that isn't completely true, my 88 Formula 305TPI Auto had no limiter.

and the video (don't make fun of my music. )
http://www.transamws6.com/video/130mph.wmv

 

Used car salesman always call the 350 TPI IROC the Camaro with the Vette engine. I would suggest that everyone use a GPS to determine top speed. Its always accurate to 1MPH no matter what you have changed to the car. Top speed advertised by Chevrolet on my brothers (new '85 TPI 305) was 143MPH. So the 350 should be able to hit 145MPH. I also have an ad from Hot Rod magazine January 1987. It says the 87 350TPI is 225HP, 330lb/ft, 3.27 BW rear, 1/4 time 14.66 @ 96.24MPH w/ a top speed of 143MPH. Check this link out if you have not already seen the Motorweek show in Owings Mills MD.http://www.thirdgen.org/newdesign/movies/index.shtml

 

your speedo might not be correct, go alittle faster, mine says 140mph before it kicks in at 125mph,

I've yet to see a 305 that wasn't limited,

no 350's were,

its also possible you chip has been changed

 

a GPS as in?

 

Put a GPS on your dash. Like a Garmin c330. It records your top speed.

 

chip was stock, as was the rest of the car and the speedo was pretty accurate.
with enough straight road, I could get it little past 140mph.
My buddy's 88 GTA 305 TPI 5 speed was the same, no limiter and we raced to 140 a couple of times. that was one of the longest races i've ever ran since it felt like it took forever to hit 140.

 

Well the difference between a BW 3.27 gear and the 3.73 is a phenominal difference, It will get to 140 without a problem - it will do it shortly after getting onto the entrance ramp of the highway...no to do that in my 1988 took forever.

 

but is your speedo correct?

if its stock your reading about 18% fast

3.73 isn't really a good gear for TPI, its a torque motor where 3.73 is a top end gear

 

Well as far as i know 3.73 and numerically higher gears develope more torque quicker. If it was a bad idea to equip them why are they on so many TPI units? the 2.73 is a god aweful gear to have on a tpi as well as the common 3.23 because the TPI does not have the high end breathing to sustain the top speed of a numerically lower gear like that...therfore a higher number gear will allow a faster take off and more torque at the sacrafice of a higher top speed - which most stock TPI units are incapable of anyway.

 

Now granted once a TPI unit aquires enough power to get to those high speeds with a numerically lower gear quicker a 3.08 gear such as the one equiped by the vettes is very useful for them. But in stock form a 3.73 is a great gear for the car because honestly a car like that wont see speeds over 150, so why not make the car get to about 140 quicker?

 

I've run 3.08's and 3.45s

I can say for sure anything higher then 3.45 would slow my car down, mine times are slightly faster on average with the 3.45 but my mph is way up with 3.08, and my fastest time ever was with 3.08's,


my bro has 3.27's, I like that gear best with these motors,

with a low rpm motor like a TPI you aren't using the adavantage they have in your first 3 gears if your stick,

a 3.27 tops off at about 90mph in 3rd, a 3.73 only does about 75mph

to do 90mph 3.73 you got to be a good chunk of the way into 4th,

so the advantage you get running the gear will get killed by the extra shift, to a 90 mph run and only being able to do just over 100mph in 4th will hinder the 3.73 as well

these car cause of there power band pull so hard and fast through 3rd that you want as much speed as possible,

this is from a racing point of veiw, a 3.73 gear is going to feel like it pulls harder cause you got shorter gears,

absoulute top speed in a 3.73 geared car with a stock tire is 140mph in 5th

 

hmmm ive had the car to just about 150mph on kumho ecsta 711, now granted maybe not the best idea. But it is stock, that is a good point as well - the 3.27 is capable of a higher speed in the 3rd gear, but as soon as you hit 4th gear on the highway it will be somewhat harder to gain speed as fast as you will with the 3.73 because of the shorter gear. Im no expert but the 3.73 is definatly faster than the 3.27 in terms of street racing, i never got my 3.27 above 125-130. The 3.73 has reached a calculated 148~mph at 5k RPM in 4th gear (.70). That is assuming that my tachometer is not freakisly inaccurate. If i had more HP/TQ i would swap my BW 3.27 into the 1989 but as of now the 3.73 work better for me.

 

To the best of my knowledge, GM didn't make any production TPI F-cars with the 3.73 ratio.........the only 3rd Gen I can think of that came with that gear was the 190 hp 5.0 carberated "H.O." L69 engine. If memory serves, a 3.42 was the numerically highest gear you could get ina TPI and that may even be a bit high.......been a while since I absorbed all these facts.

Now if people are putting 3.73 gears int heir TPI cars, that is on them.......but I really don't think GM did that.....

 

No, your right as far as i remember 3.42 was the highest ratio. But aftermarket gears such as the 3.73 and 4.10 gears show improved quarter mile times and better acceleration. Not to mention that the majority of the F-body cars sport those kind of gears, especially after mods. Ever seen a quarter mile car run with a set of 2.77 or 3.08? Now if your running 1,000hp i guess it doesnt matter...