OK If I get flamed for this so be it but this is sorta legitimate...
Has anyone ever had their speed limiter fail on them (not kick in)?
I haven't wanted to ask this lately because of all the threads lately that we all know about....
but my car recently red lined (rev limiter kicked in) in 4th gear at somewhere just over 130mph lately (has never done that before) and I can't understand how it did it. I'm running a stock tune and nothing that could cause this has been modified.... I'd take it out and see if it would do it again.... but I don't want to be doing that crap on the street. Has anyone ever had this happen even once before when there on a strip or racetrack or is it even heard of?
I wasn't street racing....it was on a strip.... I can't emphasize that enough.... and I know I'm taking a risk even asking this with some of the people around here (people just like to assume)... but it's driving me crazy that it coulda even happened..... anyone know what coulda caused it?
Its weird, but maybe its a bad ecm? Something may be wrong causing it to not cut out when it hits a certain speed. I dont really know what else it could be. If it was a bad sensor, your gauge wouldn't work. I notice a large drop in your time. Is that with the cams installed!?
You hit a buck 30 on a drag strip?
3400 SWAP DONE. 187WHP 212TQ (NA) 240WHP 310TQ (N2O)
Ya... the drop in the time is with the cams... way more than I expected..... and that was the only run (first and only try)..... I can't wait to see what it will do with some more practice and I get my wheel hop and tranny issues fixed (2.46 60 ft which kinda sucks).... the limiter malfunction actually happened when I clocked the new time in my sig..
IDK.... maybe it was just a freak thing and won't ever happen again.... I normally just wait for the limiter to kick in and then let of the gas..... but the time in question.... I noticed I was going way faster than normal and a bit past the quarter mile mark... mmediately thought WTF.... looked down at the tach and was like WHOLLY CRAP right as my rev limiter kicked in...
I had my Gtech on at the time so out of curiosity I pulled up the acceleration / mph table and it said I hit 134mph @ about 6500rpm (or close to that... I'de have to re-check to make sure)..... to bad I don't have any data logging on the car (I need to get hptuners) then at least I'd bee able to see if anything failed.
Oh well... the car isn't going to be ran or at a strip again until I get everything that needs fixed replaced... but later this summer when everything is done.... I'll purposely keep the pedal down at the strip to see if it does it again.... It's kinda strange the the ECU could have a brain fart like that.... I didn't think it was possible. But the speedo works and the car runs great so I wouldn't think the ECU is bad.
i hate to say it, but if you're talking about a 1/4 mile drag strip, there is no way in hell you would've hit 130mph. in a relatively stock LD9, you'd be hard-pressed to break 100.
In a 1/4 mile, no. There would be no way it would happen, also gtech isnt really accurate either. However, just because the track measures 1/4 mile doesn't mean it ends at a 1/4 mile. Some tracks are on older air strips, that can be well over a mile long. I dont know if thats the case here or not. Maybe he did the run on a road in mexico, and measured with the gtech?
Edited 1 time(s). Last edited Wednesday, April 02, 2008 10:22 PM
Honestly I don't know how fast I was going for sure..... I only read to gtech in an attempt to figure out what the hell happened....
All I do know is that the car red lined in 4th gear..... wich shouldn't be possible.....
and obviously I traveled past .25 miles before it happened..... there is plenty of room to slow down guys LOL.... It only happened because I normally like to hit the limiter (just for fun) before I slow down and well..... it didn't kick in this particular time.
I knew I was going to get flamed by people saying the usual "bs you where actually doing this going down the highway" crap.... but that isn't the case..... I was conflicted on if I should post this or not..... but it was just to strange for me to not at least ask.
Quote:
I don't know if that's the case here or not. Maybe he did the run on a road in mexico, and measured with the gtech?
good one..... I should try that
common guys I'm not claiming anything ridiculous...... I was just wondering if anyone has ever had the limiter fail... could we at least try to leave it at that.
If I where doing something illegal.... I wouldn't be stupid enough to post it up here on the org.... I've been around long enough to know better.
Im not flaming you. I can see you hitting that on the track. I'm pretty sure the one we use here is way longer then a 1/4 mile. Next time, see if it happens again.
steve white wrote:Im not flaming you. I can see you hitting that on the track. I'm pretty sure the one we use here is way longer then a 1/4 mile. Next time, see if it happens again.
Thats what I'm planning on doing..... and I never thought you where actually flaming me steve..... I just know its going to happen because well.... you know the org.....
It was probably just a one in a hundred hiccup or something...... the chances of it happening again have to be slim.... although if it keeps doing it..... I wont be able to sleep until I find out why. The car only sees speeds over 80mph 2 or 3 times a year anyway but I'll make a point of letting you all know if the "problem" persists when I have a chance to open her up again.
btw... a note on the 80mph thing..... The speed limit on Interstates where I live is 70mph (most people do at least 75.... so 80 every once in awhile is normal... I've even been clocked going that fast and wasn't pulled over a couple times)
Quote:
I had my Gtech on at the time so out of curiosity I pulled up the acceleration / mph table and it said I hit 134mph @ about 6500rpm (or close to that... I'de have to re-check to make sure)..... to bad I don't have any data logging on the car (I need to get hptuners) then at least I'd bee able to see if anything failed.
Hate to say it, but Gtech's are junk. What did the speedometer say?
Secondly, at a stock rev limit I do not belive the gearing of the car will allow it to hit 130mph.
Third - The governor works the same way as your rev limiter, by stopping the fuel injector pulse. It just bases it on VSS input rather than RPM input. So if your rev limiter worked your governer should have worked
Fourth - The CEL should be on for a 'governor failure' if the governor didn't work.
