Found this over at TPIS's FAQ...
Thread Starter
Safety Car
Joined: Jul 2001
Posts: 3,524
Likes: 1
From: Pinellas Florida Misfit
Cruise-In III Veteran
Found this over at TPIS's FAQ...
Q: I have a 95 LT1, it has LT4 heads and intake, LT4 fuel injectors, 1.6 roller rockers, 52mm throttle body, 1 3/4'' SLP headers, GM Performance Parts Hot Cam, ACCEL 300+ Ignition and K&N fuel injection performance kit. Idles good, but when I hit the throttle it is slow to respond, and when it does, it isn't very impressive. Do I need a re-programmed computer? A larger fuel pump or an adjustable fuel pressure regulator? Any help you can give me would be greatly appreciated.
A: The Cam is too big for a 350 motor. I get this question all the time with the LT4 Hot Cam. If you look at the duration @ .050 it doesn't look bad , but it must be huge everywhere else in it's lift range. It would be fine in a 383 or bigger motor with a lot of compression, and a deep gear. Also the intake port volume of the heads are big for a 350 street motor. In order to use these pieces you would want to stroke the motor and or raise the c/r, or add a supercharger. When you go with big cams and 1.6 rocker ratio, and add big heads you will lose a lot of your bottom end power and most of your mid-range power. What happens is the velocity of the air slows down that's why you go slower. The whole set up is still on the big side for a 383 ci motor. You will make more power but it will be all up top.
TPiS
A: The Cam is too big for a 350 motor. I get this question all the time with the LT4 Hot Cam. If you look at the duration @ .050 it doesn't look bad , but it must be huge everywhere else in it's lift range. It would be fine in a 383 or bigger motor with a lot of compression, and a deep gear. Also the intake port volume of the heads are big for a 350 street motor. In order to use these pieces you would want to stroke the motor and or raise the c/r, or add a supercharger. When you go with big cams and 1.6 rocker ratio, and add big heads you will lose a lot of your bottom end power and most of your mid-range power. What happens is the velocity of the air slows down that's why you go slower. The whole set up is still on the big side for a 383 ci motor. You will make more power but it will be all up top.
TPiS
:rolleyes:
Melting Slicks
Joined: Apr 2002
Posts: 3,019
Likes: 0
From: down that one road next to that big tree
Re: Found this over at TPIS's FAQ... (James94LT1)
i have no idea why this is on there website...what it means or why, i've been meaning to ask TPIS about it when i'm on the phone but it's slipped my mind.
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
I think it has been proven time and time again that TPiS will only offer positive advice on their own products. Anything they didn't make is crap to them. Just read their "insider hints" stuff, it is just sales propganda for their products.
Melting Slicks
Joined: Apr 2002
Posts: 3,019
Likes: 0
From: down that one road next to that big tree
Re: (scorp508)
keep in mind they also promote the zz-x which is a frigin HUGE cam as far as hyd. rollers go. something like 239@.50 if i remember right, yet they think a 218/228@.50 grind is too big. i wonder if they have ever said a MR makes more torque than a SR while they were at it :lol: :lol:
