305 TPI Startup

Startup of the new 305 TPI in the G machine

Category:

Autos & Vehicles

Tags:

• G20
• Van
• Chevy
• TPI
• 305
• GMC
• Vandura

[xxxXW4NT3DXxxx]

TPI's create great low end torque, below 4,000 rpms, but above that the motor gets no air, the only way to fix that is installing a ram air of some sort

[Fast355]

@xxxXW4NT3DXxxx The TPIs actually run VERY well on a stock 305, up to 5,500 rpm or more. When you open up the rest of the engine, the 305 responds well to intake runner upgrades. A set of 059 L30 305 Vortec heads, an Edelbrock 3817 TPI Vortec intake, TPIS oversize runners along with a nice roller cam,Tri-Y headers and a full exhaust will wake that 305 up like no other. I ran a 14.8 @ 93 in a 5,500 lbs Fullsize van with a TPI 305.

[dburrigh]

Do you have the A/C hooked up on that? I'm tempted to put a modded TPI (bigger runners, etc) on my 385 stroker. I'm currently running a Sanden 709 (the original A6 was long gone when I got my van) on my '78 G10 Shorty.

[Fast355]

A/C is hooked up and functions front and rear. I used a newer style replacement condenser and had R-134a barrier style hoses made to connect everything including the rear evaporator. I also replaced the original accessory brackets and accessories with a setup from a 1992 G20. I used a new alternator and a/c compressor. Charged with R12, I blow 42*F on high blow both front and rear. With the insulation in my van you could hang meat after 15-20 minutes, even in the hottest weather.

[Fast355]

I guess I should also mention that I have an electric fan assembly from a Nissan Altima that had great fit with the stock radiator and pulls a ton of air.

[Fast355]

I wired 4 TPI injector in parallel to one of the TBI wires and then repeated on the other side. I performed the MPI Memcal Jumper Modification. I also replaced two of the injector driver resistors out of the PCM and replaced them with a jumper wire. Peak and Hold to Saturated

I have a 4L80E transmission now, running $OE.

TPI definately has more torque in the mid-range, but falls off heavily, where the TBI motored on. Low-end torque is identical between the two.

[trucker765]

do you have any tips on getting the bird cage on and off quickly? because mine is a pain in the ass to take off and put back on.

[brapboys503]

@Fast355 Holy shit man, that's fast for a solid brick, lol.

[Mr305smallblock]

hey Z28inNC i own a 1986 chevy 1/2 ton and my 305 LG4 is not a poor motor myn kicks ass but of course i beefed it up with a holly contender intake witha built up quadrajet and im only 14

[lamiac2411]

@cohan320 U r corect TPI stock waaaayyy outperforms TBI when it comes 2 the 305. Mods may be a different story but my buddy also has an RS with a 305TBI and my bird with a 305TPI wipes the floor with his Camero big time

[lamiac2411]

I beat alot of cars in my 88 TA w/305 tpi:) They r actually pretty hauss motors. I also have a shift kit, chip, and flowmasters. All of which help greatly. However, my buddy has a 87RS Camero with a 305TBI and that thing is a damn dog:( I noticed a huge difference between TBI and TPI 4 sure. His RS wont even spin the damn tires and is slow as molasses. Im sure a better carb and some tuning would help but those carbs stock r waaaaaayyyyy slow Lol. My GF 3.1 v6 achieva would run circles round it:)

[Z28inNC]

@MrRobGT Depends on the motor. The TPI 305 is a solid motor, but some305's are crap.Both the LG4(the one with the quadrajunk) and LO3(TBI) where pretty poor motors. I've owned Camaros both(87LT and 92RS), and both where dissapointing.

They dont call'em 5.slows for nuthin.

[MrRobGT]

@CheckYourSelf24Here 305's are VERY under rated. You can make a 305 come to life just like any other SBC. There are numerous builds if you search google and thirdgen.org. If you dont have a problem keeping the 305, build it. 12's arent bad at all.

[CheckYourSelf24Here]

Here's a question for you guys. I have a all original 1985 IROC with the 305 TPI (266,000+ miles) and the engine is tired. I want to rebuild the motor, maybe pump it up from 305 to UM..343? w/ street pistons,new cam,new everything. Basically, I want to make my 'roc like showroom new (numbers matching block/original) but with more horses. Any thoughts?