vacuum or mechanical secondaries

[Chris_Wilson]

For a Class 8 or Class 3 race truck, vacuum or mechanical secondaries???
What do you use on your carburated race truck? Why?

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[bigtex]

Mechanical 100% You have way more throttle control when trying to "walk" the truck through the whoops. With a vacuum carb you will always have a slight delay. You need a double pumper so you have an accelerator pump on your secondaries. With a vacuum you cannot get a double pumper. Just worlds of differences. I dyno a good amount of race trucks and I will not even strap it down if it does not have a mechanical carb. If you have any questions pm me and I can help you find the right carb for your set up.

[partybarge_pilot]

Step out of the dark ages Tex. Vac secondaries are more responsive on the bottom if set-up right. All the dyno will show you is WOT performance, it has no bearing on how it handles through the whoops. Having run both, I prefer a well set up vac secondary over a double pumper any day of the week. Usually when you bouncing through the whoops taping the pedal those double accel pumps are just dumping loads of raw fuel down the intake and doing nothing but washing down your rings and killing fuel economy.

[bigtex]

If you have the right size squirter and it is all set up correctly you will not wash out your rings. No matter how well a vac. carb is set up you will always have a lean spot when coming into you secondaries. With a mech. you do not have the lean spot and if set up correctly you will not have a rich spot. vac. secondaries might be better below 2500 rpms but what desert race vehicle is ever below that rpm while racing? What i mean by better in the whoops is you have better throttle response with a mech. so as you are going in the holes you can use your gas pedal to move the vehicle weight around but with a vac you do not have as good of throttle response. Just my 2 cents, may ways to do the same thing. Ask 10 people get 10 different opinions.

[12LaPaz]

mechanical always, A good RACING carb is well worth the investment, call Braswell you will get your moneys worth from them dont bother with the vacuum carb it wont cut it in racing conditions. If you dont want to spend the money it takes to get a Braswell then get a new holly HP. It appears that a few other guys on here are having carb problems also, the one thing they have in common is that they are trying to make a street carb work under racing (prerunning) conditions. I have a Braswell carb if we bolted it onto your engine you would be supprised what a difference a good RACING carb makes. You cant make ice cream out of crap. Plan on spending $900.00 to $1600.00 for a good racing carb otherwise your just throwing your money away on junk. (You might be able to find a good used one for $500.00 to $700.00)