Have you succesfully put a bigger cam in a SBC with T.B.I.?

[Chevy_Finatic79]

well after driving around today i would have to say im pretty impressed with the new performance of my Burban it doesnt have a rough ide in drive while stopped at lights any more it has a steady continous purr as it should.

I want to caution anyone attempting to do this if you arent comfortable with mechanics dont do this to your vehicle i have a bunch of high dollar tools and diagnostic equipment and timing light with a tach at my disposal.

well if you understand how the butterfly's work the more you open the more air goes in.
the air introduced thru the holes i drilled was simillar to adjusting the idle screw to make it faster only the tps voltage stayed the same

as a result my idle in park jumped to like 1600rpm so i had to take off the tamper proof cover from the idle adjust screw and back it off a lil bit (well to be honset i had it off already and had been playing with it so i needed to dial it back in) dont know what it woulda done with the factory setting (tamper proof cover still in place)

heres were i used the scan tool to recalibrate the tps voltage after i backed off the idle screw i guess you could use a multimeter but way easier with the scan tool, anyway i got my idle to 1100rpm in park and 750-820rpm in drive and the burban just purrs now it actully drives alot better thru all speeds and has much smoother shifts from gear to gear the exhaust sounds alot better too.

i guess a guy could do all this by ear but having the right tools sure made it easy and who knows if i hadnt already messed with the idle screw i might not have had to recalibrate tps.

I am going to do this same mod on my 85' truck with a 70's 350 block punched over .060" with 327 crank & poshished rods and fuel injected non vortec heads and T.B.I. intake with the same cam i dropped in the burban. I will post results when i am done with that one too

[hotrodpc]

What the advantage of going with the 327 crank. That just makes a .060 over 327 being that 350 and 327 use the same block anyway in the large journal 327 that is.

[Chevy_Finatic79]

i thought it would be cooler being able to say i had a 327 braging rites you know LOL but now i want a big block or a 383 stroker. just cant seem to ever be satisfied i always want more power.

if i had a 572 id be trying to make it faster just a gearhead

[shadygrady]

I know this is an older post I just read it and find it weird,odd and all kinds of stuff.People have been succesfully putting cams in tbi equiped engines for a long time now.If your prom has not be reprogramed I would highly recomend it.I know Brian at TBI chips or harris performance does programming for OBD1 TBI,TPI and OBDII applications for MAF and SD.I know PCMs for less does them for my TPI OBD1 car not sure about tbi.It seems crazy to drill holes in the tb butterflies.If im understanding this all correctly.It seems like a bandaid to me that may work,but a properly tuned ecm would prolly have done better for you as far as all around performance,driveability and mileage.Alot of people are even tuning their own proms over on another forum I frequent.They also have some pretty easy DIY tbi mods they call the Ultimate TBI mods.That help improve overall flow of the unit.The guy that did my prom for my car made one to all my H/C/I mods.After he sent it to me I dattalogged some normal driving and WOT driving and emailed the results to him so he could make even more educated changes to the calibration.My cars fairly well dialed in but im about to do an intake swap so need to send it back in.
Im saying all this just because this may have worked for you but I don think its a good idea for alot of people to think this is a good idea for some of their idle /surging issues.Thats why GM has the ecm and all those sensors.The TBI unit is a good unit and lasts a long time the way it was designed.Glad it worked out for you and sorry for the novel.