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Discussion Starter #1
I have an SRT intake with Race ECU..... and I did like 142mph yesterday.... is it possible? or was I too tired to read correctly cuz I was driving all night?

Before I have SRT, my car was governed at 135mph, but I did 140+ couple times yesterday on my way up here from CA.....

If any one knows what made that happening, let me konw....

Thanks in advance!!! :D
 

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i've hit 143 or 144 in my stock IS (way back in the day) and hit the speed limiter, the manual and everything else say its possible, i don't think your car is out of the ordinary

-gte
 

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Discussion Starter #3
IS300GTE said:
i've hit 143 or 144 in my stock IS (way back in the day) and hit the speed limiter, the manual and everything else say its possible, i don't think your car is out of the ordinary

-gte
yeah, but before.... without SRT... I couldn't go faster than 135mph, because it was governed..... that's why I'm asking....

Does race ECU blows the governor limit???
 

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no, and if you couldn't go past that, something may have been wrong with your car. a stock auto IS should be able to reach the speed limiter as well i would think. there have been plenty of claims of such, i know my stock manual could do so.
 

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I guess I will chime in. I have had my car to 145 mph and was only at 6k rpm in 5th. It could have gone more. I thought that there is no realistic "speed governor" on the car. That what prevents increased speed is the rev limiter; not a governor and not that our car doesn't have the horsepower...
 

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I'm pretty sure that the car is electronically governed at 143 stock. Someone figure out the theoretical max, @ 6.5k once. I'm not positive, but I think it was 152 or 154. You will runout of engine before the 160s. The short gears aren't designed for high end speed, they're designed for low end get up and go.
 

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IS300GTE said:
no, and if you couldn't go past that, something may have been wrong with your car. a stock auto IS should be able to reach the speed limiter as well i would think. there have been plenty of claims of such, i know my stock manual could do so.
werd. there is no reason you shouldn't of been able to go past 135. I reached 143 plenty of times when my car was stock.
 

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he didn't, i'm sure



oneeyejack said:
wHiTeDrAgOnIS said:
i thought the IS can reach 143 due to its limited horsepower, it has nothing to do with being governed, as jedi said.
when did jedi post in this thread? :-?
 

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Discussion Starter #13
Thanks for all the info.....

I guess I wasn't hitting hard enough.... there are too many cops up here compare to CA.....

anyway.... I found out that IS is goverened at 143... so..... I will try again and see if it goes faster than that....

Thanks guys....
 

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dlee74 said:
I have an SRT intake with Race ECU..... and I did like 142mph yesterday.... is it possible? or was I too tired to read correctly cuz I was driving all night?

Before I have SRT, my car was governed at 135mph, but I did 140+ couple times yesterday on my way up here from CA.....

If any one knows what made that happening, let me konw....

Thanks in advance!!! :D
If the car were governed to 135 (it isn't), it would still top out there after your SRT. The addition of more power will not affect the governer setting, even if your car makes 300HP. You might get there faster though. :D
 

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Although my car isn't stock (air intake and exhaust) would that affect my governed high end speed...if not then why could i get to 145 without hitting the governor??? Is the 5spd. governor different then auto?
 

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Discussion Starter #16
As far as I know, Intake and exhaust shouldn't make any difference on the limit....
 

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yea, your car was probably busted before or something wasnt fastened correctly.
I have 400+ to the wheels, and I still run out of legs at 143.
 

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If you work out the gear ratios, a 5 speed would go 147.8 mph
at the 6400 rpm redline.
 

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If you think you're going more than 143, then your tires may be a little smaller diameter than normal. The same goes for getting s slower reading if your tires are a little bigger in diameter.
 
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