this may be the stupidest question i ever ask, BUT....

is it possible to "break" the speed limiter?

this question goes against all i know about cars, but i'm having some wierd stuff happen. when i first got the truck, and over the course of the first 6 months or so, my boyfriend and i periodically would test it's limits. consistantly, the truck would hit the speed limiter at 100mph. this completely disappointed me, but whatever. recently, about 2 weeks ago, my boyfriend tried again. we were going down the highway, minimal decline, and he got on the gas just to see. around 100 it began to do the normal stuff, but then due to momentum (and the decline) the truck got past it and around 105 picked right back up again. then, last week he tries to pass the 100 mark again, and the truck goes right past with no issues up to about 115! him and i both know what it feels like when you hit the speed limiter, and it definitly had one at 100. so, how could it possibly drive right through to 115 this time? i mean, can you really "break" it???? i'm just at a loss for what could be going on.

thoughts?????

 

My GX never cuts at 100mph. It always cuts at around 115-120mph. That is really weird in your case.

Charleston

 

havent had a chance to reach the 100 limit with the gx, so can say, onething for sure, is I got a superchip and installed it in the computer of my F150 truck, uff I will reach the max the needle will reach max speed but you can keep on pressing the gas and the truck just keep going, by the way I never checked if the gx can be modified with a chip, any Ideas??

 

I was able to cut pass 100 easily. Just try it with the A/C off. So give it a try with the A/C off and see what happends to yours.

 

Maybe he's got different size tires?

 

well, hate to say this, it's not safe to go over 100 on a SUV like the GX. do that on a GS or LS. GX is too tall for those speeds and if you just loose ur momentum for a split second, everything can be bad!

besides, isn't the limit 112? wasn't there someone here that got up to 110 before and i remember someone commenting that it isn't safe to drive that fast in the GX??

 

I do agree with you about driving that fast with the GX, but maybe one day you may end up being passed by a X5, Range Rover etc. you know what I mean and because of dignity you may want to impress by trying to tailgate them.

 

true true, but that's the only time i'm gonna put the pedal to the floor! lol otherwise, i'd try to stay safe (don't wana hurt my baby).

 

I think the limit is 112. Aside from the high center of gravity on the GX the limit is imposed due to the stock tires not being S or better speed rated. Allison - it could be your new rims "messing" with the limiter. As for the logic behind it I'd say it is a pretty safe bet regardless of the wheel/tires/handling mods done the GX probably shouldn't be driven that fast. Now if you don't have the proper speed rated tires then definitely it should not be going that fast - those are BIG tires with alot of rotational forces being exerted - if those belts are not being supported properly (at speed) their inclination is to seperate and fly off the wheel (read NOT GOOD).

I'd think twice about trying to defeat the limiter (if that's what you were thinking of doing).

 

allison said n another post that she owned a ZO6 so I think it's safe to say the GX is in good hands at those speeds and I doubt it was being driven through rush hour traffic, usually people attemp things like that on an open empty peace of highway and are familiar with the chance of blowing by a state trooper

another thing her truck is riding on 20, most 20's are higher rated speed tires and their SUV/truck tires on truck rims so they can handle the weight and speed

As for the speed limit, it should say in the Lexus GX Brochure what it is limited to, now the 100 top end could have been due to weather, fuel, what was the road like, vehicles are harder to top out going slightly inclined compared to going slightly declined if your going WOT on a slight incline thats much more weight the GX has to run uphill with, now going slightly downwards the GX has pretty much all the weight going with it.

The weather plays a big part, cooler colder weather cars run better and perform at their peak, and the gas should be consistently the same octane but from time to time it could vary slightly more or less but you would never know cause the ECU adjusts so that could have been your powerloss, where you running it on 87 and then 93

Only other thing I could think of is did you loose any weight

 

it was definitely done on a long virtually flat stretch of highway with no other cars anywhere around. I also made sure I got Z-rated tires, so I'm not at all concerned with the tires coming apart. And, to be honest I don't see any issue with the GX at relatively high speeds (80-90mph). It handles VERY well. But, do note you will not experience that when driving in comfort mode. My truck is ALWAYS in sport! Always use 87 octane. Not sure that I remember the weather, but I'll take note of it next time.

 

Does anybody sells a chip or any stuff the eliminate and bypass that speed limiter??

I think the GX can reach 130mph with no problem!!

 

I doubt that a stock GX with no breathing help, all that weight, a fairly large frontal area and something less than 235 HP at the rear wheels can hit 130 MPH, IMHO. Maybe with a chip change or reprogrammed factory chip it might reach close to 125 MPH.

 

The factory said the fuel cut-off at 112mph, but it didn't say you can't go beyond that speed...
So, it is possible to go even faster if you keep your engine in high RPM I think.

 

If the factory limits the speed to 112 MPH, that should be controlled by the speedometer input, regardless of the RPMs. You can't go faster than 112 MPH if the fuel is cut off unless you go over a cliff.