Power loss at 4500 RPM??
12-14-2002, 12:19 PM
#1
Senior Member
Thread Starter
iTrader: (3)
Join Date: Oct 1999
Location: Apple Valley, MN
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
Car: 92 Z28 convertible
Engine: Miniram 383
Transmission: T-56
Axle/Gears: 4.10 stk 10 bolt
Power loss at 4500 RPM??
Well I went to the track for the first time last night and I managed to run a 13.52 @ 99.4 MPH. I did spin pretty good off the line with my street tires, 60 ft times were 2.0's. The odd thing I noticed was after I got into 3rd gear and as the rpm's climed to 4500 to 4800 rpm's and would pause for about 1 second and actually drop 100 rpm and then start to climb again. I was there racing with my friend who has a 92 Mustang with a built 306 and we were both turning about 100 mph in the 1/4. My 1/8 mile mph was 82, and my friends Mustang was 80. At the 1/4 mile mark my friends Mustang was turning 102 mph and I was at 99. I was 2 mph faster to the 1/8 mile but dropped off his pace by 3 mph at the 1/4 mile. Im thinking Ive got some Fuel or spark problems with my prom tuning at that rpm. I even noticed on my rwhp dyno sheet from the Car Craft summer cruise, that my power dropped off at that RPM. I did replace my knock sensor reciently (had old one for dyno pulls) and used the trick for makeing it less senitive by putting teflon tape on it and by installing it with less torque, I know it could be knock, but wanted some more thoughts. Thanks in advance.
12-14-2002, 03:20 PM
#3
Supreme Member
Join Date: Jan 2001
Location: Someone owes me 10,000 posts
Posts: 7,164
Likes: 0
Received 1 Like
on
1 Post
Car: 99 Formula
Engine: LS1
Transmission: T56
Axle/Gears: 342
Originally posted by 89gta383
The rpm drop is from the convertor locking up, happens to all of us.
The rpm drop is from the convertor locking up, happens to all of us.
12-14-2002, 05:08 PM
#5
Senior Member
Thread Starter
iTrader: (3)
Join Date: Oct 1999
Location: Apple Valley, MN
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
Car: 92 Z28 convertible
Engine: Miniram 383
Transmission: T-56
Axle/Gears: 4.10 stk 10 bolt
I never would of thought of that. It sounds right, thats right about the time it happens 75 mph or so. I do have a ed wright chip and Ive also noticed that Im able to hold 4th gear at WOT (converter seems to stay locked up). While I was in germany, I was able to top the Z out at 155 mph (hit the rev limiter at 6500)
12-16-2002, 07:45 PM
#7
Senior Member
Thread Starter
iTrader: (3)
Join Date: Oct 1999
Location: Apple Valley, MN
Posts: 549
Likes: 0
Received 0 Likes
on
0 Posts
Car: 92 Z28 convertible
Engine: Miniram 383
Transmission: T-56
Axle/Gears: 4.10 stk 10 bolt
Sorry, I was in Virginia, I just got back from School there. I did it at Virginia Motorsports park.
Trending Topics
12-17-2002, 06:14 PM
#8
Senior Member
Join Date: Jul 1999
Location: Mpls, MN USA
Posts: 931
Likes: 0
Received 0 Likes
on
0 Posts
Car: 88 Camaro
Engine: 427 BBC
Transmission: T400
OK Thanks. I thought maybe I'd been under a rock for too long and they built a track near by and December was warm in Minnesota and...... 
Miles
Miles
Thread
Thread Starter
Forum
Replies
Last Post
theshackle
Tech / General Engine
4
09-17-2020 08:26 AM
