GM High-Tech Perf tests the Edelbrock LT1 intake
09-04-2008, 07:46 PM
#1
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GM High-Tech Perf tests the Edelbrock LT1 intake
November issue of GM High-Tech Performance tested the Edelbrock Air-Gap LT1 vs. a stock LT1 intake.
As suspected, the Edelbrock LT1 gives up a lot of plenum volume to achieve its "air gap". Stock LT1 intake measures 3,670cc, the Edelbrock is reduced to 2,632cc. That would be a 28% reduction.
The stock LT1 runners measured 2.78" long, with an inner cross-section ranging from 2.27-2.11 Sq inches. The Edelbrock has a 3.20" runner, with a cross-section ranging from 2.26-2.52 Sq inches.
Testing a stock LT1 intake and TB against the Edelbrock LT1 intake and stock TB:
NOTE: ALL DYNO NUMBERS ARE "FLYWHEEL".
Stock LT1: Peak HP = 350.4; Peak Torque = 386.7;Avg Torque = 372.5
Edelbrock LT1: Peak HP = 346.8; Peak Torque = 387.7; Avg Torque = 373.2
Adding a 53mm TB to the Edelbrock brought Peak HP = 350.3; Peak Torque = 391.3; Avg. Torque = 376.1
They did not test the stock manifold with a 52mm TB.
Test engine was 355ci, "refurbished" stock heads, 10.7:1 CR, CC 210/220 114LSA 0.500" lift at 0.05, 1.75" long tubes, dual Flowmasters, K&N filter, MSD coil, MSD 6AL, FAST EFI ECU, 24# injectors.
Conclusion:
28% plenum reduction????????
As suspected, the Edelbrock LT1 gives up a lot of plenum volume to achieve its "air gap". Stock LT1 intake measures 3,670cc, the Edelbrock is reduced to 2,632cc. That would be a 28% reduction.
The stock LT1 runners measured 2.78" long, with an inner cross-section ranging from 2.27-2.11 Sq inches. The Edelbrock has a 3.20" runner, with a cross-section ranging from 2.26-2.52 Sq inches.
Testing a stock LT1 intake and TB against the Edelbrock LT1 intake and stock TB:
NOTE: ALL DYNO NUMBERS ARE "FLYWHEEL".
Stock LT1: Peak HP = 350.4; Peak Torque = 386.7;Avg Torque = 372.5
Edelbrock LT1: Peak HP = 346.8; Peak Torque = 387.7; Avg Torque = 373.2
Adding a 53mm TB to the Edelbrock brought Peak HP = 350.3; Peak Torque = 391.3; Avg. Torque = 376.1
They did not test the stock manifold with a 52mm TB.
Test engine was 355ci, "refurbished" stock heads, 10.7:1 CR, CC 210/220 114LSA 0.500" lift at 0.05, 1.75" long tubes, dual Flowmasters, K&N filter, MSD coil, MSD 6AL, FAST EFI ECU, 24# injectors.
Conclusion:
The factory LT1 intake manifold is clearly a well-designed piece, and hard to beat when paired with the stock heads. Despite being more efficient and higher flowing, as indicated by the leaning out of the A/F ratio with the addition of the intkae (and 52mm TB) and its ability to make similar power with a much smaller plenum volume, the Edelbrock intake does not manage significant enough improvement over the factory manifold to warrant its $460 price tag if it is to be the only change. However, most likely this is only because with the larger runners the mismatch from the manifold to the heads becomes significantly increased, causing a restriction. Therefore, in our next installment we plan to test the two intake manifolds back-to-back again, only with the larger ported heads Edelbrock had originally intended for use with this manifold.
09-04-2008, 07:51 PM
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What in the hell is their logic in creating an aftermarket part with all new design and engineering and have the thing produce less power than the GM stock intake. And they want hundreds for it too.
09-04-2008, 07:54 PM
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Edelbrock has an ad on page 7 of that issue. They are featuring:
-a 2-piece timing cover for LSx engines
-a high flow water pump for LSx engines
Gives you an idea of where their product development money it going.
-a 2-piece timing cover for LSx engines
-a high flow water pump for LSx engines
Gives you an idea of where their product development money it going.
09-04-2008, 07:54 PM
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And it took them how many years to engineer that marvel of an aftermarket part?
09-04-2008, 08:08 PM
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Is there a link to the article? The shop that did my 383 was testing an Edelbrock intake for a magazine not too long ago and the owner told me about it and pretty much guessed what was going to happen before they finished... I was actually in the shop when they were testing the stock LT1, and could hear it, but couldn't see anything.
09-04-2008, 08:13 PM
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Don't blame the aftermarket, blame the consumers who wanted something ANYTHING other than stock because they think anything has to be better.
I exchanged some PMs with a vendor from another board and he was disgusted at the number of folks saying they wanted a new intake regardless of power production, he said he wont make it unless he can deliver a worthwhile product. Edelbrock tried to display that kind of integrity when in the 90s they gave up on the new LT1 intake. A decade of slipping sales and guys still clamoring for an alternative coupled with the discontinuation of the LT4 manifold meant they were finally willing to ***** out their name and put it on crap they knew would sell regardless of results or lack there of as the case may be.
I exchanged some PMs with a vendor from another board and he was disgusted at the number of folks saying they wanted a new intake regardless of power production, he said he wont make it unless he can deliver a worthwhile product. Edelbrock tried to display that kind of integrity when in the 90s they gave up on the new LT1 intake. A decade of slipping sales and guys still clamoring for an alternative coupled with the discontinuation of the LT4 manifold meant they were finally willing to ***** out their name and put it on crap they knew would sell regardless of results or lack there of as the case may be.
09-04-2008, 08:49 PM
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09-04-2008, 09:27 PM
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Why didnt they fix the a/f lean out between runs, and how much was the lean out. Not like it woulda taken 5 minutes to fix the wot fuel. Not that this would have made any huge increase in hp compared to the 5hp loss.
My only real beef with the stock lt1 intake when properly ported is that it has problems with distribution. Also, the fueling at idle gets somewhat erratic with a decent sized cam due to the way it is designed (more annoyance than problem).
I think mostly the stock intake setup looks like shat. So people hate it and want to change it naturally to a slick looking single plane.
My only real beef with the stock lt1 intake when properly ported is that it has problems with distribution. Also, the fueling at idle gets somewhat erratic with a decent sized cam due to the way it is designed (more annoyance than problem).
I think mostly the stock intake setup looks like shat. So people hate it and want to change it naturally to a slick looking single plane.
