How Fast Can A Squarebody Go?

[77 K20]

What generation S4? I’ve owned a urS4 and B5 S4. I wish I still had the urS4. One of about 3000 S4s imported in 93. It was a silver 20vt manual gearbox with factory black recaros and carbon fiber trim. Had some neat options for a 1993. All four seats had 6 setting heaters, a push button locker, projector headlights and fog lights as well as some other advanced features for it’s era. It was very smooth well into triple digits. It had various parts and a tune from 2Bennett Audimotive in Davis, Ca.

Not as quick as some other cars I’ve owned, but my favorite I think.

It was a B5 S4. My boss's boss had a 1993 S4 before I got mine. The company gave it to him to entice him into working there. About 5 years later I had a 1993 90CSQ sport. I liked my 90 but it wasn't fast. The electric locker was neat for winter time living on a ski resort.
The urS4 had a lot of options- that is for sure. I believe it was one of the first vehicles to have those "white face gauges" that everyone later copied.

 

[Frankenchevy]

It was a B5 S4. My boss's boss had a 1993 S4 before I got mine. The company gave it to him to entice him into working there. About 5 years later I had a 1993 90Q sport. I liked my 90 but it wasn't fast. The electric locker was neat for winter time living on a ski resort.
The urS4 had a lot of options- that is for sure. I believe it was one of the first vehicles to have those "white face gauges" that everyone later copied.

The gauges were nice. Looked dark with amber markings at night.

I had a pearl white 1990 Audi 90 20v I5 with a five speed. Had it less than a year. Had narrow, studded snow tires on it. Fun snow car. That 20v sounds good.

 

[80BrownK10]

I know but it was the first thing I found. I did 80+ with mine coming through Idaho. Not recommended.

80 is easy. I would think it would be 100 easy? I have a k10 and I know I have done 80 in it I'm sitting on 33s and have a 350/350/205

 

[80BrownK10]

Found a calculator:

https://spicerparts.com/calc/transratio/index.html

According to that my truck's theoretical top speed is 89.67 MPH. Without the overdrive I'd be down to 76.22.

Haha!! In theory maybe yea, do I really believe this...maybe in a vacuum that still allows the engine to cool.

154MPH! That's! putting in my rear end ratio. Calling my 33" tires only actual 32" and assuming a max rpm of 5000rpm. At 4000 rpm it says 124mph. I have no idea what the max rpm of a stock 350 is though and where you actually quit making hp on one either.

I say no way. And if it did get up to that speed I sure wouldn't want to be driving it or anything else for that reason that fast!!

 

[bucket]

My '78 454 Suburban does 100+ rather easily. That's stock with headers. In my younger days I would have run it for all it was worth. Not these days though.

 

[Turbo4whl]

Back in the early 1980's I was a lot younger, and maybe just a little wild I pushed my '82 lowrider. Turbocharged mouse, TH350C and yes, 2.56:1 rear axle.

Someone at work said, "Wow, how fast were you going when you passed me? My reply was 3 seconds. Of course they said "What?" I said, when I took my foot off the throttle, that is how long it took for the needle to come off the pin. (0-85 speedometer)

Later when I replaced the 0-85 with a earlier 0-100 speedo I could pin that too. I will tell you, the truck was definitely very squirrelly at speed.

You must be registered for see images attach

 

[MikeB]

Haven't tried it, but even with a mild 355 (Vortec heads, Ramjet roller cam, headers, low restriction mufflers) I'd bet good money my truck would hit 100, because it's just loping along at 75 mph with probably no more than 1/3 throttle with its 2.73 axle.

Mine is an 82, and either that year or in 81 they did make the squares a little more aerodynamic than the earlier ones for fuel mileage ratings.

With some trucks it would actually take lower gears and higher RPMs to do it, depending on engine power band. That was the case back in the day when a car in 3rd gear would go faster than in 3rd gear + OD.

 

[Vbb199]

My '78 454 Suburban does 100+ rather easily. That's stock with headers. In my younger days I would have run it for all it was worth. Not these days though.

Finally. Someone else with a burb!
They're long and don't have alot of drag because they don't have a pickup bed or anything.

