Not knowing a whole lot about the evolution of the TPI motors I felt like surfing for some info. I found this article pretty eye opening.

http://www.carcraft.com/techarticles/116_0305_tpi/index1.html

between 1985 and 1993 the TPI 305 and 350 gained some improvements which netted some small boosts in hp.

In 1986 however, I would not have bought a Camaro or Firebird. They took a sobering 25hp LOSS in power from the 215hp 1985 Models, crawling down to a sad 190hp. A return to its 1985 hp numbers came in 87 along with the introduction of the re introduction of the 350 f-body, but what surprised me is that the difference in hp between the 305 and 350 TPI motors was a sad 5hp!!!

I wonder what the price difference was between a brand new 350 Camaro/Firebird vs. a 305 Camaro/Firebird. I bet it was a LOT more than 5hp was worth! Was the torque difference between the two very noticable?

in 1989 the difference betwen the two grew to 15hp and they seemed to reach their best in 1990 with the removal of the mass air flow system. I am curious though with the 1990+ setup, how responsive are the 305 and 350 TPI's to mods, and is the difference in hp bewteen the 350 and 305 more noticable when you start to tinker?

I think the TPI is probably the most attractive looking V8 produced, and I like the torque numbers as well. Don't want anyone to think I am disrespecting these motors at all, because I repect them very well.

However,
On a side note, a fact about 80's F-body's that is very disturbing is that from 1982 to 1986 there were BIG, HEAVY, Camaros and Firebirds that were sold with 88hp - 92hp 2.5 Iron dukes.....these underpowered battle tanks must have been quite stressfull to drive in traffic, and personally, I can not imagine that the little duke hauling all that weight got much better mileage than a 305 V8 did in normal city driving. And FORGET about climbing hills in one of these....The 4cyl Fiero must have seemed like a drag car in comparisson....

some more info on the TPI's and 3rd gen F-Body

http://www.f-body.org/tech/tech.htm#weight3rd

[This message has been edited by FieroMonkey (edited 10-09-2005).]

quote Originally posted by FieroMonkey: However, On a side note, a fact about 80's F-body's that is very disturbing is that from 1982 to 1986 there were BIG, HEAVY, Camaros and Firebirds that were sold with 88hp - 92hp 2.5 Iron dukes.....these underpowered battle tanks must have been quite stressfull to drive in traffic, and personally, I can not imagine that the little duke hauling all that weight got much better mileage than a 305 V8 did in normal city driving. And FORGET about climbing hills in one of these....The 4cyl Fiero must have seemed like a drag car in comparisson....

My first car had an Iron Duke in it, a 4 door 1986 Oldsmobile Cutlass Ciera. Yeah the Duke REALLY labors with a heavier car my 86 Olds' topped out on the highway at a whopping 82 mph.

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

First Fiero: White 1984 Fiero SE - I miss you old friend
Current Fiero: Silver 1986 Fiero 2M4 (Daily Driver)

Having owned an 1985 IROC TPI 305 and a 1986 IROC TPI at the same time you are ignoring an important issue, the torque ratings between the 85 and 86 which had different cams, and there was at least 30 lb/ft difference between the 87 350 which was first installed in 1987 over the 305. Pay close attention to the rpm at which the spec was given because they may vary depending on the source. I don't know why GM changed the cam but the end result may have resulted in both cars performing about the same, a difference that you may not have been aware of is that the 86 had a stock 3 inch exhaust system the 85 did not. The 85 went to the wife the 86 was mine and before long had a 88 roller block installed with a roller cam from crane, Edelbrock headers and a programmable Accell power processor, and 3.73 limited slip unit installed. The engine was still a 305 and it made several 95 plus model 350 camaro owners very upset that they could not get past my tail lights or stay close, there was also a mustang cobra victimized I believe it was also at least a 95 though it took the 4th gear before I really started to pull away. That car surprised a lot of people, wait by the time the Cobra run happened I had installed a 383 stroker, and I believe the cobra was running nitrous because at one point I was pulling away strong and suddenly like a rocket he caught up to near nose to nose but then started falling off again as the rpm climbed.

i was figuring some of the things you have posted, but wanted to hear them from someone who knew the details rather than my guesses and speculation. I still wonder what salesman durring that time told customers who were reading window stickers. I am pretty sure back then the window stickers only showed hp. so seeing 5hp improvement for an engine upgrade + the higher price must have had many shoppers scratching their heads.

