Rev Limiter Setting

Discussion in '80-Series Tech' started by turbocruiser, Feb 8, 2004.

  1. turbocruiser

    turbocruiser SILVER Star

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    Hi folks, can someone share what the rev limiter setting is for a 97 LC? Also, is there any mode of operation ( 4WD Low Range, leaving the transmission in low, using engine braking ) where the rev limiter is bypassed? I ran a high speed snow run today in two foot deep snow for about forty miles and saw my tach go up above 4500 at least four times. The tach never went into the red but I always slowed the throttle before red anyway. I was just wondering if there is a rev limiter and what the rev limiter setting is. Also, as a sidebar, is the FZFE engine comfortable with higher rpms? Thanks as always.
     
  2. cruiserdan

    cruiserdan SupportingVendor Emeritus Moderator Supporting Vendor

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    I am not aware of a factory rev limiter on a 1FZ engine. Redline is 5200 and I have seen it a couple times inadvertently :whoops:. I was in 1st coming out of a parking lot and hopped on the throttle, pretty soon the needle was right up there :eek:.
    At WOT the transmission shifts around 4900 or so. I don't think it's a good idea to spin it that fast for prolonged periods. IIRC peak torque output is 3,200rpm and peak HP is 4,600rpm.
     
  3. landtoy80

    landtoy80

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    You can get a ignition box like MSD that have rev limiters.
     
  4. bjowett

    bjowett Supporting Vendor

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    No worries about pushing the inline 6 past 5k rpm.... the engine could easily handle 7k rpm if the breathing (cams etc) was set up for it. 7 main bearings, oversquare design, dohc 24V, sweeeeeet! I'll quote from a book I have...

    "This engine is a near-perfect design from a vibration and stress perspective because all forces are balanced." from - How to Build & Modify Pistons, Rods & Crankshafts
     
  5. xl715

    xl715

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    I can't remember ever hitting the limiter in my 94, however I have taged the limitter in every gear in my 93 toy pick-up. One would think if they incorporate a rev limiter in a cheap 4cylinder pick-up, there should be one in thier flagship model the landcruiser. If it was a stick I would have by now hit the limiter a few times!! Oh, my celica has a rev limiter also:}
     
  6. turbocruiser

    turbocruiser SILVER Star

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    I always assumed that the 80 series had a rev limiter. I think I read once that it has one for top speed but I also assumed the same limiter would have some setting for top rpm's too. Come to think through it, I am almost sure it has a limiter because if you try to downshift the auto tranny into too low a gear, the tranny wont do it until the vehicle speed is such that the engine will not over-rev by being in too low a gear. I guess that is another question: if there is a limiter, is it set from the tranny for things like top speed and gearing down or is it set from the engine for top rpm's or does it do both??? Thanks.
     
  7. SeanAndHis80

    SeanAndHis80

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    >I am almost sure it has a limiter because if you try to downshift the auto tranny into too low a gear, the tranny wont do it until the vehicle speed is such that the engine will not over-rev by being in too low a gear.

    Technically that is not a rev limiter. It is simply computer controlled transmission shifting. All the rev limiters I have seen cut the ignition out when the limit is reached. My Yamaha has a 13,500RPM rev limiter on it. Many have grenaded their engines by down-shifting when too close to the rev limiter. Valves float to meet the piston - Uugh does it get ugly quick! Broken cases and everything.

    Someone once implied that the 1FZ is a non-interferance engine. If so, there probably is no rev limiter as there is less chance of trouble at high RPMs.
     
  8. floatinghat

    floatinghat

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    Valves meeting pistons is not a pretty sound. I lost a cam chain tensioner in a 911 years ago. I was going up "snake hill" to my in laws. I hit about 6500 rpm in 2nd and all hell broke loose. Not a nice feeling or sound.

    andre
     
  9. cary

    cary SILVER Star

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    I think that somebody needs to go out and hold their truck in first to see if there is a rev limiter and where it cuts in. :D :D :D

    I know that on my old BMW (1982) that the rev limiter was valve float. Once when the throttle pedal broke, I saw 8000 on the tach before I got the engine killed. Have to love overbuilt motors.
     
  10. tenncrusher

    tenncrusher

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    Sean, that is why the motor in a Ducati is so wonderful.
     
  11. turbocruiser

    turbocruiser SILVER Star

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    [quote author=SeanAndHis80 link=board=2;threadid=11225;start=msg101878#msg101878 date=1076338410]

    Technically that is not a rev limiter. It is simply computer controlled transmission shifting. All the rev limiters I have seen cut the ignition out when the limit is reached. [/quote]

    Okay, maybe I am wrong about what this is called if a rev limiter actually cuts out the ignition but there must be mechanisms either in the tranny or in the computer that prevent the engine from over-revving...right!?! I found out fast that with all the lockers locked and low range selected, you can reach over 4500 rpms like nothing and when you are picking your line in between granite rocks, slipping and sliding all through thick snow, and trying to keep the momentum up, there is a real danger of over-revving cause you cant keep your peepers peeping on everything all at the same time! If the only way to get some protection from this is with the MSD ignition, what do you all think of this product compared to the stock setup? As always, thanks for the advice.

