Greasemonkey

Those are some tall *** tires.

Zepher

iTrader: (1)

Shouldn't the radius be 13"?

z28monster

iTrader: (1)

i am going to take the car out some ware ware theer isnt any one around and flog the living crap out of it just ounce and see what she will do and ill post it for u guys to see what teh old 83s can do.

Zepher

iTrader: (1)

Just be carefull.
Check the following first:
Tire pressure and wear
Engine oil
Tranny fluid
coolant
brakes
and wear a helmet if you have one as well as your seatbelts.
Remove anything that can fly around inside the car, empy the console compartment, etc...

z28monster

iTrader: (1)

believe inme more then that lol your talking like i am going on a no return trip im not going to do it unless i am totaly shure i can get away with it with out recking or something.

another ? is it going to hurt anything to bring the car up to that speed and that type of an rpm if i get caried away is it going to blow my engine up cause i dont want to do it if i am going to just end up blowing my engine up or will it be ok to just do it ounce to see what she will do all out???

Confuzed1

iTrader: (4)

Ehhh......I dunno. My car likes a good flogging every now and then.

Just get a feel for how far you can wind it out - without going "Too Far".

305LG4Cutlass

What do you think the top speed would be in my car? 87 Cutlass Supreme (a bit heavier and less aerodynamic than the Camaro), stock LG4 with open element air cleaner and accell 8mm wires, tuned up good, TH2004R (will go into 4th gear at full throttle) 2.73 gears.
My speedo tops out at 140km/h but I raced my friends Sunfire GT that shuts down at about 185km/h and I had a car and half on him and was pulling away right before his car would've shut off so I'm guessing I was doing almost 190 (120mph) and it still felt like it had quite a bit left in it.

Greasemonkey

I wouldn't think the Cutlass would do much more that 130-135. Just knowing the way these cars act (I drive an 86) I don't think I'd really want to go much faster than that.

Air_Adam

Top speed could also drastically change, depending on what you drive and what the bodywork has on it, sorta like what RB was saying about aerodynamics... a good example would be is it a Camaro or a Firebird? A Firebird is much closer to the ideal 'wedge' shape that you need for a top speed blast than a Camaro has. Also, does the car have things on the body that would create drag, like a spoiler? In that department, the Camaro would have an advantage because it has the very short, very low-drag lip spoiler on the tail, but the Firebird has the huge wrap around spoiler, which looks to me like it would create alot of drag. It may make no difference at legal speeds, but like RB said, once you get up above about 100mph, the HP needed to push the car multiplies, and the added drag from the Camaro's relatively brick-shaped nose or the Firebird's Wrap around wing could potentially create alot of drag at speeds around 120-130-140mph which would bog down the engine alot and make it seem to just run out of steam. For a top speed run, I think the best shape would be something like an 84-96 Corvette because it has the ideal wedge shape, much like the Firebird, the vette is very low to the ground and has a very low roofline, which would help to streamline the car even more than the Firebird and probably most importantly... the Corvette has no drag-adding body parts like a spoiler and even has very streamlined mirrors!! This is why the average L98 Corvette seems to have much more top end speed than any 3rd gen and probably most LT1 powered 4th gens, even though it had only about 250-280hp stock. I think i read in an old magazine that the L98 Corvette (and '89 i think) was taken to 160mph with no problems, even though it had less power than the average LT1 powered F-body, which I doubt could hit 160mph.

Zepher

iTrader: (1)

The 3rd gen trans am is more aerodynamic than C4 corvette.
The 85-90 Wraparound spoiler is actually very usefull in top speed runs, helps keep the rear of the car on the ground.
My 86 TA has more topend than my friends 87 Corvette. That is how I beat him in a race. We were side by side until he ran out of steam at 130mph.
Oh, and I had a 305 in my car at the time too.

Air_Adam

Yea, the TA spoiler helps to keep the car on the ground, but by the way it does it (making downforce) it also creates drag, like any other spoiler does, and that is what is speed limiting.

zippy

an 87 corvette isn't going to run out of steam at 130. the 87 vette isn't much worse on areo dynamics than an 86 trans am and it's stock top speed was about 15 more than an 86 trans am. the third gen pf bodies had the lowest drag of any of the major production cars in it's time. i have an 85 test and the 215hp tpi cf went 141 and the pf went 142. the stock LG4 in automatic form was only good for around 110 since it wasn't going to use 4th gear. a 5 speed LG4 is only good for around 135 area at best and couldn't do 157 if it were going downhill in stock form. of course as all good third gen guys know, the damn v6 trans am had the highest top speed of all third gen cars.

zippy

for racerx, you said you did 140 easy with a digital speedo reading in an 84. as i recall the digital speedo in an 84 would not show any speeds that high as speedometer restriction was still in effect? (85mph speedo's). another point for any to go by, the factory tach and speedometer isn't exactly a finely calibrated instrument by any means.

