Optimal shift points
09-22-2006, 11:08 AM
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Optimal shift points Where should the shift points be on a 94 A-4 LT1 with 3.23 gear ratio? The car only has free mods and a cai.
Right now the 1-2 shift is happening around 5500. The 2-3 shift is not happening until 6500. These readings are with the factory tach. The car pulls through the 1-2 shift just fine, but it feels like the engine has ran completely out of it's power band before the 2-3 shift and never really recovers before the end of the track.
The person that I bought the car from had the hypertech tuner, he is supposed to be sending it to me, so I can make the needed corrections.
Right now the 1-2 shift is happening around 5500. The 2-3 shift is not happening until 6500. These readings are with the factory tach. The car pulls through the 1-2 shift just fine, but it feels like the engine has ran completely out of it's power band before the 2-3 shift and never really recovers before the end of the track.
The person that I bought the car from had the hypertech tuner, he is supposed to be sending it to me, so I can make the needed corrections.
09-22-2006, 11:39 AM
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Launching!
With only CAI and free mods, I would set all gear shifts to about 6000. Also set the rev limiter a little higher than the shift points so it doesnt interfer with each other.
09-22-2006, 12:54 PM
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From www.speedengineeringanddyno.com
Who wants to shift at the power peak? You have to go past it for the best ET.
It's all about area under the curve. More RPM = more area.
6250 is simply not a problem even on a stock LT1.
The revlimiter is like a safety net. Not something you use daily. Just there to catch the revs if you miss a shift or spin past your shift point.
Look at the dyno curves and tell me which one you think is more complete.
I have turned bone stock LT1's to 6800 rpm without issues. I don't recommend it and the stock valvesprings won't last if you do it on a regular basis, but the fact is it can be done.
Air Fuel ratio is at 13.2
Who does dyno tuning for $50/hr??? No one!... Well, maybe the guy that got THREE hp. LOL
It's all about area under the curve. More RPM = more area.
6250 is simply not a problem even on a stock LT1.
The revlimiter is like a safety net. Not something you use daily. Just there to catch the revs if you miss a shift or spin past your shift point.
Look at the dyno curves and tell me which one you think is more complete.
I have turned bone stock LT1's to 6800 rpm without issues. I don't recommend it and the stock valvesprings won't last if you do it on a regular basis, but the fact is it can be done.
Air Fuel ratio is at 13.2
Who does dyno tuning for $50/hr??? No one!... Well, maybe the guy that got THREE hp. LOL
09-22-2006, 02:24 PM
#6
The near stock LT1 produces no power at 6000 RPM and at 6500, you got to be kidding.
I dont have an A4, but on my M6 I shift into 2nd at 5900 and the the rest of the gears at 5750-5800 RPM's. This gives the best overall performance.
Best overall shift point is slightly past maximum HP, some say 10% past or so.
I dont have an A4, but on my M6 I shift into 2nd at 5900 and the the rest of the gears at 5750-5800 RPM's. This gives the best overall performance.
Best overall shift point is slightly past maximum HP, some say 10% past or so.
09-22-2006, 02:56 PM
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Thanks for the input. Most of the posts seem to confirm my suspicions.
It is really obvious driving the car, that it is struggling for the last few hundred rpm's.
I just got a call from the guy that is sending the hypertech, so I should be able to hit the track next week and do some fine tuning. Hopefully, by keeping it in the power range I will pick up a couple of mph.
It is really obvious driving the car, that it is struggling for the last few hundred rpm's.
I just got a call from the guy that is sending the hypertech, so I should be able to hit the track next week and do some fine tuning. Hopefully, by keeping it in the power range I will pick up a couple of mph.
