0-60, seconds or minutes?

[Terrapin]

So I'm about to drop 2 grand on my first diesel, an '83 Blazer. I'm a virgin, never having even been in a light utility diesel, and I only know what I've learned here after lurking for a week.

It looks good, doesn't smoke, shifts easy, has meticulous records, but oh my god is it slow to get to speed. I'm used to my Harley Davidson Dyna and Nissan Xterra, and while they're not speed demons, at least they get to freeway speed before I reach my destination. Actually the HD is all the speed I need.

I'm not buying it to break the sound barrier, but I at least would like to be able to drive it on the freeway at a decent clip. In a 20-30 mph headwind, I could barely get above 60. Its lifted 6-8 inches with biggass tires bigger than than the wheel wells. Downwind it would easily do 70+. Eventually. Is this typical? Will it make it up a grade?

If you've made it this far, thanks for your interest and attention. If you post with sage advice, my eternal gratitude is yours. If you flame me for asking a stupid question, then I hope I learn my lesson.

Regards and thanks for being here,

Alan Prichard

[gvig]

Had a 84 Burb once, 6.2, ran nice but was not impressive. Took the IP down to a local shop with a good rep. Told the tech that I wanted power. He asked if I wanted economy too, I said "No, just power."

Two days later I came back and got the IP, installed it. Leaned it a bit to the drivers side.

Found some N/A 6.5 exhaust manifolds (don't have the cast in restrictor ring) and installed them. At the same time I took the Burb to a local muffler shop, told them I wanted a dual 3 inch exhaust with twin Magnaflow mufflers, 3 in and 3 out.

End result, impressive power and speed (for a 6.2) and way too much noise. Spent some time getting the noise modulated (finally installed a crossover behind the transmission). Nice sounding Burb, and loads of speed and power for a vintage vehicle that size.

Sold it to a friend after replacing the 6.2 with a N/A 6.5 and now with 4.10s it gets just over 20 mpg at 65/70. Same IP.

The economy was a nice benefit too.

Good luck.

George

[moondoggie]

Good Day!

I have an 82 (see signature), 3.08 gears, 4SPD manual (4th is OD). Acceleration can only be described as "discernable." Dr. Lee's 84 shortbox goes 0 - 60 in < 10 seconds. Do some searching & find out what he did, some of which involves a basically blueprinted 6.2, but some of which is easily/cheaply duplicated.

"Its lifted 6-8 inches with biggass tires bigger than than the wheel wells." Did you buy it for fuel economy? If so, get this stuff back to stock, I'll bet it would make a HUGE difference.

"If you flame me for asking a stupid question, then I hope I learn my lesson." I think you'll find that almost none of that goes on here. There are other Places where things aren't so, shall we say, civilized, which is why the Page is home for me (& others, I think). ;) To each his own, I guess.

Blessings!

[arveetek]

Its lifted 6-8 inches with biggass tires bigger than than the wheel wells. Downwind it would easily do 70+. Eventually.

Alan Prichard

You need to find out what the gear ratios in the axles are. If it has the stock gear ratios with the lift kit and big tires, that could be 90% of your problem. When installing larger tires, you have to compensate by changing the gear ratios as well, otherwise the engine is lugging way too much.

Casey

[moondoggie]

Good Day!

What arveetek said, but additionally keep in mind: oversize tires (assuming wider than stock) almost certainly decrease mpg at least a little; a lifted truck almost certainly has increased aerodynamic drag. So, getting the gearing right with what you've got will for sure help; IMHO going back to stock height & tire size will help more, with the gears you have (unless someone already changed the gears).

Let us know - it adds to our database.

Blessings!
(signature in previous post)

[Terrapin]

I found the 6.2L Diesel Volume I in my mailbox last night, and I'm eager to put it to use. My first project though is to get rid of the huge tires and lift blocks. These are great replies and much appreciated.

Thank You!

[AJMBLAZER]

Any update on this?

I'm with arveetek...I'm betting it has the typical 3.08 gears or so that were truthfully kinda high geared for the 29-31" stock tires. GM's search for gas mileage in the '80's...:rolleyes:

My CUCV has 36" tires, a TH400, and 4.56 gears and goes pretty good on take off but is top speed limited (voluntarily by me) to about 65mph. Sounds like you need a deeper gear.

[Terrapin]

Well after driving it around for a while and getting used to it, I now think I was a little harsh initially. The tires are 35 x 12.5 x 15's. The gear ratio is 4.10/1. The trans is the auto w/overdrive (TH400?). I eventually realized that the speedo is showing my speed for stock tires, and that when it reads 60 I'm doing 67.5.

After doing some investigating I have come to the conclusion that removing the body lift, rear blocks, and replacing the front leaves to get it back to stock is not worth it. This beast is actually starting to grow on me and I have to admit I'm starting to really dig it. Maybe I'll just go to 33's when it's time for new rubber.

Here's what I really need to worry about though: Twice on the freeway I had to jam on the brakes at 70 or so. The first time was going straight and it dove to the right and I could barely keep it in the lane. The second time was in a sweeping curve and it swayed back and forth severely. For now I'm making sure I keep the speed under 70 and lots of breathing room up front. It has the stock sway bar and quad-shock up front. I'm going to look into an anti-sway bar for the rear, if such a thing exists. Any suggestions?

