Engine speed limit?

Home  \  Domestic Cars  \  Engine speed limit?

While tearing up sections of Route 72 and I-84 late at night, I noticed that just after 105 MPH, the engine speed drops to 2000 RPM for a second. It looks and feels like it's downshifting and then shifting back up. It doesn't matter whether or not the engine speed is at 3000 RPM (normal at that speed) or 4500 RPM (pedal about 3/4 of the way down), it only does that just after 105 MPH.

I read that some engines have built-in speed limits. Does my car have this as well? If not, what's the problem?

posted by  SignOfZeta

It's called a governor, and yes, your car probably does, most cars do. Usually about 180kph which is about 110mph, so you're right in that area.

posted by  88GrandPrixSE

Is there any way to make this governor resign? (A little Connecticut humor there.) I imagine I'd have to reprogram the ECU, so I'm out of luck at the moment.

posted by  SignOfZeta

There are ways, but it's not legal. Why would you want to anyway, they are governed for a few reasons, one obviously being safety and so you can't go over "this fast", and another because your car is not made to handle excessive speeds. Not to mention that that's already near twice the speed limits on highways :wink2:

posted by  88GrandPrixSE

Not legal? Damn.

Well, I read about all the dangers, though: tire blowouts, engine problems, suspension, cops, accidents while reaching for that McNugget you dropped, et cetera...

That was enough to scare me, but I'd like some kind of override for those moments when you:
1.) Feel suicidally adventurous.
B.) Have to win a race or [insert horrible punishment here].
3.) Have been shot.
4.) Have to get your tax return postmarked in the next seven seconds or pay the price.
5.) Convince a girl to go out with me, fall in love, get married, bang her in the backseat, wait nine months and then have to rush her to the hospital before she gives birth in my car. ("Don't you DARE let your water break on my seats or else you and Colin Jr. are cleaning them!")

posted by  SignOfZeta

I'm assuming that the GrandPrix fellow doesn't live here in the states judging by his KPH reference first. There isn't any law against disabling/bypassing governors...how would anybody know? I guess they would know if you put a huge sign on your car the read, "MY CAR IS GOVERNED AT 105MPH" while you proceeded to whip past a cop at 140mph.

posted by  Sick88Tbird

Hahaha, it's not illegal down there? You bastards. People do get caught here by going well over what the vehicle is governed at, and if the pig happens to know that the vehicle should be goverened, $500 ticket for removing the governor + other applicable fines.. so, oof. What I find odd is how Neon's aren't governed... you'd think they'd be governed before, well, pretty much anything else.

posted by  88GrandPrixSE

They might know if they checked your speed along with your car's year, make and model against a database that says what the governed limit is. Hopefully, the government doesn't go to Car-Forums. I don't really plan to drive 140 MPH, but I'd like to hit 110 or 115 MPH at least.

posted by  SignOfZeta

105mph is a cruel place to have a governor. Anyway, governors are based on two very important things: Suspension and tire rating. You can have your car 'chipped' to beat the governor, but without upgrading the aforementioned car dynamics, I wouldn't advise it. All modern cars are governed by law to their tire rating. My CTS, for example, is limited to 143mph because it comes with V rated tires (many manufacturers limit just below the tire rating for liability reasons) and there is no need to have W rated tires on it because the car most likely won't reach 168mph with the stock drivetrain. In comparison, the 400hp V-series version wears W rated tires and is limited to 165mph. In some cases (which are becoming rarer), cars are limited because their suspension is unsafe at higher speeds.

