I got my GTO up to 163 again the other night going across the bay after work. A buddy of mine from work has a '99 Trans Am and wanted me to take him on a run like the video I posted on youtube. This was the first time I've limited it out since I put the Borla cat-back exhaust on. With a little more HP and torque, I figured it would go faster then the 163 I've done UMPTEEN times, but no such luck.
I was guessing before that it has some sort of electronic limiter/governor on it that my Diablosport Predator tuner can't fully shut off. I asked my Lingenfelter Vette buddy at work and he said if my car's going faster then 155 then it has no limiter/governor on it and that it is wind drag that is holding me back. I argued with him and said I've done my top speed runs with only myself, 1 passenger, and 2 passengers in the car with varying wind conditions and varying levels of gas in the tank. So if one day, say my car only hit 161, and then another day say 159, and another day 163, and another day 163, so on and so forth, I'd agree with him. But 163 every freaking time, and I've done it 9 or 10 times now? What do you guys think?
I'm putting my Kooks stepped 1 3/4" to 1 7/8" Signature Series long tube headers on tomorrow and gonna do another run sometime this weekend late at night and will know for sure something's holding me up if it can't break 163 then.....at least that's my hypothesis. Still waiting on the $ for a torque converter and transmission cooler before I put my CNC ported LS3 heads with hollow valve stems and custom ground Comp cam on (not to mention the 2000 dollar install and dyno tune fee...yikes...). There's a guy 2 towns over with identical setup with the exception of a different brand cat-back exhaust and his dyno sheet showed 440 RWHP. I'd hope to hell a car with that power could go faster then 163...
p.s. here's a link to the youtube video if you haven't already seen it.
Damn, I've done the run X amount of times I should be dead by now. Let me hear a SHOUT OUT from all the Goat Owners on this forum that have tested the limits of their beast MORE than once to know what is, and what is not a fluke... let alone 10 times, I just wanted to know if the Lingenfelter guy was right, that a Goat cannot go past LOW 160ish (which I do blind folded) due to wind drag and weight of the car). By the way, my maintenance buddy that was suppose to help me put my headers on in the morning crawfished out on me, but I'm still gonna call my Lingenfelter buddy and see if he'll help.
Even with the limiter set at 155 the speedo can still show a higher number. Why I don't know but that's how electronics are sometimes I guess. A few GTOs with their limiters in place have hit 160+ too. The best way to check the accuracy of your speed in by GPS. I use my portable Magellan navigation to check my speed. When I first had my tune done, my tuner raised to limiter to 205. I'll never get there for sure but one day I would love to see if I can hit 180.
The Diablosport will not remove your speed limiter, the only way to remove it is by HP Tuners, or a simalar program. Most LSx cars I know except the Corvette the limiter is set to 160 +/-.
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2004 QS/M12 w/mods
If its not BLOWN it SUCKS!
The Diablosport will not remove your speed limiter, the only way to remove it is by HP Tuners, or a simalar program. Most LSx cars I know except the Corvette the limiter is set to 160 +/-.
Did you have your limiter raised? When Charlie did my first tune he showed me where it was set to 155 in HPTuners then raised it to 205.
Did you have your limiter raised? When Charlie did my first tune he showed me where it was set to 155 in HPTuners then raised it to 205.
I know Richard got rid of my limiter the first time. I don't know if Charlie did most likely he did, I know I never see 150+. No telln' he might had the thing to 200mph during that long street tune, thats why my gas was used up. I might ask Richard this weekend to check it out for me.
__________________
2004 QS/M12 w/mods
If its not BLOWN it SUCKS!
My Diablosport for the Z28 has a seperate function in it for the top speed. You can't remove it, but you can bump it up. The standard Diablosport tune does not modify the limiter on the Z28, you need to go into this seperate function and adjust it.
I think the GTO was set at 158. That's what Car and Driver showed at least. Your speedometer might not be accurate or the factory set-up might not be right at 158. Those are common things.
I'd bet your limiter is still set low if you never have a variance in top speed. I also think an LS2 GTO is going to get above 170 with your mods.
Had mine bumped up to 200mph, with $3,000 in mods and Jet tuned. 170 mph on my GPS, but the GTO reed out was @ 174mph. Dont remember where the MPH needle was, happend so fast That was faster then I want to go with stock suspension parts, but it was a awsome rush! Setting up all the rear suspension now, then front.
Had mine bumped up to 200mph, with $3,000 in mods and Jet tuned. 170 mph on my GPS, but the GTO reed out was @ 174mph. Dont remember where the MPH needle was, happend so fast That was faster then I want to go with stock suspension parts, but it was a awsome rush! Setting up all the rear suspension now, then front.
How much power are you putting down to the wheels?
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That was faster then I want to go with stock suspension parts, but it was a awsome rush! Setting up all the rear suspension now, then front.
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