98 Z-28 extremely low dyno numbers
10-22-2008, 12:10 PM
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98 Z-28 extremely low dyno numbers I no longer have this car but never posted the results of the last dyno run in here. I still can't figure out why a 90,000 mile auto Z-28 would barely break 300 horsepower with a cam. I had the Patriot 226/226, LS6 intake, Pacesetter LT's, ORY, Hooker Aerochamber catback, lid and tune on this car with the numbers reading 309 RWHP and 297 Ft. Lbs on a Mustang Dyno. Granted those dyno's read low but shouldn't this car made around 350 or so at least? It ran perfect, didn't use oil, didn't smoke, started on the first hit everytime and ran strong. Although after the cam swap I didn't feel really any difference in power other than a little gain in the top end with a nice idle. A buddy of mine owns the car now with 142,000 miles. It still runs great but I smoke him every time in my stock 2001 M6 car. WTF is up with this thing? Neither him nor I can figure it out. Any thoughts on what could be the issue? I used Patriot Gold springs, which I love, and lined the timing gears dot to dot.
10-22-2008, 12:29 PM
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Looks like there's something up, and if you smoke him with a stock LS1 then there is. I'd get the car the track and see what kind of numbers it puts up to really find out, but it definitely looks a bit low to me.
10-22-2008, 11:47 PM
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No I didn't buy the cam used, I bought it straight from Patriot. And I'm trying to help my buddy figure out what the deal is. Notice I don't have the car anymore? So no, I really don't care but I'm trying to find some answers.
10-23-2008, 02:36 PM
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If the trans is fine, and you're sure there's nothing wrong with the cam, valvetrain or other internals, I'd check the tune. Was it mail order, or dyno tuned and who tuned it? Is it throwing any codes?
Does it have an aftermarket converter? A stock converter with a cam probably wouldn't be much faster than a stock car.
Does it have an aftermarket converter? A stock converter with a cam probably wouldn't be much faster than a stock car.
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10-23-2008, 11:57 PM
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Yes it's tuned, Scott at Intune Motorsports tuned it. And yes it has the stock converter but even with the stock converter the motor should have picked up power. That wouldn't have much to do with that issue. However I'm sure a stall would help but the car pulls flat, doesn't seem to have a powerband or RPM where it makes peak power. My bolt on 2001 pulls really hard from 3500 RPM on but that 98 is just about the same regardless of RPM. Reminds me of a regular 350 the way it pulls.
10-24-2008, 12:45 AM
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He knew what it dynoed and has driven it before so I didn't just blindly sell him a fucked up car. It runs great and gets good fuel mileage, the only problem is it's down on power. I guess if Jeff would buy a stall converter it would help so I'll mention that to him. I was going to before I sold it but never had the spare time.
10-24-2008, 12:52 AM
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He knew what it dynoed and has driven it before so I didn't just blindly sell him a fucked up car. It runs great and gets good fuel mileage, the only problem is it's down on power. I guess if Jeff would buy a stall converter it would help so I'll mention that to him. I was going to before I sold it but never had the spare time.
earlier you said your stock car could outrun it.. its a cammed car.. doesnt sound like it runs great to me.. or did you mean something else..
10-24-2008, 10:10 AM
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My 01 just has a lid and SLP catback plus it's a 6-speed and it'll pull the 98 pretty damn hard. The 98 has a cam, LS6 intake, Headers and full exhaust. It runs smooth, doesn't smoke, use oil or anything. It starts easily and has never given and problems. What I can't figure out is why the car dynoed so low and doesn't pull like it should. It runs about the same as it did before the cam swap. It doesn't seem like anyone on here knows anything either so maybe the car needs a compression test to see if all eight are making proper compression. And maybe a stall converter would wake it up.
10-24-2008, 10:14 AM
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Yes it's tuned, Scott at Intune Motorsports tuned it. And yes it has the stock converter but even with the stock converter the motor should have picked up power. That wouldn't have much to do with that issue. However I'm sure a stall would help but the car pulls flat, doesn't seem to have a powerband or RPM where it makes peak power. My bolt on 2001 pulls really hard from 3500 RPM on but that 98 is just about the same regardless of RPM. Reminds me of a regular 350 the way it pulls.
Even considering all that, I still don't think it should be that much slower than a stock one, unless you're roll racing him in his dead spots (say from 40mph if he has 3.23's).
Still doesn't explain the dyno numbers, what did it dyno before the cam? If it was like 270 on the same dyno, and now you're making 40 more at the wheels I wouldn't worry. But if it didn't gain any hp on the same dyno, then something could be wrong. Maybe the dyno is reads lower than even other mustang dynos, it happens. Has anyone else you known used that same dyno? Dyno's are good for tuning, but some read higher, and some read lower than others it's not always the best way to compare hp.
10-25-2008, 01:25 AM
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Just a converter (didn't even have headers at the time) made my car 7-9 tenths faster than the stock one. Nearly a second quicker in the 1/4 mile. The stock converter is already too small for the car, and matching the converter to a cam can make a huge difference. One thing a converter does, besides all the other awesome things, is it gets to the higher rpms much quicker than a stock one, which on a cammed car, is where all the power is. Think about when the car shifts. Without the right converter, it's going to fall out of the meat of the powerband each time it shifts, then waste all that time getting back up to where the power is good again just to shift and fall out of it again, making it slower than it should be, maybe even slower than stock. With the right converter, the shift extenstion will keep the rpms up when it shifts. For example, only dropping to 5000rpm instead of 3500rpm that it does when it's stock. Not to mention out of the hole is going to suck too.
Even considering all that, I still don't think it should be that much slower than a stock one, unless you're roll racing him in his dead spots (say from 40mph if he has 3.23's).
Still doesn't explain the dyno numbers, what did it dyno before the cam? If it was like 270 on the same dyno, and now you're making 40 more at the wheels I wouldn't worry. But if it didn't gain any hp on the same dyno, then something could be wrong. Maybe the dyno is reads lower than even other mustang dynos, it happens. Has anyone else you known used that same dyno? Dyno's are good for tuning, but some read higher, and some read lower than others it's not always the best way to compare hp.
Even considering all that, I still don't think it should be that much slower than a stock one, unless you're roll racing him in his dead spots (say from 40mph if he has 3.23's).
Still doesn't explain the dyno numbers, what did it dyno before the cam? If it was like 270 on the same dyno, and now you're making 40 more at the wheels I wouldn't worry. But if it didn't gain any hp on the same dyno, then something could be wrong. Maybe the dyno is reads lower than even other mustang dynos, it happens. Has anyone else you known used that same dyno? Dyno's are good for tuning, but some read higher, and some read lower than others it's not always the best way to compare hp.
That makes sense. I never dynoed the car before the cam so I don't know what it's stock numbers would be though I'm sure a converter would wake it up. We always roll race, even when we race from a dig I can pull on it from
2nd to third gear. I don't put car lengths on him but my 01 does pull ahead fairly quick so I can see how a converter would make a difference. Thanks
10-25-2008, 02:16 AM
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I kinda notice this too. Should my car run better than a 12.9 at 107? I have a cam headers, intake, and exhaust. Auto transmission with only 79k. I was beating stock ls1's But I thought I would beat them by more than I did. Most were running mid 13's