Which still has me wondering if, stock that is, was the torque difference between the 305 and 350 noticable without a clock?

I'll tell ya, I have driven quite a few of the 3rd gens and I own a 84 Z28 - There can be a wide differential in the way these cars perform. I think the single biggest thing is the rear axle ratio. I drove an 82 with a 305 3-speed auto with a 2.73 rear gears and it was a dog. My 84 with 4-speed auto and 3.23 rear gears is alot better than the 82. I drove an 85 with a 305 HO 3.73 rear gears - stick and it was better yet. The best / fastest stock 3rd gen I have driven is a 89 Iroc 350 TPI, 4-speed auto 3.42 posi rear gears. Many of the 3rd gens come with 2.xx rear gears and they just don't cut it for good off the line performance. Anybody who bought a 3rd gen iron duke Camaro shouldn't have been too interested in performance.

------------------
Tim
Red 88 Formula Auto 2.8 100K+ Miles

I don't care how much money you have, free stuff is always a good thing.

quote Originally posted by FieroMonkey: i was figuring some of the things you have posted, but wanted to hear them from someone who knew the details rather than my guesses and speculation. I still wonder what salesman durring that time told customers who were reading window stickers. I am pretty sure back then the window stickers only showed hp. so seeing 5hp improvement for an engine upgrade + the higher price must have had many shoppers scratching their heads. Which still has me wondering if, stock that is, was the torque difference between the 305 and 350 noticable without a clock?

92 Camaro: 305: 230HP 300TQ
350: 245HP 345TQ

http://www.camarosource.ca/php/camaro_info_db/index.php?act=engine_specs&year=1992

HP difference was small but the extra 45lbs of torque made a big difference for a heavy car. And of course the 350 has more potential to get more out of the mods. These engines where made for big torque and not big HP. The TPI in my car puts 346lbs of torque at the wheels. That's more than what an LS1 puts at the crank . I agree with you that the TPI intake is the most apealing of all GM intakes.

------------------
Palm Beach Fieros
http://pbfieros.tripod.com

91-92 fbods all got lumpyer cams.Your also false in saying most 3rdgens came with 2:xx gears.Mostly TBI auto cars came with them. The most common gear ratios were 3:23 or 3:42, 3:08

86 Sport Coupe
Berlinetta M5,A4 LB8 V6 8.9:1 2.8 (173) 135@5100 160@3900 MFI 3.42 ---- 3.42 ----
86 Sport Coupe
Firebird M5,A4 LG4 V8 9.5:1 5.0 (305) 155@4200 245@2000 4bbl 2.73 ---- 2.73 ----
86 Berlinetta
Firebird S/E A4 LG4 V8 9.5:1 5.0 (305) 155@4200 245@2000 4bbl ---- ---- 2.73 ----
86 Z28
Trans Am M5,A4 LG4 V8 9.5:1 5.0 (305) 165@4400 250@2000 4bbl 3.23 3.73 2.73 ----
86 Z28
Trans Am M5 *L69 V8 9.5:1 5.0 (305) 190@4800 240@3200 4bbl HO 3.23 3.73 ---- ----
86 Z28
Trans Am A4 LB9 V8 9.5:1 5.0 (305) 190@4000 285@2800 TPI ---- ---- 2.73 3.23
86 IROC-Z
Trans Am M5,A4 LG4 V8 9.5:1 5.0 (305) 165@4400 250@2000 4bbl 3.23 3.73 2.73 ----
86 IROC-Z
Trans Am M5 L69 V8 9.5:1 5.0 (305) 190@4800 240@3200 4bbl HO 3.23 3.73 ---- ----
86 IROC-Z
Trans Am A4 LB9 V8 9.5:1 5.0 (305) 190@4000 285@2800 TPI ---- ---- 2.73 3.42
86 IROC-Z A4 +L98 V8 9.5:1 5.7 (350) 220@4200 320@3200 TPI ---- ---- 3.27* ----
*only 74 produced +only 50 produced *Borg-Warner rear axle

