***GM Stock Shortblock - 130 MPH NA
07-06-2009, 09:25 AM
#1
***GM Stock Shortblock - 130 MPH NA Gentlemen,
I am certain some of you recall the car with our 200cc CNC'd GM LT1's and 22Xdeg HR from this thread:
https://ls1tech.com/forums/lt1-lt4-m...na-9s-n2o.html
As is always the case with a setup this refined, you often make changes and take steps backwards before showing a net improvement. Our customer has been working hard, trying different tire sizes & gearing (3.73-4.11), but with a fixed rpm limit there is not much room for large changes. When the car has made more power or improved on one end, it has naturally lost on the other. To date, in the mediocre (hot/humid) conditions this year it has not improved on the 10.5sec ET. Still, there have been updates. I'll simply quote a portion of our customer's email:
Timeslip:
With all he has learned from his hard work, we're hopeful that there will be an ET improvement as the weather begins to come around. There is likely still another tenth or two and maybe 1-2mph in this setup we would like to see before altering the engine. Hope you guys had a nice holiday!
I am certain some of you recall the car with our 200cc CNC'd GM LT1's and 22Xdeg HR from this thread:
https://ls1tech.com/forums/lt1-lt4-m...na-9s-n2o.html
As is always the case with a setup this refined, you often make changes and take steps backwards before showing a net improvement. Our customer has been working hard, trying different tire sizes & gearing (3.73-4.11), but with a fixed rpm limit there is not much room for large changes. When the car has made more power or improved on one end, it has naturally lost on the other. To date, in the mediocre (hot/humid) conditions this year it has not improved on the 10.5sec ET. Still, there have been updates. I'll simply quote a portion of our customer's email:
The best motor pass last year was 10.553 at 127.50 mph.
On Saturday, i started out in the 10.90s at 125.XX (AI: with the latest tire/gear change). The car was a little lean, so I made a few jet changes and got the AFR dialed in much better, but still could only manage 10.8X at 126.XX.
Then I started playing with the timing and found some real power gains. I thought I had the timing set at 35 deg but it turned out it was only at about 33.5. I bumped the timing up to 35deg and the car went 10.7X at 129.60. With my friends and my self not really believing that the car could actually tap that high, I made one more pass to back it up. The only adjustment I made was 2 more PSI in the tires, and I went 10.7X at 130.10MPH.
With the track about to close, I caped the breather, and put the vacuum pump belt on the car.
The first pass with the vacuum pump the timers f'ed up and I didnt get a time. I had to head straight back to make another pass with no cool down time, just a straight hot lap. The hot lap pass was my Last pass of the day, and with the vacuum pump pulling about 8lb of vacuum the car went 10.665 at 130.86mph.
On Saturday, i started out in the 10.90s at 125.XX (AI: with the latest tire/gear change). The car was a little lean, so I made a few jet changes and got the AFR dialed in much better, but still could only manage 10.8X at 126.XX.
Then I started playing with the timing and found some real power gains. I thought I had the timing set at 35 deg but it turned out it was only at about 33.5. I bumped the timing up to 35deg and the car went 10.7X at 129.60. With my friends and my self not really believing that the car could actually tap that high, I made one more pass to back it up. The only adjustment I made was 2 more PSI in the tires, and I went 10.7X at 130.10MPH.
With the track about to close, I caped the breather, and put the vacuum pump belt on the car.
The first pass with the vacuum pump the timers f'ed up and I didnt get a time. I had to head straight back to make another pass with no cool down time, just a straight hot lap. The hot lap pass was my Last pass of the day, and with the vacuum pump pulling about 8lb of vacuum the car went 10.665 at 130.86mph.
With all he has learned from his hard work, we're hopeful that there will be an ET improvement as the weather begins to come around. There is likely still another tenth or two and maybe 1-2mph in this setup we would like to see before altering the engine. Hope you guys had a nice holiday!
07-06-2009, 09:43 AM
#4
Gentlemen,
I am certain some of you recall the car with our 200cc CNC'd GM LT1's and 22Xdeg HR from this thread:
https://ls1tech.com/forums/lt1-lt4-m...na-9s-n2o.html
As is always the case with a setup this refined, you often make changes and take steps backwards before showing a net improvement. Our customer has been working hard, trying different tire sizes & gearing (3.73-4.11), but with a fixed rpm limit there is not much room for large changes. When the car has made more power or improved on one end, it has naturally lost on the other. To date, in the mediocre (hot/humid) conditions this year it has not improved on the 10.5sec ET. Still, there have been updates. I'll simply quote a portion of our customer's email:
Timeslip:
With all he has learned from his hard work, we're hopeful that there will be an ET improvement as the weather begins to come around. There is likely still another tenth or two and maybe 1-2mph in this setup we would like to see before altering the engine. Hope you guys had a nice holiday!
I am certain some of you recall the car with our 200cc CNC'd GM LT1's and 22Xdeg HR from this thread:
https://ls1tech.com/forums/lt1-lt4-m...na-9s-n2o.html
As is always the case with a setup this refined, you often make changes and take steps backwards before showing a net improvement. Our customer has been working hard, trying different tire sizes & gearing (3.73-4.11), but with a fixed rpm limit there is not much room for large changes. When the car has made more power or improved on one end, it has naturally lost on the other. To date, in the mediocre (hot/humid) conditions this year it has not improved on the 10.5sec ET. Still, there have been updates. I'll simply quote a portion of our customer's email:
Timeslip:
With all he has learned from his hard work, we're hopeful that there will be an ET improvement as the weather begins to come around. There is likely still another tenth or two and maybe 1-2mph in this setup we would like to see before altering the engine. Hope you guys had a nice holiday!
thanks.
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07-06-2009, 04:01 PM
#15
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WOW!!! Very nice. I'm sure he's spent a lot of time tweaking every aspect of the set-up, and it's good to see it's paid off for him.
Has it ever been mentioned how much nitrous he uses for the 9.8x's ?
Has it ever been mentioned how much nitrous he uses for the 9.8x's ?
