LO3 top speed?????
04-12-2010, 08:11 PM
#1
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Car: 1987 Camaro Iroc Z28
Engine: 350 S/B
Transmission: 700 R4
Axle/Gears: 2.43 Gear Ratio
LO3 top speed?????
Out of curiosity how fast will a stock L03 run in terms of M.P.H.? I know it's goverened but how fast can you go before it hits the limit?
04-13-2010, 05:00 PM
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Car: 1991 pontiac Firebird
Engine: 305 tbi, Lo3 (for now)
Transmission: auto
Axle/Gears: stock (for now)
Re: LO3 top speed?????
It appears to be 115. Might be different by year, but idk. Read the article below.
https://www.thirdgen.org/unlimited
https://www.thirdgen.org/unlimited
04-14-2010, 01:40 AM
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Car: 84' Corvette, 96' Caprice
Engine: LT1, L99
Transmission: T-56, 4L60e
Axle/Gears: 3.07 POSI, 2.93 Open
Re: LO3 top speed?????
My old 89 L03 would go 110 and no more. Gotta love the speed limiter.... 
04-16-2010, 04:35 AM
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Car: 1984 Trans Am
Engine: Built chevy 350
Transmission: TCI Built 700r4
Axle/Gears: 3.73 posi 10 bolt
Re: LO3 top speed?????
My friends camaro did well over 120 with a LO3, 5speed and unknown gears probably 2.73 or 3.08 it's a RS. He took out the TBI and installed a carb and different distributor (Screw that Speed limiter crap) when he let off the gas it took a good 15 seconds for the speedo to start dropping from the 85mph mark. If I had to take a good guess I bet we was doing 130 and it was still climbing!
04-16-2010, 06:14 AM
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Car: 84' Corvette, 96' Caprice
Engine: LT1, L99
Transmission: T-56, 4L60e
Axle/Gears: 3.07 POSI, 2.93 Open
Re: LO3 top speed?????
My friends camaro did well over 120 with a LO3, 5speed and unknown gears probably 2.73 or 3.08 it's a RS. He took out the TBI and installed a carb and different distributor (Screw that Speed limiter crap) when he let off the gas it took a good 15 seconds for the speedo to start dropping from the 85mph mark. If I had to take a good guess I bet we was doing 130 and it was still climbing!
I installed a truck TBI ECM at one point in my attempt at tuning a TBI engine and i got her to go over 130. That's about it. (Truck ECM has no speed limiter) at least the one i got didn't....
04-16-2010, 06:54 AM
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Car: 1984 Trans Am
Engine: Built chevy 350
Transmission: TCI Built 700r4
Axle/Gears: 3.73 posi 10 bolt
Re: LO3 top speed?????
Certain trucks don't have a speed limiter such as my 88 3/4 ton Suburban LO5 350 with TH400 does not have one, I don't think any 3/4 ton trucks do? I do believe all 1/2 tons with 700r4 or 4l60E do though...I could be wrong? Did you have a 5 speed? Seems like you would have to have one in order to do that mod, 3/4 ton trucks with TH400 tranny's the ECM has no control over the transmission, otherwise you would have to deal with TQ converter lockup and other issues. Just curious as how you got the 350 ECM to work on a 305? I know people who have done a 305 to 350 swap and had to change computers because the 350 would not run right with the 305 ECM.
04-16-2010, 05:15 PM
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Car: 84' Corvette, 96' Caprice
Engine: LT1, L99
Transmission: T-56, 4L60e
Axle/Gears: 3.07 POSI, 2.93 Open
Re: LO3 top speed?????
Certain trucks don't have a speed limiter such as my 88 3/4 ton Suburban LO5 350 with TH400 does not have one, I don't think any 3/4 ton trucks do? I do believe all 1/2 tons with 700r4 or 4l60E do though...I could be wrong? Did you have a 5 speed? Seems like you would have to have one in order to do that mod, 3/4 ton trucks with TH400 tranny's the ECM has no control over the transmission, otherwise you would have to deal with TQ converter lockup and other issues. Just curious as how you got the 350 ECM to work on a 305? I know people who have done a 305 to 350 swap and had to change computers because the 350 would not run right with the 305 ECM.
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10-12-2010, 08:07 AM
#8
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Car: 1992 Pontiac Firebird Formula
Engine: 5.0L LO3 TBI
Transmission: 700R4 Automatic 4spd
Axle/Gears: 2.73
Re: LO3 top speed?????
well iv got a 92 formula with a LO3, 4L60 4 spd o/d, and 2.73 gears all stock and it will run until my speedo tops out at 120 and it still pulls after that so..
10-12-2010, 08:19 AM
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Car: 1986 Trans am
Engine: 5.3 LM7
Transmission: T56 6 speed
Axle/Gears: Dana 44 w/ 3.55's
Re: LO3 top speed?????
Never really understood why they speed limited the L03 engine and not the TPI engines. You'd think the TPI's would have way more potential for top end and that they'd be the limited ones.
10-12-2010, 09:41 PM
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Car: 84' Corvette, 96' Caprice
Engine: LT1, L99
Transmission: T-56, 4L60e
Axle/Gears: 3.07 POSI, 2.93 Open
Re: LO3 top speed?????
Just curious why ppl are bringing threads back from the grave quite frequently now? Just read the thread don't post...
11-09-2010, 10:02 AM
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Car: 89 Camaro-RS
Engine: 305ci
Transmission: 700R4
Axle/Gears: 10 bolt posi
Re: LO3 top speed?????
I got my 89 RS up to 115 mph with it still pulling and climbing until I caught up to traffic.
Last edited by RAIDER-RS; 11-09-2010 at 10:12 AM.
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