LT4 Intakes Question?
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Burning Brakes
Joined: Apr 2002
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From: MO
LT4 Intakes Question?
Are all LT4 intakes Red? I think I may have located a used one if so?!?
Would I gain from going with AFR Lt4 heads and an Lt4 intake over
LT1 AFR's and my intake?
[Modified by James94LT1, 6:29 PM 6/6/2002]
Would I gain from going with AFR Lt4 heads and an Lt4 intake over
LT1 AFR's and my intake?
[Modified by James94LT1, 6:29 PM 6/6/2002]
Instructor
Joined: Feb 2002
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From: Greenville TX
Re: LT4 Intakes Question? (James94LT1)
I believe so, but keep in mind that it is easy to paint an LT1 intake. However, if you remove the pan on the bottom of the intake, you should see "LT4" cast into the intake.
Also, an LT4 has no EGR valve.
Also, an LT4 has no EGR valve.
Racer
Joined: Oct 2001
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Re: LT4 Intakes Question? (James94LT1)
All LT4 manifolds are red... If you have a rasied runner head like a LT4 or AFR LT4, then definitly go with the LT4 intake. raised runner heads & intake like the LT4 is good for maybe 15hp (in stock fashion) over stock port LT1'S.. hope this helps... P.S the additional 30hp gained from the LT4 over the LT1 was'nt managed by the heads and intake alone, it was a combo of more agressive computer calibrations, larger #28 injectors, 1.6 roller rockers for extra valve lift, 2.00 intake valves and a slight boost in compression ratio.
Safety Car
Joined: Jun 1999
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From: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Re: LT4 Intakes Question? (JB'S LT4)
The LT4 intakes are all read and the LT4 casting mark, as previously stated, appears under the oil splash shield. See my website in my signature for a photo.
I disagree slightly with the statement where the HP gain came from. The additional HP is a result of better breathing which allows power at a higher RPM by keeping the torque production for a more RPM. The LT4 produces about the same peak torque at the LT1, but delivers more torque at 6000-6400 rpm range where the LT1 cut off at about 6000. The heads have a significant increase in breathing ability over the LT1 which is partially due the .1 inch increase in port heighth. The intake is simply modified slightly to better match to the LT4 heads. I really doubt that an LT1 would reap any increase with only the LT4 intake swap. I have not tested it, but would like to hear from anyone who has.
I disagree slightly with the statement where the HP gain came from. The additional HP is a result of better breathing which allows power at a higher RPM by keeping the torque production for a more RPM. The LT4 produces about the same peak torque at the LT1, but delivers more torque at 6000-6400 rpm range where the LT1 cut off at about 6000. The heads have a significant increase in breathing ability over the LT1 which is partially due the .1 inch increase in port heighth. The intake is simply modified slightly to better match to the LT4 heads. I really doubt that an LT1 would reap any increase with only the LT4 intake swap. I have not tested it, but would like to hear from anyone who has.
Racer
Joined: Oct 2001
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Re: LT4 Intakes Question? (Mez)
MEZ- You might want to go back and reread my statement, I said the additional 30hp was not managed by the heads and intake alone, meaning by just adding LT4 heads and intake to you existing 300hp LT1 WOULD NOT COMPLETLY get you the extra 30hp, there were lots of other upgrades involved in acheiving the total 30hp gain in the LT4.
Safety Car
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From: Toronto ontario
Re: LT4 Intakes Question? (James94LT1)
believe it or not, the LT4 intake is better than the lt1 intake. Having it machined to fit an LT1 is a good idea. The ports are slightly different in that they are raised, and slightly larger.. also, they direct the fuel injectors at the back of the valve > better positioning than an LT4. Just a little secret i wanted to let out ;)
Also, going with afrlt4 heads + intake will gain you very little if you compare to nicely ported lt1 heads/intake. Maybe 10-15 hp on a 500 hp motor.
[Modified by 5abivt, 11:04 AM 6/8/2002]
Also, going with afrlt4 heads + intake will gain you very little if you compare to nicely ported lt1 heads/intake. Maybe 10-15 hp on a 500 hp motor.
[Modified by 5abivt, 11:04 AM 6/8/2002]
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From: Toronto, Canada
Re: LT4 Intakes Question? (5abivt)
It has been proven that LT1 heads and intake are plenty for making hp when massaged by a reputable porter. Modifying an LT4 intake to be used with LT1 heads is not worth it imho.
I have seen where larger stroker motors picked up very little when switching to AFR heads over the factory castings.
I have seen where larger stroker motors picked up very little when switching to AFR heads over the factory castings.
