how can you tell if your looking at an lq9
09-01-2010, 10:45 PM
#14
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K sounds good, I figured it would be a little different. What I'm planning on doing is getting a set of lt's / high flow cats and put the cam in I bought for it then get it tuned once I've done all that, I'm hoping for a decent number on the dyno. I have the CAI already as well.
Thanks
Thanks
09-02-2010, 02:36 PM
#15
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The only difference that woudl affect power output between the LQ4 and LQ9 is that the LQ9 has 10:1 compression and the LQ4 has 9.4:1 compression. Both use the same cam, heads, intake etc etc.
Both engines tuned right out with the same air intakes and exhaust will be within 5hp of each other.
The LQ4 in the HD trucks was detuned as it is subjected to WOT with very heavy loads, its slightly lower compression also helps the engine to live like this.
The LQ9 PCM tune has lots more timing than the LQ4 tune.
peace
Hog
Both engines tuned right out with the same air intakes and exhaust will be within 5hp of each other.
The LQ4 in the HD trucks was detuned as it is subjected to WOT with very heavy loads, its slightly lower compression also helps the engine to live like this.
The LQ9 PCM tune has lots more timing than the LQ4 tune.
peace
Hog
09-02-2010, 06:56 PM
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Ya, because the LQ9 came stock with 345hp's or something and the LQ4 came 305 I thought.
I'm still shocked that they sold me an LQ9 instead of a 4, oh well more power for me I guess. hehe
I'm still shocked that they sold me an LQ9 instead of a 4, oh well more power for me I guess. hehe
09-02-2010, 09:56 PM
#19
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what did pistons look like?? was it flat but had a ring around the edge that was higher?? or was the whole thing flat?
doesnt have to have that cross thing
doesnt have to have that cross thing
09-03-2010, 07:24 PM
#20
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Cams between the aluminum headed/iron block 6.0's were always the same.
LQ4 99-00 use iron heads and are rated at 300hp/355 lb/ft torque
All LQ4's from 01-07 use aluminum heads and then switched to the Y/F body LS1 cam. This is the same cam that the LQ9 uses when it came to production for the 2002 AWD Escalade, 2wd's got the 5.3.
The 01-07 LQ4 in the HD trucks were rated at 300hp@4400rpm/360lb/ft torque@ 4000rpm
325 hp@ 5200 rpm/365 lb-ft@ 4000 rpm (Sierra Denali/Yukon/Yukon XL)
315 hp@5200 rpm 360 lb-ft @4000 rpm H2 Hummer
All 2002-07 LQ's were rated at 345hp@5200rpm/380 lb/ft torque@4000rpm.
Mid year 2003 all V8 pistons went to a redesigned piston with a polymer coating on the skirts to allow for a tigheter pistons/cylidner bore clearance in an attempt to quiet the piston slap.
MY2004 saw the LQ4 get the full floating piston design that was introduced on LQ9 along with its stronger rods.
the only differences between the LQ4 and LQ9 that accounts for the 45hp/20 lb/ft torque difference is the 0.6:1 compression ratio and PCM tuning.
Either of these engines is begging for a set of L92/LS3 heads.
GMC2500
Good score with getting an LQ9 instead of the LQ4. Most of the time guys are getting shafted by receiveing an LQ4 after they paid the LQ9's premium price.
fredK
LQ9 will have the smooth/flat top surface, the LQ4 will have a raised ring like a crown around the top of the piston. This raised crown is what you are feeling/looking for when identifying an LQ4 engine.
peace
Hog
LQ4 99-00 use iron heads and are rated at 300hp/355 lb/ft torque
All LQ4's from 01-07 use aluminum heads and then switched to the Y/F body LS1 cam. This is the same cam that the LQ9 uses when it came to production for the 2002 AWD Escalade, 2wd's got the 5.3.
The 01-07 LQ4 in the HD trucks were rated at 300hp@4400rpm/360lb/ft torque@ 4000rpm
325 hp@ 5200 rpm/365 lb-ft@ 4000 rpm (Sierra Denali/Yukon/Yukon XL)
315 hp@5200 rpm 360 lb-ft @4000 rpm H2 Hummer
All 2002-07 LQ's were rated at 345hp@5200rpm/380 lb/ft torque@4000rpm.
Mid year 2003 all V8 pistons went to a redesigned piston with a polymer coating on the skirts to allow for a tigheter pistons/cylidner bore clearance in an attempt to quiet the piston slap.
MY2004 saw the LQ4 get the full floating piston design that was introduced on LQ9 along with its stronger rods.
the only differences between the LQ4 and LQ9 that accounts for the 45hp/20 lb/ft torque difference is the 0.6:1 compression ratio and PCM tuning.
Either of these engines is begging for a set of L92/LS3 heads.
GMC2500
Good score with getting an LQ9 instead of the LQ4. Most of the time guys are getting shafted by receiveing an LQ4 after they paid the LQ9's premium price.
fredK
LQ9 will have the smooth/flat top surface, the LQ4 will have a raised ring like a crown around the top of the piston. This raised crown is what you are feeling/looking for when identifying an LQ4 engine.
peace
Hog