Now if I can just find some place to go wheelin' in the Santa Barbara area and see if I can't have some fun with this Blazer.

Thanks again to those who posted with info.

[AJMBLAZER]

I'd check out all of the steering gear and make sure it's in proper working order. Also check to see if the frame has cracked around the steering box. These trucks are infamous for doing that. Also make sure when it was lifted they put some kind of a proper steering correction on for that.

I wouldn't go smaller on tires. Right now you're geared about perfect for the 35's and no-OD. Going to a smaller tire size would make the thing have to rev even more at speed.


www.ColoradoK5.com . Everything you EVER wanted to know about these trucks.

[Terrapin]

Hey AJMBlazer,

Thanks for the advice. I don't really know what to look for as far as the steering gear, but here's what I observed: bolts are tight, nothing seems to be damaged. As far as I can tell the steering is stock, and there is a noticeable angle at the top of the shaft that runs from outside the firewall to the steering box.

I meant to say that I have auto trans WITH overdrive. I have noticed that a 4/56 ratio is best for 4/10 gearing and OD trans, but that 4/10 is OK for mostly highway driving. I have also been lurking at CK5 but haven't subscibed yet. It just occured to me that the direction I'm going with this thread belongs over there, so over there I will take it.

Sorry for getting away from the purpose of this forum moderators, I 'll try and do better. FWIW, I picked up all three 6.2 books and am learning so much from them that I haven't had to post question on the motor!

[AJMBLAZER]

Ah, gotcha. I'd definately say CK5 is better for tech for those trucks overall but when you want 6.2L advice this is the place to be.

See you there.:cool:

[Frank M. Hardcastle II]

I was really enjoying your thread. I've got it in my mind that the best rock crawler would be diesel. 6.2 Banks to be specific. My 4X4 friends think I'm nuts but if you have any knowledge of why I shouldn't go with diesel for a rock buggy please let me know. I'm new to 6.2, this forum and 4 wheelin. Don't have a 4X4 yet but have been thinking about an old beat up 1 Ton 4X4 6.2. Who cares what it looks like I'll jerk off the bed, hood, fenders and doors anyway.
Thanks,
Frank

[AJMBLAZER]

You've pretty much just described a truggy. (Truck/buggy)

Once again, www.coloradoK5.com .:cool:

[moondoggie]

Good Day!

[I][COLOR=black][FONT=Verdana][COLOR=blue]

[DmaxMaverick]

And.....(Moondoggie covered it pretty well)....

Depending on how the lift was done, you could be experiencing monster bump-steer. With this, the wheels will "turn" as the front suspension is compressed/released. Bumpy or rolling hump corners will be a real bear with this. To prevent this, the steering linkage components have to be matched to the lift type and amount, primarily the pitman arm. If it has the OEM pitman arm, and more than about 2" of lift, well....There's your problem.

[Terrapin]

Frank: I'm almost as new to 4x4 and diesel as you so I have lots to learn too.

Moondoggie: great stuff there, thanks. BTW, I checked my speed against a GPS and it backed up the numbers I posted.

I'm going to check my rear brakes tonight. Meanwhile I've posted a little conversion chart on my gauges so I know my true speed and I also keep my speed in check and lots of buffer space up front. Unfortunately, here in SoCal that's like opening a new lane on the highway, and there are lots of numbnuts eager to jump in there.

[moondoggie]

Good Day!

Duh, once again, not really paying as much attention as I should have. What the heck, this is a hobby, right? :rolleyes:

What I should have said is that your odometer vary by the factors I used, & probably pretty closely. Either that, or someone changed the speedo gear. The speedo itself can be significantly off. My 95's have spoiled me - I'm used to speedos that are VERY accurate - the older stuff was never this good. ;)


Blessings!
(signature in previous post)

[Terrapin]

The pads are 1/8" at their thinnest,so I'll put a brake job on the to do list, but I'm starting to like that bump steer theory along with the short wheel base/lifted combination as to high speed instability. So lower speed and greater caution are the rules for me to live by. When I feel the need for speed I'll rely on the Harley Davidson, it's my DD anyway.

I still think that the front brakes are doing more than their share of the stopping work, since after I washed the truck there was a very noticable layer of brake dust on the front rims after less than a tank of gas. I would like to do the rear disc brake conversion eventually, I just need to build up my mechanical and welding skills a little first.

Thanks again for all the valuable input. I hope I can reciprocate someday.

[Terrapin]

The proportioning valve is stuck in front brake only mode. I finally got around to checking brake fluid level (I know, it should have been the first place to go) and the rear reservoir was bone dry. The Brake light has been on since I bought this truck and I mistakenly thought it was a bad switch at the e-brake.

The front rims were coated with brake dust when I bought the truck, and when I washed it there was a very noticable layer after just a few hundred miles.

No back brakes would sure explain the squirrelly behaviour. Unfortunately I can't get the prop. valve to reset. It looks like a trip to the repair shop is next.