My dyno results
03-23-2004, 05:21 PM
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My dyno results 
Mods are: airlid, air filter, bellows, long tube headers, off-road y-pipe, Corsa cat-back, NGK plugs, Taylor wires, and LS1eit dyno tuning by Speed, Inc.
It took me while to figure out that I was running slow because of bent pushrods. The Speed, Inc. guys took care of that, and then tuned it in and I saw those numbers. What do you think?
03-23-2004, 07:19 PM
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Originally Posted by WS6FirebirdTA00
what kinda car and what year? thats good man, so how did u end up finding out it was a pushrod bent??
03-23-2004, 07:42 PM
#7
i did the same thing u did with the shifting but i caught it real fast and i wasnt at the top of 3rd. can u give me any info on it, im tryin to figure out if i could have done anything to mine. dont know what to do really besdies dyno and see if its low.....
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03-23-2004, 09:47 PM
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Originally Posted by WS6FirebirdTA00
i did the same thing u did with the shifting but i caught it real fast and i wasnt at the top of 3rd. can u give me any info on it, im tryin to figure out if i could have done anything to mine. dont know what to do really besdies dyno and see if its low.....
If you weren't at the top of 3rd, then it might not be such a big deal.
The rev limiter doesn't help this situation because it is just a fuel cut-off... if your tires are moving 100 mph, and you bang it into 2nd, once that clutch is engaged, your tires are going to try to spin 2nd gear fast enough to move the tires at 100 mph -- the engine won't be able to catch up right away, which is why your tires will start skidding... but if the engine were to hypothetically catch up, you would be at about 8,100 RPMs
At that high of RPMs, your valve springs can't keep up, so your valves essentially "float" -- when a piston comes up, SMACK! The force can bend the pushrod on the other side of the spring... in more serious occaisions, it can also bend the valve, or "eyebrow" the piston. Luckily, that didn't happen to me.I took the car to Speed, Inc. to have them pull the valve covers to inspect the pushrods. All of them had just a minor enough of a tweak so that I was losing horsepower, without causing huge operating problems. I too, caught it really early after I banged the shift. You can either pull the valve covers and pushrods yourself, or go to a tuner to do it.
03-23-2004, 10:04 PM
#9
yeah im thinkin of having the car dyno tuned after the intake so i think if i dont see the power i think i should be gettin ill pull the vlave covers off and check it out, can u see them by just pullin the valve covers, or u have to take the rocer off and take the whole thing out. i guess its just something to keep in mind if i dyno like 320 with all the bolt ons lol
03-24-2004, 08:21 AM
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Originally Posted by WS6FirebirdTA00
yeah i know that, i have all the bolt ons, headers and all, maf ends....well everything
And you can check the pushrods yourself by pulling the valve covers off. However, I don't know what all the projest entails, because I had it professionally done.
03-26-2004, 12:22 AM
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Originally Posted by Jay02LS1ws6
but if the engine were to hypothetically catch up, you would be at about 8,100 RPMs
03-26-2004, 12:55 AM
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Originally Posted by tuffluck
so is that the presumed rpm you hit after the misshift, or did you just calculate that? how quickly did you catch that (and what guesstimate of rpm would you say) otherwise?
I saw the tach read 6900. The engine, without fuel being supplied to the cylinders, requires energy (instead of producing it) to spin... for this fact alone, I know that I didn't hit 8,100. That would be if no energy at all was lost, and the engine immediately started spinning the equivalent of 2nd gear at 100 mph. But since it requires work to spin itself without fuel, it would attempt to lock up the tires (and the tires spinning at 100 mph would attempt to do work on the engine). This is why your tires skid if you miss a shift like that.
However, I believe the engine's revs climbed higher than 6900, because I doubt the tach's transfer rate is fast enough to keep up with an instantaneous jump from 6,000 to 8,100 RPMs.
It was probably somewhere in the middle, but regardless, it was too high for the stock springs to handle.
03-26-2004, 09:17 AM
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Originally Posted by Jay02LS1ws6
I doubt I actually hit that.
I saw the tach read 6900. The engine, without fuel being supplied to the cylinders, requires energy (instead of producing it) to spin... for this fact alone, I know that I didn't hit 8,100. That would be if no energy at all was lost, and the engine immediately started spinning the equivalent of 2nd gear at 100 mph. But since it requires work to spin itself without fuel, it would attempt to lock up the tires (and the tires spinning at 100 mph would attempt to do work on the engine). This is why your tires skid if you miss a shift like that.
However, I believe the engine's revs climbed higher than 6900, because I doubt the tach's transfer rate is fast enough to keep up with an instantaneous jump from 6,000 to 8,100 RPMs.
It was probably somewhere in the middle, but regardless, it was too high for the stock springs to handle.
I saw the tach read 6900. The engine, without fuel being supplied to the cylinders, requires energy (instead of producing it) to spin... for this fact alone, I know that I didn't hit 8,100. That would be if no energy at all was lost, and the engine immediately started spinning the equivalent of 2nd gear at 100 mph. But since it requires work to spin itself without fuel, it would attempt to lock up the tires (and the tires spinning at 100 mph would attempt to do work on the engine). This is why your tires skid if you miss a shift like that.
However, I believe the engine's revs climbed higher than 6900, because I doubt the tach's transfer rate is fast enough to keep up with an instantaneous jump from 6,000 to 8,100 RPMs.
It was probably somewhere in the middle, but regardless, it was too high for the stock springs to handle.
03-26-2004, 10:55 AM
#16
Originally Posted by Jay02LS1ws6
Mods are: airlid, air filter, bellows, long tube headers, off-road y-pipe, Corsa cat-back, NGK plugs, Taylor wires, and LS1eit dyno tuning by Speed, Inc.
It took me while to figure out that I was running slow because of bent pushrods. The Speed, Inc. guys took care of that, and then tuned it in and I saw those numbers. What do you think?