tdrumm

iTrader: (18)

I also remember a chart being posted that had the runner lengths and volume for each manifold, and the truck intake had a very similar runner length to the LS6, but a larger volume, I just can't find it right now.

In theory, if the runner length is equal, then wouldn't the increased volume actually be beneficial to higher rpm power output?

mattrem

iTrader: (7)

I found this,
Plenum Vol Runner Vol Length


02+ car
5.19 L .541 L 262mm


Truck
4.0L .541L 263mm


Plenum vol is very different,

Kano

iTrader: (3)

Intake ManifoldsPart #EnginePlenum VolumeRunner VolumeRunner Length125563331997-2000 LS15.06 L0.536 L262 mm125611822001-2002 LS1/65.19 L0.541 L262 mm125735722002+ LS1/65.19 L0.541 L262 mm??LQ44.0L 0.541 L263 mm

This was on the smokemup site
but nothing on the ls2 truck


1 would think the runners were longer than 1mm difference

tdrumm

iTrader: (18)

That is the info I remember, I just had the volume screwed up. So maybe the truck intake just doesn't have the plenum volume to keep up.

Wnts2Go10O

iTrader: (12)

ok to put it simply (sorry if this is a restatement) the turck intake jus simply isnt moving the volume of air you need up top. like others have said its made for low end grunt for hauling. if you could borrow someones ls6 intake for a dyno pull or 2 you would see quite a difference

LSwonderfull

The answer lies mostly in pleum volume, LS6 has much more. Flowbench shows they have similar flow. The truck intake has reverse turn radius than LS6, this was done to gain runner length but also reduces area that makes large plenum impractical. Try using some plenum spacers behind Throttle body to add volume and retest.

mattrem

iTrader: (7)

I think this is the first time I have ever heard of using a TB spacer, I quess it would be the same as a carb spacer on a SBC?

Could you open up the plenum on a truck manifold and make it better?

tdrumm

iTrader: (18)

A 25.4mm (1") thick 78mm diameter spacer only has .12L of displacement. It would require a 10" spacer to make up the ~1.2L difference between the car and truck manifold.

422 ragtop

iTrader: (2)

I just witnessed the same thing in my 6 liter truck. Road tuned with Wideband. Pulled strong from 3000-5000 dead by 5200.

Shaved, ported Z06 heads, 216-220,525,114 cam, Volant fresh air intake, SW headers, standard truck intake.

MAF flow showed approx 450 HP at the motor.

I don't believe the Z06 intake would help much..... just move whole curve out in the RPM band. From what I've seen with Vettes it runs out around the same 380-400 RWHP. LS2 and 90MM actually makes less power on stock cubed motors.

The new 6.2 truck intake will only work with the new heads.

Not sure what the answer is?

Beast96Z

iTrader: (21)

LS6 intakes have made over 450 rwhp, so I think you should swap to that. I don't know about the truck versions, but the LS2 car maniflods have proven to be POS's. LS2 vettes are actually swapping back to the LS6's and gaining power.

oange ss

iTrader: (50)

is that heresay or you have first hand info ? i'm askin because i dont know, not tryin to be a dick or nothin.....

mattrem

iTrader: (7)

How about using a carb manifold? and fabbing up a adapter. I see they have injector bungs.

mattr228

iTrader: (10)

or just spend the $$$ and get a Beck Custom Manifold



his work is absolutely amazing

Beast96Z

iTrader: (21)

On the HP, plenty of cars have gone over 450rwhp with the LS-6. As for the LS2 manifold sucking, lots of people lost HP with those intakes when they first came out. They were the "next big thing" before you could get them, then when they did, everyone was pissed. Ed Wright talked a while back about the swap back to LS-6 intakes from the LS2, so I would call that first hand info. He's a very reputable tuner in the Vette crowd and if anyone has seen it, he has.

oange ss

iTrader: (50)

i know Hot Rod did a comparo between a FAST 78, LS2 and an LS6, the LS2 lost HP compared to the others, but the test was BS, because no adjustments were made to the PCM to compensate for any of the swaps...i'm just wondering if adjustments were made to optimize each combo what the results would look like

NO-OPTION-2002

iTrader: (2)

Just did a little research, and wow, there are alot of different "truck" manifolds

# 17113697 -- 99-02 full size truck 4.8, 5.3, & 6.0L $499.63
# 89017365 -- 2003 full size truck 4.8, 5.3, & 6.0L
-- 2004 5.3L flex fuel $472.05
# 89017363 -- 04-06 full size truck 4.8, 5.3, & 6.0L
-- 05-06 5.3L flex fuel $700.94

# 89017366 -- 03-04 Trailblazer/SSR 5.3L $472.05
# 89017588 -- 2005 Trailblazer/SSR 5.3 & 6.0L (LS2) $542.91
# 12580420 -- 2006 Trailblazer/SSR 5.3 & 6.0L (LS2) $186.76
-- 2007 New style SUV 4.8 & 5.3L $186.76

# 12580678 -- 2007 New style SUV 6.0 (L76) & 6.2L (L92) $253.59

Hope this helps you guys!

Kano

iTrader: (3)

thanks,

Did you by chance see any dimensions on these?
plenum vol, runner length that sort of thing?

NO-OPTION-2002

iTrader: (2)

Unfortunately, GM either considers this type of info "proprietary", OR thinks we (as GM parts countermen), don't need technical info.

Sorry.

AdioSS

iTrader: (2)

I find that last one very interesting. We all know that the L92 heads are like the LS7 and have a different intake port design than the other heads. Does this mean that the L92 heads will be going on the 6.0L also?

NO-OPTION-2002

iTrader: (2)

Yes, they have the same part #'s!!