Optimal shift points
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.
shifts at 6500? I wouldn't be spinning a completely stock motor that high.
I would say set redline at 6000 or just a little past that, and then shift right before that. I wouldn't go much past 6000-6100 on the stock valvetrain.
I would say set redline at 6000 or just a little past that, and then shift right before that. I wouldn't go much past 6000-6100 on the stock valvetrain.
TECH Addict
iTrader: (8)
Joined: Sep 2005
Posts: 2,401
Likes: 0
From: The beautiful Kingdom of Bahrain
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
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.
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.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
