LT1-LT4 Modifications 1993-97 Gen II Small Block V8

LT4 Hot Cam Shift points..... Help!

Thread Tools
 
Search this Thread
 
Old 07-05-2006 | 06:09 PM
  #1  
ShadyPhi's Avatar
Thread Starter
On The Tree
iTrader: (9)
 
Joined: Jul 2005
Posts: 116
Likes: 0
From: St. Louis, MO
Default LT4 Hot Cam Shift points..... Help!

Hey all

I'm getting ready to install the LT4 hot cam kit, and I'm getting a tune immediately afterwords. I'm curious, where should I be shifting (what RPM) after the install...

I need to know this in order to raise the limit on where the PCM cuts off the fuel...

Thanks!
Old 07-05-2006 | 06:26 PM
  #2  
LT1BRN's Avatar
TECH Enthusiast

iTrader: (1)
 
Joined: Feb 2006
Posts: 582
Likes: 0
From: Kingdom of Bahrain
Default

Need to know too, TTT.
Old 07-05-2006 | 08:47 PM
  #3  
Rare96WS6's Avatar
TECH Apprentice
 
Joined: Jan 2004
Posts: 314
Likes: 2
Default

I have mine set a little past peak power which is at 6200. Shift points are at 6400. Anywhere from 6200-6400 seems to be good for the Hot cam, from the other dyno and track times I've seen for this cam. Most cars make peak power from 5800-6200
with this cam, so those figures make sence.
Old 07-05-2006 | 09:56 PM
  #4  
Ed Wright's Avatar
9-Second Club
iTrader: (1)
 
Joined: Feb 2002
Posts: 3,397
Likes: 9
From: Tulsa, OK
Default

Originally Posted by ShadyPhi
Hey all

I'm getting ready to install the LT4 hot cam kit, and I'm getting a tune immediately afterwords. I'm curious, where should I be shifting (what RPM) after the install...

I need to know this in order to raise the limit on where the PCM cuts off the fuel...

Thanks!
I have found most with stock heads to run quickest shifting them at 6500. A lot of guys are uneasy with that, and settle for 6200. Most will peak about 6200, and you want to spin one with a 4L60E about 300 past that. With stock heads, I have not had one run quicker turning it past 6500. If it is a high mile engine I would be a tad more conservative with shift RPM. I like the rev limiters three or four hundred higher than the shift points. Unless you break something in the driveline while WOT, it should never "see" the rev limiters otherwise.

Good luck, Ed
Old 07-05-2006 | 10:06 PM
  #5  
ShadyPhi's Avatar
Thread Starter
On The Tree
iTrader: (9)
 
Joined: Jul 2005
Posts: 116
Likes: 0
From: St. Louis, MO
Default

Great thanks guys, looks like I'll set the shift light around 62-6400 then! Thanks!
Old 07-06-2006 | 02:53 AM
  #6  
burnzilla's Avatar
Banned
iTrader: (3)
 
Joined: Mar 2006
Posts: 1,292
Likes: 0
From: Upstate NY
Default

6500 is alot of RPM's for the LT1, even with the hotcam kit.

I wouldn't push over 6200 rpms, but thats just me.
Old 07-06-2006 | 09:44 PM
  #7  
Ed Wright's Avatar
9-Second Club
iTrader: (1)
 
Joined: Feb 2002
Posts: 3,397
Likes: 9
From: Tulsa, OK
Default

Originally Posted by burnzilla
6500 is alot of RPM's for the LT1, even with the hotcam kit.

I wouldn't push over 6200 rpms, but thats just me.
I have several customers shifting at that RPM. If the engine is healthy, and tuned correctly, the power will peak at 6100/6200. Most experienced racers know you shift them well past the hp peak. Most will run quicker if the RPM drops to the torque peak, or 100 or sp above it. Guess it depends on how good your engine is, and how fast you want to go. I have worked with that a lot at the track with several customers, that is where the 4L60E cars have run quickest. When my car was stock (120,000 miles) I shifted it at 6000. That is where it ran quickest. No headers, nothing.

Many don't really race, just pretty much want to hear it lope when idling through the Sonic. I shift those guys at 6200.




All times are GMT -5. The time now is 05:28 PM.