Dyno results from 97 LT4 SS #91
#1
FormerVendor
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I thought some people might be interested in this.
I recently purchased 97 LT4 SS #91. It is bone stock with 6,300 miles.
I work at Speed Inc. in Schaumburg Il. I do the dyno tuning there (with the LS1/LT1 edit software).
BONE STOCK it did-
285.9rwhp @5,800
311.6rwtq from 2k till 4,500 (then it trails off)
The car was running 11.8-1 air fuel, and dipped down to 10.5-1 at 5,600. Timing was 34 degrees total. I havn't looked over the program very closely, but it appears to be a stock file from a 97 Z28. The rev limiter was 5,800.
I tuned the car which included leaning out the air fuel to 12.5-1 and changing total timing to 32 degrees. It did-
306rwhp @5900
322rwtq @4200
Torque was up 35ft lbs at 5,700 (from 250 to 285) also.
I then changed the oil to Royal Purple ( 2qts 5-30, 3qts 10-30), and installed the SLP IAT resistor, and it did-
311.7rwhp @5,900
325.4rwtq @4,200
I'm very pleased with the results. The car feels 100% better with the extra power, and being able to shift it after peak horsepower (rather than right at peak horsepower).
Maybe next time I'll swap out the original spark plugs, fuel filter, and air filter.
Track times in the spring
I recently purchased 97 LT4 SS #91. It is bone stock with 6,300 miles.
I work at Speed Inc. in Schaumburg Il. I do the dyno tuning there (with the LS1/LT1 edit software).
BONE STOCK it did-
285.9rwhp @5,800
311.6rwtq from 2k till 4,500 (then it trails off)
The car was running 11.8-1 air fuel, and dipped down to 10.5-1 at 5,600. Timing was 34 degrees total. I havn't looked over the program very closely, but it appears to be a stock file from a 97 Z28. The rev limiter was 5,800.
I tuned the car which included leaning out the air fuel to 12.5-1 and changing total timing to 32 degrees. It did-
306rwhp @5900
322rwtq @4200
Torque was up 35ft lbs at 5,700 (from 250 to 285) also.
I then changed the oil to Royal Purple ( 2qts 5-30, 3qts 10-30), and installed the SLP IAT resistor, and it did-
311.7rwhp @5,900
325.4rwtq @4,200
I'm very pleased with the results. The car feels 100% better with the extra power, and being able to shift it after peak horsepower (rather than right at peak horsepower).
Maybe next time I'll swap out the original spark plugs, fuel filter, and air filter.
Track times in the spring
#2
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Very Nice. What do you think the weight of your car is?
I had the pleasure of seeing a two different 97 LT4 Firehawks that were at our local pontiac dealer at the time. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
I had the pleasure of seeing a two different 97 LT4 Firehawks that were at our local pontiac dealer at the time. <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />
#3
FormerVendor
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Thanks <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />
When my 96SS was bone stock, it weighed 3,450lbs.
The 97 SS should weigh the same, except that it's a hardtop. So, I would guess maybe 3,430?
When my 96SS was bone stock, it weighed 3,450lbs.
The 97 SS should weigh the same, except that it's a hardtop. So, I would guess maybe 3,430?
#5
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You had to have spent a good chunk of change on that car. Good buy no matter what because of the production numbers and the miles. There was one on ebay a couple of months ago for 75k because it had 13 original miles on it. Dont think it sold though. They also had a 87 GNX with 38 original miles. Good luck with it.
#6
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Two questions:
1.Why did you reduce the total timing? Do you find with the LT1/LT4 that it will end up with less knock retard with a lower curve? Maybe I should do this to mine.
2.Why did you mix 5w30 and 10w30 like that, instead of just using one or the other?
1.Why did you reduce the total timing? Do you find with the LT1/LT4 that it will end up with less knock retard with a lower curve? Maybe I should do this to mine.
2.Why did you mix 5w30 and 10w30 like that, instead of just using one or the other?