 

[bucket]

Finally. Someone else with a burb!
They're long and don't have alot of drag because they don't have a pickup bed or anything.

Lol, it just goes. I've probably never topped 80 mph in any other the other trucks because I've never felt like they "wanted" to go faster. Except the stepside truck, I've had it real fast a time or two, but the speedo only registers to 85 mph.

 

[Vbb199]

Lol, it just goes. I've probably never topped 80 mph in any other the other trucks because I've never felt like they "wanted" to go faster. Except the stepside truck, I've had it real fast a time or two, but the speedo only registers to 85 mph.

My thoughts.
High speeds in a short wheelbase pickup Truck really are scary.

And as I said before, the 90 burb getting up there around 120 was sketchy because it felt like I had 3 tons of gravel in the back... Steering was just all loosey goosey

 

[Vbb199]

An addendum to the previous message=

Reasons I love burbs...

Long wheel base

They go really fast and scare your friends and wife to death

Fairly more "aerodynamic" than the other squares

You can whip it hard and stomp the pedal and get her sideways and make people **** their pants that are watching or coming from oncoming traffic

You can haul a crew of 8 (or 9 with a front bench)

You can fit your drunk buddies moped in the back (ask me how I know)

Add fuel injection and overdrive - you've just made yourself a truck that'll drive a crew of 8 + their luggage cross country

 

[82sbshortbed]

Had my SS a little over 100 and it still wanted more but, I didn't. This was when I first got it and it needed new tires and balanced because it started to shake and that's when I had enough. Now that it has all new rubber and tuned I bet the bitch will go faster and not shake so dam much. I might have to run her up there again and see. Lol

Went 110 in the 15 v6 camaro and it handled really well for that fast. Could've gone faster but, wasn't feeling ballsey enough that day.

Have to see on the square when I get plates and tags on it.

 

[Vbb199]

Had my SS a little over 100 and it still wanted more but, I didn't. This was when I first got it and it needed new tires and balanced because it started to shake and that's when I had enough. Now that it has all new rubber and tuned I bet the bitch will go faster and not shake so dam much. I might have to run her up there again and see. Lol

Went 110 in the 15 v6 camaro and it handled really well for that fast. Could've gone faster but, wasn't feeling ballsey enough that day.

Have to see on the square when I get plates and tags on it.

The seat belts you lack to get it all legal aren't needed if you crash at over 100 mph.....
Just saying....
Post a video!!!!

 

[Itali83]

Seems I'm one of the few on this forum that owns a 87-91 2wd burb that runs right and Is daily driven

I run my 87 6.2 2 wheel drive burban daily. I’ve had that truck up to 80 and it really felt solid and wasn’t hard to do. That truck is very tight and well maintained.

back in high school I had The speedo in my 87 Jimmy 4x4 Back around to 15mph so whatever that was. I just remember the steering wheel had no resistance against it and it literally felt like the truck lifted a couple inches just about ready for takeoff lol. Don’t recommend that to anyone. Young and dumb.

I run my trucks around 75-80 on the highway Regularly no problems.

Ben

 

[Blue Ox]

Haha!! In theory maybe yea, do I really believe this...maybe in a vacuum that still allows the engine to cool.

154MPH! That's! putting in my rear end ratio. Calling my 33" tires only actual 32" and assuming a max rpm of 5000rpm. At 4000 rpm it says 124mph. I have no idea what the max rpm of a stock 350 is though and where you actually quit making hp on one either.

I say no way. And if it did get up to that speed I sure wouldn't want to be driving it or anything else for that reason that fast!!

In theory... you did see my signature, right?

That's just the math for what the powertrain numbers are capable of. Obviously aerodynamics are going to get you long before you get there. I'm trying to find a drag coefficient for these trucks. There is a formula for power required based on frontal area and drag. I'll warn you now, it's not pretty. Drag increases at the square of speed so horsepower requirements are exponential. IOW there comes a point where you need to double you horsepower to get one more MPH.

That's why I was questioning how fast a stock truck could actually go. Most of the engines of that era didn't really produce that much HP, so the parachute aerodynamics would become a limiting factor.

***edit: The engine power curves are available in the GM Heritage Center documents. If we get to aerodynamic engineering we can look that up.