Tire ratings
M 81
N 87
P 93
Q 99
R 106
S 112
T 118
U 124
H 130
V(VR) 149 (VR used to signify "above 130mph", it now limits to 149)
W(ZR) 168
Y(ZR) 186 (both of these may use "ZR" in the size description, which just signifies "in excess of 149mph")

posted by  Gothicaleigh

Nice, but I remember how scientist once said that tires wouldn't be able to go past 150 mph, but as we can see, tires are way apst that point, but how? Filling the tires with gel, or something? Also, what are the physics constraints of tires nowadays?

posted by  Godlaus

It's simple...since the 50's they've designed tires that don't come apart until higher speeds. You know you're crazy when you're in excess of 145 on bald H-rated tires :doh:

posted by  Sick88Tbird

Yep! Mine at least let's me get to 112mph. :driving:

posted by  GirlieGurl

it can also be that you have hydrolic rollers and lifters. once you are going so fast and a certan ammount of rpms for a long time the vavles will open and close out of order causing your car to "Burp" then in about a second it will come back to life. its weird for it to happen at such a low rpm so it probably is a rmp limiter in the ecu but you never know :laughing: :hi:

posted by  markman

Another entry in the "Dumbest Thing I've Ever Heard Anybody Say" sweepstakes. Good job. :thumbs:

posted by  vwhobo

Must be those damn light-weight plastic camshafts. :laughing:
.
.

posted by  BavarianWheels

He's talkin about valve float but he shouldn't even have brought it up in this topic....it's a good way to make an ass out of yourself.

posted by  Sick88Tbird

I read somewhere that these ratings are only guaranteed at a continued maximum speed rating for 60 seconds. Anything more and they are not liable.

posted by  pnettle89

yes reprogramming the ECU does eliminate the governer and/or the rev limiter. one way is to get a VIN from a police vehicle (caprice/tahoe/crown vic/ect.). and use a TECH2 (made by Vetronix, about $3500 without the needed programs) to program the ECU as if it were a law enforcement vehicle. Although if your car gets impounded they most likly will scan yer car with a TECH2 or similar scan tool and if you are caught with the police's VIN you will be facing heavy fines and possibly jail or prison time.

posted by  Mx3Kid

Never, ever, ever remove a governor without upgrading your tires. Ever ever ever ever...

posted by  Oomba

yea i forgot to add that... it wouldnt hurt to upgrade to stiffer rims(like cops have)

posted by  Mx3Kid

why on earth would they hook an impounded car up to a scan tool?



stiffer rims? who has rims that have collapsed from high speeds?

posted by  dodger65

1# if a cop caught u goin 140 they would Kno u did somthing to your governer/rev limiter, therefore they will probly impound your car and check it for non-street legal mods( such as a law enforcement ECU...).

2# Stiffer rims handle better at higher speeds (hense why cops have billet rims)

posted by  Mx3Kid

#1 you're in michigan, not russia.. (or ohio :wink2: ) they don't even check your emissions, why the f*ck would they care if you modified your "governor"?

#2 that's fine about the handling, but i defy you to show me a cop car w/ billet rims... :screwy:

posted by  dodger65

all the state troopers around here have black billet rims with chrome lug nut covers
why would they care if u modified yer gov.? they put it on there for a reason and anyway the way i suggested earlier in the topic, i said use a law enforcement VIN and that is very illegal its like stealing a cop car

posted by  Mx3Kid

those are steel... :banghead: :banghead: :banghead: :banghead:

once again, they will probably never check, even if you robbed a bank and did 220 mph away from said bank...

posted by  dodger65

yea umm u ever herd of billet steel buddy, and around here they do check alright? im done with this childish argument with you

posted by  Mx3Kid

w/e, kid... :screwy:

posted by  dodger65

I pissed myself when I read this. Cop cars with billet steel wheels. What'll they think of next... titanium door handles?

posted by  vwhobo

neon's are governed...

lower models are governed at 118mph (T rated tires), and the R/T and ACR models are governed at 130mph (H rated tires). no clue about the SRT-4, but then again, that car is in a completely seperate league as compared to any of the other cars i mentioned.

and no, i'm not going to confirm that for you, i havnt even touched 100mph.

posted by  pik_d

And another bites the dust....



Check the dates pik_d - the hobo caught you ;)

posted by  dodgerforlife

it's only four months old. :ticking:









:doh:

posted by  pik_d

not all cars are governed

posted by  Aondor

No definetly floating wooden valves and too high compression plastic pistons/cylinder walls.

posted by  PontiacFan27

I swear, I'm going to make a thread to link all the threads that Hobo has resurrected and someone has replied to without realizing it....I wonder how often and how many...

posted by  dodgerforlife

Your Message