difference between a 5.0 tpi and a 5.0 tbi?
10-01-2002, 07:20 PM
#2
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Join Date: Mar 2002
Location: Anderson, SC
Posts: 123
the 305TPI is WAY better than a TBI, trust me i know from experience. The TBI is about the same thing as a V6 but you have the V8 sound. There is NO power coming from the TBI. Go with the TPI you can get A LOT more out of it. the TBI 
to the TPI.
to the TPI.
10-01-2002, 07:38 PM
#4
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Join Date: Mar 2002
Location: Anderson, SC
Posts: 123
The main thing is the induction. You get a lot more air in there through the TPI setup. Plus when you start modding it you can get the runners and all the extras on the TPI ported and get A LOT more horsepower out of it than you would with the crappy TBI.
10-01-2002, 07:46 PM
#5
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Thread Starter
Join Date: Sep 2002
Posts: 39
alright. so the induction is the main difference.. i was looking through google looking for how big a difference (in hp) there was in tbi and tpi. the tpi had 205 hp (35 more than the tbi).. i'm just trying to get my car to beat this car that has a 5.0 tpi (it is stock).. any ideas on how i can beat him? and what's the cheapest way to get more horse?
10-02-2002, 11:12 AM
#9
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Join Date: Sep 2002
Posts: 107
I think the TPI motors typically also came with a more aggressive camshaft and better heads also. Generally the LB9s had the same cam as the l98. The roller with around .410 inches lift. I think the TBIs have flat tappet cams and the swirl port heads.
10-02-2002, 11:23 AM
#10
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Join Date: May 1999
Location: Spfd, MO USA
Posts: 32
The 305TBI (LO3) has a smaller cam and crappy heads vs. the 305TPI (LB9). You can do the open element mod, add no more than a .460 lift cam to the LO3 (and a new chip burned), and you will have the 305TPI's begging for mercy.......or you can just converto to carb like I did and never look back!
JW
JW
10-02-2002, 11:26 AM
#11
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Join Date: Jul 2001
Location: Duluth, Ga., USA
Posts: 192
The tbi's also have smaller exhaost than the tpi. The heads were also different. Most of them had the same cam as the tbi. The tpi just makes tons more torque then the tbi.
If you are going to make the swap find a tpi car with the same trans and year to make the swap as easy as possible on you. Make sure you get everything. Computer, wireing harness, fuel pump, intake manifold, throttle cable and kickdown cable if you have an auto, and the air box. Your going to need gasgets and some fuel lines also.
If you are going to make the swap find a tpi car with the same trans and year to make the swap as easy as possible on you. Make sure you get everything. Computer, wireing harness, fuel pump, intake manifold, throttle cable and kickdown cable if you have an auto, and the air box. Your going to need gasgets and some fuel lines also.
10-02-2002, 12:21 PM
#12
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Join Date: Aug 1999
Location: Cincinnati, OH
Posts: 2,612
The 5-speed tpis got a better cam than the tbi. TPI cars also had the luxury of posi traction, and 3.23 gears, along with an exhaust that wasnt 2.25" and didnt have the swirl port 187 heads. Basically everything that came stock on a 305 tbi motor is restrictive. I would have liked to pull some good times outa my car this year, but the lack of a posi rear and 2.73s along with stock tuning and a ****ty track didnt let me. But Im looking forward to next year. The only thing that kept me from doing the tpi route was the fact that it cost less to do heads/cam than to do the tpi swap.
10-02-2002, 01:54 PM
#15
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Join Date: Jan 2001
Location: Florida. USA
Posts: 1,790
Yes they were options, TPI, Different gear ratios and Limited Slip to name a few. However; some of the original owner's did not buy these options. When I bought my IROC New in 1987 I had some financial limitations at the time. So some options were not considered which I am correcting to this day. Still glad I got the IROC.