Well, I made it to the 13's w/ tbi, here are the Mods.
350 4 bolt main block, 10.1 compression
Edelbrock rpm alumiminum heads
Comp Cams 8-502-8 Extreme Energy Hyd. roller cam
Edelbrock rpm intake 7101
Holley tbi w/ 80pph injectors
Built tranny and 3.73 gears
Spohn rear adjustable LCA's
Custom chip
Megashifter

I think that the tbi is restricting the limits of this combo. I think it would be maybe a second faster with a good holley 4150 carb. Im not complaining though, I am happy so far with the results. Here is my best track slip from last night, and it just so happened that my car number was 350. Give me some opinions on going to carb, I think it will be the only way to make this engine perform at its peak.

 

Here is pic other file to big.

 

The TBI may be a limiting factor, but the cam is also not a huge cam for a 350. i would guess that cam is a mid-low 13sec cam in any engine.

 

I think that the tbi is restricting the limits

What data have you collected that suggests this?

I think you can trap atleast 103mph like JPrevost and Birmass have with their TBIs and smaller cams.

 

I also don't think that Holley TBI should be holding you back at this point. r90camarors trapped I think close to 106 or 107 not positive. You should have some room before its a restriction. Good times for that combo though.

 

have you tuned it any?

tbi (like carb) doesnt tune itself.

 

If you have one of the later holley tbis youll be short on fuel at the stock pressure. They holleys use the smaller stock tbi injectors for FWDers. Theyre rated at the same pressure as teh standard tbi injectors but only flow up to around 60 pph. I have the '65' pph ones and they just berely flow enough to feed my motor up to around 4500 rpm. You definatly need an adj. fuel pressure regulator + high pressure/flow pump to avoid damage to your motor. You'll need to tune it yourself as well. The custom chip is probably nothing more then a stock calibration with more fuel and timing added in at WOT. The catch is that the stock calibration already has the injectors skirting static at over 3k so adding in fuel in teh calibration will have no effect. Since there wont be more fuel available youll pretty much just have extra timing, which can cause some problems on a high compression motor.

 

Crank up the fuel pressure! I'm running 28#'s and almost ran out of injector (90% DC). I'm using smaller injectors but you still need more pressure.
As for the "custom chip" if you're only trapping 99mph then take that chip, send it to the worthless dolt that sold it to you and ask for a full refund with shipping and then settle for just a refund but not before a fight .
If you are doing your own chip work then please visit the DIY eprom board to get tips on tuning the TBI. It isn't rocket science but one thing is VERY apparent; TBI needs a lot of injector if it's a healthy motor. Also timing is picky and I wouldn't be suprised if you're getting upwards of 12 degrees of knock retard in 2nd gear and down the track.
Trust me that the TBI flowing air is the least of your problems right now... it's definatly a fuel and spark issue, air flow should be fine! Although you might want to check that you're getting WOT and not having the carpet stop it at 2/3 .

 

i've been saying that for a long time Jon

The current TBI limitation don't seem to be air-flow, it seems to be fueling. I have always questioned the validity of the ultimate TBI mods, ect. since i haven't ever pulled vacume at WOT, even on the stock TBI unit with my combo. but i do run out of fuel.

 

Are these your cam specs?



Part Number 08-502-8
Engine -9999 Chevrolet
305ci-350ci
8cyl.
Grind Number CS XR269HR-12
Description

--------------------------------------------------------------------------------

Intake Exhaust
Valve Adjustment 0 0
Gross Valve Lift 0.495 0.503
Duration At 0.006 Tappet Lift 269 276

--------------------------------------------------------------------------------

Valve Timing At 0.006
Open Close
Intake 26 62
Exhaust 74 22

--------------------------------------------------------------------------------

These Specs Are For The Cam Installed At 108 Intake CL
Intake Exhaust
Duration At 0.05 218 224
Lobe Lift 0.33 0.335
Lobe Separation 112



The X268 makes 342 HP and 413 lb/ft, and I assume the X269 is bigger right?

 

The debate was pretty much settled a long time ago that it was fuel not air that tbi needed. Thats why I quit design work on my tbi 2 years ago....

DualTbi would be so nice Fuel problem gone. whala... tuning problem introduced