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Discussion Starter · #1 · (Edited)
I've noticed strange rev limiter behaviour at 1st gear on my 2000 gt-s (actually, it's JDM SS-II).
I were racing from stop. Car was warmed up well.
I've launched from ~ 3K (have light JUN flywheel). Got some wheel slipping and started to move forward. When rpms reached ~7000 car started bouncing in rev limiter. Wtf? Normal rev limiter is at ~8500. And I noticed that such thing happens only sometimes. Sometimes I can reach normal 8500 limiter on 1st gear. No such problems on other gears.

I assume that something wrong with tacho/speed meters/sensors. Looks like there are some kind of lag and ECM "think" that car is not moving. It's like flooring on not moving car.

I've talked with guy on Toyota Allex (2zz-ge, 6spd) and he had the same problem. I did some search on this forum and saw similar posts, but no solution. Everyone talking about just warming it up.

Again, car was warmed up (Oil ~98 C, Water ~ 95 C, Oil Press ~ 1.5-2 Bars at idle). My oil is 5w40 Mobil 1 full synth. Mods are: Butterly, TRD clutch (disk and cover), JUN flywheel, TRD short shifter, 1.5-way LSD (JDM SS-II have it in stock).

Any ideas/solutions?

Thanks.
 

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Doesn't sound like its fully warmed up. The car will rev past 7k with completely broken lift bolts by the way, trust me.
 

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Zettai Unmei Mokushiroku
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Pulsar1 said:
Doesn't sound like its fully warmed up. The car will rev past 7k with completely broken lift bolts by the way, trust me.
Depends on how they're broken. If they're just in two pieces, lift will still work. If they become separated, though, you might get lift randomly, and if the lower half completely falls out, no lift at all.
 

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Discussion Starter · #6 ·
Blue Bomber said:
Depends on how they're broken. If they're just in two pieces, lift will still work. If they become separated, though, you might get lift randomly, and if the lower half completely falls out, no lift at all.
Lift working ok on all gears every time and kicking pretty well. And not sure how lift bolts can affect rev limiter. And it's on 1st gear only.

Maybe ECU "think" that car is not moving yet and revs increasing too fast? It's like flooring gas pedal on not moving car. Same thing will happen (cutoff at 7krpm).

Any other ideas?
 

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Reset the ECU or make sure your engine is warmed enough. otherwise :shrugs: have you changed your lift bolts?
 

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actually contrary to what everyone is thinking here. the reason why u cant go past 7k when ur car is fully warmed and everything u said is because you cant spin the wheels past 30 mph or so. the ecu limits it because past that point you have a probability to break your axles. i had this happen to me, but this only happens when you try to launch not when you are standing still with e-brake doing a burnout.
 

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Discussion Starter · #9 · (Edited)
BuRn1nG said:
actually contrary to what everyone is thinking here. the reason why u cant go past 7k when ur car is fully warmed and everything u said is because you cant spin the wheels past 30 mph or so. the ecu limits it because past that point you have a probability to break your axles. i had this happen to me, but this only happens when you try to launch not when you are standing still with e-brake doing a burnout.

That sounds reasonable. How did you know that? Since I got new clutch (forced TRD organic disk and forced TRD cover), I'm learning how to start on it. It's catching too strong and I'm getting too much wheels slipping on 1st. Actually, I'm slipping tires during entire 1st gear. And looks like my speed is less than 48kmh (30mph). And yes, I'm doing burnout.
I will try to make some tests when it will stop raining here.

How did you solved problem? Starting from ebrake? Could you please tell more about this technique?

Thanks for your input!
 

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the way to solve the problem is launch at an appropriate rpm. if you rev too high and let the clutch drop amd floor it then u will get a bad launch and spin through the entire gear. you need to launch at about 5k rpm or a little lower (4800) and dump the the clutch OR you can rev all the way to 7k and "feather" or slip the clutch and launch with moderating the pressure on the gas pedal (this takes practice and might burn the clutch if you dont do it properly, you have to slip quickly, yet not dump it) just practice ur launch.
 

