For CNC ported heads absoutely; for stock heads maybe, maybe not.

You said the L92 intake limits high lift airflow, yet the L92 intake shows and increase in intake flow from .600-.650 lift in both comparisons (Port 2 and Port 5). In fact the stock combo (Port 2) outflows the CNC head (Port 5) in the entire flow range except between .450-.600. Port 6 shows nice gains above .450 lift, but at .650 the stock head outflows the CNC head (slightly).

I think this proves GM did a great job matching the L92 heads to both the L76 and L92 intake for a nice, flat curve. I can't help wonder if you switched stock valves to the CNC head and flowed them. Then backcut a stock valve and flow it. I would think you would pick up some low lift airflow.

Thanks for the great information, it sheds a lot of light on the subject.

 

Hey don't forget about the customer that's planning to use a big turbo setup AND swap it into an early car. You should have said something, I would have sent my intake along with the heads. If I can make it over to the shop this weekend I'll grab the intake and send it to you Monday/Tuesday. The carb intake won't be any restriction at all. You can literally look at the intake valves when the carb isn't sitting on it.





BTW, I picked up my LS2 block last night in Austin.

 

FYI the stock OEM intake valves are backcut and with a pretty wide angle I might add. That's one of the reasons why the L92 flow so well out of the box. In fact the stainless valves only out pace the OEM valves above .500" lift. They're within a cfm or two through the low and mid lift areas.


Sure thing. Send me the intake and I'll runs some tests on it. The timing will be perfect. I can test it on your heads.

Richard

 

Thank you for taking the time to put that article together. Sounds good, for a truck manifold; 0- 4 or 4,500rpm. How much better is it than the LM7? would it be worth the trouble..................
Thanks

 

It's kind of tough to compare to the LM7 because the LM7 is a 5.3l setup and they flow mcuh less throughout the range do to the different heads and especiall the bore size. By in general, the L92 truck intake does flow better than a cathedral truck intake.

Richard

 

I'm not sure if the market will ever support an aftermarket intake for the L92 heads. I'm debating weather to pitch the L92 heads & L76 intake and go with the TEA 235 heads and FAST 90 intake. Maybe I'm being impatient.

 

just go with the L92 heads and a carb style with injector bungs welded..... if you are worried about the low end tq......... go ahead and do the fast 90 setup.

Personally.... I think if you went with a carb style and bad *** heads, you will pick up power down low over the L76 anyway... vs the 90/90 setup and the L76 intake setup. Just make sure you have good heads to help pick up more power on your block down low.

Richard.... is it possible to see what would happen if you increase the flow on the heads and put the L76 back on.... what percent does it gain up top or lose? Basically comparing the numbers from stock, stg 1, then stg 2 .... etc etc?

 

Lift____.100”_.150”__.200”_.250”_.300”_.350”_.400” _.450”_.500”_.550”_.600”_.650”
Port 1_ 76.3_113.1_155.7_191.1_225.5_252.5_276.3_296.1_312 .0_322.4_311.9_310.3
Port 4_ 73.9_110.7_146.7_188.2_220.6_252.7_278.9_298.8_322 .3_337.3_352.2_361.5

why did you fail to gain flow from the CNC work down low.... one would figure you should be at 300cfm with .400 lift???

 

someone else needs to do what I did!

 

I was out of the game for a while and now I come back and there are LS2, LS7, L92, L76.

I have 3 questions:

1.) Will L92 intake fit on a 2000 LS1?
2.) If it does. What kind of difference will it make?
3.) What all is needed to make this swap.

I searched but couldnt find any definate answers on this.

Thank you

 

not trying to be a smartass, but i think you should try and search a little harder. i found everything i need for the swap here. but anyways you need at least a 4.0" bore ls1 is 3.898" stock so it wont fit period. l92/l76 intake only fit l92 heads ports are way different. l92 heads will fit any lsx motor with at least a 4.0" bore.

 

I have the new l92 heads and l76 intake on a 408 but the injectors are flooding my old ls1 tune can any one help ?

 

I can send you the IFR numbers to use but you will need EFILive or HP Tuners to actually make the change.

 

Wtf ^^^^^....????

 

Please tell me you've flowed the carb intake!

I'm on stand-by to see if the car intake is supperior to the L76. GM High Tech Performance did an article from livernois motorsports, and the carb intake didn't make as much power as the L76 intake.

As soon as I hear the verdict, I'm going to purchase.

Thanks for the write up and comparision. That was one of the questions that I had asked b-4.

Moss

 

Richard,

Thanks a mill for all of your research. I have an 07' Sierra Denali with the 6.2L. Do you think a L76 intake manifold swap would payoff on such a heavy truck? I see where the top end flow gains are on the L76 vs L92. Do you think the L76 manifold runners would cause a loss low end tq? I need all the low end I can to get in order to get this big boat moving..In your opinion would it be worth the swap or should I wait and see what the new LS3 manifold will be like?

Thanks again...

Mark

 

The L76 runners are pretty long and should help maintain low end torque. Is it worth the hassle to make the swap? I can't say for sure. If your application calls for massive torque from just off idle, I would start with the L92 intake and evaluate from there. Truck's don't typically dwell in the upper rpm ranges in daily driven street form so it stands to reason that the L92 intake manifold may do exactly what you're looking for especially if your cam is stock or near stock.

Good luck,

Richard

 

U da man!

Based on this dyno from GM do you think the CAM profile is pretty aggresive in the upper end for a stock "truck"? If so maybe it could be worth a LS3 or L92 intake maifold swap just to see the diff at the track and my 60' times...

 

Curious - is that L92 intake manifold different than the LS2 truck manifold from the SSR or TBSS? I think it is (I'm pretty sure my SSR mani has the cathedral style ports), but I'm not 100% sure.

 

I think I answered my own question. Here are the L92 and LS2 truck manifolds together. You can see the difference where the gasket would go.