LT-4 Intake Issue
08-04-2014, 09:50 PM
#1
11 Second Club
Thread Starter
iTrader: (12)
Join Date: Dec 2007
Posts: 478
Likes: 0
Received 0 Likes
on
0 Posts
LT-4 Intake Issue Bought an LT-4 Intake some years back and used it on the 396 build. Performance on that build was a bit disappointing and while I believe most of it was the result of the totally boned chassis, I was getting the intake ready to put back on top and I noticed this:
Clearly the intake runners are a lot smaller than the runners on the gasket, which I had trimmed myself to match the previous AFR heads. So THAT tells me that despite the larger heads, the INTAKE was knocking down what the heads could get.
I am thinking that I should send the Intake to Lloyd and have him port it out. Has anyone else had their intake ported? And did you notice any gains?
Clearly the intake runners are a lot smaller than the runners on the gasket, which I had trimmed myself to match the previous AFR heads. So THAT tells me that despite the larger heads, the INTAKE was knocking down what the heads could get.
I am thinking that I should send the Intake to Lloyd and have him port it out. Has anyone else had their intake ported? And did you notice any gains?
08-04-2014, 10:17 PM
#2
TECH Addict
Talk directly to Lloyd. He does port intakes, and on a 396 I'd imagine he'd recommend it. They are good for some horsepower (how much depends on your build), but it really only shows up high.
On my build I'd probably gain about 10 whp (414 rwhp as it sits) over 6000 rpms. Not worth it to me, but for your 396 it would probably add more power starting at a lower rpm from your additional cubes.
On my build I'd probably gain about 10 whp (414 rwhp as it sits) over 6000 rpms. Not worth it to me, but for your 396 it would probably add more power starting at a lower rpm from your additional cubes.
08-05-2014, 12:05 AM
#3
Yeah just call him. He will probably reccomend it. Remember a stock ported intake is worth about 10 hp above 6k where an LT4 manifold has more room to port so there will be more gain. Port size on a stock LT4 intake is the same actual size as an LT1 intake...but there is more room to port. Lloyd told me a ported LT4 intake will make about 10hp more than a ported LT1 intake. 15-20 hp for $200 is pretty good plus a smoother transition from intake to head might net more.
08-06-2014, 06:11 PM
#5
The information that an LT4 intake is internally the same as a small trapezoidal LT1 runner intake(earlier ones were bigger rectangles) has been repeated a lot on this forum. Only "problem" is that so few people take the time to understand the parts they buy.
Trending Topics
08-23-2014, 02:13 AM
#12
You should man. Car already makes good power with those heads and cam. 10-12 hp above 6k is not a bad deal. You should see what the opening looks like. I have a pic of one of my old LE manifolds I'll send you.
$200 plus shipping each way. If you're not making over 400rwhp and spinning past 6k though it's probably not going to net much.
$200 plus shipping each way. If you're not making over 400rwhp and spinning past 6k though it's probably not going to net much.
08-23-2014, 03:53 PM
#14
11 Second Club
Thread Starter
iTrader: (12)
Join Date: Dec 2007
Posts: 478
Likes: 0
Received 0 Likes
on
0 Posts
You should man. Car already makes good power with those heads and cam. 10-12 hp above 6k is not a bad deal. You should see what the opening looks like. I have a pic of one of my old LE manifolds I'll send you.
$200 plus shipping each way. If you're not making over 400rwhp and spinning past 6k though it's probably not going to net much.
$200 plus shipping each way. If you're not making over 400rwhp and spinning past 6k though it's probably not going to net much.
Here's a lousy picture of the throat. It is a significant difference.
(This unit is opened to 58mm.)
. 