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BuRn1nG said:
actually contrary to what everyone is thinking here. the reason why u cant go past 7k when ur car is fully warmed and everything u said is because you cant spin the wheels past 30 mph or so. the ecu limits it because past that point you have a probability to break your axles. i had this happen to me, but this only happens when you try to launch not when you are standing still with e-brake doing a burnout.
What!? NO.

I don't know how you got that. Are you talking about a GT?? Because non of that is true for a GTS. The ECU doesn't limit anything so you don't break your axles. The ECU does have three revlimiters in place however. One limits the revs to 7K until the car is fully warmed up. The second limits the revs while in neutral to 7K as well. The last limits it to 8300 or 7800rpm on some years when the car is fully warmed up and in gear. Like I was saying before the car will rev past 7k even if the Lift bolts are broken and lift is not functioning at all. Theres no change over noise and no increase in power when it does.
 

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Discussion Starter · #14 ·
Pulsar1 said:
What!? NO.

I don't know how you got that. Are you talking about a GT?? Because non of that is true for a GTS. The ECU doesn't limit anything so you don't break your axles. The ECU does have three revlimiters in place however. One limits the revs to 7K until the car is fully warmed up. The second limits the revs while in neutral to 7K as well. The last limits it to 8300 or 7800rpm on some years when the car is fully warmed up and in gear. Like I was saying before the car will rev past 7k even if the Lift bolts are broken and lift is not functioning at all. Theres no change over noise and no increase in power when it does.
What is the source of your information?
 

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Pulsar1 said:
What!? NO.

I don't know how you got that. Are you talking about a GT?? Because non of that is true for a GTS. The ECU doesn't limit anything so you don't break your axles. The ECU does have three revlimiters in place however. One limits the revs to 7K until the car is fully warmed up. The second limits the revs while in neutral to 7K as well. The last limits it to 8300 or 7800rpm on some years when the car is fully warmed up and in gear. Like I was saying before the car will rev past 7k even if the Lift bolts are broken and lift is not functioning at all. Theres no change over noise and no increase in power when it does.
I am sorry but Brurn1ng is right. The reason why you hit the cutoff in first at 7k is either due to a too cold engine temp or because of too much wheel spin. I dont know how the ecu evaluates wheel spin but it is true. It has nothing to do with a broken lift bolt, dont worry. A fuel cut comes from the ecu regarding what the different sensors trigger. i doubt the ecu would trigger a broken lif bolt and set a fuel cut. the lift would just not work in that case.
I have experienced this a couple of times with the stock ecu a the strip. I then run 13s NA in the same month. So, I doubt it is related to a broken part in your engine. Just launch the car better and you'll be fine ...

I am certainly not the only drag racer who experienced this. I know 00silvergts (Mike) found the same thing.
 

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Discussion Starter · #16 · (Edited)
danGTS said:
I am sorry but Brurn1ng is right. The reason why you hit the cutoff in first at 7k is either due to a too cold engine temp or because of too much wheel spin. I dont know how the ecu evaluates wheel spin but it is true. It has nothing to do with a broken lift bolt, dont worry. A fuel cut comes from the ecu regarding what the different sensors trigger. i doubt the ecu would trigger a broken lif bolt and set a fuel cut. the lift would just not work in that case.
I have experienced this a couple of times with the stock ecu a the strip. I then run 13s NA in the same month. So, I doubt it is related to a broken part in your engine. Just launch the car better and you'll be fine ...

I am certainly not the only drag racer who experienced this. I know 00silvergts (Mike) found the same thing.
That sounds reasonable as well (at least that could be somehow explained). But how it's detecting wheel spin? As I understand, ECU receiving speed signal from sensor located in tranny. And when my wheels spinning at start, I should get good speed on speedometer as well. Maybe ABS sensors involved, the way how TRC detect wheel slipping?

Btw, I've noticed strange delay in speedometer reaction. I'm launching (at 4k rpm, for example), my wheels are spinning and just after 2 seconds I see that my spedometer started to move. Some kind of delay.

Maybe Mike (00silvergts) will tell something about this thread?

That's strange.
 

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Discussion Starter · #17 ·
Ok. I did test today and figured out that wasn't temperature issue. It's revving pretty well on a bit warmed car (I know that's not good) if I do not let weels to spin when launching.
 

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Yup, mine won't rev past 7k in first if I launch too high or burn out too long.
 
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