Yr Model Trans Engine
code/type CR Displ. HP Torque Induc-
tion Manual
std. Manual
opt.
(G92) Auto
std. Auto
opt.
(G92)
87 Sport Coupe
LT
RS*
Firebird M5,A4 LB8 V6 8.9:1 2.8 (173) 135@4900 160@3900 MFI 3.42 ---- 3.42 ----
87 LT
Firebird A4 LG4 V8 9.3:1 5.0 (305) 165@4400 245@2800 4bbl ---- ---- 2.73 ----
87 IROC-Z
Z28
Formula
Firebird
Trans Am M5,A4 LG4 V8 9.3:1 5.0 (305) 170@4400 250@2800 4bbl 3.23 ---- 2.73 ----
87 Z28
Formula
Trans Am A4 LB9 V8 9.3:1 5.0 (305) 190@4000 295@3200 TPI ---- ---- 2.73 ----
87 Z28
Formula
Trans Am M5 LB9 V8 9.3:1 5.0 (305) 215@4400 295@3200 TPI 3.08 ---- ---- ----
87 IROC-Z
Formula
Trans Am
GTA A4 LB9 V8 9.3:1 5.0 (305) 190@4000 295@3200 TPI ---- ---- 2.73 3.23
87 IROC-Z
Formula
Firebird
Trans Am M5,A4 LG4 V8 9.3:1 5.0 (305) 170@4400 250@2800 4bbl 3.23 ---- 2.73 ----
87 Z28
Formula
Trans Am A4 LB9 V8 9.3:1 5.0 (305) 190@4000 295@3200 TPI ---- ---- 2.73 ----
87 IROC-Z
Formula
Trans Am
GTA M5 LB9 V8 9.3:1 5.0 (305) 215@4400 295@3200 TPI 3.08 3.45* ---- ----
87 IROC-Z
Formula
Trans Am
GTA A4 L98 V8 9.3:1 5.7 (350) 225@4400 330@2800 TPI ---- ---- 3.27* ----
*Borg-Warner rear axle *RS available in only California
Yr Model Trans Engine
code/type CR Displ. HP Torque Induc-
tion Manual
std. Manual
opt.
(G92) Auto
std. Auto
opt.
(G92)
88 Sport Coupe
RS*
Firebird M5,A4 LB8 V6 8.9:1 2.8 (173) 135@4900 160@3900 MFI 3.42 ---- 3.42 ----
88 Sport Coupe
Firebird M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4000 255@2400 TBI 3.08 ---- 2.73 ----
88 IROC-Z
Formula
Trans Am M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4000 255@2400 TBI 3.08 ---- 2.73 ----
88 IROC-Z
Formula
Trans Am A4 LB9 V8 9.3:1 5.0 (305) 195@4000 295@2800 TPI ---- ---- 2.73 3.23
88 IROC-Z
Formula
Trans Am
GTA M5 LB9 V8 9.3:1 5.0 (305) 220@4400 290@3200 TPI 3.08 3.45* ---- ----
88 IROC-Z
Formula
Trans Am
GTA A4 L98 V8 9.3:1 5.7 (350) 230@4400 330@3200 TPI ---- ---- 2.77* 3.27*
*Borg-Warner rear axle *RS available in California, Texas, and Florida only
Yr Model Trans Engine
code/type CR Displ. HP Torque Induc-
tion Manual
std. Manual
opt.
(G92) Auto
std. Auto
opt.
(G92)
89 RS
Firebird M5,A4 LB8 V6 8.9:1 2.8 (173) 135@4900 160@3900 MFI 3.42 ---- 3.42 ----
89 RS
Firebird M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4400 255@2400 TBI 3.08 ---- 2.73 ----
89 IROC-Z
Formula
Trans Am M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4400 255@2400 TBI 3.08 ---- 2.73 ----
89 IROC-Z
Formula
Trans Am A4 LB9 V8 9.3:1 5.0 (305) 195@4000 295@2800 TPI ---- ---- 2.73 ----
