LSA setup of the camshaft 112 is min. A 114LSA is better. A quick lift camshaft with quick high lobe design and closing. Super charger or turbo camshafts work better than straight carb motors. I don't have the answer for the EFI question but in my motor, it doesn't seam to care with a pro tuning of the EFI system. I do have a torque issue with TOO much from 2,000 rpms to 3,000 rpms. I need to advance the camshaft to kill a little of the low end power. The reversion problem with over lap cams have a serious effect on the vacuum sign that these carbs need to work the best. Higher vacuum signal the better, steadier too. If the intake valve and exhaust valve are open at the same time, this causes reversion in the intake and up to the carb. This is why you see some weber motors spitting or a mist around the intakes. There is alot more to it than this but would take about 2-3 hours for a full theory explaination. Bottom line, they work better than a carb in mid range. They make more torque, don't worry about more HP. Torque moves the car not hp from a standing start up to went the torque curve drops below the HP curve that is still climbing. Rick L.