Hey all, i was wondering if anyone has tried this or knows...

What is the rated top speed of a 5.0 LB9 TPI?

I have an 85 mph factory speedo and buried it quite a few times for a few seconds... Cant really tell...

Anyone knows what factory top speed they are capable of?

 

What year? Also depends what gear ratio your running and tranny. Normally 130 i believe if auto 5 speed probably close to 140

 

I know the T5 would be quicker a bit, but im looking for auto primarily
i have 3.27 gears with Posi
GW6 and G80 codes on RPO

 

There is a fuel cut off in the programing $1f I want to say it was around 110mph.

 

I had my 5.0 up to 130 before I built the 355. Since then, I've had it up to 197 before it hit the 6,500 rev limit. Now with the rev limit at 6,900, I expect to make 200+. The stock 700R4 won't stay in 4th gear above 1/2 throttle. This means that, even if you have the power, you will only go as fast as the engine will pull in 3rd gear. I spent a few dollars having my trans custom built to hold 4th gear at full throttle above 100mph, and to withstand alot of power. With the aerodynamics of these cars, it feels like it's just getting started at about 160.

 

On my 89, the ecm fuel cutoff is 125 MPH. Naturally it was the first thing I modified on my bin

Only had it up to 115 though, wind coming in through my bad window seal sounded ferocious lol.

 

The guy in this video is doing a top speed run in a 1992 Camaro Z28 with the G92 performance package.

This car has the 305 with the L98 style cam, 5-speed trans, and 10 bolt rear with 3.42 gears and posi and N10 dual cat exhaust.

The video claims the car is mostly stock.

 

lb9 auto is capable of doing 130 if the bin is changed. Ive pushed my L98 to 150 with some more climb but the car felt unstable i didnt push it to the all out potential but i have a general idea of what the car does at that speed. 305s with the smaller injectors and cam in the autos ive only seen a capable speed of 130 with fuel cutout changed, granted if that was stock.

 

what is this "bin" you guys are talking about?

U mean re-tune the car?

 

a .bin is a binary file extracted from the ecm's eprom or memcal calibration unit.

 

so pretty much computer work.

I have a shop by my house that deals with TPI tuning. HK motorsports i believe.

 

I have an 88 iroc factory: Lb9/5speed/g92(3:45s) coupe, lowered, at the time had the original CAT on the car at 58,000 orig miles, went 150 barried the 145 speedo racing a 96 Vette and his speedo was at 150 we were dead even all the way from 30 mile roll to 150. Car felt good, now has headers and bolt in stright pipe. Cars fastest run 14:01 consistent 14:30s. Everything else stock. I believe top gear I was about 5100-5300..

 

When I had everything bone stock with paper filters at 59,000 miles, went 14:60s on old street tires

 

My 5.0 is in an 84 pickup..At 85mph it feels like 140mph..LOL

 

Any more recent experiences about LB9 top speeds

I have a 91 with a T5 that I'm thinking about taking to a top speed event. Interested to hear about some top speed experiences of the LB9.

Wonder if the sleeker firebird (with the headlights down!) will edger a little higher than the equiv. Camaro

 

I had a flat out stretch and was late for an appointment years back. My 240 kmh speedo was a little bit past the 240 tick in my transam.