Top speed? (1 Viewer)

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Very dumb question, but just looking at all my options on the way to go. I have a 74 fj-40 with 3 speed and am doing the v8 swap. I wanted to know what kind of top speed you can "safely" get with this combination. I was going to do the 700r4 deal, but money is tight and wanted to know if you can get by with a v8 and 36-38s and keep up with traffic without red lining the crap out of it. If anybody has any thoughts on this set-up it would really help out. ???
 
Regardless of engine/tranny setup you really do not want to do any more than 65-70 in a 40. Waay too dangerous. That said, you should easily exceed that with a v8 and 38's, but not safely. With those size tires I wouldn't worry about having an O/D.
With 31's and a stock F i could go faster than I should in rig the size of a 40.
With stock diff ratios, a 1:1 first gear and 38's you'll be doing 82mph at 3000 rpm.
 
1st question, are your diffs stock geared? If so, then the V8 will move those big tires pretty well, but not great on the road. 35's make a huge difference in how the rigs run on the road when compared to 33's. I run an H41 tranny, and I used to love 2nd gear starts with 33's. With 35's I have to slip the clutch a lot more. I can cruise all day long at 75 mph, (an indicated 60 on the speedo) and not have the engine anywhere near running out of power. Truth be told, I don't even want to go faster in a 40 than that! ::) Just too twitchy for my taste.
I know a few guys who have 4.88's and they swear by them for turning big rubber. (mostly 36's and up...) I guess it just comes down to what you are willing to compromise on. I'll tell you this, if you don't get a low range boost (like an Orion or Marlin) you will hate those huge tires off-road :slap:....Maybe an SM420 or 465 would be a better choice for you??
 
38.5 tires, 4.11 diffs, 350 TBI. Does just fine on the highway, 70 is not a problem, under 3000 rpm. Mine handles like a dream at 70, but I would never try corners and I drive VERY defensively at those speeds.

You will hate the 3-speed in town, I hate my SM465 (3-speed + granny) but on the trails it rocks.

Now, for the real test, roll it over twice on a trail ride and see how it handles on the 10 miles drive back to camp :flipoff2: (BTW, mine suffered no ill effects!)

Hate to say it, but if you are adapting a 350 to the stock 3-speed, you better be getting the adapter for nearly free...
 
Yea I know,
I'm finishing my degree in MD and am moving back to AZ in December. Then when the cabbage is flowing I will be doing 1 tons, TPI, and 700r4. I've done S/O, have an aluminum tub and other odds and ends, but I'm broke as hell. I have waaaayyyyyy to many vehicles (Have a bad addiction) and my newest ride(50 Buick) used up all of my toy money. I'm just trying to make it more road reliable, I have no problems out in the woods and am usually pulling everyone else out of the mud. I just want to have a higher reving motor at this point and some power steering.
Just trying to get by with what I have at this point...... ;)
 
I am sure you can go fast as hell. With the drum brake ft end I wonder how well you will stop?
 
I fear Diablo623 is shooting for the Darwin awards :flipoff2: :flipoff2:

Butch
 
My personal favorite is the Polish wood cutters.
 
All Right, Share! I don't remember hearing that one, Dave.
 
Yea,
I guess stopping would be a problem if I had a drum brake front end, but I don't. This would be classified under "odds and ends".
 
With stock gears you can go plenty fast. I think that 4.10s and 35 are a good balance on the road & trail if you have a good tranny.

I have 4.88s and 37's, and its great on the trail, but I have to run some pretty high RPMs on the freeway (I am not holding 70MPH), and my gas mileage drops like crazy - especially if I don't air up on the way home!

Jim
 
[quote author=Diablo623 link=board=1;threadid=7086;start=msg59213#msg59213 date=1068047812]
Yea,
I guess stopping would be a problem if I had a drum brake front end, but I don't. This would be classified under "odds and ends".
[/quote]
We can't all read minds.
A couple 85 MPH stops and you'd be through some pads and rotors pretty fast up front, I'd probably go for 4 wheel disks with that kinda rubber.
 
IMO, stock front discs and rear drums are plenty, if properly adjusted. And also IMO, 85 is silly in a FJ40, tho 70 is realistic. I HAVE done over 100 with 4wheel drums and 31" tires (way over-modded 350) and it was workable...but a straight road too :D

Cruisers aren't exactly sports cars regardless of what you do, so added driving caution is always advised....I know my brakes died on mine once and I learned the hard way it could take a corner at 30....uugh
 
[quote author=woody link=board=1;threadid=7086;start=msg59447#msg59447 date=1068078261]
...I know my brakes died on mine once and I learned the hard way it could take a corner... [/quote]
WEEEEEEEHHHAAAAAAAAA!!! :eek: :eek:
 
bless that low center of gravity.
 

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