View Full Version : Best street LY6 carb intake?


jarheadl34
05-12-2012, 06:09 PM
I have a GMPP single plane intake for the LY6 and I'm wondering if a dual plane would work better on the street.
I have a 2008 LY6 and its going in a 57 chevy with turbo 400, an MSD controller and a 750 Holley, headers and dual exhaust.
Not sure on the cam yet but for sure I'm ditching the VVT, probably fairly mild something along the line of a LS6 cam.
Anyone here try a back to back single plane to dual plane intake test?
Also is the GMPP dual plane taller than the single plane I have now?
And how much are the GMPP dual planes?
Thanks
Jarhead

speedtigger
05-13-2012, 12:27 PM
I have done back to back tests on cathedral port heads. I have not seen anyone do it on square port heads.

In my test on cathedral port headed 6.0, I found that overall drivability was very similar. No real difference. Power wise, in my combination, there was not much difference either.

I would say this. It is a lot to do with the torque converter on the street. If you have a stock stall converter, you will likely notice quite an advantage with the dual plane, but if you have a higher stall converter over 2500, it will matter much less.

Either will work fine for sure, but with a stock stall converter the dual plane will have noticeably more torque down low.

jarheadl34
05-13-2012, 05:25 PM
Thanks speetigger you have a sharp ride.
I appreciate your input.
Since I already have the single plane I'll start with it.
I've seen pictures of the dual plane for square port heads but I can't seem to find any info or dyno test reports.
Mabe someone here will chime in?
Jarhead

jarheadl34
05-14-2012, 04:12 PM
I found the GMPP manifold #19244037 at Pace Performance for a $460, Summit wants a hundred bucks more!
It looks taller than my single plane and I cannot find any dyno tests posted.
Jarhead

topbrent
05-14-2012, 06:23 PM
D&A Machine has done back to back test comparing the GMPP intakes, both single plane and dual plane. The dual plane was stronger throughout most of the curve.

There are some threads on the topic:

http://ls1tech.com/forums/carbureted-lsx-forum/1497585-l-92-dual-plane-intakes.html

http://www.performancetrucks.net/forums/classic-trucks-182/carbd-gen-iv-ly6-6-0l-w-gmpp-lsx-ls3-dual-plane-intake-467036/

http://www.popularhotrodding.com/tech/1201phr_409ci_lq4_iron_block_ls/viewall.html

http://www.ls1tech.com/forums/generation-iv-external-engine/1193614-ls3-l92-dual-plane-carb-intake.html

http://www.youtube.com/watch?v=DWi313BaF2M

jarheadl34
05-14-2012, 09:55 PM
Thanks for the link, an interesting comparisson.
I would have thought the dual plane would have been alot better down low.
Since a new dual plane costs so much I guess I'll stick with the single plane I have.
Jarhead

topbrent
05-15-2012, 12:40 AM
Thanks for the link, an interesting comparisson.
I would have thought the dual plane would have been alot better down low.
Since a new dual plane costs so much I guess I'll stick with the single plane I have.
Jarhead

One thing to keep in mind, is that in the test they performed, they were using a cam that was spec'ed at 224/228 108LSA +6.

That cam will make a lot of torque regardless of intake selection. If the cam was larger or the LSA wider, you would really start to see the differences reveal themself between the two intakes. IMHO.

Maybe Don or Andy will see this post and give some updates.

Pop N Wood
05-15-2012, 05:29 AM
Thanks for the link, an interesting comparisson.
I would have thought the dual plane would have been alot better down low.
Since a new dual plane costs so much I guess I'll stick with the single plane I have.
Jarhead

One thing to keep in mind the average LS build has way more low end torque and way better street manners than the traditional SBC anyway. I figure the better cam profiles offered by the LS roller gear have a lot to do with this. Also not every car can use all that bottom end so might as well trade it for some top end. You have a heavy chevy, but you still may still be traction limited by your tires.

speedtigger
05-15-2012, 10:04 AM
Also, I have heard that the Victor Jr is notable more powerful than the GMPP single plain.

jarheadl34
05-15-2012, 10:55 AM
57 Chevys aren't that heavy, most around 3500 or so which is still a bunch lighter than a new Camaro!
I have seen some great dyno numbers with a Victor Jr but I'll start out with what I have and see how it works out.
Jarhead