1989CamaroRs

ok whats everyone thing what are the pros and cons of each

Andy89RS

If you're talking about the induction system only, the TPI has better low end torque while the TBI has better top end power. If you're talking about the engine that came underneath the different setups from the factory it's a whole different story. It's all con for the TBI: Cam barely has enough of a profile to even be recognized as a cam, heads flow enough for an engine 1/3 it's size, exhaust manifolds would be restrictive for a 200 cubic inch engine, let alone a 305 and the rest of the exhaust is little better... If you put identical engines under the different injection systems, and optimize both for that engine, you'll see 2 powerful engines that have 2 very different power curves. The TPI will have pavement wrinkling torque from low rpm, but will fade away above about 4000-4500 rpm, while the TBI will show a curve that peaks much higher due to the shorter intake runners. TPI's low rpm punch is better for street/strip use, while the TBI is better suited for canyon carving/road course use.

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"Racing is life. Everything else is just waiting." - Steve McQueen - LeMans

305 TBI, T-5. 15.4@92 mph
Member Southern California Third Gen F-Bodies

AOL IM: Andy89RS

JoeCool TA

Look at the archives for this stuff, seems this question is asked every week.

Joe

Dan87IROC-Z

I think I have to dissagree with Andy, the TPI is better at all RPM. My friend has an SLP cam, Flowmaster cat-back, and random tech cat on his 89 RS TBI and it still runs out of breath above 4000 RPM. My TPI 350, when stock, would pull to the red line.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission

Current Mods: Edelbrock TES Headers, Hooker Cat-Back System, Performance Resource Chip, 160* Thermostat, Accel 8.8mm Ignition Wires, K&N high flow air filters, gutted air box, gutted MAF sensor, Throttle Body Coolant By-Pass, Homemade Ram-Air, Falken ZIEX Z-Rated Tires.

1/4 mile times without chip:
Best ET: 15.7 @ 89MPH
Best Corrected ET: 14.5 @ 96MPH

Dan87IROC-Z

Thats 4500 it runs out of breath, when it was stock it would die out around 4000.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission

Current Mods: Edelbrock TES Headers, Hooker Cat-Back System, Performance Resource Chip, 160* Thermostat, Accel 8.8mm Ignition Wires, K&N high flow air filters, gutted air box, gutted MAF sensor, Throttle Body Coolant By-Pass, Homemade Ram-Air, Falken ZIEX Z-Rated Tires.

1/4 mile times without chip:
Best ET: 15.7 @ 89MPH
Best Corrected ET: 14.5 @ 96MPH

Mike92

My tbi revs to 5grand as an optimum shift point with stock cam. It CAN rev to 5500rpms but has no power. And TBI tends to **** up alot more than TPI when you are trying to mod the engine (heavily). TBI is more uncharted territory than TPI. Even if you get a TBI to run with a TPI, the TPI would probably get better mileage, more torque and idle smoother because you wouldn't need such a wild cam due to the torque of TPI. But hey TBI is alot cheaper if you can deal with the extra headaches.

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305TBI FireBird, Holley Intake and TBI, Headers, Torquer Heads, Gears. Best E.T. 15.08 at 92.5, 0-60 6.45.(Before Heads)

Z28Freak

I bought my '85 Z28 TPI 305 for $2700. I bet it would be hard to find a similarly equiped TBI Camaro for less.

z28wiz

got my 91rs for 2800 mint condition

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91 RS' TBI 305
mods:
dynomax exhaust, lakewood control arms, gutted cat, pioneer deck, tbi spacer, jet stage 2 chip, K&N four inch element and open element, accel cap and rotor, moroso plug wires, msd blaster coil, bosche +4 spark plugs. Alot more mods to come!!
visit my page http://www.geocities.com/motorcity/pit/8410

Mike92

I got my 92 Bird back in 1997 for $4000. It was only 5 years old at the time with 80,000miles on it. I know it's a different body style but it would kinda be like getting a 95 firebird for $4000. Even a six is more than that now. Probably about 6-8 thousand.

Guest

TPI: Hmmmm I dunno...

TBI: Slow as molasses

Here's TBI times. Tell me which one is faster than the Magnum TPI car, which everyone agrees is running much slower than it should. https://www.thirdgen.org/forum/Forum26/HTML/000238.html
Oh yea, not one of them.

Slow88RS

bought my car in PERFECT condition for $2600. all was wrong was it it was high miles, so im just gonna run this engine into the ground and when it *** up. im gonna race it. my friends got 3 454's in his garage, can we say...BIG BLOCK power? and then for normal driving i get my GTA! woohoo!

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K&N Air Filter 14x3' Open Element, Edelbrock Catback 3", TES Edelbrock Headers, 3" Dynomax Hi-Flow Cat, 8.8mm Accel Spark Plugs, Underdrive Pulleys, JET Chip (Thurs of this week)
My 88 RS