Hey Old School....Wisdom needed !

[BushWakr - RIP]

Am i correct in my understanding that the 'star wheel' makes the most difference in performance in general, and that it has the most effect on total boost assuming the other adjustments remain the same???
If not could you fill me in a bit on this please. I have rotated my diaphram to the 6 o'clock position which is the max position according to visual inspection. My lock collar on the 'full fuel adjustment' is still in place and I am about 1/3 of a turn from bottoming out against it. Any more and I get some healthy smoke and ratty mileage. The star wheel is at the 3 o'clock position from stock (12 o'clock). Timing is approx. 1. 37mm
Any input greatly appreciated. I don't wanna blow it up just perfect my settings a bit more.

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93. 5 D250 4X4,HD Spring Pkg, Rancho 7000's, Rear Swaybar,Dual Shock Front Stabilizer,BD Injectors,31/2" Mandrel bent exhaust,16cm 'Hot End',Modest Pump Tweaks/Timed,K&N Air,Isspro Pyro,Tach,transmission Temp,Auto Meter Oil Filled Boost Ga. , 3:54's, 4 Speed Auto, Clubcab, Aftermarket Reclining Buckets w/ctr Drop Down seat/console, Black over Silver, 21psi,285-65R-16's,American Racing Clear Coat Mags, Amsoil 15W-40HD Marine,12,000 lb. Warn Winch,KC Spots. 97,000 Kms.

[This message has been edited by BushWakr (edited 02-28-2001). ]

 

[Piers]

The star wheel effects preboost response. It has virtually no effect on total fueling, just how quick the fuel comes in while building boost.

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Piers, BD engine R&D

 

[BushWakr - RIP]

PIERS ! Thanks bud, I really appreciate that quick answer. Since I don't deal with this every day I admit some of our conversation has kinda slipped what little mind I have, so... .
I remember you said that the 'full power fuel adjust' sent more of the extra fuel to the low/mid range. Which adjust. (if any) has the single most effect on total boost generation?
Which has most effect on low end 'launch' power?
Thanks again Piers!


[This message has been edited by BushWakr (edited 03-01-2001). ]

 

[F Simkowski (In Memory)]

Just got in and as usual Piers has responded instantly!
He's right on the money for the adjustments and their "in flight" effects.
Frank

 

[Piers]

Your diaphram effects you fueling all the way through the rpm band, the star wheel effects how much preboost or launch fueling you get. The main fuel screw also effects total fueling amounts, but gives more fuel in the lower & midrange than it does in the top end. Clear as mud #ad


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Piers, BD engine R&D

 

[BushWakr - RIP]

Thanks guys, thats a big help. I promise to try and remember, but when its not your daily job sometimes it gets hazzy.
Thanks again !!

 

[mark93]

Hi Everyone.

I think Piers may have made a SLIGHT error in stating that the star wheel helps "preboost".

Turning the diaphragm and/or turning the "smoke limiter" screw adds fuel immediately off idle with no boost.

A loose star wheel causes the boost fuel to come in early but there has to be some boost to begin moving the diaphragm down. The spring under the diaphragm is strong enough to hold the diaphragm all the way up against its cover even with the star wheel very loose.

With the PW injectors, I have my smoke limiter screw all the way backed off, the diaphragm rotated for max fuel, the full load screw in about 1 turn and the diaphragm spring VERY tight.

The diaphragm and full load screw allow maximum power. The injectors and rotated diaphragm supply plenty of fuel and smoke off idle so no need for the smoke limiter to be used at all. The tight diaphragm spring allows no boost fuel until the smoke begins to clear. Fuel is added more proportionately during boost runup and full boost fuel (diaphragm bottomed) occurs closer to maximum manifold pressure.

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'93 W350 Club Cab, Bright White, 5 sp. , 136K, Factory Options: LE package, 4. 10 Limited Slip, 7600 lb. rear springs, tachometer, front stabilizer bar. Mods: Banks stinger plus, Linex bedliner, 25,000 lb gooseneck ball, 10,000 lb receiver, Tekonsha brake controller, POWER WAGON injectors-WAY faster than stock!.