Idle, Gearing, and Speed. Thoughts?
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Idle, Gearing, and Speed. Thoughts?
Ok, so I'm new to the 3.4. Just bought myself a 2000 taco, 3.4 r150f xtracab 4.10 gears, picked it up from a friend for $6.5k. Anyhow, I've been discussing my road speed issue over on the 86-96 forum for a while in my rollover thread, and figured I'd move it over here where it belongs to keep my other thread on topic.
So, here's the main beef (pretty much copied from various posts from my other thread):
As for how I like the 3.4 with the r150f compared to the 22r and 22re's I've owned... Well, honestly it feels like just the tiniest bit more powerful (able to hold hwy speed decently), but other than that, no different.
The thing that has me thrown for a loop is that at 70mph, the rpm sits at 4k... Wondering if that's normal, or just the fact that I have the 4.10s with 31s. Dunno what, but I need to look into that. Been getting about 250ish miles to the tank (15gals), mostly highway, which is about 16-17mpg, so that's kind of blah. Especially since these were rated at 22mpg hwy and mines pretty much stock on 31s...
I figured the the rpms were a little high. According to my calculations, with a 5th gear ratio of 0.84, tcase with 1:1 high range, 4.10 gears, and 31" tires, my road speeds and rpms should be something more like this:
2000rpm - 54mph
2500rpm - 67mph
3000rpm - 80mph
3500rpm - 94mph
4000rpm - 107mph
The taco made the same speed at the same rpm steadily since I've gotten it. The clutch isn't slipping (done the clutch test). Brakes dragging wouldn't cause the rpms to be higher than normal, the truck would just seem sluggish and seem not to have as much grunt, aside from the massive heat buildup and the smell of burnt asbestos lol.
The tcase is DEFINITELY not stuck in lo range. Lmao, you'd grenade your clutch at 40mph...
And nah, even if the truck was geared higher, lets say with 5.71s for the sake of argument, my 5th gear roadspeeds and rpms would still only be around this area:
2000rpm - 38mph
2500rpm - 48mph
3000rpm - 58mph
3500rpm - 67mph
4000rpm - 77mph
So basically, even with 5.71s, at 70mph my engine would only be at 3639rpm, NOT the 4000rpm it is currently. For me to hit 70mph at 4000rpm, with 31s, stock tcase gearing in high range of 1:1, and a stock r150f tranny with a 5th gear of 0.84, I would have to be running 6.28s in the diffs. Which, I can tell you is quite impossible. There are no such things (as far as I know) 6.28s for toyota axles.
No, I'm kind of thinking that my tach is off...
And you know what... I dunno what these 3.4's are supposed to idle at, but I just remembered that mine was idling at 1200rpm. I didn't think that was normal. Seems to idle smooth as velvet though, so maybe my tach IS off... Then again I come from the diesel world, where my cummins idled at 500rpm, and none of my other toyoters ever had a tach, so I never paid it any mind. Thoughts?
So, here's the main beef (pretty much copied from various posts from my other thread):
As for how I like the 3.4 with the r150f compared to the 22r and 22re's I've owned... Well, honestly it feels like just the tiniest bit more powerful (able to hold hwy speed decently), but other than that, no different.
The thing that has me thrown for a loop is that at 70mph, the rpm sits at 4k... Wondering if that's normal, or just the fact that I have the 4.10s with 31s. Dunno what, but I need to look into that. Been getting about 250ish miles to the tank (15gals), mostly highway, which is about 16-17mpg, so that's kind of blah. Especially since these were rated at 22mpg hwy and mines pretty much stock on 31s...
I figured the the rpms were a little high. According to my calculations, with a 5th gear ratio of 0.84, tcase with 1:1 high range, 4.10 gears, and 31" tires, my road speeds and rpms should be something more like this:
2000rpm - 54mph
2500rpm - 67mph
3000rpm - 80mph
3500rpm - 94mph
4000rpm - 107mph
The taco made the same speed at the same rpm steadily since I've gotten it. The clutch isn't slipping (done the clutch test). Brakes dragging wouldn't cause the rpms to be higher than normal, the truck would just seem sluggish and seem not to have as much grunt, aside from the massive heat buildup and the smell of burnt asbestos lol.
The tcase is DEFINITELY not stuck in lo range. Lmao, you'd grenade your clutch at 40mph...
And nah, even if the truck was geared higher, lets say with 5.71s for the sake of argument, my 5th gear roadspeeds and rpms would still only be around this area:
2000rpm - 38mph
2500rpm - 48mph
3000rpm - 58mph
3500rpm - 67mph
4000rpm - 77mph
So basically, even with 5.71s, at 70mph my engine would only be at 3639rpm, NOT the 4000rpm it is currently. For me to hit 70mph at 4000rpm, with 31s, stock tcase gearing in high range of 1:1, and a stock r150f tranny with a 5th gear of 0.84, I would have to be running 6.28s in the diffs. Which, I can tell you is quite impossible. There are no such things (as far as I know) 6.28s for toyota axles.
No, I'm kind of thinking that my tach is off...
And you know what... I dunno what these 3.4's are supposed to idle at, but I just remembered that mine was idling at 1200rpm. I didn't think that was normal. Seems to idle smooth as velvet though, so maybe my tach IS off... Then again I come from the diesel world, where my cummins idled at 500rpm, and none of my other toyoters ever had a tach, so I never paid it any mind. Thoughts?
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