    Ohh, and I almost forgot, :beer: for all !!!
     
  12. IdahoDoug

    IdahoDoug

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    This rev limiter stuff reminded me of a good story. Years ago, I was a product planner for GM. When we got done with competitive vehicles, they couldn't be sold for liability reasons, and many were flown over from other countries. One day, I learned the Porsche 944T was heading to the crusher so I volunteered to drive it. Took it out on the highway and simply tromped it in 1st gear until it began rythmically bouncing off the rev limiter to see if it would let go. The answer? No. After about 5 minutes of this unholy chorus (to those of us who "feel" mechanical pain), the water temp climbed a bit, the oil pressure dropped a bit and it stabilized like that for another 15-20 minutes. Seemed like it would continue for quite some time without letting go. Of course, I'm sure the valves and pistons were getting damaged, but no outward sign of duress. Later that week, it was a 4 foot cube....

    And no, don't ask me what became of a German spec M6 coupe with factory buffalo hide upholstery, a factory rear seat cooler, and a whole bunch o' German spec power. (boo hoo)

    DougM
     
  13. SeanAndHis80

    SeanAndHis80

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    All said, the "redline" is very low on these. 4500 RPM really is not that fast - and I would guess that it is that way because the engine is tuned for low RPM power. I would guess it simply "runs out of steam" rather than gets to the danger point of the valves floating.

    I think we would have seen more blown 1FZs if there was a practical danger of overrevving them. JMO, others will probably know much more than me.
     
  14. turbocruiser

    turbocruiser SILVER Star

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    [quote author=SeanAndHis80 link=board=2;threadid=11225;start=msg102266#msg102266 date=1076380396]
    All said, the "redline" is very low on these. 4500 RPM really is not that fast - and I would guess that it is that way because the engine is tuned for low RPM power. I would guess it simply "runs out of steam" rather than gets to the danger point of the valves floating.

    I think we would have seen more blown 1FZs if there was a practical danger of overrevving them. JMO, others will probably know much more than me.
    [/quote]

    Good point! Thanks.
     
  15. 97 FZJ80

    97 FZJ80

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    Redline on the tach is 5000 RPM but the rev limiter is set on my truck to 5400 RPM. Unlike some other engine control system that allows the RPM to bounce off the rev limiter (i.e. engine cutoff at 5400 RPM and turned back on at 4800 RPM), the LC rev limiter caps the RPM at 5400 and keeps it there. This is a great feature as I have experience the engine cutoff during a low gear passing manuever in another car. To run out of RPM before shifting while overtaking is not a fun experience.

    John
     
  16. Beowulf

    Beowulf

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    John,
    Is the 5400 RPM number from a test you did or from the FSM or some other source? Do you know if all North American 1FZ-FE's have the same rev limiter or did this come in to play during a model year?

    -B-
     
  17. 97 FZJ80

    97 FZJ80

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    It's from my live test - low range in 1st. I was pleasantly surprised at the 400RPM past redline and the RPM limiting capability. It could vary between vehicles and it's always a good idea to know where the RPM limitor of the engine.
     
  18. turbocruiser

    turbocruiser SILVER Star

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    [quote author=97 FZJ80 link=board=2;threadid=11225;start=msg102933#msg102933 date=1076465760]
    It's from my live test - low range in 1st. I was pleasantly surprised at the 400RPM past redline and the RPM limiting capability. It could vary between vehicles and it's always a good idea to know where the RPM limitor of the engine.
    [/quote]

    Wow! Thanks for the act of courage! Its great to know that the cruiser takes the safety of the engine seriously! Man that took some guts to let the needle go higher and higher!!! Just to clarify, you have in your cruiser an auto tranny right? Dont know if I read the 'low range in 1st' right? Again, thanks.
     
  19. 97 FZJ80

    97 FZJ80

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    Yep, it's a A343 auto trans locked in first gear and the transfer case set in low range. I guess I'm used to bouncing off the rev limiter in my other car and don't think much of doing the same with the cruiser.

    The FZ-FE is a DOHC engine that can tolerate much higher RPMs than the redline. It's interesting to note that on the UZJ V8 engine, Toyota also set the redline at 5K RPM (or is that 5.5k?) when the engine was originally designed to tolerate much higher rev.

    I wonder if the diesel has a rev limiter?


    John
     

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