Morley

Lets see if I can remember this right. Back in the 90's Car Craft did a compo of the "fast cars", a late 80's 'Vette, late 80's T/A (GTA I think), mid '80's IROC (350 TPI), '95? Impalla SS, and a GT Moosestang. All were tested for top speed on a long stretch of road near Vegas.

#1 'Vette @ 154 MPH

#2 GTA @ 148 MPH

#3 IROC @ 146 MPH

#4 Impalla SS @ 138 MPH

Dead last...Moosestang @ 135 MPH

So, looking at those cars and the amount of power they had/have, I'd say that you'd be VERY lucky if an LG4 would hit the 130's (in stock form).

zippy

i can back that up, i have that issue and the motor trend issue that went with it. also tested on that same day were to 4th gen cars. auto trans am went 155 and m6 camaro z28 went 157. if i'm correct the LT1 vette they test also went 167. on the mustang, that was a gt and the cobra tested only went 138. these were all the current at the time 95 models and they listed the top speeds of the older one's from previous testing.

Zepher

iTrader: (1)

I've riden in his 87 Vette and it sounds good as ****, but between 4500-5000rpm, there isn't any pull. And the muncie 4+3 didn't seem to help any either.
Here is a vid of me on the highway taking out a built 72 Chevelle. I had the tpi on the car at the time. This is a quick 65-140.
http://www.transamws6.com/video/Zepher_vs_Chevelle.mpg

zippy

hard to judge speed from the video, but reguardless i'm not sure if your referring to your ta with the 305 in stock form. the 86 which i had a camaro version of was only a whopping 190hp in tpi form and sure the hell didn't pull rpm any better than an L98. i have a few tests from the 80's with the 4+3 trans and one of them was the worthless crossfire injected vette which ran 148 mph stock. my 86 irocz i ran up to 138 on the speedo in stock form with about 40k miles on it and it only had a few mph left proving the numbers right.

Zepher

iTrader: (1)

My T/A in stock form was slow, my brothers 96 V6 Camaro would beat me easily. In the vid above, I had some mods on the car, cam, ignition, 52mm tb, 3.42 gears, and a 5 speed. It got up to speed really quick.
When I had installed the Edelbrock parts, the car would tear up my brothers 96 Camaro.
Car weighed 3520 with me in it:
I have no time for the stock LG4 setup
Edelbrock setup: 14.94 @ 91.67mph, 2.1 60' time
TPI Seup: 14.1 @ 99mph 2.3 60' time.

rx7speed

not all spilers increase drag

some small spoilers ( ie like the one I have) can reduce drag and reduce lift as well

rx7speed

sorry bud have you beat there

cd drag for for firebird is around .30-.32
for the rx7 with sport package it is around .28

also the rx7 I'm sure has less frontal area then the firebird

samdog1232000

I think MORELy said that my car has a govenor because it came out of the factory with non speed rated tires from the factory??? Can someone or MORELY further explain that!!!!!!!!

zippy

hence the major production. an rx7 in the 80's was however a production car, but hardly major production. 80's rx7's are about as popular as prowlers. i'm sure there were a couple others in the era that had lower drag if i look into it, but not any volume sold cars. as for spoilers, anytime you put something on a car able to catch wind, it increases drag.

Redarrow1

Yeah, if that vette ran out of guts at 130, it had some serious issues. I'm old enough to remember when the c4 first came out with the tpi, everyone was touting it as Americas 150+mph supercar. The slightly modified LG4 from above, I just don't see hitting 157. Especially not with 3.23 gears. I don't even think the tpi's from that era were good for much more than 140. I don't even think my LT1 formula with 3.73s would hit 157. Maybe down hill with a good tail wind, it might, but I still doubt it.

I will edit, and say that Zephyr has been here forever, and I've never known him to B.S.

SLP IROC-Z

iTrader: (1)

my 89 iroc came with out speed rated tiers and on jack stands it ran up 5th gear way up there and it didnt cut out. on the highway in 4th gear with 3.08 gears and 25.6" tall tires(5spd tranny) i can go from 70 to 125 pretty quickly, never tryed to pull fifth to fast for me. it hits 125 quickly enough that its not to dangerous, better then barreling for miles down the higway tryin to hit 130. takes me under 10 seconds to go from 70 to 125.

5000Revs, 1:1 ratio, 3.08:1 gear ratio, 25.6" tires=124mph, speedo said 110-115(its ****ed) at low speeds my speedo reads to fast at high speeds it reads to slow, at 55 its perfect, lol

Zepher

iTrader: (1)

The Vette probably could have gone faster, but at 130 I started to pull away and he shut down. This was a race from a stand still for about 1/2 mle on a non-completed toll road. That was one of my best races. He wouldn't race me again after that since he had a 350 and I had a 305.

My brothers 96 T/A with 4.10 gears will peg the speedo with no problems. I can't remember if it hits that speed at the top of 5th or in the bottom of 6th.