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Building a jeep chassis and using a 04ish LQ4 (6.0 3/4 ton truck) in it. Also have already bought my Holley terminator for engine management for the LQ4 optioned with the multec injector. The truck intake is hitting the firewall. Need to go with a lower profile intake to make it fit. I have an ls3 intake leftover from my c10 build and decided to throw it out there for trade for an LS1 intake (not before test fitting it seeing how I was going to land with the ls1 and it had plenty of clearance) Got a few offers but everything is a decent drive off but have a guy willing to swap me an ls2 intake.
From what I’ve gathered with either I need to address the water pump and an idler location.
Will the ls2 create more issues for me vs the ls1? Have read the ls2 flows better but don’t want to create and unneeded headache.
Both the LS1 and the LS2 will be down some on power compared to a LS6 intake. A number of years ago Hot Rod magazine ran a big test on all LS intakes.
In regards to the FEA maybe change over to 2002 body FEA? Then you can use all stock parts.
I have heard "richard holder" westtech ,say that the ls1 is the worst flowing intake gm ever made for ls engines , truck intake or trail blazer are some of the best , research,,, Richard said ls1 was down 50 hp over the truck allmost everywhere on the dyno , for tight spaces I would look for an ls6 intake , you will definatly feel 50 hp
I have heard "Richard Holdener" at Westech, say that the LS1 is the worst flowing intake gm ever made for LS engines , truck intake or trail blazer are some of the best , research shows Richard said LS1 was down 50 hp over the truck almost everywhere on the dyno , for tight spaces I would look for an LS6 intake , you will definitely feel 50 hp
Worst = LS4, down big numbers. Then LS2, but I don't have numbers on it. Next is LS1. Truck intake makes about 10-15 hp more than LS1. LS6 makes another 5hp. TBSS makes another 5 hp on top of that, and then the FAST intakes make another 5-20hp on top of that.
Dorman replacement LS2s are mostly like an LS6 with the bigger TB opening, and perform about the same as a TBSS.
All of those are plastic intakes with long runner, and give a good meaty power curve, so most of these gain everywhere, not just at the top.
I personally could feel the improvement going from my Truck intake/TB to my TBSS intake/92mm TB on my heads/cam LQ4.
Aftermarket intakes are all over the place, many make good top end HP, but few will make the midrange power that you likely want in this application. The ones that do will be tall.
In a Jeep application, I'd grab an LS6, Dorman LS2 (which got stupid in price), or a FAST intake of any size.
Located an LS6 intake that the guy is willing to trade for my LS3 intake. Then I started daydreaming.
What about sourcing a set of LS3 heads and using my intake that I already have. Would it be that beneficial in the lower rpm’s for the trouble? Or should I stick the ls6 route?
Located an LS6 intake that the guy is willing to trade for my LS3 intake. Then I started daydreaming.
What about sourcing a set of LS3 heads and using my intake that I already have. Would it be that beneficial in the lower rpm’s for the trouble? Or should I stick the ls6 route?
Using the LS3 heads with the LS3 intake is the best option that you have.
This is a comparison of 799 heads + Dorman LS2 vs LY6 intake/rec ports on a 6.0 LQ4. You can see the crossover point in the torque around 4000 rpm, this is typical from what I've seen. the Rect ports are higher torque down low. (Hard to tell, they do cross at that point, and the rect point is below until 4200, then jumps way up and is on top)
02-07-2023 | 07:21 PM
Ls1 or ls2 intake on LQ4? 
