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TPI was the "High output" of the 305. That is how it is generally referenced a TPI motor in many books, publications, along with the side of the cars. There was no internal modifications outside of differences among years to the TPI system to make the motor a true High (or higher) output than the car sitting next to it in the dealerships when sold as new.
TPI was the "High output" of the 305. That is how it is generally referenced a TPI motor in many books, publications, along with the side of the cars. There was no internal modifications outside of differences among years to the TPI system to make the motor a true High (or higher) output than the car sitting next to it in the dealerships when sold as new.
The '86 tpi may not feel too high output though. That was (one of) the worst year(s) for them. GM put a tiny tiny cam in them to avoid a gas guzzler tax being put on the car. In later years they got past that tax with a shift light lol.
"5.0 high output" usually refers to the L69, the carbed engine that was available from 82-87. There was no stock TPI setup referred to as "high output", although I guess you could consider the 350TPI the "HO" version :P
__________________ North Texas Third Gen Association 1988 GTA 5.0/M5/3.45 LSD, T-Tops, Digital Dash, Leather - Current Ride 1983 Firebird S/E - Stripped 1995 Chevy 1500 5.7 Ext. Cab - Daily Driver
I've seen 5.0L High Output on the side of a tuned port trans am. When i ordered my 85/86 trans am decal kit from pheonix graphix it came with 5.0L High Output or 5.7L High Output decals.
Edit, sorry... 5.0 Litre H.O. is how it was worded.
Maybe the cars I've seen were incorrect, because there is also a 5.0 Litre F.I. option available as well in later years. But pretty sure it started in 85 to like 87 as 5.0 HO was the TPI 305, and then in like 87 or 88 they showed the 5.0 Litre F.I. Could be wrong but going off of the cars i've seen original with tpi.
My '83 Z28 with the 5.0 HO carbed engine (IIRC) was rated for 190 HP and 265 ft. lbs. of torque. My '86 IROC Z28 with the 5.0 TPI engine was rated for 190 HP and 285 ft. lbs. of torque.
The difference in the way they run when the have the same HP and the TPI has more torque? The '83 winds up to 5500 rpm and shifts pretty quickly. The '86 winds up to about 4500 rpm pretty quickly and then takes nap from 4500 to 5500 rpm when it finally shifts. That 5500 rpm foot to the floor shift point was a mistake on the TPI engines. They struggle to "breathe" above 4600 rpm.
__________________ Blue 81 Z28 350 w/4 spd
Black 86 IROC Z w/TPI 305 & 700r4
74 Camaro LT w/400 4brl/turbo 400/3.08 pos rear