89 IROC-Z
Formula
Trans Am M5 LB9 V8 9.3:1 5.0 (305) 220@4400 290@3200 TPI 3.08 ---- ---- ----
89 IROC-Z
Formula
Trans Am
GTA M5 LB9 V8 9.3:1 5.0 (305) 230@4600 300@3200 TPI ---- 3.45* ---- ----
89 IROC-Z
Formula
Trans Am A4 L98 V8 9.3:1 5.7 (350) 230@4400 330@3200 TPI ---- ---- 2.77* ----
89 IROC-Z
Formula
Trans AM
GTA A4 L98 V8 9.3:1 5.7 (350) 240@4400 345@3200 TPI ---- ---- ---- 3.27*
89 Turbo Trans Am (TTA) A4 LC2 V6 8.0:1 3.8 (231) 250@4400 340@2800 SFI ---- ---- 3.27* ----
*Borg-Warner rear axle
Yr Model Trans Engine
code/type CR Displ. HP Torque Induc-
tion Manual
std. Manual
opt.
(G92) Auto
std. Auto
opt.
(G92)
90 RS
Firebird M5,A4 LH0 V6 8.5:1 3.1 (191) 140@4400 180@3600 MFI 3.42 ---- 3.23 ----
90 RS
Firebird M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4000 255@2400 TBI 3.08 ---- 2.73 ----
90 IROC-Z
Formula
Trans Am
GTA M5,A4 LB9 V8 9.3:1 5.0 (305) 210@4400 285@3200 TPI 3.08 ---- 2.73 ----
90 IROC-Z
Formula
Trans Am M5 LB9 V8 9.3:1 5.0 (305) 230@4400 300@3200 TPI ---- 3.42 ---- ----
90 IROC-Z
Formula
Trans Am
GTA A4 L98 V8 9.3:1 5.7 (350) 245@4400 345@3200 TPI ---- ---- ---- 3.23
Yr Model Trans Engine
code/type CR Displ. HP Torque Induc-
tion Manual
std. Manual
opt.
(G92) Auto
std. Auto
opt.
(G92)
91 RS
Firebird M5,A4 LH0 V6 8.5:1 3.1 (191) 140@4400 185@3600 MFI 3.42 ---- 3.23 ----
91 RS
Firebird M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4000 255@2400 TBI 3.08 ---- 2.73 ----
91 Z28
Formula
Trans Am
GTA M5,A4 LB9 V8 9.3:1 5.0 (305) 205@4200 285@3200 TPI 3.08 ---- 2.73 ----
91 Z28
Formula
Trans Am
GTA M5 LB9 V8 9.3:1 5.0 (305) 230@4200 300@3200 TPI ---- 3.42 ---- ----
91 Z28
Formula
Trans Am
GTA A4 L98 V8 9.3:1 5.7 (350) 245@4400 345@3200 TPI ---- ---- ---- 3.23
Yr Model Trans Engine
code/type CR Displ. HP Torque Induc-
tion Manual
std. Manual
opt.
(G92) Auto
std. Auto
opt.
(G92)
92 RS
Firebird M5,A4 LH0 V6 8.5:1 3.1 (191) 140@4400 180@3600 MFI 3.42 ---- 3.23 ----
92 RS
Firebird M5,A4 LO3 V8 9.3:1 5.0 (305) 170@4000 255@2400 TBI 3.08 ---- 2.73 ----
92 Z28
Formula
Trans Am
GTA M5,A4 LB9 V8 9.3:1 5.0 (305) 205@4200 285@3200 TPI 3.08 ---- 2.73 ----
92 Z28
Formula
Trans Am
GTA M5 LB9 V8 9.3:1 5.0 (305) 230@4200 300@3200 TPI ---- 3.42 ---- ----
92 Z28
Formula
Trans Am
GTA A4 L98 V8 9.3:1 5.7 (350) 245@4400 345@3200 TPI ---- ---- ---- 3.23
Note: These are Camaro ratings. It is said to take around 5-10 HP and TQ from TPI Firebirds because of intake design.

[This message has been edited by STIFFLER (edited 10-09-2005).]