LS1, LS6 & LS2 intake manifolds

[LF24Participant Ipswich- \'99 ls1 Holden VS ute - \'02 HSV Maloo R8 View build HERE Member since: March 1, 2015 Posts: 57]

Just came across this discussion with accompanying article about which manifold works the best.  It would seem that the stock ls6 manifold trumps a stock ls2 manifold the whole rev range!  Quite interesting considering I was always under the impression the ls2 manifold was an upgrade over the ls6 manifold.

 

http://www.ls1gto.com/forums/showthread.php?t=289456#/forumsite/20899/topics/289456?page=1

 

 

I’d also like to see how these manifolds would match up with some ported heads.

[Phire aka GmfanParticipant VictoriaVT LS1 Wagon View build HERE Member since: March 3, 2015 Posts: 105]

I think the LS2 benefits from porting but i think the misconception is the LS2 is better just because opening for throttle is larger than ls6.

[pir4teParticipant Mallala640 HP hyper-cruising SS-V Flagonwagon View build HERE Member since: March 2, 2015 Posts: 154]

Another link explains the reason is not plenum volume nor throttle opening but the radius bars first implemented on the LS6 that help the air transition from the plenum to the runner.

http://forums.justcommodores.com.au/ve-holden-commodore-2006-2013/75497-difference-between-l67-l98-6-0l-engines.html#post2569642

In effect it promotes tumble of more air down the runners which has an effect on velocity. Rick Crawford, the World Record holder for N/A 6/6.2 discovered a means to implement radius bars on the L76/LS3 intake and is one of the most important mods for the GenIV dragsters.

The overall effect of tumble on combustion phasing is significant, however obviously it is not a power adder per sé, without proper tuning the gain is about 5rwhp on bolt on cars and 12-15 rwhp on cammed setups.

Removing the posts, installing radius bars and porting the throttle body is a popular alternative to FAST, with core exchange services available through RCR and GPI.

I did this on my NA unopened bolt-on L77 in 2012 and was around 300rwkw.

Naturally as-pirated, all-motor.

[VRSenator065Participant Adelaide SAVR Senator LSx454 1960 Kombi (project) 1921 Nash Hot Rod (future project) View build HERE Member since: February 17, 2015 Posts: 5 777]

^nice info Pir4te, thanks for sharing.

[LF24Participant Ipswich- \'99 ls1 Holden VS ute - \'02 HSV Maloo R8 View build HERE Member since: March 1, 2015 Posts: 57]

VRSenator065 wrote:

^nice info Pir4te, thanks for sharing.

 

Seconded!!  very useful information right there!

 

I’m quite interested in this at the moment after reading this discussion : http://www.ls1.com.au/forum/archive/index.php/t-99931.html

 

I’m seriously considering going cnc ported ls3 heads decked .020″ and FAST lsxr manifold with the standard ls2 cam for something different.  Obviously not going to be close to a monster with stock cam but should have a somewhat tame idol and street manners. Plus ridiculously easy to make whatever I want with a cam swap afterwards.

[Phire aka GmfanParticipant VictoriaVT LS1 Wagon View build HERE Member since: March 3, 2015 Posts: 105]

Pretty sure dale bickham did similar but took heaps off the heads and had to cut valve reliefs into pistons. Think it performed okay. He detailed it on the old forum. Put engine in vk in the end and think was in the 10s? Sketchy on exact details but should be able to find it

[cava454Moderator 93 VR BT1 View build HERE Member since: February 20, 2015 Posts: 2 390]

Phire aka Gmfan wrote:

Pretty sure dale bickham did similar but took heaps off the heads and had to cut valve reliefs into pistons. Think it performed okay. He detailed it on the old forum. Put engine in vk in the end and think was in the 10s? Sketchy on exact details but should be able to find it

 

 

The 10 seconds motor had a big stick in it. His vz is the one your thinking of. It ran high 11’s

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