Thread: whats the most you can make n/a?

Originally Posted by MrTube

"I think it bases it off what the computer tells it for the torque values. Do you have a stall converter in your car?"

All torque converters have a stall speed and the ECM knows nothing about the amount of torque the engine is producing.

it does a hell of a job of guessing at it, though. my car was making over 350 ft lbs of calculated torque which in turn made KR appear in the form of torque management and transmission safe guards. once i pulled all that my car didnt ever knock again. then my transmission bit the dust. good times.

Originally Posted by MrTube

"I think it bases it off what the computer tells it for the torque values. Do you have a stall converter in your car?"

All torque converters have a stall speed and the ECM knows nothing about the amount of torque the engine is producing.

I meant 'higher than stock'. And the VCM most certainly knows what the engine is producing. That is how it knows when to start pulling back the timing (torque management).

Originally Posted by MrTube

I'm pretty sure the way it controls power is completely based on things that have been pre-measured and programed in as I do not see any way for the ECM to measure torque in the vehicle unless it can as bios said "guess" it based on how fast the rpm climbs vs what gear the vehicle is in.

What I am also assuming is the newer systems do not retard timing but simply close the throttlebody on shifts? Would seem a far better way then retarding the timing.

They will retard timing, close the throttle body (if it's electronic). If we are talking traction control or speed limiter it can also shut off the injectors for a bit.

The VCM will base it off of VE, which makes sense of you think about it. It knows how much air is moving through thanks to the MAF/MAP. When you start changing out parts it can throw off the accuracy, but if you are tuning you will be changing VE which will change power output. It gives you an idea of if what you are doing is making it better or worse. It's not super-exact but a lot of folks have used it and it's been fairly close. GM claims it is ~15 ft/lbs of actual power. You can take Calculate Torque and use it to plot out horsepower, too.

Originally Posted by MrTube

GeosGP : interesting. I suppose it does make sense now that you explained it. And like you said, accuracy doesn't matter that much as long as it gives you an idea of whether you made it worse or better the actual number doesn't really matter.

If you think about it, even different dyno's will vary. You just want something that can give you a number to look at. The butt dyno isn't always the most accurate tool.

I ran the formula on my GTO, but I never followed it up with a dyno run to see if it's close or not. I will try it on my 07 GP soon as I'm trying to get some sort of tune into it. Granted the low-load knock I keep getting is simply weird. The V6 is foreign to me as I've spent a large portion of my car life with LSx in various forms. These 3800 engines aren't that different, but yet they are.

The GTO is a great car, really. Mine is modded up a bit, and it's a hoot. I need to look through my log files and see if any of them have the horsepower/torque numbers recorded in them. I will say it doesn't have the quiet interior of my Grand Prix. The GTO resale has gone down a lot lately, which is why I've not sold mine.

I'm going to be modding my Grand Prix more in the short term. I will not be staying NA, as I'll never get the power output I want. These are nothing like the LS engines, especially the later ones. The 06-08 Grand Prix not being able to be tuned sucked until I bought an 05 VCM to put in my car. There are one or two annoyances, but the car is so much nicer to drive 120 miles a day than the Goat.

My biggest issue with the SBC is the weight. My LS2 weighs about 150 lbs less and puts out more power by far. Granted, the SBC has more options, is cheaper, and is more than plentiful.

When do you get that number? On takeoff?

That is really odd. I've seen dyno numbers spike when the converter flashes. I wonder if the VE is way off on your tune.

I have my 99 Tahoe which had a 350 in it, will have a 5.3L iron block in it soon. Then a turbo to top it off. I had a Procharger once. Fun. Ate belts though, making it not fun.

They only had a 6 rib for that Tahoe when I got their kit back in 2002, so I didn't really have any options. If it was an LSx truck/car, I would have been golden.

Definitely. But it sold me on turbocharging.