The only way I could see it possible on a stock tune is if you were to have some other mod. More specifically, the F terminal on the alternator wired directly to the battery. Unfortunately, this would also not allow you to turn the car off. (i never really have understood exactly WHY that happens either). Or you'd have to have a massive injector leak.
Quote:
the limiter malfunction actually happened when I clocked the new time in my sig..
At either rate, I would trust the speed read by the tracks timing system over the speedometer and the GTECH. Why one would continue to hold on the gas after the finish line is beyond me, but to each their own. Though, it could be possible that the ECU was getting an incorrect RPM reading, and I have no idea what would cause that. Normally that would probably make the car start to run rough, but with the addition of big cams and whatever else you're using for power you could be getting pretty close to 100% injector duty cycle so it may not matter. I will say one thing your MPH is kinda high, my guess is with some better hook off the line and lowering your 60' time, that your trap speed will go down too. Along with the other benefit of a lower ET.
Ya... the Gtech is more of a toy than anything......
As for the speedo..... I didn't even look at it until I was on the brakes so I don't know.... but the tach was at where it normally is when the rev limiter kicks in....
the fact that one would work and the other wouldn't doesn't make sense either.... it actually seems so imposable that I'm wanting to second guess myself and wonder if it really happened.... but it did... so I don't have a clue.... about the only thing I can think of would be the VSS malfunctioning.... I'l make sure to watch the speedo carefully for a few days and see if it hesitates or something.
Oh well.... not like it matters or anything I guess..... I just thought it was really strange.... I'm curious if anyone else has ever had this happen... but I doubt it... It's probably just the gremlins again... for some reason I tend to have them in surplus.
Your G-Tech is wrong, that's all. If you hit 99mph in the 1/4, you certainly didn't accelerate up to 130 by the end of the strip, or even 108.
I will say this... I HAVE done 130mph in my cavalier, and it takes a LONG time go go from 108 to 130, a lot longer than you have on a strip. There are people in the low 13's that aren't hitting 108 in the 1/4.
4cyltuner.com - Information Source For 4 Cylinder Tuners
Buy stuff from CarCustoms Ebay! Won't be disappointed!
Ya I'm starting to think the Gtech might be wrong myself (maybee the calibrations are off from it sitting all winter or something)... I re-ckecked it and it said that I made it to 135.6mph in 4th gear and that seems a little high to me...(although the 1st 2nd and 3rd mph per rmp readings check out)
Either way..... the Gtech deosnt really matter at all.... I was just going through it because it was really the only reference I had after 98mph....
The car still redlined in 4th... regardless of any usless electronics that are in the car...
[qoute]All I do know is that the car red lined in 4th gear..... wich shouldn't be possible.....
I'm pretty sure redline in 4th is right around 170km/h, or about 104 or so. 134mph is like what, 220kph? Not happening in 4th gear.
Its about 120 MPH in 4th on my 02. It takes a hell of a long time to get to 130 or even 140. Even a SS S/C takes a while to get to 142.
Im still saying like others theres no way to hit that speed even continuing past the 1/4 mile mark... Wind resistance goes up exponentially...
3400 SWAP DONE. 187WHP 212TQ (NA) 240WHP 310TQ (N2O)
I call shenanigans on ataining those speed at a drag strip. Maybe an airstrip but certianly not any drag strip I have ever seen.
I got a chart off of some website that you put in your gear ratios and tire size, and it gives you your mph's. According to this at 6200 rpm in 4th gear = 128 mph. So I don't think you hit 135.
And as for hitting 130 at the dragstrip? No not happening. The timed part of the strip is a quarter mile with about another quarter mile of slowdown space... roughly, not sure, but thats what my guess would be. I don't see your car going that fast in that short of time.
I know that with your mods you did not hit 135mph in 4 gear. 98mph in the 1/4 is off as well. For the ET you have a 92-93mph is about what you should have. I have done 122MPH in 4 gear at redline in my 01 Z24. This is per the VSS using HPT. That is with some tuning of the fuel. On a stock tune it did 118mph in 4, once leaned it out some got to 122mph. Most I see someone getting is about 125mph in 4 gear. Most I have ever heard of anyone getting in 5 is 151mph in a turbo Ecotec. This same car pulled 113 mph in the 1/4.
FU Tuning
he said he THOUGHT ABOUT THATS WHAT IT HIT. he didnt say yeah i hit 135 on the nose because thats what my speedo goes up to. he said ROUGHLY chill out yikes
Ha ha ... thanks man
And just to let everyone know..... I don't know what trannys your all running..... but my speed limiter kicks in before I hit redline in 4th gear.... it always has.....
It's an Izuzu tranny (for now)... maybee the getrags are different or something.
When my speed limiter activates in 4th gear my tach is somewhere in the area below 5K rpm. so it's def the speed limiter kicking in and not the rev limiter.
If it helps..... just forget every single number posted, all this crap about track length and everything.....
All I was wondering is how the limiter could fail.... thats it guys.
Edited 1 time(s). Last edited Friday, April 04, 2008 8:57 PM
Slipping clutch and poopy electronic gadgets in car, that is how it went 135 at the top of 4th .
mitdr774 wrote:Slipping clutch and poopy electronic gadgets in car, that is how it went 135 at the top of 4th .
How is a slipping clutch going to help you go faster? I really do not understand that.
Even with the getrag stock speed limiter is hit before you hit the rev limiter in 4 gear.
FU Tuning
If the clutch slipps you can hit the rev limiter in 4th without actualy going over 108MPH and a faulty reading on the Gtech could give you 135 MPH reading.
