Stock Josh

I havent removed the filter yet. I'll have to do that in the next couple of days.





I'm running 3 1/2 psi through a small 175 valve. I went to my local weber retailer and picked up the biggest needle valve they had, a 250. I'm lost when you are refering to a "Gross" jet, and its large size of 400. Can you explain this?







I dont have an EGT, so I was aiming for an A/F in the mid 12's. Dropping it from the 16's to the 13's has made a noticeable increase in power. Keeping it richer on the big end has made it want to rev past 8200 now too. I bought a set of 145 air bleeds (3 sizes smaller), and threw them in last night (webers sure are easy when it comes to changing the jets). I'll take her for a drive today to see what kind of difference it made. If I can keep her from 12.40's to 12.80's through the pull, I'd be the happiest guy on earth.

DJ Rotor

Off-topic but isn't that the first electric in the 300 club? Awesome achievement.



Jason

Stock Josh

Well, I dropped the air bleeds to 145's from the 160's. Now the fuel curve is a flat mid 13's from 5000 to 8500. I need it a whole point lower, so Im at a point where Im not sure if I'll try smaller bleeds or bigger mains. Im going to swap out the needle valve and remove the filter before changing jets again, to see what kind of change that nets.

Lynn E. Hanover

If the bug screen inlet filter has picked up anything at all it makes jet changing pointless. It becomes a too small main jet, and changing anything behind it has little effect.



Here is some data from a dyno sheet from our best engine from 5 years ago (Daryl Drummond).



Best torque at 7,800 154.3 foot pounds (229.4 HP) A/F 12.3 EGT (F) 1518 ®1503.

Best power at 9,400 244.9 (136.7 foot pounds) A/F 13.8 EGT (F) 1565 ® 1565.



There is your target.



Lynn E. Hanover

Stock Josh

I realize this is months later, but i thought I'd let people know. After months of messing with the weber, I switched it out for a Holley 600 double pumper on a racing beat intake manifold. I ported a plenum into the manifold, and bolted a box stock Holley from Summit to it. A couple jet changes later, and smaller accelerator pump squirters, and she runs like a champ. I had it dialed quick. Much more drivable than the weber was too. I like this setup a lot more. More drivable, more power, less hassle, oh, and a plate kit fits under it!

No more float bowl problems either, what a pain.

heretic

Interesting. The idle circuits didn't need to be reworked?



I would imagine that a 600 would be too large for a 12A, but hey, if it works, why question.

Stock Josh

[quote name='heretic' date='Aug 11 2005, 06:50 PM']Interesting. The idle circuits didn't need to be reworked?



I would imagine that a 600 would be too large for a 12A, but hey, if it works, why question.


[/quote]



600 double pumper is what RB recommends for a 12a bridgeport, so I went that route. Back the idle mixture screws out two full turns and it runs at 12.80's A/F at idle (needs to be a little fat to idle stable with the bridge). Idles at 1600, the weber I could get it to idle at 1300. Other than that, the Holley outperforms the 48IDF big time. I love my 4 barrel.

heretic

Sure, for their manifold. When you go to a non Racing Beat manifold, something a bit more akin to what the carburetors are designed for, you might want to consider something smaller.



A 600 double pumper is just peachy for a rorty 300 cubic inch range engine, like say a well built 283/289/302. You have about 2/3rds of the airflow capacity, adjusted for RPM differences.



I'm just sayin'. For a full out race engine, overcarburetion can be tolerated. Not so for something on the street, especially with something with mechanical secondaries because they are not "self adjusting" to the required airflow.



I turned a customer's horrible pig of a car into a sweet driving street machine that didn't lose a bit at the track, by removing his over large mechanical secondary carb and putting on a proper sized vacuum secondary. You can look at that two ways: The smaller carb drove better, or the too large carb wasn't any faster.

Stock Josh

[quote name='heretic' date='Aug 15 2005, 01:51 PM'] You can look at that two ways: The smaller carb drove better, or the too large carb wasn't any faster.


[/quote]



Or I can look at it like I bolted a $300 600cfm double pumper to a plenum ported RB manifold, slipped a plate kit under it, and it runs like a champ, way better than a super fancy Weber I might add. Using a power valve on the front, and only driving around on the primaries makes it quite a pleasant little drive, thanks for caring. You can disapprove all you want but it works just fine. Maybe the Holley elves sprinkled fairly dust on it at the factory.

heretic

Like I said, if it works, then kick ***. Don't need to read into it any more than that.