1987ZTPI

I am just wondering if anyone knows the CFM rating of a stock TPI throttle body i belive they are all dual 48mm, and i would also like to kno the CFM rating of the stock MAF sensor , i have heard that they can flow 650-700cfm de-screened and fins removed?

convas

Throttle body 668 CFM
MAF 529 CFM
Modified MAF 750 CFM

Above taken from TPIS insider hints, how accurate I don't know.

1987ZTPI

Thats amazing thanks man, i have been looking for that book for a while now but have not been able to find it. I have the MAF sensor de-sreened and de-finned, and everyone is telling me that is my biggest restriction on my mild 305, I kno the throttle body is good for 350rwhp, i'm thinking runners is the biggest restriction. My plenum is ported and siamesed. Where did you find the TPI insider hints book.

Fast355

iTrader: (2)

I don't believe the runners are holding you back on your mild 305. My van is making over 300 HP at the crankshaft on the stock runners with loads of torque. The stock 48mm throttle body will support ALOT more than 350 RWHP. GMPP uses it on the Ramjet 502 which makes 502 flywheel HP.

The stock plenum and lower intake manifold both need LOTS of work to make them flow. I am running modified stock parts and I could not be happier with the 310 that is in my van. Even with 3.08 gears turning P295/50/R17 tires, the van would spin the tires when WOT is applied from a dead stop and pull linearly past 5,500 rpm. I've even pulled it to 6,000 a few times, torque was down noticeably, but it was still pulling strongly even with the lightly modified TBI swirl ports. I recently put 3.42 gears and an upgraded posi unit in the rear-end. I run a 1993 LT1 Camaro/Firebird governor in my 700r4. It shifts @ 5,600 rpm when the pedal is on the floor. If this video isn't all it takes to tell the little 305s making power, I don't know what else is. 5,600 rpm shifts make it 45 mph at the 1-2 shift and 86 mph at the 2-3.