WHEN should i shift?????
WHEN should i shift?????
i have a lg4 305 with a 5 speed,hooker headers, full exuast back with 3 inch cat. Also a dual snorkel air cleaner,3.27 gears, and soon a edelbrock intake. When should i shift in rpms to get the best performance i can out of this thing. Also it would be nice to have an estimate on the horsepower of this thing. i know it started with 165 in 86
Supreme Member
iTrader: (1)
Joined: Feb 2000
Posts: 7,964
Likes: 4
From: Norfolk, VA. USA
Car: 86 Trans Am, 88 Formula
Engine: 95LT4, 305TPI
Transmission: T56, T5
Well, today I was shifting at 4500rpm at the track. car ran very strong today. First time drag racing and I had a blast.
My best run was a 14.94 @ 91.67mph.
My very first run ever was a 15.12 @ 92.80mph.
here is a break down of the time slip.
R/T .827
60' 2.126
330 6.176
1/8 9.582
mph 73.11
1000 12.466
1/4 14.943
mph 91.67
------------------
Zepher
'86 Pontiac Trans Am WS6, 5 Speed:
Edelbrock 1406 Carb, Edelbrock Performer RPM 7101 Intake Manifold.
Edelbrock Open Element Air Cleaner: Flowmaster Exhaust, 160* Thermostat,
Grant GT Steering Wheel, MSD HEI Coil, Taylor 8mm Wires, Recaro Seats,
Alpine CD+Changer,Rockford & Soundstream Amps, Premier TS-1040C Subs, Polk Audio highs/mids.
WS6 Trans Am
My best run was a 14.94 @ 91.67mph.
My very first run ever was a 15.12 @ 92.80mph.
here is a break down of the time slip.
R/T .827
60' 2.126
330 6.176
1/8 9.582
mph 73.11
1000 12.466
1/4 14.943
mph 91.67
------------------
Zepher
'86 Pontiac Trans Am WS6, 5 Speed:
Edelbrock 1406 Carb, Edelbrock Performer RPM 7101 Intake Manifold.
Edelbrock Open Element Air Cleaner: Flowmaster Exhaust, 160* Thermostat,
Grant GT Steering Wheel, MSD HEI Coil, Taylor 8mm Wires, Recaro Seats,
Alpine CD+Changer,Rockford & Soundstream Amps, Premier TS-1040C Subs, Polk Audio highs/mids.
WS6 Trans Am
Well, thats simple. The higher the RPMs the faster you are going. So if you wanna go as fast as you can (hey guys do we have that thing where you can only go so high in the RPMs? I think its called the retard or something lol. Might be wrong though). Anyways dont shift until you hit the RPM max if we have one. Or get to know your highest RPM range and shift right at that. Not saying you wont blow your engine cause I dont know what going into the red alot will do. If I were you I would red line it some but not alot. Sorry this is so sloppy it sounded better in my head.
Member
Joined: Dec 1999
Posts: 139
Likes: 0
From: Sanford NC
Car: 92 RS
Engine: 396 sbc
Transmission: t5
Axle/Gears: 3.23
I would not shift that 305 any higher than 5grand
4750 is where I manually shift my automatic though
Turn it until it begs for mercy! LOL
------------------
3" custom FloPro Catback
14X3 K&N open element
15.6 best 1/4 mile before any mods
4750 is where I manually shift my automatic though
Turn it until it begs for mercy! LOL

------------------
3" custom FloPro Catback
14X3 K&N open element
15.6 best 1/4 mile before any mods
smallblocks make their power in high rpms you need to wind it out to 6 grand, but dont go much higher, any higher and you might damage your valve train. you can take a motor pretty high as long as you dont hook up really good like if you have slicks or something.
------------------
"to hell with gas mileage and looks! this is for horsepower"
------------------
"to hell with gas mileage and looks! this is for horsepower"
Joined: Mar 2000
Posts: 43,187
Likes: 46
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
My mostly stock LG4 floats the valves at 5200, and by then it hasn't been making any more power for awhile.
I spent most of the season (all but the first two races) letting the tranny shift itself. It typically shifted at 4750 into 2nd and 4500 into 3rd. I tried manually shifting at 5000 and the times were slower.
You need more cam if you want the RPMs to go any higher.
------------------
82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.
I spent most of the season (all but the first two races) letting the tranny shift itself. It typically shifted at 4750 into 2nd and 4500 into 3rd. I tried manually shifting at 5000 and the times were slower.
You need more cam if you want the RPMs to go any higher.
------------------
82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.
Thread
Thread Starter
Forum
Replies
Last Post
darwinprice
Organized Drag Racing and Autocross
17
Oct 11, 2015 11:51 PM






